State of the Art Imaging of Osteoporosis.

Osteoporosis is a common disease, particularly prevalent in geriatric populations, which causes significant worldwide morbidity due to increased bone fragility and fracture risk. Currently, the gold-standard modality for diagnosis and evaluation of osteoporosis progression and treatment relies on dual-energy x-ray absorptiometry (DXA), which measures bone mineral density (BMD) and calculates a score based upon standard deviation of measured BMD from the mean. However, other imaging modalities can also be used to evaluate osteoporosis. Here, we review historical as well as current research into development of new imaging modalities that can provide more nuanced or opportunistic analyses of bone quality, turnover, and density that can be helpful in triaging severity and determining treatment success in osteoporosis. We discuss the use of opportunistic computed tomography (CT) scans, as well as the use of quantitative CT to help determine fracture risk and perform more detailed bone quality analysis than would be allowed by DXA . Within magnetic resonance imaging (MRI), new developments include the use of advanced MRI techniques such as quantitative susceptibility mapping (QSM), magnetic resonance spectroscopy, and chemical shift encoding-based water-fat MRI (CSE-MRI) to enable clinicians improved assessment of nonmineralized bone compartments as well as a way to longitudinally assess bone quality without the repeated exposure to ionizing radiation. Within ultrasound, development of quantitative ultrasound shows promise particularly in future low-cost, broadly available screening tools. We focus primarily on historical and recent developments within radiotracer use as applicable to osteoporosis, particularly in the use of hybrid methods such as NaF-PET/CT, wherein patients with osteoporosis show reduced uptake of radiotracers such as NaF. Use of radiotracers may provide clinicians with even earlier detection windows for osteoporosis than would traditional biomarkers. Given the metabolic nature of this disease, current investigation into the role molecular imaging can play in the prediction of this disease as well as in replacing invasive diagnostic procedures shows particular promise.

Culture-negative primary sternal osteomyelitis in a patient with uncontrolled type 2 diabetes mellitus.

Primary sternal osteomyelitis (PSO) is a rare condition defined as an infection of the sternal bone marrow with no contiguous source of infection. The overlap in symptoms of PSO with other cutaneous and malignant pathologies often leads to misdiagnosis and delay of appropriate care. In this case report, we outline the presentation of PSO in a 30 year-old male patient who was newly diagnosed with type 2 diabetes mellitus. The patient was successfully treated with antibiotic therapy alone, without need for surgical intervention. Interestingly, the patient's workup returned with negative microbial cultures. To our knowledge, this patient represents the first reported case of a spontaneously presenting, culture-negative PSO.

Th17 Cells Provide Mucosal Protection against Gastric Trypanosoma cruzi Infection.

Trypanosoma cruzi is the intracellular parasite of Chagas disease, a chronic condition characterized by cardiac and gastrointestinal morbidity. Protective immunity requires CD4+ T cells, and Th1 cells and gamma interferon (IFN-γ) are important players in host defense. More recently, Th17 cells and interleukin 17A (IL-17A) have been shown to exert protective functions in systemic T. cruzi infection. However, it remains unclear whether Th17 cells and IL-17A protect in the mucosa, the initial site of parasite invasion in many human cases. We found that IL-17RA knockout (KO) mice are highly susceptible to orogastric infection, indicating an important function for this cytokine in mucosal immunity to T. cruzi. To investigate the specific role of Th17 cells for mucosal immunity, we reconstituted RAG1 KO mice with T. cruzi-specific T cell receptor transgenic Th17 cells prior to orogastric T. cruzi challenges. We found that Th17 cells provided protection against gastric mucosal T. cruzi infection, indicated by significantly lower stomach parasite burdens. In vitro macrophage infection assays revealed that protection by Th17 cells is reduced with IL-17A neutralization or reversed by loss of macrophage NADPH oxidase activity. Consistently with this, mice lacking functional NADPH oxidase were not protected by Th17 cell transfer. These data are the first report that Th17 cells protect against mucosal T. cruzi infection and identify a novel protective mechanism involving the induction of NADPH oxidase activity by IL-17A. These studies provide important insights for Chagas vaccine development and, more broadly, increase our understanding of the diverse roles of Th17 cells in host defense.

Evidence-based guidelines for the secondary prevention of falls in older adults.

BACKGROUND: Falls are a significant problem for older adults. Individuals who have sustained a fall come to the attention of health care providers and are at risk of further falls. To promote the highest quality of care and reduce variation in care, a practice guideline is needed. Summarization of evidence regarding falls may be useful to researchers in this field. OBJECTIVES: To provide evidence-based guidelines of assessment and treatment to prevent falls in older adults and to provide researchers with tables of risk factor studies and randomized controlled trials of falls prevention. METHODS: A template for the development of practice guidelines from the Agency for Health Care Policy and Research was used. Evidence for risk factors was accepted from prospective studies with more than 80% follow-up. Potentially modifiable risk factors were selected and a schema for evaluating the importance of each risk factor was used. Evidence for interventions was examined from randomized controlled trials and strength of the evidence was graded. Recommendations for aspects of care where judgment was required were made by panel consensus. RESULTS: Information was drawn from 46 risk factor studies and 37 randomized controlled trials to develop a practice guideline consisting of assessment items and recommended interventions for community-dwelling and institution-dwelling older adults separately. For clinicians, a check list is provided. Summary tables of the results of studies are given to substantiate the recommendations. CONCLUSIONS: For community-dwelling older adults, there is strong evidence for multi-factorial specific risk assessment and targeted treatment. Balance exercises are recommended for all individuals who have had a fall and there is evidence for a program of home physiotherapy for women over 80 years of age regardless of risk factor status. For institutional settings, the establishment of a falls program for safety checks, ongoing staff education and monitoring is substantiated by research. Residents who have fallen need to be assessed for specific risk factors and clinical indicators to determine relevant management options.