Opportunistic computed tomography screening shows a high incidence of osteoporosis in ankylosing spondylitis patients with acute vertebral fractures.

Advanced ankylosing spondylitis is associated with reductions in bone mineral density (BMD), contributing to pain and predisposing to fractures. Quantifying this reduction is complicated because overgrowth of bone and loss of trabecular bone occur concurrently. Traditional methods such as dual-energy X-ray absorptiometry struggle to generate accurate estimates of BMD in these patients. The aim of this study was to evaluate the utility of computed tomography (CT) attenuation in generating estimates of BMD in patients with severe AS who had sustained vertebral fractures. Patients with severe AS and bridging syndesmophytes who presented, with acute fractures of the spine, were reviewed to assess whether they had a CT scan in the 6 mo before or after injury that included an image of the L1 vertebra; if it did, the scans were selected for analysis. A total of 17 patients were evaluated. Using a CT attenuation threshold of 135 HU balanced for sensitivity and specificity, 14 of 17 (82%) patients were osteoporotic. Using a CT attenuation threshold for higher sensitivity (160 HU), 15 of 17 (88%) patients were osteoporotic. Even using the L1 CT attenuation threshold of 110 HU for higher specificity, 14 of 17 (82%) patients were osteoporotic. CT attenuation demonstrates that a high proportion of AS patients who sustain fractures have osteoporosis. This overcomes some of the difficulties that have been encountered with the use of dual-energy X-ray absorptiometry in this group of patients. This simple and accessible method saves on time, cost, and exposure to radiation and can help in the planning of a patient's management.

A single-dose pilot trial of intranasal rapid-acting insulin in apolipoprotein E4 carriers with mild-moderate Alzheimer's disease.

INTRODUCTION: Intranasal (IN) insulin acutely improves verbal memory in mild cognitive impairment (MCI)/Alzheimer's disease (AD), but its therapeutic effects may be attenuated in apolipoprotein E4 (ApoE4) carriers. Furthermore, rapid-acting (RA) insulins may have superior therapeutic effects compared with regular insulin types. OBJECTIVES: To measure the safety and efficacy of intranasally delivered RA glulisine in ApoE4 carriers with mild-moderate AD. METHODS: We performed a double-blinded, randomized, cross-over study of RA insulin glulisine in nine mild-moderate AD subjects to better understand the relationship between RA insulin, ApoE4 carrier status and memory performance. RESULTS: IN glulisine was well tolerated but failed to have an acute impact on cognition in ApoE4 carriers with AD. Serum insulin levels acutely dropped following treatment, but peripheral glucose levels remained unchanged. CONCLUSION: Larger clinical trials of longer duration are necessary to better understand the relationships between RA insulin, ApoE4 carrier status and cognitive performance in AD.

The use of computed tomography attenuation to evaluate osteoporosis following acute fractures of the thoracic and lumbar vertebra.

BACKGROUND: Relatively few patients have dual-energy x-ray absorptiometry to quantify the magnitude of bone loss as they age. Recent work correlates mean computed tomography (CT) attenuation in the level I (L1) vertebra with bone mineral density (BMD), making it possible to objectively evaluate the magnitude of bone loss in osteoporosis by this method. The aims of this study were to evaluate the utility of using CT scans in patients with acute thoracic and lumbar spine fractures to diagnose osteoporosis and using CT attenuation to evaluate the association between age and BMD. METHODS: We performed a retrospective study of patients with acute fractures of the thoracic or lumbar spine who had also undergone an abdominal (or L1) CT scan and compared mean CT attenuation in L1 against threshold values. We also compared differences in CT attenuation between younger (<65 years) and older (≥65 years) and older patients. RESULTS: A total of 124 patients were evaluated (74 thoracic and 50 lumbar fractures). Overall, there was a strong correlation between age and bone density as measured by CT attenuation (r = -.76). Among those with thoracic fractures (<65 years), mean CT attenuation was 196.51 HU. Forty-one patients were ≥65 years and had mean CT attenuation of 105.90 HU (P < .001). In patients with lumbar fractures, 27 patients were <65 years and had a mean CT attenuation of 192.26 HU and 23 patients were ≥65 years and had mean CT attenuation of 114.31 HU (P < .001). At the threshold of 110 HU, set for specificity, the magnitude of difference between the age-stratified cohorts was greater in the thoracic spine (P < .0001 vs P = .003). DISCUSSION: Using opportunistic CT, we demonstrate the relative frequency of osteoporosis in patients with acute fractures of the thoracic and lumbar spine and confirm that the association increases with age. The CT attenuation may provide a cheap and convenient method to help confirm a clinical diagnosis of osteoporosis in patients with fractures.

Sauropod dinosaur osteoderms from the Late Cretaceous of Madagascar.

Osteoderms are bones embedded within the dermis, and are common to select members of most major tetrapod lineages. The largest known animals that bear osteoderms are members of Titanosauria, a diverse clade of sauropod dinosaurs. Here we report on two titanosaur osteoderms recovered from the Upper Cretaceous Maevarano Formation of Madagascar. Each osteoderm was discovered in association with a partial skeleton representing a distinct ontogenetic stage of the titanosaur Rapetosaurus krausei. Combined, these specimens provide novel insights into the arrangement and function of titanosaur osteoderms. Taphonomic data confirm that Rapetosaurus developed only limited numbers of osteoderms in its integument. The adult-sized osteoderm is the most massive integumentary skeletal element yet discovered, with an estimated volume of 9.63 litres. Uniquely, this specimen possesses an internal cavity equivalent to more than half its total volume. Large, hollow osteoderms may have functioned as mineral stores in fecund, rapidly growing titanosaurs inhabiting stressed environments.