Programmed cell death and its role in inflammation

Cell death plays an important role in the regulation of inflammation and may be the result of inflammation. The maintenance of tissue homeostasis necessitates both the recognition and removal of invading microbial pathogens as well as the clearance of dying cells. In the past few decades, emerging knowledge on cell death and inflammation has enriched our molecular understanding of the signaling pathways that mediate various programs of cell death and multiple types of inflammatory responses. This review provides an overview of the major types of cell death related to inflammation. Modification of cell death pathways is likely to be a logical therapeutic target for inflammatory diseases

Randomised trial of magnesium in the treatment of Irukandji syndrome

Objectives: Irukandji syndrome is a distressing condition characterised by pain, hypertension and tachycardia. Some develop cardiac failure and there have been two reported deaths. Magnesium sulphate has become the standard of care despite minimal evidence. The aim of this study was to investigate if magnesium would reduce analgesic requirement and length of stay for patients with Irukandji syndrome.\ud \ud Methods: This was a double-blind, randomised controlled clinical trial. Patients with Irukandji syndrome who required parenteral opioid analgesia were randomised to receive either 10 mmol of magnesium as a bolus, and then a 5 mmol/h magnesium infusion for 6 h or saline. Fentanyl patient-controlled analgesia was commenced to allow patients to self-regulate their pain relief. The primary outcome measure of the study was comparison of total analgesic requirements between the two groups. The secondary outcome measure was to compare length of stay.\ud \ud Results: The study ran from November 2003 to May 2007. Thirty-nine patients were enrolled in the study; 26 were male with a median age of 28. Twenty-two received magnesium. There was no significant difference in the morphine equivalent dose used, peak CK, peak troponin, peak pulse, peak blood pressure, peak mean arterial pressure (MAP), percentage MAP rise and length of stay for those receiving magnesium compared with placebo.\ud \ud Conclusion: Our study did not demonstrate a benefit in the use of magnesium in the treatment of Irukandji syndrome. As such the current use of magnesium needs to be reconsidered until there is good evidence to support its use

Delamination of southern Puna lithosphere revealed by body wave attenuation tomography

Artículo de publicación ISIThe southern Puna Plateau has been proposed to result from a major Pliocene delamination event that has previously been inferred from geochemical, geological, and some preliminary geophysical data. Seventy-five seismic stations were deployed across the southern Puna Plateau in 2007–2009 by scientists fromthe U.S., Germany, Chile, and Argentina to test the delamination model for the region. The Puna passive seismic stations were located between 25 and 28°S. Using the seismic waveform data collected from the PUNA experiment,we employ attenuation tomography methods to resolve both compressional and shear quality factors (Qp and Qs, respectively) in the crust and uppermost mantle. The images clearly show a high-Q Nazca slab subducting eastward beneath the Puna plateau and another high-Q block with a westward dip beneath the Eastern Cordillera. We suggest that the latter is a piece of delaminated South American lithosphere. A significant low-Q zone lies between the Nazca slab and the South American lithosphere and extends southward from the northernmargin of the seismic array at 25°S before vanishing around 27.5°S. This low-Q zone extends farther west in the crust and uppermost mantle at the southern end of the seismic array. The low-Q zone reaches ~100 km depth beneath the northern part of the array but only ~50 km depth in the south. Lateral variations of the low-Q zone reflect the possible mechanism conversion between mantle upwelling related to delamination and dehydration. The depth of the Nazca slab as defined by Q images decreases from north to south beneath the plateau, which is consistentwith the steep-flat transition of the angle of the subducting slab as defined by previous earthquake studies.This research is supported by the National Natural Science Foundation of China under grant 41340040, 91128210, the Continental Dynamics, National Science Foundation (USA) under grant EAR- 0538245, and by the Deutsche Forschungsgemeinschaft KI 314/27-1

Velocity structure beneath the southern Puna plateau: evidence for delamination

The high elevation of the southern Puna plateau, the widespread melting of its crust, the gap in intermediate depth seismicity and the recent eruptions of ignimbrite complexes can be explained by delamination of the lithospheric mantle beneath it. To test this hypothesis, an array consisting of 73 broad band and short period seismic stations was deployed in the region for a period of 2 years starting in 2007. We inverted the data using the two plane wave approach and obtained 1-D and 3-D Rayleigh wave phase velocities. Our dispersion curve shows that at short periods (<70 s) the phase velocities are slightly higher than those of the Tibetan plateau and lower than those of the Anatolian plateau. At periods of 100–140 s we observe a low velocity zone that might be remnant hot asthenosphere below a flat slab (7–10 Ma). We estimate the average continental lithosphere thickness for the region to be between 100 and 130 km. Our three-dimensional Rayleigh wave phase velocities show a high velocity anomaly at low frequencies (0.007, 0.008, and 0.009 Hz) slightly to the north of Cerro Galan. This would be consistent with the hypothesis of delamination in which a piece of lithosphere has detached and caused upwelling of hot asthenosphere, which in turn caused widespread alkaline-collision related volcanism. This interpretation is also corroborated by our shear wave velocity model, where a high velocity anomaly beneath the northern edge of Cerro Galan at 130 km depth is interpreted as the delaminated block on top of the subducting Nazca slab.Fil: Calixto, Frank J.. University of Missouri; Estados UnidosFil: Sandvol, Eric. University of Missouri; Estados UnidosFil: Kay, Suzanne. Cornell University; Estados UnidosFil: Mulcahy, Patrick. Cornell University; Estados UnidosFil: Heit, Benjamin. Helmholtz-Centre Potsdam. Deutsches GeoForschungsZentrum; AlemaniaFil: Yuan, Xiaohui. Helmholtz-Centre Potsdam. Deutsches GeoForschungsZentrum; AlemaniaFil: Coira, Beatriz Lidia Luisa. Universidad Nacional de Jujuy. Instituto de Geología Minera; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Comte, Diana. Universidad de Chile; ChileFil: Alvarado, Patricia Monica. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geofísica y Astronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Central Andean mantle and crustal seismicity beneath the Southern Puna plateau and the northern margin of the Chilean-Pampean flat slab.

Earthquake hypocenters recorded in the Andean Southern Puna seismic array (25–28°S, 70–65°W) provide new constraints on the shape of the subducting Nazca plate beneath the Puna plateau, the transition into the Chilean-Pampean flat slab and the thermal state of the mantle and crust. Some 270 new mantle hypocenters suggest that the subducting slab under the Puna shoals into the flat-slab segment more abruptly and farther to the north than previously indicated. The revised geometry is consistent with the Central Volcanic Zone Incapillo caldera being the southernmost center with Pleistocene activity until reaching the southern side of the flat-slab region. Evidence for the revised slab geometry includes three well-defined hypocenter clusters in the Pipanaco nest (27.5–29°S, 68–66°W), which are interpreted to reflect slab-bending stresses. A few low-magnitude earthquakes with strongly attenuated S waves in the long-recognized Antofalla teleseismic gap (25.5–27.5°S) support a continuous slab under the Southern Puna. The paucity of gap earthquakes and the presence of mafic magmas are consistent with a hot mantle wedge reflecting recent lithospheric delamination. Evidence for a hot overlaying Puna crust comes from new crustal earthquake hypocenters concentrated at depths shallower than 5 km. Two notable short-duration swarms were recorded under the resurgent dome of the ~2 Ma back-arc Cerro Galán caldera and the near-arc Cerro Torta dome. New crustal earthquake focal mechanisms from 17 events in the array along with two existing mechanisms have strike slip, oblique reverse, and oblique normal solutions fitting with regional E-W compression and N-S extension.Fil: Mulcahy, Patrick. Cornell University; Estados Unidos. Shell Exploration Company. New Orleans; Estados UnidosFil: Chen, Chen. Cornell University; Estados Unidos. Shell Exploration Company. New Orleans; Estados UnidosFil: Kay, Suzanne M.. Cornell University; Estados UnidosFil: Brown, Larry D.. Cornell University; Estados UnidosFil: Isacks, Bryan L.. Cornell University; Estados UnidosFil: Sandvol, Eric. University of Missouri; Estados UnidosFil: Heit, Benjamin. Deutsches GeoForschungs; AlemaniaFil: Yuan, Xiaohui. Deutsches GeoForschungs; AlemaniaFil: Coira, Beatriz Lidia Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Jujuy. Universidad Nacional de Jujuy. Centro de Investigaciones y Transferencia de Jujuy; Argentin