Determining crystal structures through crowdsourcing and coursework

We show here that computer game players can build high-quality crystal structures. Introduction of a new feature into the computer game Foldit allows players to build and real-space refine structures into electron density maps. To assess the usefulness of this feature, we held a crystallographic model-building competition between trained crystallographers, undergraduate students, Foldit players and automatic model-building algorithms. After removal of disordered residues, a team of Foldit players achieved the most accurate structure. Analysing the target protein of the competition, YPL067C, uncovered a new family of histidine triad proteins apparently involved in the prevention of amyloid toxicity. From this study, we conclude that crystallographers can utilize crowdsourcing to interpret electron density information and to produce structure solutions of the highest quality

How to assess, detect, and manage joint involvement in the era of transformational therapies: Role of point-of-care ultrasound

Background: Patients with haemophilia experience recurring hemarthroses, mainly involving knees, elbows and ankles, which lead to haemophilic arthropathy, the major chronic complication of haemophilia. With new approaches to haemophilia treatment leading to fewer joint bleeds and, in some cases, no bleeding events, assessing whether current outcome assessment tools provide adequate sensitivity and specificity for management and care of patients with haemophilia is needed. Methods: An overview of current imaging tools for monitoring joint health, novel osteochondral damage and synovial proliferation biomarkers, and the relationship between assessments for functionality and imaging modalities is provided. Usefulness and sensitivity of point-of-care ultrasound (POCUS) to complement other assessments and use of ultrasound to monitor haemophilic arthropathy are also examined. Results: This review provides rationale for haemophilia teams to move beyond traditional outcomes in joint imaging, as well as guidance and evidence on assessment of joint health for potential new treatment modalities, such as gene therapy. The role of POCUS in the existing paradigm for haemophilia care and management along with the use of ultrasound as a complement to other outcome assessment tools are also discussed. Finally, the clinical effects of subclinical bleeding on joint function are described, to motivate screening for synovial proliferation. Conclusion: POCUS can facilitate the early detection of joint damage and can monitor disease progression while providing insights into the efficacy of treatment regimens and should be considered as an essential assessment tool for managing the care of patients with haemophilia

Tin protoporphyrin provides protection following cerebral hypoxia-ischemia: involvement of alternative pathways.

The contribution of heme oxygenase (HO)-linked pathways to neurodegeneration following cerebral hypoxia-ischemia (HI) remains unclear. We investigated whether HO modulators affected HI-induced brain damage and explored potential mechanisms involved. HI was induced in 26-day-old male Wistar rats by left common carotid artery ligation, followed by exposure to a humidified atmosphere of 8% oxygen for 1 hr. Tin protoporphyrin (SnPP; an HO inhibitor), ferriprotoporphyrin (FePP; an HO inducer), or saline was administered intraperitoneally once daily from 1 day prior to HI until sacrifice at 3 days post-HI. SnPP reduced (P < 0.05) infarct volume compared with saline-treated animals, but FePP had no effect on brain injury. SnPP did not significantly inhibit HO activity at 3 days post-HI, but SnPP increased (P < 0.001) total nitric oxide synthase (NOS) activity compared with HI + saline. Both inducible NOS and cyclooxygenase activities were attenuated (P < 0.05) by SnPP, whereas mitochondrial complex I and V activities were augmented (P < 0.05) by SnPP. SnPP had no effect on NMDA receptor currents. Overall, like other HO inhibitors, SnPP produced many nonselective effects, such as attenuation of inflammatory enzymes and increased mitochondrial respiratory function, which were associated with a protective response 3 days post-HI

Tin protoporphyrin provides protection following cerebral hypoxia-ischemia: involvement of alternative pathways.

The contribution of heme oxygenase (HO)-linked pathways to neurodegeneration following cerebral hypoxia-ischemia (HI) remains unclear. We investigated whether HO modulators affected HI-induced brain damage and explored potential mechanisms involved. HI was induced in 26-day-old male Wistar rats by left common carotid artery ligation, followed by exposure to a humidified atmosphere of 8% oxygen for 1 hr. Tin protoporphyrin (SnPP; an HO inhibitor), ferriprotoporphyrin (FePP; an HO inducer), or saline was administered intraperitoneally once daily from 1 day prior to HI until sacrifice at 3 days post-HI. SnPP reduced (P < 0.05) infarct volume compared with saline-treated animals, but FePP had no effect on brain injury. SnPP did not significantly inhibit HO activity at 3 days post-HI, but SnPP increased (P < 0.001) total nitric oxide synthase (NOS) activity compared with HI + saline. Both inducible NOS and cyclooxygenase activities were attenuated (P < 0.05) by SnPP, whereas mitochondrial complex I and V activities were augmented (P < 0.05) by SnPP. SnPP had no effect on NMDA receptor currents. Overall, like other HO inhibitors, SnPP produced many nonselective effects, such as attenuation of inflammatory enzymes and increased mitochondrial respiratory function, which were associated with a protective response 3 days post-HI

Smectites and zeolites in ash from the 2010 summit eruption of Eyjafjallajökull volcano, Iceland

Hydrothermal alteration minerals are often incorporated in volcanic ash from phreatic and phreatomagmatic activity. Here we assess the presence and abundance of such minerals in the ash materials produced during the April- May 2010 initial phreatomagmatic (phase I) and subsequent magmatic (phases II and III) eruptions of Eyjafjallajökull volcano, Iceland. The results of X-ray diffraction analyses reveal significant quantities of smectites (up to 4 wt%, mainly as saponite) and zeolites (up to 7 wt%) in ash from phase I. While a minor amount of smectites (<0.5 wt%) is present in ash from the subsequent weak explosive activity (phase II), both smectites and zeolites are absent in phase III ash. This material was generated following abrupt rejuvenation of explosive activity in the absence of magma-ice/water interaction. Smectites and zeolites in phase I ash result primarily from scouring of altered volcanic rocks in the subsurface, although some may derive also from water-rock interaction within the summit ice cauldrons through which fragmented magma was injected.We show that incorporation of smectites and zeolites in phase I ash can explain its anomalously high specific surface area. Further, the presence of these minerals in ash may enhance its ability to act as ice nuclei as well as favour particle aggregation processes in the volcanic plume/cloud. Finally, the Eyjafjallajökull eruption represents another case in which ash fallout acted as an exogenic source of 2:1-type clay minerals in volcanic soils