---

News 23 april 2009

---

Alterations in vitamin D status and anti-microbial peptide levels in patients in the intensive care unit with sepsis

This study demonstrates an association between critical illness and lower 25(OH)D and DBP levels in critically ill patients as compared to healthy controls. It also establishes a positive association between vitamin D status and plasma LL-37, which suggests that systemic LL-37 levels may be regulated by vitamin D status. Optimal vitamin D status may be important for innate immunity especially in the setting of sepsis. Further invention studies to examine this association are warranted.

Identified a molecule that increases the risk of cardiac insufficiency

A team of scientists from the Center for Applied Medical Research (CIMA) of the University of Navarra has identified a key enzyme in the development of cardiac insufficiency. This enzyme is involved in the accumulation of fibrous tissues in the hearts of patients with chronic cardiac diseases and deterioration of heart functions.
The research project, published in the journal Hypertension, is part of a project of the “Red Europea de Excelencia en Hipertensión y Enfermedades Cardiovasculares” [European Network of Excellence in Hypertension and Cardiovascular Diseases], in which research groups from Belgium, the Netherlands, Italy, Great Britain, France, Germany, Finland and Poland are all participating. The project also forms part of the “Red Española de Investigación de las Enfermedades Cardiovasculares” [Spanish Network for Research on Cardiovascular Diseases].

MR Enterography Eliminates Unnecessary Radiation Exposure in Patients with Small Bowel Disease

MR enterography is an effective tool to evaluate and guide treatment of patients with Crohn’s Disease (a common form of inflammatory bowel disease that typically affects young people) without exposing them to radiation, according to a study performed at the Warren Alpert School of Medicine/Brown University in Providence, RI. “MR enterography is an MR examination targeted at the small bowel. The study included approximately 100 patients and 15 physicians,” said David Grand, MD, lead author of the study. “Nearly one-hundred percent of physicians who use MR enterography reported that they found information from the test useful for guiding patient management; patients overwhelmingly preferred MR to the CT,” he said. “This is an ongoing study,” he added. “Crohn’s disease typically effects young people and will be a chronic disease throughout their life, requiring them to have multiple diagnostic imaging procedures. These young patients are too often exposed to multiple doses of ionizing radiation, the long-term effects which may be quite dangerous. Additionally, patients are often given very effective but potentially toxic “biologic” therapies to help reduce inflammation,” said Dr. Grand. “MR can also be used to see if these agents are working without exposure to radiation,” he said.

Majority of Ordering Physicians Lack Knowledge of Radiation Exposure Risks from CT

Ordering physicians have limited knowledge of CT-related radiation exposure and its associated risks, according to a study performed at the Carilion Clinic in Roanoke, VA.
“More than 100 surveys were completed by physicians from various specialties who order CT scans at a tertiary-care teaching hospital,” said Jeremy McBride, MD, lead author of the study. “When physician knowledge regarding radiation was assessed, 63% underestimated the radiation dose of one abdominal-pelvic CT in chest radiograph equivalents. When asked if they believed a single abdominal-pelvic CT increases a patients’ risk of cancer nearly 80% responded affirmatively; however, 74% significantly underestimated the risk as published in literature. When asked if they regularly disclose the risks associated with CT scans with patients, nearly 60% responded affirmatively; however only 20% said the risk of exposure was part of that disclosure,” said Dr. McBride. “When asked if radiation exposure and cumulative prior radiation exposure influenced their decision, 48% and 59% respectively, responded it had no or little influence on their decision. Forty-seven percent reported that risk of litigation significantly influenced their decision to order a CT scan on a given patient,” he said. Ben E. Paxton, MD, and Richard M. Wardrop III, MD, worked with Dr. McBride on this study. “Most of the time, when a CT scan is ordered it can be justified. When a CT is appropriately ordered patients should be aware that the examination has been recommended based upon its diagnostic value and that radiation exposure will be minimized. If patients are concerned, they should feel comfortable asking their physician how an imaging examination will answer a specific question and how it will affect their clinical management. They can also make their physician aware of their concern about radiation exposure from medical imaging and discuss appropriate alternatives,” said Dr. McBride.

Hypertension, Diabetes and Increased Carotid Artery Wall Thickness Means Increased Risk of Stroke

Increased carotid artery wall thickness (CAWT), which can cause heart attack and stroke in many patients, is significantly related to diabetes and hypertension, according to a study performed at A.O.U. in Cagliari Sardegna, Italy (Chairman, Professor Giorgio Mallarini). During the study, 186 patients were evaluated using multidetector row CT to see if CAWT is associated with cardiovascular risk factors such as hypertension, diabetes mellitus, dyslipidemia and a history of smoking. Results showed that there is a statistically significant relationship between diabetes and hypertension. “There was no significant statistical correlation between the increase of carotid wall thickness, smoking and dyslipidemia,” said Luca Saba, MD, lead author of the study. “Our group demonstrated that the presence of CAWT greater than 1mm in patients with diabetes or hypertension is strongly correlated with a risk to suffer a stroke. Patients at higher risk should be monitored every 12 months,” said Dr. Saba.

Diffusion Tensor Imaging Allows Radiologists to See Areas of the Brain Rarely Seen Using Other Imaging Modalities

Radiologists are now able to look at parts of the brain using diffusion tensor imaging (DTI) that are rarely visible with any other imaging method, according to a study performed at Beth Israel Deaconess Medical Center in Boston, MA. “DTI data was available in 179 cases. DTI is a technique that measures diffusion in a series of different spatial directions (XYZ). We used DTI to evaluate the white matter anatomy (layer found beneath the outer layer of the brain),” said Fargol Booya, MD, lead author of the study. “Based on the pattern of color changes, we could somewhat predict whether white matter tracts were displaced. Evaluation of white matter anatomy is usually not possible with any other imaging method. Tumor (21 patients), hemorrhage (15 patients) and infarction (27 patients) had different manifestations on DTI,” she said. “This method offers an overall view of brain anatomy, including the degree of connectivity between the different regions of the brain. Characterization of sensorimotor pathways or language center involvement by acute ischemic insults has a strong correspondence to clinical symptoms, prognosis and long-term management,” said Dr. Booya.

New Women’s Imaging Technique Allows for a More Accurate Diagnosis of Breast Cancer

Breast elastography allows physicians to give a more accurate diagnosis of breast cancer, according to a study performed at Singapore General Hospital in Singapore. Breast elastography is a new technique which looks at the mechanical properties of tissues (relative stiffness) as opposed to conventional ultrasound which looks at the backscatter of transmitted ultrasound waves through tissues. Ninety-nine women with 110 sonographically visible lesions were evaluated with ultrasound, elastography and combined ultrasound and elastography. 26 lesions were malignant and 84 were benign on histology. “All breast cancers (100%) in the study were diagnosed correctly by elastography alone compared to 88.5% by conventional ultrasound,” said Llewellyn Sim, MD, lead author of the study. “The use of breast elastography alone or combined with ultrasound provides a more accurate diagnosis of breast cancer,” said Dr. Sim.
“Breast elastography improves the sonographic diagnosis of breast cancer. It also potentially reduces unnecessary work-up i.e. biopsies of benign breast lesions and patient anxiety,” he said.

Ultrasound Can Help Low-Risk Patients Avoid Invasive Thyroid Biopsy

The prevalence of benign thyroid nodules is high and there are certain ultrasound features, suggesting malignancy, that can help radiologists determine whether or not a biopsy is needed, according to a study performed at the University of California San Francisco Medical Center, San Francisco, CA. A total of 245 patients (54 patients with cancer, 191 patients with no cancer) were analyzed. “Our study supports previous data showing that some sonographic features of thyroid nodules are suggestive of malignant nature and should lead to biopsy,” said Dorra Sellami, MD, lead author of the study. “These features include microcalcifications (which increase the risk of cancer 16 folds), a shape taller than wide (increases the risk of cancer 3.7 folds) and hypoechogenicity (two-fold increase in risk of cancer). Other features may suggest that a nodule is benign, such as hyperechogenicity (40% increase in risk of cancer),” she said. “Current clinical guidelines recommend biopsy of all lesions greater than or equal to 10 mm. However, in our study of patients with no thyroid cancer, 49% had at least one nodule greater than or equal to 10 mm,” said Dr. Sellami. “Very few thyroid nodules are obviously malignant or benign. Most thyroid nodules we see by ultrasound are indeterminate, and in order to rule out cancer, a fine needle aspiration is often recommended. This results in a ratio of ten benign nodules sampled for one cancer diagnosed,” she said. “Our findings will help radiologists and clinicians determine which nodules are definitely not suspicious and can be watched. I think that our study is one step toward decreasing the number of invasive procedures in patients with benign thyroid nodules—while maintaining the same vigilance in detecting thyroid cancer in its early stages,” said Dr. Sellami.

Even modest exercise can reduce negative effects of belly fat

A new University of Illinois study suggests that moderate amounts of exercise alone can reduce the inflammation in visceral fat—belly fat, if you will—that has been linked with metabolic syndrome, a group of risk factors that predict heart disease and Type 2 diabetes. "In the study, the benefits of exercise were apparent, even without a change in diet. We saw improvements in insulin sensitivity, less fat in the liver, and less inflammation in belly fat," said Jeffrey Woods, a U of I professor of kinesiology and community health and faculty member in the U of I Division of Nutritional Sciences and the Integrative Immunology and Behavior Program. Belly fat is particularly dangerous because it produces inflammatory molecules that enter the bloodstream and increase the risk of heart disease and diabetes, he said. "Scientists now know that obesity is associated with a low-grade systemic inflammation. Obese people have higher levels of circulating inflammatory markers, such as C-reactive protein (CRP), which are produced and secreted by fat tissue. This inflammation then triggers the systemic diseases linked with metabolic syndrome, such as Type 2 diabetes and heart disease," he said. In the study, Woods and his colleagues examined the effects of diet and exercise on the inflammation of visceral fat tissue in mice. A high-fat diet was first used to induce obesity in the animals. After 6 weeks, mice were assigned to either a sedentary group, an exercise group, a low-fat diet group, or a group that combined a low-fat diet with exercise for 6 or 12 weeks so the scientists could compare the effects in both the short and long term. "The surprise was that the combination of diet and exercise didn't yield dramatically different and better results than diet or exercise alone," said Vicki Vieira, the lead author of the study.

Type of vitamin B1 could treat common cause of blindness

University of Texas Medical Branch at Galveston researchers have discovered that a form of vitamin B1 could become a new and effective treatment for one of the world's leading causes of blindness. Scientists believe that uveitis, an inflammation of the tissue located just below the outer surface of the eyeball, produces 10 to 15 percent of all cases of blindness in the United States, and causes even higher rates of blindness globally. The inflammation is normally treated with antibiotics or steroid eye drops. In a paper appearing in the May issue of the journal Investigative Ophthalmology and Visual Science, however, the UTMB researchers describe striking results achieved with benfotiamene, a fat-soluble form of vitamin B1. In their experiments, they first injected laboratory rats with bacterial toxins that ordinarily produce a reaction mimicking uveitis. When those rats are fed benfotiamene, they fail to develop any signs of the inflammatory disorder. "Benfotiamene strongly suppresses this eye-damaging condition and the biochemical markers we associate with it," said UTMB associate professor Kota V. Ramana, senior author of the study. "We're optimistic that this simple supplementation with vitamin B1 has great potential as a new therapy for this widespread eye disease."
The researchers' data shows benfotiamene works by suppressing the activation of a crucial signaling molecule called NF-kappa B, which is normally triggered by the stress caused by infection. Shutting down NF-kappa B, they said, prevents the runaway production of inflammatory proteins that generates uveitis. Benfotiamene's low cost, rapid absorption by the body and lack of negative side effects make it an ideal candidate for uveitis prevention, according to Ramana.

Radiation device in the breast reduces complications for early stage breast cancer patients

A new study shows that the SAVI™ applicator, a small, expandable device inserted inside the breast to deliver partial breast irradiation, carries a low infection risk, a potential complication of such devices. The research, led by radiation oncologists and surgeons at the Moores UCSD Cancer Center and Fort Myers, Florida-based 21st Century Oncology, also indicates that other complications – such as seromas, pockets of fluid that build with the use of internal radiation devices – are unlikely to occur.
That's good news for those women with early-stage breast cancer who opt to have such devices inserted for their radiation therapy after breast-sparing lumpectomy surgery, said Cate Yashar, MD, associate professor of radiation oncology at the UC San Diego School of Medicine and chief of breast and gynecological radiation services at the Moores UCSD Cancer Center. Their use is increasing, she added, noting that the Moores UCSD Cancer Center was one of the first medical facilities in the country to offer SAVI. SAVI, which consists of flexible catheters through which radiation is given, provides customized radiation therapy and minimizes exposure to healthy tissue after a woman has undergone a lumpectomy to remove a cancerous tumor. Radiation specialists sometimes decide to give women internal radiation – a process called brachytherapy – with the goal of giving concentrated doses of radiation to areas of concern while avoiding healthy tissue.

New mediator of smoking recruits

Current research suggests that smoking increases the production of osteopontin in the lungs, which contributes to the development of smoking-related lung disease. The related report by Prasse et al, "Essential role of osteopontin in smoking-related interstitial lung diseases," appears in the May 2009 issue of The American Journal of Pathology.
Nearly one billion people worldwide smoke tobacco products. Long-term exposure to compounds found in smoke can lead to both cardiovascular and lung disease. Although lung exposure to cigarette smoke leads to immune cell recruitment and tissue fibrosis, how cigarette smoke causes these changes is largely unknown. To determine if osteopontin, a molecule that attracts immune cells, mediates cell recruitment in smokers, Prasse et al compared osteopontin levels from smokers with different types of lung diseases, healthy smokers, and healthy non-smokers. They found high levels of osteopontin expression in patients with interstitial lung disease, whereas healthy smokers had lower levels, and healthy non-smokers produced no osteopontin. Osteopontin expression could be stimulated directly by nicotine treatment. In addition, expressing osteopontin in rat lung resulted in recruitment of immune cells, resulting in symptoms similar to smoking-related interstitial lung diseases. These results indicate that osteopontin may be pathogenic in smoking-initiated lung disease.

Stopping Autoimmunity Before It Strikes

Current research describes a new method to track the development of autoimmune diseases before the onset of symptoms. The related report by Zangani et al, “Tracking early autoimmune disease by bioluminescent imaging of NF-?B activation reveals pathology in multiple organ systems,” appears in the April 2009 issue of The American Journal of Pathology. Autoimmune diseases such as lupus, multiple sclerosis, rheumatoid arthritis and diabetes are caused when the immune system attacks
the body’s own cells. Normally, immune cells are prevented from attacking normal cells; however, in patients with autoimmune disease, this “tolerance” is lost. The immediate causes of autoimmune diseases remain unknown, partially due to the inability to detect disease before the onset of symptoms. Early detection of autoimmune disease is critical for assessing new treatments.