In patients with glioblastoma, the average survival time with current treatments is short, mainly due to recurrences and resistance to therapy. This insufficient treatment success is, in large parts, due to the tremendous molecular heterogeneity of gliomas, which affects the overall prognosis and response to therapies and plays a vital role in gliomas’ grading. In addition, the tumor microenvironment is a major player for glioma development and resistance to therapy. Active communication between glioma cells and local or neighboring healthy cells and the immune environment promotes the cancerogenic processes and contributes to establishing glioma stem cells, which drives therapy resistance. Besides genetic alterations in the primary tumor, tumor-released factors, cytokines, proteins, extracellular vesicles, and environmental influences like hypoxia provide tumor cells the ability to evade host tumor surveillance machinery and promote disease progression. Moreover, there is increasing evidence that these players affect the molecular biological properties of gliomas and enable inter-cell communication that supports pro-cancerogenic cell properties. Identifying and characterizing these complex mechanisms are inevitably necessary to adapt therapeutic strategies and to develop novel measures. Here we provide an update about these junctions where constant traffic of biomolecules adds complexity in the management of glioblastoma. Graphical abstract

OBJECTIVE: Current guidelines for subarachnoid hemorrhage (SAH) include early aneurysm treatment within 72 hours after ictus. However, aneurysm rebleeding remains a crucial complication of SAH. The aim of this study was to identify independent predictors allowing early stratification of SAH patients for rebleeding risk.METHODS: All patients admitted to the authors’ institution with ruptured aneurysms during a 14-year period were eligible for this retrospective study. Demographic and radiographic parameters, aneurysm characteristics, medical history, and medications as well as baseline parameters at admission (blood pressure and laboratory parameters) were evaluated in univariate and multivariate analyses. A novel risk score was created using independent risk factors.RESULTS: Data from 984 cases could be included into the final analysis. Aneurysm rebleeding occurred in 58 cases (5.9%), and in 48 of these cases (82.8%) rerupture occurred within 24 hours after SAH. Of over 30 tested associations, preexisting arterial hypertension (p = 0.02; adjusted odds ratio [aOR] 2.56, 1 score point), aneurysm location at the basilar artery (p = 0.001, aOR 4.5, 2 score points), sac size ≥ 9 mm (p = 0.04, aOR 1.9, 1 score point), presence of intracerebral hemorrhage (p = 0.001, aOR 4.29, 2 score points), and acute hydrocephalus (p < 0.001, aOR 6.27, 3 score points) independently predicted aneurysm rebleeding. A score built upon these parameters (0–9 points) showed a good diagnostic accuracy (p < 0.001, area under the curve 0.780) for rebleeding prediction.CONCLUSIONS: Certain patient-, aneurysm-, and SAH-specific parameters can reliably predict aneurysm rerupture. A score developed according to these parameters might help to identify individuals that would profit from immediate aneurysm occlusion.

Animal models are still indispensable for understanding the basic principles of glioma development and invasion. Preclinical approaches aim to analyze the treatment efficacy of new drugs before translation into clinical trials is possible. Various animal disease models are available, but not every approach is useful for addressing specific questions. In recent years, it has become increasingly evident that the tumor microenvironment plays a key role in the nature of glioma. In addition to providing an overview, this review evaluates available rodent models in terms of usability for research on the glioma microenvironment.

OBJECTIVE: Tuberous sclerosis complex (TSC) is a rare multisystem genetic disease. Arterial wall developmental disorders, such as aneurysms, in association with TSC have been well described for extracranial vasculature. The characteristics of intracranial aneurysms (IAs) in TSC have not previously been addressed in the literature. This systematic review was performed to identify and assess the distinct characteristics of IAs in patients with TSC.METHODS: The authors searched PubMed, Scopus, and Web of Science for publications describing cases of TSC and IA reported before August 7, 2018. They also report 2 cases of IAs in TSC patients treated at their own institution.RESULTS: Thirty-three TSC patients with a total of 42 IAs were included in this review. Three individuals presented with subarachnoid hemorrhage. The IAs were large or giant in 57.1% and fusiform in 45.2% of the cases. Most of the IAs (61.9%, 26 of 42) originated from the internal carotid artery. There was a higher prevalence of pediatric cases (66.7%) and male patients (63.6%, 21 of 32 individuals with known sex) among the collected series.CONCLUSIONS: TSC patients with IAs are characterized with a higher proportion of large/giant and fusiform IAs and young age, suggesting rapid aneurysmal growth. Furthermore, there is a distinct location pattern of IAs and an inverse sex ratio than in the healthy population. Large population-based patient registers are required to improve the understanding of epidemiology and pathophysiology of IA formation in TSC.

Background/Aims: Cationic currents (Ih) through the fast activating and relatively cAMP insensitive subtype of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, HCN1, are limited by cytosolic factors in mammalian cells. This cytosolic HCN1 break is boosted by changes in membrane voltage that are not characterized on a biophysical level, yet. Methods: We overexpressed rat (r)HCN1 in human embryonic kidney cells (HEK293) and recorded pharmacologically isolated Ih in cell-attached or whole-cell mode of the patch-clamp technique. Results: Recurring activation of rHCN1 reduced and slowed Ih in intact HEK293 cells (cell-attached mode). On the contrary, sustained disruption of the intracellular content (whole-cell mode) ceased activity dependence and partially enables voltage dependent hysteresis. The activity induced Ih attenuation in intact cells was independent of the main external cation, depended on the number of previous forced activations and was - at least in part - due to a shift in the voltage dependence of activation towards hyperpolarization as estimated by an adapted tail current analysis. Intracellular elevation of cAMP could not reverse the changes in Ih. Conclusion: Reduction of rHCN1 mediated Ih is use dependent and may involve the coupling of voltage sensor and pore.