The role of perivascular and meningeal macrophages in experimental allergic encephalomyelitis

The perivascular (PVM) and meningeal (MM) macrophages constitute a major population of resident macrophages in the central nervous system (CNS). To investigate a possible role of PVM and MM during CNS inflammation, we have analysed PVM and MM during experimental allergic encephalomyelitis (EAE), an experimental model for MS, in the rat. Our results demonstrate a remarkable increase in the expression of the ED2 antigen on PVM and MM (already at day 9 post-EAE induction), which precedes the onset of clinical symptoms and infiltration of leukocytes into the CNS (at day 13). Therefore, the onset of EAE is accompanied by alterations of PVM and MM, and the ED2 antigen provides an early marker of pathology during CNS inflammation. Moreover, selective depletion of the ED2-positive macrophages in the CNS using clodronate liposomes resulted in a suppression of the clinical symptoms. These observations indicate that PVM and MM play a role during the early stages of EAE developmen

Lipoic acid affects cellular migration into the central nervous system and stabilizes blood-brain barrier integrity

Reactive oxygen species (ROS) play an important role in various events underlying multiple sclerosis (MS) pathology. In the initial phase of lesion formation, ROS are known to mediate the transendothelial migration of monocytes and induce a dysfunction of the blood-brain barrier (BBB). In this study, we describe the beneficial effect of the antioxidant alpha-lipoic acid (LA) on these phenomena. In vivo, LA dose-dependently prevented the development of clinical signs in a rat model for MS, acute experimental allergic encephalomyelitis (EAE). Clinical improvement was coupled to a decrease in leukocyte infiltration into the CNS, in particular monocytes. Monocytes isolated from the circulation of LA-treated rats revealed a reduced migratory capacity to cross a monolayer of rat brain endothelial cells in vitro compared with monocytes isolated from untreated EAE controls. Using live cell imaging techniques, we visualized and quantitatively assessed that ROS are produced within minutes upon the interaction of monocytes with brain endothelium. Monocyte adhesion to an in vitro model of the BBB subsequently induced enhanced permeability, which could be inhibited by LA. Moreover, administration of exogenous ROS to brain endothelial cells induced cytoskeletal rearrangements, which was inhibited by LA. In conclusion, we show that LA has a protective effect on EAE development not only by affecting the migratory capacity of monocytes, but also by stabilization of the BBB, making LA an attractive therapeutic agent for the treatment of MS

Three-dimensional histochemistry and imaging of human gingiva

In the present study, 3D histochemistry and imaging methodology is described for human gingiva to analyze its vascular network. Fifteen human gingiva samples without signs of inflammation were cleared using a mixture of 2-parts benzyl benzoate and 1-part benzyl alcohol (BABB), after being immunofluorescently stained for CD31, marker of endothelial cells to visualize blood vessels in combination with fluorescent DNA dyes. Samples were imaged in 3D with the use of confocal microscopy and light-sheet microscopy and image processing. BABB clearing caused limited tissue shrinkage 13 +/- 7% as surface area and 24 +/- 1% as volume. Fluorescence remained intact in BABB-cleared gingiva samples and light-sheet microscopy was an excellent tool to image gingivae whereas confocal microscopy was not. Histochemistry on cryostat sections of gingiva samples after 3D imaging validated structures visualized in 3D. Three-dimensional images showed the vascular network in the stroma of gingiva with one capillary loop in each stromal papilla invading into the epithelium. The capillary loops were tortuous with structural irregularities that were not apparent in 2D images. It is concluded that 3D histochemistry and imaging methodology described here is a promising novel approach to study structural aspects of human gingiva in health and diseas

Optical clearing and fluorescence deep-tissue imaging for 3D quantitative analysis of the brain tumor microenvironment

Background: Three-dimensional visualization of the brain vasculature and its interactions with surrounding cells may shed light on diseases where aberrant microvascular organization is involved, including glioblastoma (GBM). Intravital confocal imaging allows 3D visualization of microvascular structures and migration of cells in the brain of mice, however, with limited imaging depth. To enable comprehensive analysis of GBM and the brain microenvironment, in-depth 3D imaging methods are needed. Here, we employed methods for optical tissue clearing prior to 3D microscopy to visualize the brain microvasculature and routes of invasion of GBM cells. Methods: We present a workflow for ex vivo imaging of optically cleared brain tumor tissues and subsequent computational modeling. This workflow was used for quantification of the microvasculature in relation to nuclear or cellular density in healthy mouse brain tissues and in human orthotopic, infiltrative GBM8 and E98 glioblastoma models. Results: Ex vivo cleared mouse brain tissues had a >10-fold imaging depth as compared to intravital imaging of mouse brain in vivo. Imaging of optically cleared brain tissue allowed quantification of the 3D microvascular characteristics in healthy mouse brains and in tissues with diffuse, infiltrative growing GBM8 brain tumors. Detailed 3D visualization revealed the organization of tumor cells relative to the vasculature, in both gray matter and white matter regions, and patterns of multicellular GBM networks collectively invading the brain parenchyma. Conclusions: Optical tissue clearing opens new avenues for combined quantitative and 3D microscopic analysis of the topographical relationship between GBM cells and their microenvironment. Electronic supplementary material The online version of this article (doi:10.1007/s10456-017-9565-6) contains supplementary material, which is available to authorized users

Off to a good start after a cancer diagnosis : implementation of a time out consultation in primary care before cancer treatment decision

PURPOSE: Supportive care for cancer patients may benefit from improving treatment decisions and optimal use of the family physicians' and specialists' strengths. To improve shared decision-making (SDM) and facilitate continuity of primary care during treatment, a cancer care path including a "time out consultation" (TOC) in primary care before treatment decision, was implemented. This study assesses the uptake of a TOC and the added value for SDM. METHODS: For patients with metastatic lung or gastro-intestinal cancer, a TOC was introduced in their care path in a southern region of The Netherlands, from April until October 2016. Uptake of a TOC was measured to reflect on facilitation of continuity of primary care. The added value for SDM and overall experiences were evaluated with questionnaires and semi-structured interviews among patients, family physicians, and specialists. RESULTS: Of the 40 patients who were offered a TOC, 31 (78%) had a TOC. Almost all patients, family physicians, and specialists expressed that they experienced added value for SDM. This includes a stimulating effect on reflection on choice (expressed by 83% of patients) and improved preparation for treatment decision (75% of patients). Overall added value of a TOC for SDM, only evaluated among family physicians and specialists, was experienced by 71% and 86% of these physicians, respectively. CONCLUSION AND IMPLICATIONS FOR CANCER SURVIVORS: The first experiences with a TOC in primary care before cancer treatment decision suggest that it may help to keep the GP "in the loop" after a cancer diagnosis and that it may contribute to the SDM process, according to patients, family physicians, and specialists

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)