by University of Medicine and Dentistry of New Jersey

(Medical Xpress) -- Researchers from the University of Medicine and Dentistry of New Jersey (UMDNJ), collaborating with scientists from Northwestern University in Illinois, have provided direct experimental evidence that diabetes is linked to the onset of Alzheimer's disease. The study, published online this week in the Journal of Alzheimer's Disease, used an experimental model that shows potential as an important new tool for investigations of Alzheimer’s disease and of drugs being developed to treat Alzheimer’s.

UMDNJ researchers Peter Frederikse, PhD, and Chinnaswamy Kasinathan, PhD, collaborated with William Klein, PhD, at Northwestern University, to build on prior studies from the Klein lab and others that indicated close links between Alzheimer’s disease and diabetes. Working with Claudine Bitel and Rajesh Kaswala, students at UMDNJ, the researchers tested whether untreated diabetes would provide a physiological model of Alzheimer neuropathology.

“The results were striking,” Frederikse said. “Because we used diabetes as an instigator of the disease, our study shows – for the first time directly – the link between Alzheimer’s and diabetes.”

The researchers found substantial increases in amyloid beta peptide pathology – a hallmark of Alzheimer’s disease – in the brain cortex and hippocampus concurrent with diabetes. They also found significant amyloid beta pathology in the retina and by contrast, when diabetes is not present, no observable pathology was detected in either the brain or the retina.

“Second, our study examined the retina, which is considered an extension of the brain, and is more accessible for diagnostic exams,” Frederikse added. “Our findings indicate that scientists may be able to follow the onset and progression of Alzheimer’s disease through retinal examination, which could provide a long sought after early-warning sign of the disease.”

This experimental model replicated spontaneous formation of amyloid beta “oligomer” assemblies in brain and retina which may help to explain one of the most widely recognized symptoms of Alzheimer’s. “This is exciting,” Klein said. “Oligomers are the neurotoxins now regarded as causing Alzheimer’s disease memory loss. What could cause them to appear and buildup in late-onset Alzheimer’s disease has been a mystery, so these new findings with diabetes represent an important step.”

Previous research indicated that insulin plays an important role in the formation of memories. Once attached to neurons, oligomers cause insulin receptors to be eliminated from the surface membranes, contributing to insulin resistance in the brain. This launches a vicious cycle in which diabetes induces oligomer accumulation which makes neurons even more insulin resistant.

“In light of the near epidemic increases in Alzheimer’s disease and diabetes today, developing a physiological model of Alzheimer neuropathology has been an important goal,” Kasinathan added. “It allows us to identify a potential biomarker for Alzheimer’s disease and may also make important contributions to Alzheimer drug testing and development.”

The current research was supported by a grant from the National Eye Institute of the National Institutes of Health, the National Institute of Aging, and the Neuroscience Research and Education Foundation. Drs. Kasinathan and Frederikse have applied for patent protection regarding this novel experimental model of Alzheimer neuropathology.

Journal information: Journal of Alzheimer's Disease 

Provided by University of Medicine and Dentistry of New Jersey 

Treating gum disease reduces prostate symptoms, researchers find

by Case Western Reserve University

Treating gum disease reduced symptoms of prostate inflammation, called prostatitis, report researchers from Case Western Reserve University School of Dental Medicine and the Departments of Urology and Pathology at University Hospitals Case Medical Center.

Previous studies have found a link between gum disease and prostatitis, a disease that inflames the gland that produces semen. Inflammation can make urination difficult.

"This study shows that if we treat the gum disease, it can improve the symptoms of prostatitis and the quality of life for those who have the disease," said Nabil Bissada, chair of Case Western Reserve's Department of Periodontics and the new study's corresponding author.

The researchers reported their findings in the Dentistry article, "Periodontal Treatment Improves Prostate Symptoms and Lowers Serum PSA in Men with High PSA and Chronic Periodontitis." Naif Alwithanani, a graduate student in the dental school, led the investigation as part of his residency in periodontics.

Bissada explained that gum disease not only affects the mouth, but is a system-wide condition that can cause inflammation in various parts of the body. The dental school has previously found a link between gum disease and fetal deaths, rheumatoid arthritis and heart disease.

The new prostate study

Researchers studied 27 men, 21 years old and older. Each had had a needle biopsy within the past year that confirmed inflammation of the prostate gland, and a blood test that showed elevated prostate specific antigen (PSA) levels—possible signs of inflammation and cancer.

The men were assessed for symptoms of prostate disease by answering questions on the International-Prostate Symptom Score (IPSS) test about their quality of life and possible urination issues.

Researchers found 21 of the 27 participants had no or mild inflammation, but 15 had biopsy-confirmed malignancies. Two had both inflammation and a malignancy.

The men also had to have at least 18 teeth and were examined for signs of gum disease, such as increased levels of inflammation and bleeding and/or loose teeth due to attachment and bone loss.

All the men had moderate to severe gum disease, for which they received treatment. They were tested again for periodontal disease four to eight weeks later and showed significant improvement.

During the periodontal care, the men received no treatment for their prostate conditions. But even without prostate treatment, 21 of the 27 men showed decreased levels of PSA. Those with the highest levels of inflammation benefited the most from the periodontal treatment. Six participants showed no changes.

Symptom scores on the IPSS test also showed improvement.

Bissada is now conducting follow-up research to support the first study's findings. He hopes to make periodontal treatment a standard part of treating prostate disease, much like cardiac patients are often encouraged to visit their dentist before undergoing heart procedures and a dental checkup is advised for women who are pregnant or considering pregnancy.

Provided by Case Western Reserve University