The transplantation of neural stem cells (NSCs) offers a new potential therapeutic approach as a cell-based delivery system for gene therapy in brain tumors. This is based on the unique capacity of NSCs to migrate throughout the brain and to target invading tumor cells. However, the signals controlling the targeted migration of transplanted NSCs are poorly defined. We analyzed the in vitro and in vivo effects of angiogenic growth factors and protein extracts from surgical specimens of brain tumor patients on NSC migration. Here, we demonstrate that vascular endothelial growth factor (VEGF) is able to induce a long-range attraction of transplanted human NSCs from distant sites in the adult brain. Our results indicate that tumor-upregulated VEGF and angiogenic-activated microvasculature are relevant guidance signals for NSC tropism toward brain tumors.

Abstract The COVID-19 outbreak is posing unprecedented risks and challenges for all communities and health care systems, worldwide. There are unique considerations for many adult patients with gliomas who are vulnerable to the novel coronavirus due to older age and immunosuppression. As patients with terminal illnesses, they present ethical challenges for centers that may need to ration access to ventilator care due to insufficient critical care capacity. It is urgent for the neuro-oncology community to develop a proactive and coordinated approach to the care of adults with gliomas in order to provide them with the best possible oncologic care while also reducing their risk of viral infection during times of potential health care system failure. In this article, we present an approach developed by an international multidisciplinary group to optimize the care of adults with gliomas during this pandemic. We recommend measures to promote strict physical distancing and minimize exposures for patients, address risk and benefit of all therapeutic interventions, proactively develop end-of-life plans, educate patients and caregivers, and ensure the health of the multidisciplinary neuro-oncology workforce. This pandemic is already changing neuro-oncologic care delivery around the globe. It is important to highlight opportunities to maximize the benefit and minimize the risk of glioma management during this pandemic and potentially, in the future.

Compared with patients with grade II or III left temporal lobe glioma, patients with grade IV tumors exhibit greater difficulty with verbal learning, processing speed, executive functioning, and language. Differences in NCF associated with glioma grade were independent of lesion volume, seizure status, and antiepileptic or steroid use, lending support to the concept of "lesion momentum" as a primary contributor to deficits in NCF of newly diagnosed patients prior to surgery.

MicroRNAs (miRNAs) are small, non-protein-coding RNA molecules that modulate gene translation. Their expression is altered in many central nervous system (CNS) injuries suggesting a role in the cellular response to stress. Current studies in brain tissue have not yet described the cell-specific temporal miRNA expression patterns following ischemic injury. In this study, we analyzed the expression alterations of a set of miRNAs in neurons and astrocytes subjected to 60 minutes of ischemia and collected at different time-points following this injury. To mimic ischemic conditions and reperfusion in vitro, cortical primary neuronal and astrocytic cultures prepared from fetal rats were first placed in oxygen and glucose deprived (OGD) medium for 60 minutes, followed by their transfer into normoxic pre-conditioned medium. Total RNA was extracted at different time-points after the termination of the ischemic insult and the expression levels of miRNAs were measured. In neurons exposed to OGD, expression of miR-29b was upregulated 2-fold within 6 h and up to 4-fold at 24 h post-OGD, whereas induction of miR-21 was upregulated 2-fold after 24 h when compared to expression in neurons under normoxic conditions. In contrast, in astrocytes, miR-29b and miR-21 were upregulated only after 12 h. MiR-30b, 107, and 137 showed expression alteration in astrocytes, but not in neurons. Furthermore, we show that expression of miR-29b was significantly decreased in neurons exposed to Insulin-Like Growth Factor I (IGF-I), a well documented neuroprotectant in ischemic models. Our study indicates that miRNAs expression is altered in neurons and astrocytes after ischemic injury. Furthermore, we found that following OGD, specific miRNAs have unique cell-specific temporal expression patterns in CNS. Therefore the specific role of each miRNA in different intracellular processes in ischemic brain and the relevance of their temporal and spatial expression patterns warrant further investigation that may lead to novel strategies for therapeutic interventions.

Assessment of therapy efficacy using animal models of tumorigenic cancer requires the ability to accurately measure changes in tumor volume over the duration of disease course. In order to be meaningful, in vivo tumor volume measurements by non-invasive techniques must correlate with tumor volume measurements from endpoint histological analysis. Tumor volume is frequently assessed by endpoint histological analyses approximating the tumor volume with geometric primitives such as spheroids and ellipsoids. In this study we investigated alternative techniques for quantifying histological volume measurements of tumors in a xenograft orthotopic mouse model of human glioblastoma multiforme, and compared these to in vivo tumor volume measurements based on magnetic resonance imaging (MRI) data. Two techniques leveraging three-dimensional (3D) image analysis methods were investigated. The first technique involves the reconstruction of a smoothed polygonal model representing the tumor volume from histological section images and is intended for accuracy and qualitative assessment of tumor burden by visualization, while a second technique which approximates the tumor volume as a series of slabs is presented as an abbreviated process intended to produce quantitatively similar volume measurements with a minimum of effort required on behalf of the investigator. New software (QuickVol) designed for use in the first technique, is also discussed. In cases where tumor growth is asymmetric and invasive, we found that 3D analysis techniques using histological section images produced volume measurements more consistent with in vivo volume measurements based on MRI data, than approximation of tumor volume using geometric primitives. Visualizations of the volumes represented by each of these techniques qualitatively support this finding, and suggest that future research using mouse models of glioblastoma multiforme (genetically engineered or xenograft) will benefit from the use of these or similar alternative tumor volume measurement techniques.

Cerebrospinal fluid rhinorrhea is a serious and potentially fatal condition because of an increased risk of meningitis and brain abscess. Approximately 80% of all cases occur in patients with head injuries and craniofacial fractures. Despite technical advances in the diagnosis and management of CSF rhinorrhea caused by craniofacial injury through the introduction of MRI and endoscopic extracranial surgical approaches, difficulties remain. The authors review here the pathophysiology, diagnosis, and management of CSF rhinorrhea relevant exclusively to traumatic anterior skull base injuries and attempt to identify areas in which further work is needed.

Object Primary spine infection secondary to intravenous drug abuse (IVDA) is a difficult clinical entity encountered by spine surgeons and infectious disease specialists. Patients tend to be noncompliant with the treatment and follow-up, and some continue to use IV recreational drugs even after the diagnosis of spine infection. The authors undertook this study to analyze the presentation, etiology, demographic characteristics, treatment, and outcome of primary pyogenic spinal infection in patients with IVDA as the major risk factor. Methods The medical records, radiology imaging, and laboratory results (white blood cell count, inflammatory markers, bacteriology cultures) of all patients with pyogenic spine infection and history of IVDA presenting to a tertiary care center from August 2005 through December 2013 were retrospectively reviewed. The department of neurosurgery database and the hospital electronic medical records of University Hospital in San Antonio were used to identify the cohort for our study. Results A total of 164 patients with spinal infection were evaluated during the study period; 102 of these patients had a history of IVDA. Their average age was 45.4 years, and only 14 (13.7%) were women. The mean laboratory values at presentation included a white blood cell count of 11.1 × 103 cells/μl (range 0.5–32 × 103 cells/μl), erythrocyte sedimentation rate (ESR) of 74 mm/hr (range 9.9–140 mm/hr), and C-reactive protein (CRP) level of 67 mg/L (range 0.1–327 mg/L). Twenty-six patients (25.4%) had an associated epidural abscess. The most common organism isolated from cultures of the bone and/or blood was methicillin-sensitive Staphylococcus aureus (MSSA), which was found in 37 cases. A close second was methicillin-resistant S. aureus (MRSA), found in 23 cases. The most commonly involved region was the lumbar spine (24 cases [57.8%]), and most patients (69.6%) had involvement of only a single level. Eighty patients were initially treated with long-term IV antibiotic therapy, and only 22 underwent surgical intervention (24 procedures). Of the latter group, 8 patients underwent laminectomy alone while 16 required some type of instrumented stabilization. Of the patients requiring stabilization procedures, 2 (12.5%) required reoperation with extension of their surgical constructs to other levels. The average follow-up was 29.7 weeks (range 6 weeks to 3 years). Conclusions Diagnosis and management of spinal infection in patients with a history of IVDA is challenging. The data from this study show that initial laboratory values are difficult to interpret given that only a minority of these patients present with leukocytosis. Back pain was the only reliable predictor of spine infection. The authors' experience indicates that the majority of patients with spine infection and a history of IVDA can be successfully treated with IV antibiotic therapy alone.

A major obstacle in the treatment of gliomas is the invasive capacity of the tumor cells. Previous studies have demonstrated the capability of neural stem cells (NSCs) to target these disseminated tumor cells and to serve as therapeutic delivery vehicles. Less is known about the factors involved in brain tumor tropism of NSCs and their interactions within the tumor environment. As gliomas progress and invade, an extensive modulation of the extracellular matrix (ECM) occurs. Tumor-ECM derived from six glioblastoma cell lines, ECM produced by normal human astrocytes and purified ECM compounds known to be upregulated in the glioma environment were analyzed for their effects on NSCs motility in vitro. We found that tumor-produced ECM was highly permissive for NSC migration. Laminin was the most permissive substrate for human NSC migration, and tenascin-C the strongest inducer of a directed human NSC migration (haptotaxis). A positive correlation between the degree of adhesion and migration of NSCs on different ECM compounds exists, as for glioma cells. Our in vitro data suggest that the ECM of malignant gliomas is a modulator of NSC migration. ECM proteins preferentially expressed in areas of glioma cell invasion may provide a permissive environment for NSC tropism to disseminated tumor cells.