Exploring Best Ways to Manage Diabetes Risk
Saint Louis University researchers recently published a study in Diabetes Care that examined the role of exercise and diet in managing Type 2 diabetes risk through weight loss. The research team recorded subjects’ insulin sensitivity, which indicates how well the body uses insulin. Subjects were attempting to lose weight via exercise, diet or both.
“Your blood sugar may be perfectly normal, but if your insulin sensitivity is low, you are on the way to blood-sugar issues and, potentially, Type 2 diabetes,” says Dr. Edward Weiss, an associate professor of nutrition and dietetics.
Results show that both exercise and restricting calories have positive effects on insulin sensitivity. The study group that used both approaches showed the most benefit. “What we found is that calorie restriction, like exercise, may be providing benefits beyond those associated with weight loss alone,” Weiss says.
LGBT Students at Higher Risk for Eating Disorders
Using data from a survey of 289,024 college students, researchers at the Brown School at Washington University found that transgender, lesbian, gay and bisexual students are at greater risk for eating disorders than their heterosexual peers.
“Transgender people were more likely to report a diagnosis of an eating disorder—bulimia nervosa or anorexia nervosa—in the past year,” says Dr. Alexis Duncan, assistant professor at the Brown School. “They also reported using vomiting, laxatives or diet pills more for weight control in the past 30 days than cisgender (not transgender) men and women, regardless of their sexual orientation.”
Duncan adds that she is not surprised by the results. “There is a lot of anecdotal evidence of eating disorders among transgender people; however, there have been few previous studies that have compared transgender people to cisgender people, and to our knowledge, no single previous study has compared transgender people to both cisgender heterosexual and sexual minority individuals.”
A One-Time Flu Vaccine?
Someday we may not need an annual flu shot. Researchers at Saint Louis University received a federal contract to study a universal flu vaccine that would be similar to other vaccines requiring one or more doses for years of protection. The vaccine would protect against potential flu pandemics and seasonal influenza A.
“The ultimate aim of a universal influenza vaccine is to provide protection against all strains of influenza A viruses for many years without the need for annual vaccine strain changes or annual vaccinations,” says Dr. Daniel Hoft, principal investigator of SLU’s Vaccine and Treatment Evaluation Unit (VTEU) and director of the division of infectious diseases.
Hoft and colleagues will design and conduct a human study of a flu vaccine approach that has worked in animal models to protect against multiple strains of influenza A, which is the type of flu that can develop into a pandemic. A global outbreak of disease, pandemic flu can cause more severe symptoms and higher death rates than seasonal flu because it comes from a new influenza virus for which people have no built-in immunity.
Researchers Studying Nanotherapy as Cancer Treatment
Researchers at Washington University designed a new treatment that has proven effective in mice with multiple myeloma, a cancer of the bone marrow’s immune cells. The therapy uses nanoparticles to deliver drugs to the malignant cells without degrading in the bloodstream during the delivery process. This marks a breakthrough in targeted cancer treatment because drug degradation was a major obstacle in past attempts. Attaching the drug to the protective nanoparticles appears to allow it to reach its target, while still potent enough to have an effect.
“We’re excited about our results because there was no guarantee the nanotherapy would increase survival,” says Dr. Michael Tomasson, associate professor of medicine. “We injected the nanoparticles intravenously, and they found the tumors throughout the body, whether they were in the bone marrow, the spleen or elsewhere.”
Tomasson hopes that the improved drug delivery will allow the drug to more effectively find its mark, destroying even hidden cancer cells, and increasing the likelihood of long-term remission. If the nanoparticle treatment continues to be effective in subsequent studies, it may hold promise for treating a variety of cancers.
A New Method for Relieving Chronic Pain
A Saint Louis University scientist, leading an international team, has discovered that drugs targeting a pain receptor in the spinal cord may provide relief from chronic pain. The discovery could pave the way for new types of more effective pain treatments.
“Chronic pain can result from the loss of regulatory mechanisms in the nervous system pathway that transmits pain,” says Dr. Daniela Salvemini, professor of pharmacological and physiological sciences. “Adenosine acts as a regulatory signaling molecule in other areas of the nervous system, so we hypothesized that A3AR (the A3 adenosine receptor) might also play a role in regulating pain signals during pain processing.”
Indeed, Salvemini and colleagues found that A3AR drugs not only relieved pain, but did so by activating an inhibitory transmitter system known as the gamma amino-butyric acid (GABA) system. In areas of the spinal cord and brain dedicated to pain processing, A3AR activation promoted GABA signaling by preventing the breakdown and removal of GABA from neuronal synapses.
“In chronic pain, GABA signaling is often lost or diminished. Our A3AR drugs were able to restore GABA signaling in areas that process pain and ‘turn off’ the signals that maintain the pain state,” Salvemini says.
Diabetes Drug May Benefit HIV Patients
Researchers at Washington University have found that a common diabetes drug may prevent cardiovascular problems by reducing inflammation in patients who have HIV. People who have HIV are at a higher risk of heart attacks and diabetes, in part due to chronic inflammation.
“The goal has been to identify treatments that not only address problems with blood sugar and lipids, but also can lower inflammation, which can play a substantial role in heart disease and stroke,” says principal investigator Dr. Kevin Yarasheski, a professor of medicine. “With sitagliptin (Januvia), sugar levels fell, and several markers of immune activation and inflammation were reduced, indicating the drug may provide long-term benefits for these patients’ hearts, bones and livers.”
Longer-term studies are needed to learn whether lower markers of inflammation after eight weeks of treatment can lead to lower risk for heart attacks and metabolic problems, but the preliminary signs are promising, says Yarasheski, also a professor of cell biology and physiology and of physical therapy.
New Method for Treating Dangerous Side Effect of Bone-Marrow Transplants
Bone-marrow transplants can save the life of blood-cancer patients. But a serious side effect known as ‘graft-versus-host disease’ can develop, in which donor immune cells attack the recipient’s skin, digestive tract, liver and other organs. Now, researchers at Washington University may have found a way to prevent that complication.
In a pilot study, immune cells were genetically modified to self-destruct when an antiviral drug is administered. The pilot study’s success led to a larger study, now underway. If more studies return positive results, someday, patients who develop graft-versus-host disease could be given the drug, stopping the immune cells from damaging organs.
The treatment also includes an imaging component so that physicians could determine which patients are most susceptible to the complication.
An Easier Way to Accurately Replicate Genetic Code
As DNA replicates, problems sometimes occur that cause defects leading to cancer, genetic abnormalities and premature aging. In a paper published in the Journal of Cell Biology, Dr. Alessandro Vindigni, professor in the Edward Doisy Department of Biochemistry and Molecular Biology at Saint Louis University, shares a discovery that explains how cells use a process called ‘replication fork reversal’ in order to deal with these roadblocks and transmit accurate genetic data.
DNA lesions occur frequently and, when not properly repaired, result in genetic mutations. Depending on the degree of genome instability, these alterations will determine whether a cell survives, goes into a growth-arrest state or dies. If the cell’s replication machinery collides with the lesion, a strand break can occur.
While these scenarios pose serious threats, our cells have evolved elegant mechanisms to cope, Vindigni says. “Fork reversal is a central mechanism that our replication machinery uses to deal with DNA lesions,” Vindigni explains. “Once the damage on the DNA is recognized, DNA replication reverses its course by forming reversed forks, the repair is made, and collision with the lesion is prevented.” In this study, Vindigni and team have identified new enzymes that enable cells to resume replication once the DNA lesion has been repaired.
Vindigni’s research may help other scientists better understand how to control these mechanisms and use that knowledge for better types of medical treatments, such as more effective chemotherapy.
Endurance Athletes Don’t Benefit from Salt Supplements
In a paper published in The Journal of Sports Science and Medicine, a Saint Louis University researcher wrote that taking salt pills does not help or hurt endurance athletes’ sports performance.
Some athletes use the salt supplements to help replace sodium lost while sweating, or to encourage more sweating during intense activity. The idea is that sweating is a sign of efficient thermoregulation of the body, which enhances performance. Electrolyte supplements laden with sodium also are used by some athletes. While common sports drinks are generally not concerning in terms of sodium content, the use of salt and electrolyte pills or powdered additives for drinks can result in excessive sodium intakes.
Dr. Edward Weiss, assistant professor of nutrition and dietetics, followed 11 endurance athletes in a double-blind study in which they underwent two hours of endurance exercise at 60 percent heart rate reserve (the difference between maximum heart rate and resting heart rate), followed by an exercise performance test. The exercise resulted in more than two liters of water loss in the form of sweat. During one session, the athletes received 1,800 mg of sodium supplementation; and during the other, they received a placebo.
Weiss and fellow researchers found that sodium supplementation did not appear to impact thermoregulation. “While moderate sodium consumption is perfectly reasonable and should be encouraged, high sodium intake is associated with health concerns, like hypertension,” Weiss says. “Many Americans already consume too much salt on a daily basis. I recommend that athletes use caution with sodium supplementation, especially when daily intakes already exceeds the upper safe limit of 2,300 mg per day for most Americans.”