Energetics of stalk intermediates in membrane fusion are controlled by lipid composition

We have used X-ray diffraction on the rhombohedral phospholipid phase to reconstruct stalk structures in different pure lipids and lipid mixtures with unprecedented resolution, enabling a quantitative analysis of geometry, as well as curvature and hydration energies. Electron density isosurfaces are used to study shape and curvature properties of the bent lipid monolayers. We observe that the stalk structure is highly universal in different lipid systems. The associated curvatures change in a subtle, but systematic fashion upon changes in lipid composition. In addition, we have studied the hydration interaction prior to the transition from the lamellar to the stalk phase. The results indicate that facilitating dehydration is the key to promote stalk formation, which becomes favorable at an approximately constant interbilayer separation of 9.0 ± 0.5 Å for the investigated lipid compositions.     

The effects of systemic treatment with aminobisphosphonates and statins on circulating Vγ9Vδ2-T cells in patients with advanced cancer

Aminobisphosphonates (NBP) are used for treatment of metastatic bone disease. Frequently, patients undergoing NBP-treatment experience side-effects, known as acute phase response (APR), resulting from cytokine production by Vγ9Vδ2-T cells. As opposed to NBP, statins reduce intracellular phosphoantigen levels and prevent NBP-induced Vγ9Vδ2-T cell activation in vitro. We conducted a pilot study in patients with (bone-)metastasized malignancies receiving NBP-treatment and evaluated the phenotype and function of circulating Vγ9Vδ2-T cells in vivo and the effects of statins on Vγ9Vδ2-T cell responses and the associated APR. We observed reduced expression of perforin, granzyme B and HLA-DR on Vγ9Vδ2-T cells in patients treated with NBP and statins. However, statins could not prevent NBP-induced changes in circulating Vγ9Vδ2-T cell numbers or production of IFNγ and TNFα. Consistent with this, simvastatin could not prevent the occurrence of APR upon NBP-infusion. These observations call for the exploration of alternative strategies to prevent collateral APR upon NBP treatment.     

ASKyphoplan: a program for deformity planning in ankylosing spondylitis

A closing wedge osteotomy of the lumbar spine may be considered to correct posture and spinal balance in progressive thoracolumbar kyphotic deformity caused by ankylosing spondylitis (AS). Adequate deformity planning is essential for reliable prediction of the effect of surgical correction of the spine on the sagittal balance and horizontal gaze of the patient. The effect of a spinal osteotomy on the horizontal gaze is equal to the osteotomy angle. However, the effect of a spinal osteotomy on the sagittal balance depends on both the correction angle and the level of osteotomy simultaneously. The relation between the correction angle, the level of osteotomy and the sagittal balance of the spine can be expressed by a mathematical equation. However, this mathematical equation is not easily used in daily practice. We present the computer program ASKyphoplan that analyses and visualizes the planning procedure for sagittal plane corrective osteotomies of the spine in AS. The relationship between the planned correction angle, level of osteotomy and sagittal balance are coupled into the program. The steps taken during an ASKyphoplan run are outlined, and the clinical application is discussed. The application of the program is illustrated by the analysis of the data from a patient recently treated by a lumbar osteotomy in AS. The software can be used free of charge on the internet at under the heading “research” in the menu.     

Computational pathology definitions,best practices,and recommendations for regulatory guidance: a white paper from the Digital Pathology Association

In this white paper, experts from the Digital Pathology Association (DPA) define terminology and concepts in the emerging field of computational pathology, with a focus on its application to histology images analyzed together with their associated patient data to extract information. This review offers a historical perspective and describes the potential clinical benefits from research and applications in this field, as well as significant obstacles to adoption. Best practices for implementing computational pathology workflows are presented. These include infrastructure considerations, acquisition of training data, quality assessments, as well as regulatory, ethical, and cyber-security concerns. Recommendations are provided for regulators, vendors, and computational pathology practitioners in order to facilitate progress in the field. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

Activated iNKT cells promote Vγ9Vδ2-T cell anti-tumor effector functions through the production of TNF-α

Vγ9Vδ2-T cells constitute a proinflammatory lymphocyte subpopulation with established antitumor activity. Phosphoantigens activate Vγ9Vδ2-T cells in vivo and in vitro. We studied whether the antitumor activity of Vγ9Vδ2-T cells can be potentiated by invariant NKT cells (iNKT), an important immunoregulatory T cell subset. When activated by the glycolipid α-galactosylceramide (α-GalCer), iNKT produce large amounts of cytokines involved in antitumor immune responses. Monocyte-derived dendritic cells were loaded with both phosphoantigens (using aminobisphosphonates) and α-GalCer during maturation and subsequently co-cultured with Vγ9Vδ2-T and iNKT cells. Aminobisphosphonates dose-dependently enhanced Vγ9Vδ2-T cell activation, and this was potentiated by α-GalCer-induced iNKT co-activation. iNKT co-activation also enhanced the IFN-γ production and cytolytic potential of Vγ9Vδ2-T cells against tumor cells. Using transwell experiments and neutralizing antibodies cross-talk between iNKT and Vγ9Vδ2-T cells was found to be mediated by TNF-α. Our data provide a rationale for combining both activating ligands to improve Vγ9Vδ2-T cell based approaches in cancer-immunotherapy.     

Influenza A H1N1 induces declines in alveolar gas exchange in mice consistent with rapid post‐infection progression from acute lung injury to ARDS

Background Patients with severe seasonal or pandemic influenza pneumonia frequently develop acute respiratory distress syndrome (ARDS). One clinical diagnostic criterion for ARDS is the P_aO₂:F_iO₂ ratio, which is an index of alveolar gas exchange. However, effects of H1N1 influenza infection on P_aO₂:F_iO₂ ratios and related pathophysiologic readouts of lung function have not been reported in mice. Methods To develop a method for determining P_aO₂:F_iO₂ ratios, uninfected mice were anesthetized with pentobarbital, diazepam/ketamine, or inhaled isoflurane. Subsequently, they were allowed to breathe spontaneously or were mechanically ventilated. After 15 minutes exposure to room air (F_iO₂ = 0·21) or 100% O₂ (F_iO₂ = 1·0), carotid P_aO₂ was measured. To determine influenza effects on P_aO₂:F_iO₂, mice were challenged with 10 000 p.f..u./mouse influenza A/WSN/33. Results P_aO₂:F_iO₂ ratios were abnormally low (≤400 mmHg) in spontaneously breathing mice. Mechanical ventilation with positive end‐expiratory pressure was required to obtain P_aO₂:F_iO₂ ratios in uninfected mice consistent with normal values in humans (≥600 mmHg). At day 2 following infection P_aO₂:F_iO₂ ratios indicated the onset of acute lung injury. By day 6, P_aO₂:F_iO₂ ratios were <200 mmHg, indicating progression to ARDS. Impaired gas exchange in influenza‐infected mice was accompanied by progressive hemoglobin desaturation, hypercapnia, uncompensated respiratory acidosis, hyperkalemia, and polycythemia. Conclusions Influenza infection of mice results in impairment of alveolar gas exchange consistent with rapid development of acute lung injury and progression to ARDS. P_aO₂:F_iO₂ ratios may be of utility as clinically relevant and predictive outcome measures in influenza pathogenesis and treatment studies that use mouse models.