Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC.

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28} cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25} cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C.

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

Fludarabine as a cost-effective adjuvant to enhance engraftment of human normal and malignant hematopoiesis in immunodeficient mice.

There is still an unmet need for xenotransplantation models that efficiently recapitulate normal and malignant human hematopoiesis. Indeed, there are a number of strategies to generate humanized mice and specific protocols, including techniques to optimize the cytokine environment of recipient mice and drug alternatives or complementary to the standard conditioning regimens, that can be significantly modulated. Unfortunately, the high costs related to the use of sophisticated mouse models may limit the application of these models to studies that require an extensive experimental design. Here, using an affordable and convenient method, we demonstrate that the administration of fludarabine (FludaraTM) promotes the extensive and rapid engraftment of human normal hematopoiesis in immunodeficient mice. Quantification of human CD45+ cells in bone marrow revealed approximately a 102-fold increase in mice conditioned with irradiation plus fludarabine. Engrafted cells in the bone marrow included hematopoietic stem cells, as well as myeloid and lymphoid cells. Moreover, this model proved to be sufficient for robust reconstitution of malignant myeloid hematopoiesis, permitting primary acute myeloid leukemia cells to engraft as early as 8 weeks after the transplant. Overall, these results present a novel and affordable model for engraftment of human normal and malignant hematopoiesis in immunodeficient mice.

Monomeric, porous type II collagen scaffolds promote chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro.

Osteoarthritis (OA) is a common cause of pain and disability and is often associated with the degeneration of articular cartilage. Lesions to the articular surface, which are thought to progress to OA, have the potential to be repaired using tissue engineering strategies; however, it remains challenging to instruct cell differentiation within a scaffold to produce tissue with appropriate structural, chemical and mechanical properties. We aimed to address this by driving progenitor cells to adopt a chondrogenic phenotype through the tailoring of scaffold composition and physical properties. Monomeric type-I and type-II collagen scaffolds, which avoid potential immunogenicity associated with fibrillar collagens, were fabricated with and without chondroitin sulfate (CS) and their ability to stimulate the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells was assessed. Immunohistochemical analyses showed that cells produced abundant collagen type-II on type-II scaffolds and collagen type-I on type-I scaffolds. Gene expression analyses indicated that the addition of CS - which was released from scaffolds quickly - significantly upregulated expression of type II collagen, compared to type-I and pure type-II scaffolds. We conclude that collagen type-II and CS can be used to promote a more chondrogenic phenotype in the absence of growth factors, potentially providing an eventual therapy to prevent OA.

Black hole physics. Black hole lightning due to particle acceleration at subhorizon scales.

Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.

The diagnostic classification of eating disorders: current situation, possible alternatives and future perspectives.

The current nosography of eating disorders (ED) has various limitations in terms of validity and accuracy. The changes adopted in the DSM-5 limit some of the current problems, such as excessive prevalence of ED not otherwise specified (EDNOS) and the lack of longitudinal stability, but are unlikely to adequately capture the clinical complexity of ED. Many authors suggest the need for a thorough review of the current nosography to support evidence-based classification. In this paper, we discuss the validity of the current diagnostic categories and their possible reorganization. Furthermore, we review the main empirical models of classification and the diagnostic approach from a personality perspective, with particular attention to research and to the prognostic and therapeutic implications.

Prophylaxis and treatment of GVHD: EBMT-ELN working group recommendations for a standardized practice.

GVHD remains the major impediment to broader application of allogeneic haematopoietic SCT. It can be prevented completely, but at the expense of other complications, rejection, relapse or delayed immune reconstitution. No optimal prevention or treatment method has been defined. This is reflected by enormous heterogeneity in approaches in Europe. Retrospective comparisons between different policies, although warranted, do not give definite answers. In order to improve the present situation, an European Group for Blood and Marrow Transplantation and the European LeukemiaNet working group has developed in a Delphi-like approach recommendations for prophylaxis and treatment of GVHD in the most common allogeneic transplant setting, transplantation from an HLA-identical sibling or unrelated donor for standard risk malignant disease. The working group proposes these guidelines to be adopted as routine standard in transplantation centres and to be used as comparator in systematic studies evaluating the advantages and disadvantages of practices differing from these recommendations.

Escalating-dose HLA-mismatched DLI is safe for the treatment of leukaemia relapse following alemtuzumab-based myeloablative allo-SCT.

Although the feasibility of using HLA-mismatched unrelated donors as an alternate graft source for haematopoietic SCT (HSCT) has been shown, little is known about the safety of HLA-mismatched DLI for the treatment of relapse. We examined the outcome of 58 consecutive leukaemia patients who received escalating-dose DLI for treatment of relapse after alemtuzumab-conditioned myeloablative unrelated donor HSCT at our institution. High-resolution HLA typing on stored DNA samples revealed mismatches in 28/58 patients who were considered HLA-matched at the time of transplantation. Following DLI from HLA-matched (10/10) (n=30) or -mismatched (7-9/10) (n=28) unrelated donors, we found no significant difference in the incidence of acute GVHD (17.2% versus 23.1%, P=0.59), probability of remission at 3 years (62.1% versus 63.9%, P=0.89) or 5-year OS (89.8% versus 77.7%, P=0.22). We conclude that escalating-dose DLI can be safely given to HLA-mismatched recipients following T-depleted myeloablative HSCT.

Donor lymphocyte infusions for the treatment of chronic myeloid leukemia relapse following peripheral blood or bone marrow stem cell transplantation.

Peripheral blood used as a source of stem cells for transplantation (PBSCT) is known to exert stronger immune-mediated effects compared with BM (BMT). We decided to retrospectively analyze the impact of stem cell source on the OS of CML patients who relapsed after either matched related donor PBSCT (N=168) or BMT (N=216) and were treated with donor lymphocyte infusions (DLI). Univariate analysis revealed a lower probability of OS after DLI in patients relapsing after PBSCT vs BMT (66% vs 79% at 5 years, P=0.013). However, a multivariate Cox analysis did not reveal any significant impact of PBSCT as a risk factor for decreased OS for patients transplanted in first chronic phase (CP1; hazard ratio (HR) 1.036, 95% confidence interval (CI) 0.619-1.734). A statistical interaction term suggested that the impact of stem cell source on OS after DLI was different for those transplanted in advanced phases (negative impact of previous PBSCT-HR 2.176, 95% CI 0.930-5.091). In summary, the stem cell source does not affect the OS of CML patients who underwent PBSCT in CP1, relapsed and were treated with DLI. However, when the patients were transplanted in advanced phases, previous PBSCT seems to negatively affect OS after DLI compared with BMT.

Prolonged duodenal paralysis after PEG placement in a patient with traumatic brain injury: a case report.

Percutaneous endoscopic gastrostomy (PEG) has recently become a usual procedure for patients with prolonged disorders of consciousness after brain injuries. Despite a high rate of success and a very low procedure-related mortality, morbidity associated to PEG placement reaches 9.4% in a recent large meta-analysis. This case report describes an uncommon complication of PEG placement in a patient with vegetative state after traumatic brain injury: the development of prolonged duodenal paralysis. This patient was treated by placement of a transient jejunostomy until recovery of duodenal functional activity, to permit adequate nutrition. This procedure-related complication is previously unreported in scientific literature.

Haemopoietic stem cell transplantation induces tolerance to donor antigens but not to foreign FVIII peptides.

A 22-year-old male with severe haemophilia A and high responding factor VIII (FVIII) inhibitor underwent sibling haematopoietic stem cell transplantation in an attempt to eradicate the inhibitor. A reduced intensity conditioning regimen was followed by bone marrow infusion and continuous FVIII administration during immune reconstitution. Although substantial levels of FVIII:C (>100 IU dL(-1)) were maintained initially, at day +23 inhibitor titres rose, indicating boosting of recipient memory repertoire, despite complete donor chimerism. On day +46, he developed Klebsiella pneumoniae septicaemia and died. This case shows that, despite very successful transplantation tolerance, the procedure failed to control long-term memory effector immune cells.

Outcome of patients developing GVHD after DLI given to treat CML relapse: a study by the Chronic Leukemia Working Party of the EBMT.

We studied GVHD after donor lymphocyte infusion (DLI) in 328 patients with relapsed CML between 1991 and 2004 . A total of 122 patients (38%) developed some form of GVHD. We analyzed GVHD by clinical presentation (acute or chronic GVHD) and onset time after the first DLI (early (< or =45 days) or late (>45 days)). There was a significant overlap between onset time and clinical presentation. Some form of GVHD occurred at a median of 104 days, acute GVHD at 45 days and chronic GVHD at 181 days after DLI. The clinical presentation was acute GVHD in 71 patients, of whom 31 subsequently developed chronic GVHD subsequently. De novo chronic GVHD was seen in 51 patients. OS for all patients was 69% (95% confidence interval (CI) 63-75) at 5 years, DLI-related mortality was 11% (95% CI 8-15) and disease-related mortality was 20% (95% CI 16-25). Risk factors for developing GVHD after DLI were T-cell dose at first DLI, the time interval from transplant to DLI and donor type. In time-dependent multivariate analysis, GVHD after DLI was associated with a risk of death of 2.3-fold compared with patients without GVHD. Clinical presentation as acute GVHD and early onset GVHD were associated with increased mortality.

Basic research and clinical applications of non-hematopoietic stem cells, 4-5 April 2008, Tubingen, Germany.

From 4 to 5 April 2008, international experts met for the second time in Tubingen, Germany, to present and discuss the latest proceedings in research on non-hematopoietic stem cells (NHSC). This report presents issues of basic research including characterization, isolation, good manufacturing practice (GMP)-like production and imaging as well as clinical applications focusing on the regenerative and immunomodulatory capacities of NHSC.

Observation of pulsed gamma-rays above 25 GeV from the Crab pulsar with MAGIC.

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.

Very-high-energy gamma rays from a distant quasar: how transparent is the universe?

The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.

Long-term clinical results of autologous infusion of mobilized adult bone marrow derived CD34+ cells in patients with chronic liver disease.

Evidence is growing in support of the role of stem cells as an attractive alternative in treatment of liver diseases. Recently, we have demonstrated the feasibility and safety of infusing CD34(+) adult stem cells; this was performed on five patients with chronic liver disease. Here, we present the results of long-term follow-up of these patients. Between 1 x 10(6) and 2 x 10(8) CD34(+) cells were isolated and injected into the portal vein or hepatic artery. The patients were monitored for side effects, toxicity and changes in clinical, haematological and biochemical parameters; they were followed up for 12-18 months. All patients tolerated the treatment protocol well without any complications or side effects related to the procedure, also there were no side effects noted on long-term follow-up. Four patients showed an initial improvement in serum bilirubin level, which was maintained for up to 6 months. There was marginal increase in serum bilirubin in three of the patients at 12 months, while the fourth patient's serum bilirubin increased only at 18 months post-infusion. Computed tomography scan and serum alpha-foetoprotein monitoring showed absence of focal lesions. The study indicated that the stem cell product used was safe in the short and over long term, by absence of tumour formation. The investigation also illustrated that the beneficial effect seemed to last for around 12 months. This trial shows that stem cell therapy may have potential as a possible future therapeutic protocol in liver regeneration.

The highway code of T cell trafficking.

Coordinated migratory events are required for the development of effective and regulated immunity. Naïve T lymphocytes are programmed to recirculate predominantly in secondary lymphoid tissue by non-specific stimuli. In contrast, primed T cells must identify specific sites of antigen location in non-lymphoid tissue to exert targeted effector responses. Following priming, T cells acquire the ability to establish molecular interactions mediated by tissue-selective integrins and chemokine receptors (homing receptors) that allow their access to specific organs, such as the skin and the gut. Recent studies have shown that an additional level of specificity is provided by the induction of specific T cell migration into the tissue following recognition of antigen displayed by the endothelium. In addition, co-stimulatory signals (such as those induced by CD28 and CTLA-4 molecules) have been shown not only to regulate T cell activation and differentiation, but also to orchestrate the anatomy of the ensuing T cell response.