The deep biosphere of the subseafloor crust is believed to contain a significant part of Earth's biomass, but because of the difficulties of directly observing the living organisms, its composition and ecology are poorly known. We report here a consortium of fossilized prokaryotic and eukaryotic micro-organisms, occupying cavities in deep-drilled vesicular basalt from the Emperor Seamounts, Pacific Ocean, 67.5 m below seafloor (mbsf). Fungal hyphae provide the framework on which prokaryote-like organisms are suspended like cobwebs and iron-oxidizing bacteria form microstromatolites (Frutexites). The spatial inter-relationships show that the organisms were living at the same time in an integrated fashion, suggesting symbiotic interdependence. The community is contemporaneous with secondary mineralizations of calcite partly filling the cavities. The fungal hyphae frequently extend into the calcite, indicating that they were able to bore into the substrate through mineral dissolution. A symbiotic relationship with chemoautotrophs, as inferred for the observed consortium, may be a pre-requisite for the eukaryotic colonization of crustal rocks. Fossils thus open a window to the extant as well as the ancient deep biosphere.

Our results are the first to describe apparent luminal dilatation, suprarenal branch ruptures, and intramural haematoma formation in dissecting abdominal aortic aneurysms in mice. Moreover, we validate and demonstrate the vast potential of phase contrast X-ray tomographic microscopy in cardiovascular small animal applications.

In the present study, the in vivo distribution of polyelectrolyte multilayer coated gold nanoparticles is shown, starting from the living animal down to cellular level. The coating was designed with functional moieties to serve as a potential nano drug for prion disease. With near infrared time-domain imaging we followed the biodistribution in mice up to 7 days after intravenous injection of the nanoparticles. The peak concentration in the head of mice was detected between 19 and 24 h. The precise particle distribution in the brain was studied ex vivo by X-ray microtomography, confocal laser and fluorescence microscopy. We found that the particles mainly accumulate in the hippocampus, thalamus, hypothalamus, and the cerebral cortex.

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A ortic aneurysm is clinically defined as a local increase in aortic diameter of at least 50% compared with the normal diameter.1 Abdominal aortic aneurysms (AAA) are associated with cardiovascular risk factors, such as smoking, age, male sex, hyperlipidemia, hypertension, and chronic obstructive pulmonary disease.2 Although these factors also underlie the majority of thoracic aortic aneurysms, the latter subgroup incidence is more often related to family history than to the above mentioned factors.3 Because most aneurysms remain asymptomatic until-often fatal-complications such as rupture occur, our understanding of the pathogenesis, especially in early stages, is limited. Angiotensin II infusion into hypercholesterolemic ApoE −/− mice is a well-known experimental model of both AAAs 4 and thoracic aortic aneurysms. 5 We have recently explored a novel imaging technique, phase contrast X-ray tomographic microscopy (PCXTM), to visualize the abdominal lesions of angiotensin II-infused mice. 6 Because the axial resolution of our PCXTM scans (6.5 μm) was close to the thickness of histological coupes for routine morphological evaluation (4 μm), we introduced PCXTM-guided histology to select sections of the aorta in a highly precise manner for pathology analysis. 6 This approach allowed us to demonstrate that the abdominal lesions in these mice stem from medial ruptures in the suprarenal side branches, leading to media-adventitia dissection with intramural bleeding and thrombus formation. 6 Much like in humans, data on thoracic aortic aneurysms are scarcer than data on AAAs in mouse models. Daugherty et al reported dilatation of the ascending aorta as semiquantified on histological sections after 28 days of continuous angiotensin II infusion in ApoE −/− mice. 5 They observed expansion of interlaminar spaces, collagen deposition, and macrophage © 2016 American Heart Association, Inc. Objective-To understand the anatomy and physiology of ascending aortic aneurysms in angiotensin II-infused ApoE −/− mice. Approach and Results-We combined an extensive in vivo imaging protocol (high-frequency ultrasound and contrastenhanced microcomputed tomography at baseline and after 3, 10, 18, and 28 days of angiotensin II infusion) with synchrotron-based ultrahigh resolution ex vivo imaging (phase contrast X-ray tomographic microscopy) in n=47 angiotensin II-infused mice and 6 controls. Aortic regurgitation increased significantly over time, as did the luminal volume of the ascending aorta. In the samples that were scanned ex vivo, we observed one or several focal dissections, with the largest located in the outer convex aspect of the ascending aorta. The volume of the dissections moderately correlated to the volume of the aneurysm as measured in vivo (r 2 =0.46). After 3 days of angiotensin II infusion, we found an interlaminar hematoma in 7/12 animals, which could be linked to an intimal tear. There was also a significant increase in single laminar ruptures, which may have facilitated a progressive enlargement of the focal dis...

In vitro expanded beating cardiac myocytes derived from induced pluripotent stem cells (iPSC-CMs) are a promising source of therapy for cardiac regeneration. Meanwhile, the cell sheet method has been shown to potentially maximize survival, functionality, and integration of the transplanted cells into the heart. It is thus hypothesized that transplanted iPSC-CMs in a cell sheet manner may contribute to functional recovery via direct mechanical effects on the myocardial infarction (MI) heart. F344/NJcl-rnu/rnu rats were left coronary artery ligated (n = 30), followed by transplantation of Dsred-labeled iPSC-CM cell sheets of murine origin over the infarct heart surface. Effects of the treatment were assessed, including in vivo molecular/cellular evaluations using a synchrotron radiation scattering technique. Ejection fraction and activation recovery interval were significantly greater from day 3 onward after iPSC-CM transplantation compared to those after sham operation. A number of transplanted iPSC-CMs were present on the heart surface expressing cardiac myosin or connexin 43 over 2 weeks, assessed by immunoconfocal microscopy, while mitochondria in the transplanted iPSC-CMs gradually showed mature structure as assessed by electron microscopy. Of note, X-ray diffraction identified 1,0 and 1,1 equatorial reflections attributable to myosin and actin-myosin lattice planes typical of organized cardiac muscle fibers within the transplanted cell sheets at 4 weeks, suggesting cyclic systolic myosin mass transfer to actin filaments in the transplanted iPSC-CMs. Transplantation of iPSC-CM cell sheets into the heart yielded functional and electrical recovery with cyclic contraction of transplanted cells in the rat MI heart, indicating that this strategy may be a promising cardiac muscle replacement therapy.