Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies

Gross N transformations vary with soil moisture and time following urea deposition to a pasture soil

Ruminant urine patches in grazed grasslands significantly change the chemical and biological properties of the affected soils due to the predominance of urea within ruminant urine and the high rates deposited onto pastures. The net result is the loss of reactive N (Nr) but little is known about the gross N transformation rates leading to Nr losses or the long-term fate of urine-N in pasture soils. Using data from a previous incubation study, that simulated ruminant urine application by applying ¹⁵N-urea, we investigated the effects of differing soil moisture regimes on gross soil N transformation rates, including urea hydrolysis and ammonia (NH₃) formation. Gross transformation rates were quantified using a ¹⁵N tracing tool ‘NtraceBasic’ that was extended with a urea submodel. The new model (NtraceUrea) matched the measured data well (NH₄⁺, NO₃¯ concentrations and their respective ¹⁵N enrichments over time). Soil moisture affected urea hydrolysis dynamics and was postulated to regulate the magnitude of the NH₃ dynamics due to constraints on gas diffusion under wetter (−1 kPa) soil conditions. Under drier soil conditions (−10 kPa) sorption and release of NH₄⁺, the movement of NH₄⁺ into and out of the soil labile N pool, the movement of NO₃¯ into and out of the soil recalcitrant N pool, and the mineralisation of the recalcitrant N pool were all enhanced relative to −1 kPa, as were the gross N transformation rates in general due to the high urea N rate applied. This study shows that the time required for soils to re-establish equilibrium following urea deposition is substantial, and provides an explanation for the long-term ¹⁵N recoveries observed under ruminant urine patches in soils. The results highlight future research directions including the need to understand the potential role of NH₃ in contributing to the recalcitrant N pool

Genetic studies of body mass index yield new insights for obesity biology

Note: A full list of authors and affiliations appears at the end of the article. Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P 20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.</p