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.

Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A

Previous detections of individual astrophysical sources of neutrinos are limited to the Sun and the supernova 1987A, whereas the origins of the diffuse flux of high-energy cosmic neutrinos remain unidentified. On 22 September 2017, we detected a high-energy neutrino, IceCube-170922A, with an energy of ~290 tera–electron volts. Its arrival direction was consistent with the location of a known γ-ray blazar, TXS 0506+056, observed to be in a flaring state. An extensive multiwavelength campaign followed, ranging from radio frequencies to γ-rays. These observations characterize the variability and energetics of the blazar and include the detection of TXS 0506+056 in very-high-energy γ-rays. This observation of a neutrino in spatial coincidence with a γ-ray–emitting blazar during an active phase suggests that blazars may be a source of high-energy neutrinos.

Search for γ-Ray Line Signals from Dark Matter Annihilations in the Inner Galactic Halo from 10 Years of Observations with H.E.S.S

Spectral lines are among the most powerful signatures for dark matter (DM) annihilation searches in very-high-energy γ rays. The central region of the Milky Way halo is one of the most promising targets given its large amount of DM and proximity to Earth. We report on a search for a monoenergetic spectral line from self-annihilations of DM particles in the energy range from 300 GeV to 70 TeV using a two-dimensional maximum likelihood method taking advantage of both the spectral and spatial features of the signal versus background. The analysis makes use of Galactic center observations accumulated over ten years (2004-2014) with the H.E.S.S. array of ground-based Cherenkov telescopes. No significant γ-ray excess above the background is found. We derive upper limits on the annihilation cross section ⟨σv⟩ for monoenergetic DM lines at the level of 4×10^{-28}  cm^{3} s^{-1} at 1 TeV, assuming an Einasto DM profile for the Milky Way halo. For a DM mass of 1 TeV, they improve over the previous ones by a factor of 6. The present constraints are the strongest obtained so far for DM particles in the mass range 300 GeV-70 TeV. Ground-based γ-ray observations have reached sufficient sensitivity to explore relevant velocity-averaged cross sections for DM annihilation into two γ-ray photons at the level expected from the thermal relic density for TeV DM particles.

Anaesthesia for hemipelvectomy--a series of 49 cases

We undertook an audit of 49 consecutive hemipelvectomies performed for primary or secondary malignancy. Combined epidural and general anaesthesia was used in 41 patients. The operations were long (range 90 to 600 minutes). The median crystalloid requirement was 8500 ml (range 1000 to 42000 ml) and a median of seven units of packed red blood cells were transfused (range 0 to 44 units). All measures of coagulation were normalised by the first postoperative day using fresh frozen plasma, platelets and cryoprecipitate. Warmed blood was administered at high flow rates using a custom designed system consisting of a roller pump and high capacity fluid warmer Thirty-five patients were managed postoperatively in the intensive care unit, of whom 31 remained intubated for postoperative ventilation. In 41 patients, postoperative pain management was by a continuous epidural infusion of local anaesthetic and opioid. The average duration of infusion was 4.25 days (range 3 to 6 days). One patient died during surgery from complications relating to massive blood loss, 14 had wound infections and one had an acute brain syndrome. There was significant utilisation of resources involving anaesthesia, surgery, intensive care and blood transfusion services. Anaesthesia for hemipelvectomy is challenging because of the extensive tissue trauma involved, the potential for massive blood loss and the potential for severe postoperative pain. The perioperative management necessitates care from a well coordinated, directed and focused healthcare team.

Coupled transport of p24 family members

Recent studies show that small trans-membrane proteins of approximately 22–24 kDa (the p24 family), which are grouped into 4 sub-families by sequence homology (p23, p24, p25 and p26), are involved in the early secretory pathway. In this study, we have investigated the mutual requirements of ectopically expressed members of the p24 family for targeting to their proper cellular destination. We find that coexpression of p23 and p24 is both necessary and sufficient for each protein to be transported to the cis-Golgi network/Golgi complex. Proteins from other subfamilies did not substitute for either p23 or p24, even after multiple coexpression. However, trafficking of the p23/p24 couple was facilitated by coexpression of proteins from other sub-families. In addition, we find that the sequence resembling an endoplasmic reticulum retrieval signal present in the cytoplasmic domain of p23 (but not p24) is dispensable. In contrast, the conserved coiled-coil region in the lumenal domain is absolutely required in both p23 and p24 for proper targeting of the p23/p24 couple. These data demonstrate that p23 and p24 must interact with each other to reach their destination, but that this strict requirement is combined with a mutual dependence amongst p24 proteins. We speculate that p24 proteins can form different oligomeric complexes, which contribute to confer specialized sorting/trafficking properties to membranes of the early secretory pathway, perhaps serving as membrane organizers.

The transmembrane protein p23 contributes to the organization of the Golgi apparatus

In previous studies we have shown that p23, a member of the p24-family of small transmembrane proteins, is highly abundant in membranes of the cis-Golgi network (CGN), and is involved in sorting/trafficking in the early secretory pathway. In the present study, we have further investigated the role of p23 after ectopic expression. We found that ectopically expressed p23 folded and oligomerized properly, even after overexpression. However, in contrast to endogenous p23, exogenous p23 molecules did not localize to the CGN, but induced a significant expansion of characteristic smooth ER membranes, where they accumulated in high amounts. This ER-derived, p23-rich subdomain displayed a highly regular morphology, consisting of tubules and/or cisternae of constant diameter, which were reminiscent of the CGN membranes containing p23 in control cells. The expression of exogenous p23 also led to the specific relocalization of endogenous p23, but not of other proteins, to these specialized ER-derived membranes. Relocalization of p23 modified the ultrastructure of the CGN and Golgi membranes, but did not affect anterograde and retrograde transport reactions to any significant extent. We conclude (i) that p23 has a morphogenic activity that contributes to the morphology of CGN-membranes; and (ii) that the presence of p23 in the CGN is necessary for the proper organization of the Golgi apparatus.

Incidence of phrenic nerve block and hypercapnia in patients undergoing carotid endarterectomy under cervical plexus block

Deep cervical plexus blockade blocks the second, third and fourth cervical nerve roots. The phrenic nerve arises from C3, C4, C5 and should therefore be commonly blocked with cervical plexus blockade. The aim of this study was to report the incidence of phrenic nerve block and to assess the effect of this on arterial carbon dioxide tension (PaCO2) in premedicated and sedated patients. Forty patients were studied, blood gases being taken on the day before surgery, immediately before performing the block and then every 20 minutes until the operation was completed. Fluoroscopy was used to determine ipsilateral hemidiaphragmatic dysfunction due to phrenic nerve block. The patients were then divided into two groups of analysis. Group A patients had evidence of phrenic nerve block, Group B patients had no evidence of phrenic nerve block. Fluoroscopy showed that 22 patients (55%) had evidence of phrenic nerve block (Group A), 18 patients showed no change (Group B). PaCO2 levels increased in both groups following premedication, from 41 +/- 5 mmHg (mean +/- SD) to 46 +/- 5 mmHg in Group A, and 41 +/- 4 mmHg in Group B; twenty minutes after cervical plexus block the PaCO2 rose to 49 +/- 6 mmHg in Group A, and 48 +/- 6 mmHg in Group B. These changes were not statistically significantly different when the two groups were compared.

Involvement of the transmembrane protein p23 in biosynthetic protein transport

Here, we report the localization and characterization of BHKp23, a member of the p24 family of transmembrane proteins, in mammalian cells. We find that p23 is a major component of tubulovesicular membranes at the cis side of the Golgi complex (estimated density: 12,500 copies/micron2 membrane surface area, or approximately 30% of the total protein). Our data indicate that BHKp23-containing membranes are part of the cis-Golgi network/intermediate compartment. Using the G protein of vesicular stomatitis virus as a transmembrane cargo molecule, we find that p23 membranes are an obligatory station in forward biosynthetic membrane transport, but that p23 itself is absent from transport vesicles that carry the G protein to and beyond the Golgi complex. Our data show that p23 is not present to any significant extent in coat protein (COP) I-coated vesicles generated in vitro and does not colocalize with COP I buds and vesicles. Moreover, we find that p23 cytoplasmic domain is not involved in COP I membrane recruitment. Our data demonstrate that microinjected antibodies against the cytoplasmic tail of p23 inhibit G protein transport from the cis-Golgi network/ intermediate compartment to the cell surface, suggesting that p23 function is required for the transport of transmembrane cargo molecules. These observations together with the fact that p23 is a highly abundant component in the intermediate compartment, lead us to propose that p23 contributes to membrane structure, and that this contribution is necessary for efficient segregation and transport.

Comparison of the short term efficacy and tolerability of lovastatin and simvastatin in the management of primary hypercholesterolemia

OBJECTIVES

To compare the safety and efficacy of lovastatin and simvastatin in patients with primary hypercholesterolemia.

METHODS

Fourteen Canadian centres participated in this double-blind, randomized, parallel-design study with a six-week screening period, a four-week placebo baseline period and an 18-week active treatment period. Patients were included in the study if their total cholesterol (TC) was at least 6.2 mmol/L and total triglycerides (TG) were 4.0 mmol/L or less at baseline. Half of the patients were in stratum I (TC 6.2 to 7.8 mmol/L at baseline and placebo period) and half in stratum II (TC greater than 7.8 mmol/L). The initial dose of lovastatin or simvastatin (20 and 10 mg/day, respectively) was doubled if the patient's cholesterol was greater than 5.2 mmol/L after six and/or 12 weeks, to a maximum of 80 mg/day lovastatin or 40 mg/day simvastatin. Of 298 randomized patients, two had baseline data only (and were excluded from the efficacy analysis), while 77 were treated with lovastatin and 74 with simvastatin in stratum I, and 72 were on lovastatin and 75 on simvastatin in stratum II.

RESULTS

In stratum I, both lovastatin and simvastatin lowered TC (-26.0% in both the lovastatin and simvastatin groups), low density lipoprotein (LDL) cholesterol (-33.4% in lovastatin and -34.4% in simvastatin), TG (-11.4% in lovastatin and -16.2% in simvastatin), apolipoprotein (apo)-B (-24.8% in lovastatin and -26.3% in simvastatin) and the TC:high density lipoprotein (HDL) cholesterol ratio (from 6.65 to 4.73 in lovastatin and from 6.45 to 4.46 in simvastatin), and increased HDL cholesterol (+3.6% in lovastatin and +7.8% in simvastatin) and apo-A1 (+6.3% in lovastatin and +9.0% in simvastatin) with P < 0.001 in all within-group tests except for HDL cholesterol (P < 0.05). Similar results were obtained in stratum II for TC (-30.7% in lovastatin and -30.3% in simvastatin), LDL cholesterol (-37.6% in lovastatin and -36.8% in simvastatin), TG (-21.9% in lovastatin and -16.9% in simvastatin), apo-B (-32.0% in lovastatin and -31.7% in simvastatin), TC:HDL cholesterol ratio (from 8.62 to 5.47 in lovastatin and from 8.96 to 5.77 in simvastatin), HDL cholesterol (+9.7% in lovastatin and +7.5% in simvastatin) and apo-A1 (+7.2% in lovastatin and +8.8% in simvastatin), with P < 0.001 in all within-group tests. Serious adverse events (clinical and laboratory) were reported in four patients in the lovastatin group and three in the simvastatin group. The most reported nonserious adverse effects were gastrointestinal tract (15 patients in the lovastatin group and 16 in the simvastatin group) and musculoskeletal (14 patients in the lovastatin group and 11 in the simvastatin group). Medication was withdrawn in eight patients.

CONCLUSIONS

Both lovastatin and simvastatin were found to be effective and well tolerated in each stratum. However, there were no significant differences between lovastatin and simvastatin in the treatment of moderate or severe primary hypercholesterolemia.

Ketoconazole. Use in the treatment of ectopic adrenocorticotropic hormone production and Cushing's syndrome in small-cell lung cancer

Recently, ketoconazole, an imidazole derivative with antifungal properties, has been shown to inhibit adrenal corticosteroid and androgen production. We treated a patient with small-cell lung cancer and Cushing's syndrome secondary to ectopic secretion of adrenocorticotropic hormone in whom it was necessary to discontinue chemotherapy. The patient was treated with ketoconazole, with a resultant reduction in urinary free cortisol and ketosteroid excretion and improvement in electrolyte balance. Ketoconazole may be a useful adjunct in the treatment of small-cell lung cancer or other malignancies associated with excessive corticosteroid production or as a hormonal therapy in breast or prostatic cancer.