410 research outputs found
NanTroSEIZE Stage 1 expeditions: introduction and synthesis of key results
Integrated Ocean Drilling Program Expeditions 314, 315, and 316 were carried out as a unified program of drilling collectively known as Stage 1 of the Nankai Trough Seismogenic Zone Experiment, a multistage complex drilling project. A transect of eight sites was selected for riserless drilling to target the frontal thrust region, midslope megasplay fault region, and Kumano forearc basin region. Two of these sites are preparatory pilot holes for planned deep riser drilling operations, whereas the others targeted fault zone material in the shallow, presumed aseismic zone. Expedition 314 was dedicated to in situ measurement of physical properties and borehole imaging through logging while drilling in holes dedicated to that purpose. Expedition 315 was devoted to core sampling and downhole temperature measurements at one site in the megasplay region and one site in the forearc basin. Expedition 316 targeted the frontal and out-of-sequence megasplay fault region in the mid-slope environment. Results on accretionary complex structure, lithology and age, physical properties, and state of stress, which are documented in full in the site chapters of this volume, are here synthesized across the expeditions
Invariant NKT Cell Response to Dengue Virus Infection in Human
BACKGROUND:Dengue viral infection is a global health threat without vaccine or specific treatment. The clinical outcome varies from asymptomatic, mild dengue fever (DF) to severe dengue hemorrhagic fever (DHF). While adaptive immune responses were found to be detrimental in the dengue pathogenesis, the roles of earlier innate events remain largely uninvestigated. Invariant natural killer T (iNKT) cells represent innate-like T cells that could dictate subsequent adaptive response but their role in human dengue virus infection is not known. We hypothesized that iNKT cells play a role in human dengue infection. METHODS:Blood samples from a well-characterized cohort of children with DF, DHF, in comparison to non-dengue febrile illness (OFI) and healthy controls at various time points were studied. iNKT cells activation were analyzed by the expression of CD69 by flow cytometry. Their cytokine production was then analyzed after α-GalCer stimulation. Further, the CD1d expression on monocytes, and CD69 expression on conventional T cells were measured. RESULTS:iNKT cells were activated during acute dengue infection. The level of iNKT cell activation associates with the disease severity. Furthermore, these iNKT cells had altered functional response to subsequent ex vivo stimulation with α-GalCer. Moreover, during acute dengue infection, monocytic CD1d expression was also upregulated and conventional T cells also became activated. CONCLUSION:iNKT cells might play an early and critical role in the pathogenesis of severe dengue viral infection in human. Targeting iNKT cells and CD1d serve as a potential therapeutic strategy for severe dengue infection in the future
Standalone portable xenon-129 hyperpolariser for multicentre clinical magnetic resonance imaging of the lungs
Objectives
Design and build a portable xenon-129 (129Xe) hyperpolariser for clinically accessible 129Xe lung MRI.
Methods
The polariser system consists of six main functional components: (i) a laser diode array and optics; (ii) a B0 coil assembly; (iii) an oven containing an optical cell; (iv) NMR and optical spectrometers; (v) a gas-handling manifold; and (vi) a cryostat within a permanent magnet. All components run without external utilities such as compressed air or three-phase electricity, and require just three mains sockets for operation. The system can be manually transported in a lightweight van and rapidly installed on a small estates footprint in a hospital setting.
Results
The polariser routinely provides polarised 129Xe for routine clinical lung MRI. To test the concept of portability and rapid deployment, it was transported 200 km, installed at a hospital with no previous experience with the technology and 129Xe MR images of a diagnostic quality were acquired the day after system transport and installation.
Conclusion
This portable 129Xe hyperpolariser system could form the basis of a cost-effective platform for wider clinical dissemination and multicentre evaluation of 129Xe lung MR imaging
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Balloon pulmonary angioplasty for inoperable chronic thromboembolic pulmonary hypertension: the UK experience.
OBJECTIVE: Inoperable chronic thromboembolic pulmonary hypertension (CTEPH) managed medically has a poor prognosis. Balloon pulmonary angioplasty (BPA) offers a new treatment for inoperable patients. The national BPA service for the UK opened in October 2015 and we now describe the treatment of our initial patient cohort. METHODS: Thirty consecutive, inoperable, anatomically suitable, symptomatic patients on stable medical therapy for CTEPH were identified and offered BPA. They initially underwent baseline investigations including Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) quality of life (QoL) questionnaire, cardiopulmonary exercise test, 6 min walk distance (6MWD), transthoracic echocardiography, N-terminal probrain natriuretic peptide (NT pro-BNP) and right heart catheterisation. Serial BPA sessions were then performed and after completion, the treatment effect was gauged by comparing the same investigations at 3 months follow-up. RESULTS: A median of 3 (IQR 1-6) BPA sessions per patient resulted in a significant improvement in functional status (WHO functional class ≥3: 24 vs 4, p<0.0001) and QoL (CAMPHOR symptom score: 8.7±5.4 vs 5.6±6.1, p=0.0005) with reductions in pulmonary pressures (mean pulmonary artery pressure: 44.7±11.0 vs 34.4±8.3 mm Hg, p<0.0001) and resistance (pulmonary vascular resistance: 663±281 vs 436±196 dyn.s.cm-5, p<0.0001). Exercise capacity improved (minute ventilation/carbon dioxide production: 55.3±12.2 vs 45.0±7.8, p=0.03 and 6MWD: 366±107 vs 440±94 m, p<0.0001) and there was reduction in right ventricular (RV) stretch (NT pro-BNP: 442 (IQR 168-1607) vs 202 (IQR 105-447) pg/mL, p<0.0001) and dimensions (mid RV diameter: 4.4±1.0 vs 3.8±0.7 cm, p=0.002). There were no deaths or life-threatening complications and the mild-moderate per-procedure complication rate was 10.5%. CONCLUSIONS: BPA is safe and improves the functional status, QoL, pulmonary haemodynamics and RV dimensions of patients with inoperable CTEPH
Endothelial nitric oxide pathways in the pathophysiology of dengue: a prospective observational study.
Background: Dengue can cause increased vascular permeability that may lead to hypovolemic shock. Endothelial dysfunction may underlie this; however the association of endothelial nitric oxide pathways with disease severity is unknown. Methods: We performed a prospective observational study in two Vietnamese hospitals, assessing patients presenting early (<72 hours fever) and patients hospitalized with warning signs or severe dengue. The reactive hyperaemic index (RHI), which measures endothelium-dependent vasodilation and is a surrogate marker of endothelial function and NO bioavailability was evaluated using peripheral artery tonometry (EndoPAT) and plasma levels of L-arginine, Arginase-1 and ADMA were measured at serial time-points. The main outcome of interest was plasma leakage severity. Results: 314 patients were enrolled, median age of the participants was 21 (IQR 13-30) years. No difference was found in the endothelial parameters between dengue and other febrile illness (OFI). Considering dengue patients, the RHI was significantly lower for patients with severe plasma leakage compared to those with no leakage (1.46 vs. 2.00, P<0.001), over acute time-points, apparent already in the early febrile phase (1.29 vs. 1.75, P=0.012). RHI correlated negatively with arginase-1, and positively with L-arginine (P=0.001). Endothelial dysfunction/NO bioavailability is associated with worse plasma leakage, occurs early in dengue illness and correlates with hypoargininaemia and high arginase-1 levels
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Deep subsurface carbon cycling in the Nankai Trough (Japan)-Evidence of tectonically induced stimulation of a deep microbial biosphere
The abundance of microbial life and the sources of energy necessary for deep subsurface microbial communities remain enigmatic. Here we investigate deep microbial processes and their potential relationships to tectonic events in sediments from the Nankai Trough offshore Japan, drilled and sampled during IODP (Integrated Ocean Drilling Program) Expedition 316. Observed methane isotope profiles indicate that microbially mediated methane production occurs at Sites C0006 and C0007 in sediments below ∼450 meters below seafloor (mbsf) and ∼425 mbsf, respectively. The active carbon cycling in these deep subsurface sediments is likely related to the highly dynamic tectonic regime at Nankai Trough. We propose that transient increases in temperature have restimulated organic matter degradation at these distinct depths and explore several candidate processes for transient heating. Our favored hypothesis is frictional heating associated with earthquakes. In concert with transient heating leading to the reactivation of recalcitrant organic matter, the heterogeneous sedimentary system provides niches for microbial life. The newly available/accessible organic carbon compounds fuel the microbial community—resulting in an onset of methanogenesis several hundred meters below the seafloor. This process is captured in the methane C-isotope signal, showing the efficacy of methane C-isotopes for delineating locations of active microbial processes in deeply buried sediments. Additionally, simple model approaches applied to observed chemical pore water profiles can potentially constrain timing relationships, which can then be linked to causative tectonic events. Our results suggest the occurrence of slip-to-the-trench earthquake(s) 200–400 year ago, which could relate to historical earthquakes (1707 Hoei and/or 1605 Keicho earthquakes)
Antibodies targeting epitopes on the cell-surface form of NS1 protect against Zika virus infection during pregnancy
Zika virus is an arthropod-transmitted flavivirus that can cause microcephaly and other fetal abnormalities during pregnancy. Here Wessel et al. develop antibodies against the Zika virus nonstructural protein 1 that protect non-pregnant and pregnant mice against infection, and define particular antibody epitopes and mechanisms underlying this protection
International ocean discovery program expedition 372 preliminary report: Creeping gas hydrate slides and Hikurangi LWD
International Ocean Discovery Program (IODP) Expedition 372 combined two research topics, slow slip events (SSEs) on subduction faults (IODP Proposal 781A-Full) and actively deforming gas hydrate-bearing landslides (IODP Proposal 841-APL). Our study area on the Hikurangi margin, east of the coast of New Zealand, provided unique locations for addressing both research topics.SSEs at subduction zones are an enigmatic form of creeping fault behavior. They typically occur on subduction zones at depths beyond the capabilities of ocean floor drilling. However, at the northern Hikurangi subduction margin they are among the best-documented and shallowest on Earth. Here, SSEs may extend close to the trench, where clastic and pelagic sediments about 1.0-1.5 km thick overlie the subducting, seamount-studded Hikurangi Plateau. Geodetic data show that these SSEs recur about every 2 years and are associated with measurable seafloor displacement. The northern Hikurangi subduction margin thus provides an excellent setting to use IODP capabilities to discern the mechanisms behind slow slip fault behaviour
UK Lung Cancer RCT Pilot Screening Trial: baseline findings from the screening arm provide evidence for the potential implementation of lung cancer screening.
BACKGROUND: Lung cancer screening using low-dose CT (LDCT) was shown to reduce lung cancer mortality by 20% in the National Lung Screening Trial. METHODS: The pilot UK Lung Cancer Screening (UKLS) is a randomised controlled trial of LDCT screening for lung cancer versus usual care. A population-based questionnaire was used to identify high-risk individuals. CT screen-detected nodules were managed by a pre-specified protocol. Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction. RESULTS: 247 354 individuals aged 50-75 years were approached; 30.7% expressed an interest, 8729 (11.5%) were eligible and 4055 were randomised, 2028 into the CT arm (1994 underwent a CT). Forty-two participants (2.1%) had confirmed lung cancer, 34 (1.7%) at baseline and 8 (0.4%) at the 12-month scan. 28/42 (66.7%) had stage I disease, 36/42 (85.7%) had stage I or II disease. 35/42 (83.3%) had surgical resection. 536 subjects had nodules greater than 50 mm(3) or 5 mm diameter and 41/536 were found to have lung cancer. One further cancer was detected by follow-up of nodules between 15 and 50 mm(3) at 12 months. The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening, under the UKLS protocol, was £8466 per quality adjusted life year gained (CI £5542 to £12 569). CONCLUSIONS: The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80% of cases. Health economic analysis suggests that the intervention would be cost effective-this needs to be confirmed using data on observed lung cancer mortality reduction. TRIAL REGISTRATION: ISRCTN 78513845
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