Creation of Laryngeal Grafts from Primary Human Cells and Decellularized Laryngeal Scaffolds

Current reconstruction methods of the laryngotracheal segment fail to replace the complex functions of the human larynx. Bioengineering approaches to reconstruction have been limited by the complex tissue compartmentation of the larynx. We attempted to overcome this limitation by bio-engineering laryngeal grafts from decellularized canine laryngeal scaffolds recellularized with human primary cells under one uniform culture medium condition. First, we generated laryngeal scaffolds with preserved glycosaminoglycan content and biomechanical properties by detergent perfusion-decellularization over nine days. We proofed biocompatibility by absence of a CD3 lymphocyte response to subcutaneously implanted scaffolds in immune-competent rats. We then developed a uniform culture medium that strengthened the endothelial barrier over 5 days after an initial growth phase. Simultaneously, this culture medium supported airway epithelial cell and skeletal myoblast growth while maintaining their full differentiation and maturation potential. We then applied the uniform culture medium composition to whole laryngeal scaffolds seeded with endothelial cells from both carotid arteries and external jugular veins and generated re-endothelialized arterial and venous vascular beds. Under the same culture medium condition, we bio-engineered epithelial monolayers onto laryngeal mucosa and repopulated intrinsic laryngeal muscle. We were then able to demonstrate early muscle formation in heterotopic transplantations in immuno-deficient mice. The model supported the formation of three humanized laryngeal tissue compartments under one uniform culture condition, possibly a key factor in developing, complex, multicellular, ready-to-transplant tissue grafts

GRB 070724B: the first gamma ray burst localized by SuperAGILE and its Swift X-ray afterglow

GRB 070724B is the first gamma ray burst localized by SuperAGILE, the hard X-ray monitor aboard the AGILE satellite. The coordinates of the event were published similar to 19 h after the trigger. The Swift X-Ray Telescope pointed at the SuperAGILE location and detected the X-ray afterglow inside the SuperAGILE error circle. The AGILE gamma-ray Tracker and Minicalorimeter did not detect any significant gamma ray emission associated with GRB 070724B in the MeV and GeV range, neither prompt nor delayed. Searches for the optical afterglow were performed by the Swift UVOT and the Palomar automated 60-inch telescopes, resulting in no significant detection. Similarly, the Very Large Array did not detect any radio afterglow. This is the first GRB event associated with an X-ray afterglow with a firm upper limit in the 100 MeV-30 GeV energy range

Intramural haematoma of the thoracic aorta: who's to be alerted the cardiologist or the cardiac surgeon?

This review article is written so as to present the pathophysiology, the symptomatology and the ways of diagnosis and treatment of a rather rare aortic disease called Intra-Mural Haematoma (IMH). Intramural haematoma is a quite uncommon but potentially lethal aortic disease that can strike as a primary occurrence in hypertensive and atherosclerotic patients to whom there is spontaneous bleeding from vasa vasorum into the aortic wall (media) or less frequently, as the evolution of a penetrating atherosclerotic ulcer (PAU). IMH displays a typical of dissection progress, and could be considered as a precursor of classic aortic dissection. IMH enfeebles the aortic wall and may progress to either outward rupture of the aorta or inward disruption of the intima layer, which ultimately results in aortic dissection. Chest and back acute penetrating pain is the most commonly noticed symptom at patients with IMH. Apart from a transesophageal echocardiography (TEE), a tomographic imaging such as a chest computed tomography (CT), a magnetic resonance (MRI) and most lately a multy detector computed tomography (MDCT) can ensure a quick and accurate diagnosis of IMH. Similar to type A and B aortic dissection, surgery is indicated at patients with type-A IMH, as well as at patients with a persistent and/or recurrent pain. For any other patient (with type-B IMH without an incessant pain and/or without complications), medical treatment is suggested, as applied in the case of aortic dissection. The outcome of IMH in ascending aorta (type A) appears favourable after immediate (emergent or urgent) surgical intervention, but according to international bibliography patients with IMH of the descending aorta (type B) show similar mortality rates to those being subjected to conservative medical or surgical treatment. Endovascular surgery and stent-graft placement is currently indicated in type B IMH

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta