Credit Newswire — Athletes, the elderly and others who suffer from injuries and arthritis can lose cartilage and experience a lot of pain. Researchers are now reporting, however, that they have found a way to produce cartilage tissue by 3-D bioprinting an ink containing human cells, and they have successfully tested it in an in vivo mouse model. The development could one day lead to precisely printed implants to heal damaged noses, ears and knees. The researchers presented their work today at the 251st National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features more than 12,500 presentations on a wide range of science topics. A brand-new video on the research is available at http://bit.ly/ACS3DPrint. "Three-dimensional bioprinting is a disruptive technology and is expected to revolutionize tissue engineering and regenerative medicine," says Paul Gatenholm, Ph.D. "Our team’s interest is in working with plastic surgeons to create cartilage to repair damage from injuries or cancer. We work with the ear and the nose, which are parts of the body that surgeons today have a hard time repairing. But hopefully, they’ll one day be able to fix them with a 3-D printer and a bioink made out of a patient’s own cells." Gatenholm’s team at the Wallenberg Wood Science Center in Sweden is tackling this challenge step by step. First, they had to develop an ink with living human cells that would keep its shape after printing. Previously, printed materials would collapse into an amorphous pile. To create a new bioink, Gatenholm’s team mixed polysaccharides from brown algae and tiny cellulose fibrils from wood or made by bacteria, as well as human chondrocytes, which are cells that build up cartilage. Using this mixture, the researchers were able to print living cells in a specific architecture, such as an ear shape, that maintained its form even after printing. The printed cells also produced cartilage in a laboratory dish. "But under in vitro conditions, we have to change the nutrient-filled liquid that the material sits in every other day and add growth factors," Gatenholm says. "It’s a very artificial environment." So the next step was to move the research from a lab dish to a living system. Gatenholm’s team printed tissue samples and implanted them in mice. The cells survived and produced cartilage. Then, to boost the number of cells, which is another hurdle in tissue engineering, the researchers mixed the chondrocytes with human mesenchymal stem cells from bone marrow. Previous research has indicated that stem cells spur primary cells to proliferate more than they would alone. Preliminary data from in vivo testing over 60 days show the combination does indeed encourage chondrocyte and cartilage production. Gatenholm says further preclinical work needs to be done before moving on to human trials. To ensure the most direct route, he is working with a plastic surgeon to anticipate and address practical and regulatory issues. In addition to cartilage printing, Gatenholm’s team is working with a cosmetic company to develop 3-D bioprinted human skin. Cosmetic companies are now prohibited in Europe from testing cosmetics on animals, so they hope to use printed skin to try out makeup, anti-wrinkling techniques and strategies to prevent sun damage.
Credit Newswise — Drug therapies for many conditions end up treating the whole body even when only one part — a joint, the brain, a wound — needs it. But this generalized approach can hurt healthy cells, causing nasty side effects. To send drugs to specific disease locations and avoid unwanted symptoms, researchers developed cellular "backpacks" that are designed to carry a therapeutic cargo only to inflamed disease sites. The researchers present their work today at the 251st National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features more than 12,500 presentations on a wide range of science topics. "What we want to do is take advantage of immune cells whose job it is to seek out disease in the body, and use them to deliver cargo for us," says Roberta Polak, a postdoctoral research associate. "How do we do that? Our lab developed cellular backpacks that can be loaded with therapeutic compounds and unloaded." Polak and fellow researchers in the Massachusetts Institute of Technology (MIT) labs of Michael Rubner, Ph.D., and Robert Cohen, Ph.D., make the backpacks by stacking ultra-thin layers of polymer materials on top of each other. According to Rubner, they could be used to treat a wide range of diseases from cancer to Parkinson’s. The resulting pack has different functional regions. One is Velcro-like, attaching via antibody-antigen binding to immune cells, such as monocytes and macrophages. These are the body’s defense cells that travel to sites of inflammation — a natural reaction to infection and disease — and gobble up foreign invaders or attack cancer cells. In vitro testing has shown that the backpacks can stick to the surfaces of the immune cells without getting engulfed. In collaboration with the group of Samir Mitragotri at the University of California at Santa Barbara, the MIT team has also demonstrated in mice that these backpack-functionalized immune cells accumulate in locations where inflammation — a sign of disease — occurs. But there was a problem. The medicine they were using to test the backpacks, a cancer drug called doxorubicin, was leaking out — even during the initial fabrication process. So Polak worked on this part of the backpack, its payload region. To stop the premature release of the drug, she trapped it in liposomes, tiny bubbles that have already been used to carry therapeutic compounds for other delivery systems, and then incorporated them into the backpacks. She found that she could fit nine times the amount of doxorubicin in the liposomes than in the backpacks alone, potentially transforming them into an even more potent weapon. To control the release of the drug payload, Polak used liposomes that are echogenic, or sensitive to ultrasound. So in principle, when backpacks infused with these bubbles reach their destination, they can be burst open with ultrasound waves. Now, to see how well they work to treat a specific disease, Polak is collaborating with Elena Batrakova, Ph.D., at the University of North Carolina at Chapel Hill. Batrakova has been working with mice to develop new treatments for brain inflammation, a characteristic of diseases such as Parkinson’s and Alzheimer’s. They want to see if they can use the backpacks to carry an inflammation-fighting enzyme across the blood-brain barrier.
Credit Newswise — Could an unhealthy diet and lack of exercise be making you age faster? Researchers at Mayo Clinic believe there is a link between these modifiable lifestyle factors and the biological processes of aging. In a recent study, researchers demonstrated that a poor diet and lack of exercise accelerated the onset of cellular senescence and, in turn, age-related conditions in mice. Results appear today in Diabetes. Senescent cells are cells that contribute to diseases and conditions associated with age. Researchers from the Mayo Clinic Robert and Arlene Kogod Center on Aging found that exercise prevents premature senescent cell accumulation and protects against the damaging effects of an unhealthy diet, including deficiencies in physical, heart, and metabolic function, equivalent to diabetes. “We think at both a biological level and a clinical level, poor nutrition choices and inactive lifestyles do accelerate aging,” says Nathan LeBrasseur, Ph.D., director of the Center on Aging’s Healthy and Independent Living Program and senior author of the study. “So now we’ve shown this in very fine detail at a cellular level, and we can see it clinically. And people need to remember that even though you don’t have the diagnosis of diabetes or the diagnosis of cardiovascular disease or the diagnosis of Alzheimer’s disease today when you’re in midlife, the biology underlying those processes is hard at work.” In the study, researchers introduced mice to either a normal, healthy diet or a diet that they termed a “fast food diet” – one that was high in saturated fat and cholesterol, along with a sugar-sweetened beverage. Mice on the fast food diet showed harmful changes in health parameters, including body weight and composition, increasing their fat mass by nearly 300 percent over the course of about four months. The fat mass accumulated largely in the midsection surrounding internal organs, an area that is often linked to a number of diseases related to obesity. While the harmful effects of the fast food diet were clear, researchers found significant health improvements after introducing exercise. Half the mice, including mice on both the healthy and unhealthy diets, were given exercise wheels. Mice that had been exposed to the fast food diet but exercised showed suppression in body weight gain and fat mass accumulation, and were protected against the accumulation of senescent cells. Mice on a normal diet benefited from exercise as well. “Some of us believe that aging is just something that happens to all of us and it’s just a predestined fate, and by the time I turn 65 or 70 or 80, I will have Alzheimer’s disease and cardiovascular disease and osteoporosis,” says Dr. LeBrasseur. “And this clearly shows the importance of modifiable factors so healthy diet, and even more so, just the importance of regular physical activity. So that doesn’t mean that we need to be marathon runners, but we need to find ways to increase our habitual activity levels to stay healthy and prevent processes that drive aging and aging-related diseases.”
Credit Newswise — Older patients, minorities, and male patients are more likely to develop substernal thyroid goiters that are difficult to remove surgically, putting them at risk for treatment complications and death, say researchers in the January 6 online in the American Journal of Surgery. A substernal goiter is so large it extends below a person’s collarbones into the upper chest. The study, which looked at almost 111,000 patients from the National Inpatient Sample years 2000-2010 who had surgery to remove their goiters, documents what investigators say appears to be disparity in demographics and outcomes. The findings “raise issues of potential access to care or delays in treatment,” says the study’s senior author, Alliric I. Willis, M.D., an associate professor of surgery at Sidney Kimmel Medical College. “This is the first study to thoroughly describe the demographic and clinical disparities associated with substernal goiters,” he says. “Awareness of such disparities may allow health care providers to better identify patients at risk for this distinct issue and provide more timely care — before the goiters grow so large that they risk health and life.” A goiter is an enlargement of a thyroid gland that swells the neck. In much of the world goiters are caused by a lack of iodine, but in the U.S., where salt is enriched with iodine, goiters develop due to a number of factors — which may include an overactive thyroid (Graves’ disease), an underactive thyroid (Hashimoto’s disease), family history, or differences in anatomy. Substernal goiters grow slowly but steadily over time, and the incidence of these large goiters is between 3 to 13 percent of all goiters, according to different studies that examined goiter surgery. The research team, which included investigators from the University of Pennsylvania and Temple University, examined data on 110,889 patients who underwent thyroidectomy for goiters. In this group, 5,525 patients were diagnosed with a substernal goiter. These patients were substantially more likely to be older, male, Black, Hispanic, or to have Medicare insurance. While the vast majority of goiters occur among women, men were significantly more likely to present with substernal goiters. Compared to patients with typical-sized goiters, researchers found that patients with substernal goiters had higher comorbidity (such as hypertension, diabetes, and obesity), were more likely to be admitted to a hospital on an emergency basis, and to have postoperative complications including hemorrhage, lung collapse, and pulmonary embolism. Furthermore, substernal patients were 73 percent more likely to die during hospital admission. “Reasons for the increased risk of complications and death may be due to the increased complexity of surgery associated with substernal goiters,” says Dr. Willis. He adds that the risk of dying from the surgery is very low overall. Researchers found that there was a significant difference in the frequencies of substernal goiters across different regions of the U.S. Substernal goiters were most common in the South followed by the Northeast. “These findings raise the possibility of disparate access to surgical care for black and Hispanic patients as well as possible delays in seeking treatment along ethnic and gender lines,” says Dr. Willis.
Credit Newswise — April is National Autism Awareness Month, dedicated to raising awareness about the developmental disability among Americans. But a recent study that examines knowledge about autism spectrum disorder (ASD) among undergraduates in healthcare-related majors shows there is still room for improvement in spreading accurate information. The study was conducted last year by Skott Freedman, an assistant professor in the Department of Speech-Language Pathology and Audiology at Ithaca College. He surveyed 252 majoring in speech-language pathology, occupational therapy, physical therapy, health education, and therapeutic recreation. The purpose was to assess the knowledge of ASD among those in the earliest stages of their professional education. “By examining what and how students are learning about ASD at the undergraduate level, we can better understand the background students are bringing to graduate school and/or the workforce,” Freedman wrote in the study. Freedman’s survey gathered background info on each of the respondents and asked 18 questions about ASD for which there was only one correct answer. All participants were enrolled in the School of Health Sciences and Human Performance at Ithaca. He examined the influence of four variables: level of education (freshman, sophomore, junior, or senior); personal experience with autistic individuals; academic exposure to information about ASD; and their perceived likelihood of working with autistic clients in the future. The findingsFreedman found that the level of education had little bearing on students’ knowledge about ASD. While seniors answered the 18 questions with near 70 percent accuracy, freshmen were the second-most accurate cohort. Personal experience played a significant factor in how accurately respondents answered. Those that knew seven or more autistic individuals responded with a 76.5 percent accuracy rate; those that reported knowing four to six autistic individuals came in at about 70 percent; those that knew one to three had almost 67 percent correct responses, and those that knew none came in at about 66 percent. Academic exposure through college courses also increased the accuracy of respondents. Those that learned “A lot” about autism spectrum disorder in their courses correctly answered the questions about ASD 77.5 percent of the time. “A little”: 70 percent; “Not at all”: 64 percent. Finally, students who planned to, or suspected they would, work with autistic clients in the future had the most accurate responses, at about 70 percent. “Maybes” and “Nos” came in at about 66 percent and 65 percent, respectively. Implications Freedman notes in the study that general knowledge about ASD is encouraging, but that misconceptions remain. For example, many respondents believed autism is more prevalent among lower socio-economic classes. One-quarter of respondents thought the parents of a child diagnosed with ASD had to seek permission for the child to attend public school. He also observes that most respondents knew individuals with ASD but had no coursework on the disorder. He advises that common misconceptions about ASD should be addressed in initial coursework. “This is an important step in teaching students the value of their prior personal experiences, but also the limited generalization of them,” he writes. He also advises it is important for students to have both personal and professional experiences with ASD-diagnosed clients, so that these experiences aren’t gained later, on the job and without the benefit of a supervisor’s guidance or feedback.
Credit Newswise — Children who are allergic to peanuts are far more likely to be exposed to them in their own homes that at school, says University of Montreal’s Sabrine Cherkaoui. Cherkaoui and her colleagues at McGill University came to the discovery after reviewing the circumstances surrounding 567 incidents of accidental peanut exposure to allergic children. “Our study looked at 1,941 children who had been diagnosed as being allergic to peanuts to determine how exposure occurs, how serious the outcomes of the exposure are, and what treatment is given,” explained Cherkaoui, who was first author of the study. “We discovered that children are most at risk of exposure in their own homes. Furthermore, when children do have a moderate or severe reaction to an exposure, parents and medical professionals often do not know how to react appropriately.” The research was directed by her research supervisor, McGill’s Dr. Ann Clarke. The children were recruited from allergy clinics and allergy advocacy organizations. All the children in the study had suffered allergic reactions to peanuts in the past. The mean age of the children at the time of their recruitment into the study was 6.9 years, and the mean length of their participation was 2.9 years. During this time, 567 exposures would occur to 429 of them. The researchers classified 11.3% of the reactions to these exposures as “severe” and 50.1% as “moderate.” “Only 42% of severe peanut allergy reactions recorded in this study were evaluated by a medical professional, and almost one in six went totally untreated. For moderate reactions, the situation is far worse – medical attention was sought only 25% of the time,” Cherkaoui said. “This is despite 37% of exposures occurring in the child’s own home. Other people’s homes and restaurants accounted for 14.3% and 9.3% of exposures respectively. Schools and daycares where peanuts are forbidden represented 4.9% of the cases exposure; for schools and daycares where peanuts are allowed, it’s 3%.” Other and unknown places accounted for 31.6% of exposures. The researchers did find that accidental exposures were less and less likely as the study went on, and they believe this is due to children and parents developing better avoidance strategies. However, adolescents were at a high-risk, something the team imputes to teenagers’ general predilection towards risk-taking behaviour. They also put forward two possible explanations for the lack of difference between peanut and peanut-free schools and daycares. “Firstly, schools and daycares that allow peanuts may be doing a good job of controlling risk due to heightened awareness of the dangers. Secondly, when peanuts are not allowed, the child may be lulled into a false sense of security, as peanut-foods may inadvertently be brought in and shared with the child,” Cherkaoui explained. “The most significant finding of this study is the discovery that most moderate and severe accidental exposures are managed inappropriately by caregivers and physicians. We believe that more education is required on the importance of strict allergen avoidance and the need for prompt and correct management of anaphylaxis.”
COMBINING TWO TECHNIQUES TO 'REWIRE' THE BRAIN MAY IMPROVE ARM AND HAND MOVEMENT FOR STROKE SURVIVORS
Credit Newswise — Used in combination, two innovative rehabilitation approaches can promote better long-term recovery of arm and hand movement function in stroke survivors, suggests a paper in the American Journal of Physical Medicine & Rehabilitation, the official journal of the Association of Academic Physiatrists. The journal is published by Wolters Kluwer. Adding peripheral nerve stimulation (PNS) to "constraint-based" therapy enhances recovery of movement in the affected arm and hand—even more than one year after a stroke, according to the study by Dr. Lumy Sawaki and colleagues of University of Kentucky, Lexington. Adding Nerve Stimulation Improves Results of Constraint-Based TherapyThe preliminary study evaluated the effects of combining two emerging approaches to post-stroke rehabilitation of partial paralysis (hemiparesis). Constraint-induced therapy (CIT) is an approach that forces "intensive, task-oriented use" of the affected hand. This is done by limiting movement of the less-affected hand, forcing the patient to use the partially paralyzed limb. Peripheral nerve stimulation consists of non-invasive, low-level electrical stimulation applied to the nerves in the paralyzed arm muscles, which in turn increases activity in the brain area that controls the arm. Both CIT and PNS take advantage of the brain's potential for "neuroplasticity"—the ability to reorganize or "rewire" itself after injury. The study included 19 stroke survivors who were left with mild to moderate hemiparesis of one upper limb, at least one year after a stroke. All received a modified CIT approach, including wearing a padded mitt on the less-affected hand during therapy sessions. Subjects were also asked to wear the mitt for 90 percent of waking hours during their daily lives. In addition, subjects received either active or "sham" (inactive) PNS, delivered through electrodes placed on the affected arm. At each session, PNS was applied for two hours, followed by four hours of CIT. After ten sessions, arm and hand function improved for both groups. But on most measures, improvement was significantly greater for patients who received active PNS added to CIT. Grip strength was the only measure to show no significant added advantage with active PNS. Significant differences between groups persisted to one-month follow-up. "Compared with the sham PNS group, the active PNS group may have made more extensive use of the affected upper extremity in settings outside the lab, such as in activities of daily living," Dr. Sawaki and coauthors write. However, they caution that further studies are needed to provide conclusive evidence in this regard. There's a crucial need for treatments to enhance long-term recovery of function after a stroke—particularly after the first year, when most spontaneous improvement occurs. Both CIT and PNS can enhance movement function after stroke. The new study is the first to suggest that combining these two techniques can lead to further improvement in arm and hand movement in stroke survivors with mild-to-moderate chronic hemiparesis. "It appears that PNS has enormous promise as a clinical intervention to enhance outcomes of motor training for stroke survivors with mild to moderate hemiparesis," Dr. Sawaki and colleagues conclude. They emphasize the need for further research to maximize the benefits of combined PNS and other rehabilitation techniques—including studies to optimize the PNS sites and settings and the other approaches used.
Credit Newswise Scientists in California have provided the first detailed look at how human antibodies, proteins critical for the body's defense against invading pathogens, may actually drive human immunodeficiency virus (HIV) to mutate and escape detection by the immune system. The findings, reported online March 18 in the Proceedings of the National Academy of Sciences, may be key in efforts to develop an effective AIDS vaccine. A team led by Douglas D. Richman, MD, a virologist and physician with the Veterans Affairs (VA) San Diego Healthcare System and the University of California, San Diego (UCSD) School of Medicine, found that patients infected with HIV rapidly develop a strong antibody response against the virus. But the same antibodies tasked with recognizing and disabling the germ appear to force its ongoing evolution into new strains that dance around the antibody response and continue to replicate. "The neutralizing antibodies are exerting a very strong selective pressure on the virus, and the virus is continually mutating to avoid it," said Richman, a noted AIDS researcher who recently won VA's Middleton Award, the agency's highest honor for biomedical researchers. The researchers used sophisticated new technology, made by California-based ViroLogic, Inc., to clone actual virus from the blood plasma of HIV patients and genetically combine it with a gene that makes luciferase, the same light-emitting enzyme in fireflies. The glowing enzyme helped the scientists track the virus' replication. Richman and colleagues took viral samples periodically from HIV patients and incubated the virus with antibody-containing plasma samples from the same patients. Blood plasma contains antibodies but no white blood cells. This way, the researchers could tease out the effects of antibodies alone on the virus, independent of the rest of the immune system. The results, based on tests of 19 patients over 39 months, showed that most patients developed a high concentration, or titer, of antibodies to HIV within a few months, and the antibodies continually changed their "spectrum of activity" to keep pace with the ever-changing virus. That is, the antibodies evolved in their ability to recognize different protein shapes on the outer coating of the virus. However the virus consistently evolved faster than the antibody response, developing new protein structures on its surface, so that antibodies from previous months' samples were ineffective in neutralizing new virus from the same patient. "The bad news is that the virus is always staying a step ahead, and the neutralizing antibody response can't control it," said Richman. At the same time, Richman said neutralizing antibodies could hold promise as a therapy, or vaccine, if scientists can engineer them to recognize many different strains of virus. "An optimistic view is that this antibody response is a very potent selective force," said Richman. "If it were present at the time of exposure [to the virus], it could provide some protection." The AIDS virus has been described as a "genetic moving target" because of its frustrating ability to rapidly mutate and escape the body's efforts to neutralize or destroy it. In fact, up to dozens of strains can develop within the same person. Also, HIV infects and disables the very immune cells, helper T cells, which are supposed to mobilize the immune system against the virus. Richman's study is the first to track in detail how the virus outpaces the antibody response over time. Since 1987, researchers have studied about 60 potential HIV vaccines to help stem the AIDS epidemic. So far, no vaccine has won Food and Drug Administration approval as safe and effective. Most scientists agree that for a vaccine to work, it will need to activate both arms of the immune system: antibodies, which are key in thwarting the initial infection; and killer white blood cells, which provide longer-term protection. In recent years, AIDS scientists have made progress on the cellular front; several vaccines using this approach are in the pipeline for clinical trials. But understanding how to get neutralizing antibodies to work against HIV has proved a tougher challenge. According to the Centers for Disease Control and Prevention, 800,000 to 900,000 Americans are living with HIV infection. VA, the nation's largest health-care system, is also the nation's largest single provider of health care to those with HIV. In fiscal year 2001, more than 18,500 veterans received care for HIV at VA medical centers and clinics. Richman directs VA's Research Center for AIDS and HIV Infection and the Center for AIDS Research at UCSD. Collaborating with him on the study were Susan J. Little, MD, a principal investigator in UCSD's Antiviral Research Center and a VA infectious disease specialist; and Terri L. Wrin and Christos J. Petropoulos of ViroLogic, Inc. The firm, which specializes in HIV drug resistance testing, developed the DNA viral test used in the study. Richman serves on the company's scientific advisory board.
Credit Newswise — Researchers at University of California, San Diego School of Medicine and Shiley Eye Institute, with colleagues in China, have developed a new, regenerative medicine approach to remove congenital cataracts in infants, permitting remaining stem cells to regrow functional lenses. The treatment, which has been tested in animals and in a small, human clinical trial, produced much fewer surgical complications than the current standard-of-care and resulted in regenerated lenses with superior visual function in all 12 of the pediatric cataract patients who received the new surgery. The findings are published in the March 9 online issue ofNature. Congenital cataracts – lens clouding that occurs at birth or shortly thereafter – is a significant cause of blindness in children. The clouded lens obstructs the passage of light to the retina and visual information to the brain, resulting in significant visual impairment. Current treatment is limited by the age of the patient and related complications. Most pediatric patients require corrective eyewear after cataract surgery. “An ultimate goal of stem cell research is to turn on the regenerative potential of one’s own stem cells for tissue and organ repair and disease therapy,” said Kang Zhang, MD, PhD, chief of Ophthalmic Genetics, founding director of the Institute for Genomic Medicine and co-director of Biomaterials and Tissue Engineering at the Institute of Engineering in Medicine, both at UC San Diego School of Medicine. In the new research, Zhang and colleagues relied upon the regenerative potential of endogenous stem cells. Unlike other stem cell approaches that involve creating stem cells in the lab and introducing them back into the patient, with potential hurdles like pathogen transmission and immune rejection, endogenous stem cells are stem cells already naturally in place at the site of the injury or problem. In the case of the human eye, lens epithelial stem cells or LECs generate replacement lens cells throughout a person’s life, though production declines with age. Current cataract surgeries largely remove LECs within the lens; the lingering cells generate disorganized regrowth in infants and no useful vision. After confirming the regenerative potential of LECs in animal models, the researchers developed a novel minimally invasive surgery method that preserves the integrity of the lens capsule – a membrane that helps give the lens its required shape to function – and a way to stimulate LECs to grow and form a new lens with vision. In subsequent tests in animals with cataracts and in a small human trial, they found the new surgical technique allowed pre-existing LECs to regenerate functional lenses. In particular, the human trial involved 12 infants under the age of 2 treated with the new method and 25 similar infants receiving current standard surgical care. The latter control group experienced a higher incidence of post-surgery inflammation, early-onset ocular hypertension and increased lens clouding. The scientists reported fewer complications and faster healing among the 12 infants who underwent the new procedure and, after three months, a clear, regenerated biconvex lens in all of the patients’ eyes. “The success of this work represents a new approach in how new human tissue or organ can be regenerated and human disease can be treated, and may have a broad impact on regenerative therapies by harnessing the regenerative power of our own body,” said Zhang, who also has an appointment at Veterans Affairs San Diego Healthcare System. Zhang said he and colleagues are now looking to expand their work to treating age-related cataracts. Age-related cataracts is the leading cause of blindness in the world. More than 20 million Americans suffer from cataracts, and more than 4 million surgeries are performed annually to replace the clouded lens with an artificial plastic version, called an intraocular lens. Despite technical advances, a large portion of patients undergoing surgery are left with suboptimal vision post-surgery and are dependent upon corrective eyewear for driving a car and/or reading a book. “We believe that our new approach will result in a paradigm shift in cataract surgery and may offer patients a safer and better treatment option in the future.”
Credit Newswise — Chronic psychosocial and emotional stress has well-documented negative effects upon the human immune system, measurably increasing the risk of disease. Much less is known about the health effects of acute but transitory episodes of stress, such as jumping out of an airplane. Do these panic-inducing moments also raise the risk of stress-related conditions and disorders, such as cardiovascular disease, sleep dysfunction, impaired wound healing, depression and obesity? A team of researchers at University of California, San Diego School of Medicine, Stony Brook University in New York and elsewhere addressed that question by asking study participants to literally jump out of a plane, taking blood samples before and after to measure key immune response indicators. Their findings are published in the March 4 issue of Brain, Behavior and Immunity. “In our everyday lives, acute stress is manageable and does not cause physiological damage,” said study co-author Brinda Rana, PhD, associate professor in the Department of Psychiatry at UC San Diego School of Medicine. “However, for those who experience it frequently, it can be a risk for chronic diseases and disorders, such as cardiovascular and immune modulated inflammation. And since the health of the immune system is crucial to protection against pathogens and other diseases, it’s important to understand the impact of stressful life events on the ability of our immune system to properly do its job.” The study involved 39 individuals (24 males, 15 females) who had independently contacted a New York-area skydiving school to schedule a first-time tandem sky dive in which the student skydiver was connected by harness to an instructor who guided the student through the jump, freefall and landing. All of the participants were healthy adults with no history of cardiac or mental illness. They were divided into two groups: 13 would have their RNA expression profiles measured to understand molecular signatures associated with stress, and 26 would be studied by flow cytometry to access changes in immune cell composition in blood. Blood sampling was precisely scheduled by the lab of co-author Lilianne R. Mujica-Parodi, PhD, associate professor in the Department of Biomedical Engineering at Stony Brook University. Participants provided a baseline blood sample at 9:15 a.m. within one week prior to or one day after the sky dive. On the day of the skydive, all participants awoke at 6:30 a.m. and arrived at Stony Brook University Hospital at 7:30 a.m. where “pre-boarding” samples were collected at 9:15 a.m., one hour before take-off. The actual jump occurred at 10:30 a.m., when the airplane reached an altitude of 11,550 feet. Skydivers landed five minutes later, with post-landing samples taken at 10:45 a.m. and again at 11:30 a.m. back at the hospital. “Our tandem skydive instructor is also a phlebotomist,” said Mujica-Parodi. “He carried the blood draw supplies with him on the jump and was poised to draw blood as soon as the skydivers hit the ground.” In addition, saliva samples were collected every 15 minutes from 9:15 a.m. to 11:30 a.m. on both the day of the sky dive and the baseline hospital day. Previous research has shown that acute, short-term stress provokes a mixed bag of immune responses, some beneficial, some not. For example, numbers of natural killer cells, which are part of the innate immune response, increase, but skin healing capacity is reduced. The novelty of the study, said Rana, is leveraging advanced computational and molecular tools to assess large-scale immune system responses, to more finely detail the effects of acute, short-term stress. “Our study is the first to probe the rapid transcriptomic (messenger RNA) changes in white blood cells that occur before and after an acute psychological stressor,” said Rana. “We identified specific genes and pathways involved in both the innate and the adaptive immune response that were dysregulated in response to the acute stress of the sky dive, and which returned rapidly to natural baseline levels one hour after the jump.” Interestingly, the researchers noted that modules of coordinately expressed genes responding to stress were different between male and female skydivers, which they say may help explain gender differences observed in development of stress related cardiovascular and autoimmune disorders, as well as conditions like post-traumatic stress disorder (which is twice as common in women). Nadejda Beliakova-Bethell, PhD, first co-author of the study and an assistant project scientist at UC San Diego, with background in infectious diseases, said while the research was exploratory, it laid the foundation for future, more detailed experiments to elucidate the contribution of stressful life events and exposure to pathogens to the functioning of the immune system. “The immune response to stress is similar to the response to pathogens,” said Beliakova-Bethell. “An instance of an acute stress or infection activates the immune system, while chronic stress or infection results in the exhaustion of the immune system, making it less effective at responding to new stressful events or new pathogens. The effects on the transcriptome of white blood cells, observed in this study, were very transient, returning to baseline levels within one hour after landing, but with repeated acute or chronic stress, these transcriptomic changes would be expected to be more permanent, and may be similar, at least in part, to the effects of chronic viral infection. “Future studies could make an important contribution to identifying gene targets for developing therapeutic strategies that would help people to cope with the prolonged effects of a stressor or to fight new infections. This would be specifically important for the elderly, who would have accumulated effects of stressors and infections throughout their lifetimes.”