Case series of three adult patients with exceptional clinical presentations of haemophagocytic lymphohistiocytosis.

Macrophage activation syndrome (MAS) is a secondary form of haemophagocytic lymphohistiocytosis (HLH). MAS-HLH is an underrecognised and life-threatening condition associated with a heterogeneous group of diseases including connective tissue disease and inflammatory disorders. Here, we report three cases of adult patients with MAS-HLH triggered by different entities, including systemic lupus erythematosus, Griscelli syndrome type 2, and Adult onset Still's disease.

Multinational evidence-based recommendations on how to investigate and follow-up undifferentiated peripheral inflammatory arthritis: integrating systematic literature research and expert opinion of a broad international panel of rheumatologists in the 3E Initiative.

OBJECTIVE: To develop evidence-based recommendations on how to investigate and follow-up undifferentiated peripheral inflammatory arthritis (UPIA). METHODS: 697 rheumatologists from 17 countries participated in the 3E (Evidence, Expertise, Exchange) Initiative of 2008-9 consisting of three separate rounds of discussions and modified Delphi votes. In the first round 10 clinical questions were selected. A bibliographic team systematically searched Medline, Embase, the Cochrane Library and ACR/EULAR 2007-2008 meeting abstracts. Relevant articles were reviewed for quality assessment, data extraction and synthesis. In the second round each country elaborated a set of national recommendations. Finally, multinational recommendations were formulated and agreement among the participants and the potential impact on their clinical practice was assessed. RESULTS: A total of 39,756 references were identified, of which 250 were systematically reviewed. Ten multinational key recommendations about the investigation and follow-up of UPIA were formulated. One recommendation addressed differential diagnosis and investigations prior to establishing the operational diagnosis of UPIA, seven recommendations related to the diagnostic and prognostic value of clinical and laboratory assessments in established UPIA (history and physical examination, acute phase reactants, autoantibodies, radiographs, MRI and ultrasound, genetic markers and synovial biopsy), one recommendation highlighted predictors of persistence (chronicity) and the final recommendation addressed monitoring of clinical disease activity in UPIA. CONCLUSIONS: Ten recommendations on how to investigate and follow-up UPIA in the clinical setting were developed. They are evidence-based and supported by a large panel of rheumatologists, thus enhancing their validity and practical use.

Shared oxidative pathways in response to gravity-dependent loading and gamma-irradiation of bone marrow-derived skeletal cell progenitors.

Astronauts are exposed to radiation during space travel under conditions of dramatically reduced weightbearing activity. However, we know little about how gravity-dependent loading affects tissue sensitivity to radiation. We hypothesize gravity-dependent loading and irradiation share common molecular signaling pathways in bone cell progenitors that are sensitive to stress-induced reactive oxygen species (ROS), species capable of impacting skeletal health. To address this, progenitor cells with potential to differentiate into bone-forming osteoblasts were extracted from bone marrow, then cells were centrifuged (from 5-gravity (g) to 50-g for 5-180 min) on day 2 in culture, or were exposed to a single dose (1-5 Gy) of irradiation (137Cs 1 Gy/min) on day 3 or 4. Production of ROS was measured via fluorescence-activated cell sorting (FACS) using an oxidation-sensitive dye. Cell numbers were assessed by measurement of DNA content (CyQUANT). Osteoblastogenesis was estimated by measurement of alkaline phosphatase (ALP) activity and production of mineralized matrix (Alizarin Red staining). Transient centrifugation was a potent stimulus to bone marrow stromal cells, increasing production of ROS (1.2-fold), cell number (1.5-fold to 2.2-fold), and ALP activity (2.7-fold). Radiation also caused dose- and time-dependent increases in ROS production (1.1-fold to 1.4-fold) by bone marrow stromal cells, but inhibited subsequent osteoblast differentiation. In summary, gravity-dependent loading by centrifugation stimulated ROS production and increased numbers of osteoblasts. Although radiation increased production of ROS by bone marrow stromal cells, cell number and differentiation of osteoprogenitors appeared reduced. We conclude gravity-dependent loading and radiation both stimulate production of ROS and affect critical bone cell functions including growth and differentiation.

Rapid discrimination among individual DNA hairpin molecules at single-nucleotide resolution using an ion channel.

RNA and DNA strands produce ionic current signatures when driven through an alpha-hemolysin channel by an applied voltage. Here we combine this nanopore detector with a support vector machine (SVM) to analyze DNA hairpin molecules on the millisecond time scale. Measurable properties include duplex stem length, base pair mismatches, and loop length. This nanopore instrument can discriminate between individual DNA hairpins that differ by one base pair or by one nucleotide.