[ESTABLISHING A NEW TEAM FOR ENDOSCOPIC ENDONASAL SKULL BASE SURGERY: THE LEARNING CURVE FROM BASIC TO ADVANCED COMPLEXITY LEVEL].

INTRODUCTION: Establishing a new team for endoscopic endonasal skull base surgeries (EES) requires a period of adjustment. Our team was established 4 years ago and consists of surgeons with previous experience. Our objective was to examine the learning curve associated with the establishment of such a team. METHODS: All patients who underwent EES between January 2017 and October 2020 were reviewed. The first 40 patients were defined as the 'early group' and the last 40 as the 'late group'. Data was retrieved from electronic medical records and surgical videos. Study groups were compared in terms of the level of surgical complexity, (II to V according to EES complexity level scale; level I cases were excluded), surgical outcome and complication rate. RESULTS: 'Early group' cases and 'late group' cases were operated on in 25 and 11 months, respectively. Complexity level II surgeries, which mainly included pituitary adenomas, were the most common in both groups (77.5% and 60%, respectively); of these, functional adenomas and reoperations were more common in the 'late group'. The rate of advanced complexity surgeries (III - V) was higher in the 'late group' (40% vs. 22.5%); level V surgeries were performed only in the 'late group'. No significant differences were observed in terms of surgical outcomes or complications; postoperative cerebrospinal fluid (CSF) leaks were less common in the 'late group' (2.5% vs. 7.5%). CONCLUSIONS: Our findings indicate that the establishment of a new EES team, even if it includes experienced skull base surgeons, is associated with a learning curve, which requires about 40 cases.

[COMPARISON OF HIGH GAMMA ELECTROCORTICOGRAPHY AND DIRECT CORTICAL STIMULATION MAPPING OF CORTICAL FUNCTION IN AWAKE CRANIOTOMY: INITIAL EXPERIENCE].

INTRODUCTION: The use of intraoperative electrical cortical stimulation (ECS) to map function is the standard of care in modern neurosurgery. Recently, high gamma electrocorticography (hgECOG) mapping has had encouraging results. In this study we aim to compare hgECOG and fMRI with ECS for motor and language mapping. METHODS: We retrospectively evaluated medical records of patients who underwent awake surgery for tumor resection between January 2018 and December 2021. The first 10 consecutive patients who underwent ECS and hgECOG for mapping of motor and language functions were defined as the study group. Pre- and intra-operative imaging and electrophysiology data were used for analysis. RESULTS: ECS and hgECOG motor mapping demonstrated functional motor areas in 71.4% and 85.7% of patients, respectively. All motor areas identified with ECS were also demonstrated using hgECOG. In 2 patients, hgECOG-based mapping demonstrated motor areas not demonstrated with ECS but present in preoperative fMRI imaging. Of the 15 hgECOG tasks performed for language mapping, the findings of 6 (40%) were in accordance with the ECS mapping. Two (13.3%), showed language areas that were demonstrated using ECS and in addition, showed areas that were not. Four mappings (26.7%) showed language areas that were not demonstrated using ECS. In 3 mappings (20%), the functional areas identified by ECS were not demonstrated by hgECOG. CONCLUSIONS: Intraoperative hgECOG for mapping of motor and language functions provide a fast and reliable method without the risk of stimulation-induced seizures. Further studies are needed to assess functional outcome of patients undergoing hgECOG-guided tumor resection.

[INTRAOPERATIVE ELECTROPHYSIOLOGY MAPPING OF CORTICAL FUNCTION: A BRIEF HISTORY AND EVOLVING ALTERNATIVE].

INTRODUCTION: Multiple studies have demonstrated that the improved extent of resection for patients with glioma is associated with improved survival. The use of intraoperative electrophysiology cortical mapping to demonstrate function became a standard of care in modern neurosurgery and an indispensable tool to achieve the goal of maximal safe resection in tumor surgery. In this study, we review the brief history of intraoperative electrophysiology cortical mapping from the first cortical mapping study back in 1870 to the innovative tool of broad gamma cortical mapping used today.

Comparison of matched formalin-fixed paraffin embedded and fresh frozen meningioma tissue reveals bias in proteomic profiles.

Tissue biopsies are most commonly archived in a paraffin block following tissue fixation with formaldehyde (FFPE) or as fresh frozen tissue (FFT). While both methods preserve biological samples, little is known about how they affect the quantifiable proteome. We performed a 'bottom-up' proteomic analysis (N = 20) of short and long-term archived FFPE surgical samples of human meningiomas and compared them to matched FFT specimens. FFT facilitated a similar number of proteins assigned by MetaMorpheus compared with matched FFPE specimens (5378 vs. 5338 proteins, respectively (p = 0.053), regardless of archival time. However, marked differences in the proteome composition were apparent between FFPE and FFT specimens. Twenty-three percent of FFPE-derived peptides and 8% of FFT-derived peptides contained at least one chemical modification. Methylation and formylation were most prominent in FFPE-derived peptides (36% and 17% of modified FFPE peptides, respectively) while, most of phosphorylation and iron modifications appeared in FFT-derived peptides (p < 0.001). A mean 14% (± 2.9) of peptides identified in FFPE contained at least one modified Lysine residue. Importantly, larger proteins were significantly overrepresented in FFT specimens, while FFPE specimens were enriched with smaller proteins.

Unraveling the transcriptional regulation of TWIST1 in limb development.

The transcription factor TWIST1 plays a vital role in mesoderm development, particularly in limb and craniofacial formation. Accordingly, haploinsufficiency of TWIST1 can cause limb and craniofacial malformations as part of Saethre-Chotzen syndrome. However, the molecular basis of TWIST1 transcriptional regulation during development has yet to be elucidated. Here, we characterized active enhancers in the TWIST1-HDAC9 locus that drive transcription in the developing limb and branchial arches. Using available p300 and H3K27ac ChIP-seq data, we identified 12 enhancer candidates, located both within and outside the coding sequences of the neighboring gene, Histone deacetyase 9 (HDAC9). Using zebrafish and mouse enhancer assays, we showed that eight of these candidates have limb/fin and branchial arch enhancer activity that resemble Twist1 expression. Using 4C-seq, we showed that the Twist1 promoter region interacts with three enhancers (eTw-5, 6, 7) in the limb bud and branchial arch of mouse embryos at day 11.5. Furthermore, we found that two transcription factors, LMX1B and TFAP2, bind these enhancers and modulate their enhancer activity. Finally, using CRISPR/Cas9 genome editing, we showed that homozygous deletion of eTw5-7 enhancers reduced Twist1 expression in the limb bud and caused pre-axial polydactyly, a phenotype observed in Twist1+/- mice. Taken together, our findings reveal that each enhancer has a discrete activity pattern, and together comprise a spatiotemporal regulatory network of Twist1 transcription in the developing limbs/fins and branchial arches. Our study suggests that mutations in TWIST1 enhancers could lead to reduced TWIST1 expression, resulting in phenotypic outcome as seen with TWIST1 coding mutations.

Androgen Receptor Activation in Glioblastoma Can Be Achieved by Ligand-Independent Signaling through EGFR-A Potential Therapeutic Target.

Androgen receptor (AR) is a ligand-mediated transcription factor that belongs to the superfamily of steroid receptors. AR is overexpressed in most glioblastomas and is a potential therapeutic target. In prostate and breast cancers, AR activation can be achieved also by a ligand-independent signaling through receptor tyrosine kinases such as epidermal growth factor receptor (EGFR). Considering its major role in glioblastoma, we explored whether EGFR is involved in AR signaling in this tumor. Analysis of mRNA expression in 28 glioblastoma samples with quantitative real-time reverse-transcription polymerase chain reaction revealed a positive and significant correlation between AR and EGFR mRNA expression levels (R = 0.47, p = 0.0092), which was validated by The Cancer Genome Atlas dataset (n = 671) analysis (R = 0.3, p = 0.00006). Using Western blotting and immunofluorescence staining, we showed that the transduced overexpression of EGFR or its variant EGFRvIII in the U87MG cells induced AR protein overexpression and nuclear translocation and Protein kinase B (AKT) S473 and AR S210/213 phosphorylation. The EGFR kinase inhibitor afatinib and the AKT inhibitor MK2206 reduced AR nuclear translocation. Afatinib diminished AKT phosphorylation at 30 min and 6 h in the EGFR- and EGFRvIII-overexpressing cells, respectively, and decreased AR phosphorylation in EGFR-overexpressing cells at 4 h. Afatinib or MK2206 combination therapy with the AR antagonist enzalutamide in the EGFR and EGFRvIII-overexpressing cells had synergistic efficacy. Our findings suggest that EGFR signaling is involved in AR activation in glioblastoma and buttresses the concept of combining an EGFR signaling inhibitor with AR antagonists as a potential glioblastoma treatment.

Neurocognitive evaluation of brain metastases patients treated with post-resection stereotactic radiosurgery: a prospective single arm clinical trial.

PURPOSE: Post-operative radiation therapy for brain metastases (BM) has become standard treatment. Concerns regarding the deleterious cognitive effects of Whole Brain Radiation Therapy spurred a trend to use focal therapies such as stereotactic radiosurgery (SRS). The purpose of this study was to prospectively evaluate the neuropsychological effects following post-resection SRS treatment since limited data exist in this context. METHODS: We conducted a prospective single arm cohort study of patients with 1-2 BM, who underwent resection of a single BM between May 2015 to December 2016. Patients were evaluated for cognitive functions (NeuroTrax computerized neuropsychological battery; Modiin, Israel) and quality of life (QOL; QLQ-30, QLQ-BN20) before and 3 months following post-resection SRS. RESULTS: Twelve out of 14 patients completed pre- and post-SRS neurocognitive assessments. Overall, we did not detect significant neurocognitive or QOL changes 3 months following SRS. In a subgroup analysis among patients younger than 60 years, median global cognitive score increased from a pre-treatment score of 88 (72-102) to 95 (79-108), 3 months following SRS treatment, p = 0.042; Wilcoxon paired non-parametric test. Immediate verbal memory and executive functions scores increased from 86 (72-98) to 98 (92-112) and 86 (60-101) to 100 (80-126), respectively, p = 0.043. No significant cognitive changes were discovered among patients at the age of 60 or older. CONCLUSIONS: Post-resection radiosurgery has a safe neuro-cognitive profile and is associated with preservation of nearly all quality of life parameters. Patients younger than 60 years benefit most and may even regain some cognitive functions within a few months after treatment.

A non-aggressive, highly efficient, enzymatic method for dissociation of human brain-tumors and brain-tissues to viable single-cells.

BACKGROUND: Conducting research on the molecular biology, immunology, and physiology of brain tumors (BTs) and primary brain tissues requires the use of viably dissociated single cells. Inadequate methods for tissue dissociation generate considerable loss in the quantity of single cells produced and in the produced cells' viability. Improper dissociation may also demote the quality of data attained in functional and molecular assays due to the presence of large quantities cellular debris containing immune-activatory danger associated molecular patterns, and due to the increased quantities of degraded proteins and RNA. RESULTS: Over 40 resected BTs and non-tumorous brain tissue samples were dissociated into single cells by mechanical dissociation or by mechanical and enzymatic dissociation. The quality of dissociation was compared for all frequently used dissociation enzymes (collagenase, DNase, hyaluronidase, papain, dispase) and for neutral protease (NP) from Clostridium histolyticum. Single-cell-dissociated cell mixtures were evaluated for cellular viability and for the cell-mixture dissociation quality. Dissociation quality was graded by the quantity of subcellular debris, non-dissociated cell clumps, and DNA released from dead cells. Of all enzymes or enzyme combinations examined, NP (an enzyme previously not evaluated on brain tissues) produced dissociated cell mixtures with the highest mean cellular viability: 93 % in gliomas, 85 % in brain metastases, and 89 % in non-tumorous brain tissue. NP also produced cell mixtures with significantly less cellular debris than other enzymes tested. Dissociation using NP was non-aggressive over time-no changes in cell viability or dissociation quality were found when comparing 2-h dissociation at 37 °C to overnight dissociation at ambient temperature. CONCLUSIONS: The use of NP allows for the most effective dissociation of viable single cells from human BTs or brain tissue. Its non-aggressive dissociative capacity may enable ambient-temperature shipping of tumor pieces in multi-center clinical trials, meanwhile being dissociated. As clinical grade NP is commercially available it can be easily integrated into cell-therapy clinical trials in neuro-oncology. The high quality viable cells produced may enable investigators to conduct more consistent research by avoiding the experimental artifacts associated with the presence dead cells or cellular debris.

Expression level of miRNAs on chromosome 14q32.31 region correlates with tumor aggressiveness and survival of glioblastoma patients.

The 54 microRNAs (miRNAs) within the DLK-DIO3 genomic region on chromosome 14q32.31 (cluster-14-miRNAs) are organized into sub-clusters 14A and 14B. These miRNAs are downregulated in glioblastomas and might have a tumor suppressive role. Any association between the expression levels of cluster-14-miRNAs with overall survival (OS) is undetermined. We randomly selected miR-433, belonging to sub-cluster 14A and miR-323a-3p and miR-369-3p, belonging to sub-cluster 14B, and assessed their role in glioblastomas in vitro and in vivo. We also determined the expression level of cluster-14-miRNAs in 27 patients with newly diagnosed glioblastoma, and analyzed the association between their level of expression and OS. Overexpression of miR-323a-3p and miR-369-3p, but not miR-433, in glioblastoma cells inhibited their proliferation and migration in vitro. Mice implanted with glioblastoma cells overexpressing miR323a-3p and miR369-3p, but not miR433, exhibited prolonged survival compared to controls (P = .003). Bioinformatics analysis identified 13 putative target genes of cluster-14-miRNAs, and real-time RT-PCR validated these findings. Pathway analysis of the putative target genes identified neuregulin as the most enriched pathway. The expression level of cluster-14-miRNAs correlated with patients' OS. The median OS was 8.5 months for patients with low expression levels and 52.7 months for patients with high expression levels (HR 0.34; 95 % CI 0.12-0.59, P = .003). The expression level of cluster-14-miRNAs correlates directly with OS, suggesting a role for this cluster in promoting aggressive behavior of glioblastoma, possibly through ErBb/neuregulin signaling.

Visual deterioration during pregnancy due to skull base tumors compressing the optic apparatus.

Intracranial tumors may rapidly enlarge during pregnancy. When the tumor abuts the optic apparatus, tumor growth may cause visual deterioration. The decisions regarding the management of these tumors should take into consideration visual function, fetal and maternal safety, and the ability for total resection of the tumor. The objective of the study was to describe our experience and to establish principles for management of intracranial tumors compressing the optic apparatus that present during pregnancy or in the early post partum period. A retrospective case-series review was conducted. Women who presented with visual deterioration either during pregnancy or in the early post partum period due to an intracranial tumor were included. Neurosurgical and obstetrical data were collected from the patients' hospital files and outpatient clinic records. Between 2005 and 2011, nine pregnant women with visual deterioration were diagnosed and treated. Of them, four underwent a neurosurgical procedure during pregnancy. Of the five patients who underwent surgery for tumor resection after delivery, three required urgent cesarean section either due to acute visual deterioration or obstetrical reasons. There was no maternal or fetal mortality and a good overall neonatal outcome was achieved. Improvement in visual acuity and visual fields was achieved in all patients. Postoperative complications included two cases of CSF leak, which resolved after treatment. Visual deterioration during pregnancy due to tumors that compress the optic apparatus requires treatment by a multi-disciplinary team. Surgery is well tolerated by mother and fetus during early and midpregnancy; thus, in cases where visual deterioration is detected, delay of surgery is not justified.

Thermo-controlled microfluidic generation of monodisperse alginate microspheres based on external gelation.

Droplet-based microfluidic systems have received much attention as promising tools for fabricating monodisperse microspheres of alginate solutions with high accuracy and reproducibility. The immediate and simple ionotropic gelation of alginate, its biocompatibility, and its tunability of mechanical properties make it a favorable hydrogel in the biomedical and tissue engineering fields. In these fields, micron-sized alginate hydrogel spheres have shown high potential as cell vehicles and drug delivery systems. Although on-chip microfluidic gelation of the produced alginate droplets is common, several challenges remain. Complicated chemical and microfabrication processes are required, and the risk of microchannel clogging is high. In the current study, we present an easy-to-use microfluidic external gelation process to produce highly spherical and monodisperse microspheres from very low-concentrated alginate-RGD solution [0.5% (w/v)]. To accomplish this, gelatin, a thermo-sensitive and inexpensive biomaterial, was incorporated into the alginate solution as a sacrificial biomaterial that mediates the off-chip external gelation of the alginate with Ca2+, and avoids droplet coalescence. Utilizing the methodology mentioned above, we successfully generated monodisperse alginate microspheres (AMs) with diameters ranging from 27 µm to 46 µm, with a coefficient of variation of 0.14, from a mixture of Arg-Gly-Asp (RGD)-modified very low viscosity alginate and gelatin. These RGD-AMs were used as microcarriers for human umbilical vein endothelial cells. The described easy-to-use and cost-effective microfluidic off-chip external gelation strategy exhibits comparable advantages to on-chip external gelation and demonstrates superiority over the latter since clogging is impossible.

Frequencies of 4 tumor-infiltrating lymphocytes potently predict survival in glioblastoma, an immune desert.

BACKGROUND: GBM is an aggressive grade 4 primary brain tumor (BT), with a 5%-13% 5-year survival. Most human GBMs manifest as immunologically "cold" tumors or "immune deserts," yet the promoting or suppressive roles of specific lymphocytes within the GBM tumor microenvironment (TME) is of considerable debate. METHODS: We used meticulous multiparametric flow cytometry (FC) to determine the lymphocytic frequencies in 102 GBMs, lower-grade gliomas, brain metastases, and nontumorous brain specimen. FC-attained frequencies were compared with frequencies estimated by "digital cytometry." The FC-derived data were combined with the patients' demographic, clinical, molecular, histopathological, radiological, and survival data. RESULTS: Comparison of FC-derived data to CIBERSORT-estimated data revealed the poor capacity of digital cytometry to estimate cell frequencies below 0.2%, the frequency range of most immune cells in BTs. Isocitrate dehydrogenase (IDH) mutation status was found to affect TME composition more than the gliomas' pathological grade. Combining FC and survival data disclosed that unlike other cancer types, the frequency of helper T cells (Th) and cytotoxic T lymphocytes (CTL) correlated negatively with glioma survival. In contrast, the frequencies of γδ-T cells and CD56bright natural killer cells correlated positively with survival. A composite parameter combining the frequencies of these 4 tumoral lymphocytes separated the survival curves of GBM patients with a median difference of 10 months (FC-derived data; P < .0001, discovery cohort), or 4.1 months (CIBERSORT-estimated data; P = .01, validation cohort). CONCLUSIONS: The frequencies of 4 TME lymphocytes strongly correlate with the survival of patients with GBM, a tumor considered an immune desert.

Human Purkinje cells outperform mouse Purkinje cells in dendritic complexity and computational capacity.

Purkinje cells in the cerebellum are among the largest neurons in the brain and have been extensively investigated in rodents. However, their morphological and physiological properties remain poorly understood in humans. In this study, we utilized high-resolution morphological reconstructions and unique electrophysiological recordings of human Purkinje cells ex vivo to generate computational models and estimate computational capacity. An inter-species comparison showed that human Purkinje cell had similar fractal structures but were larger than those of mouse Purkinje cells. Consequently, given a similar spine density (2/µm), human Purkinje cell hosted approximately 7.5 times more dendritic spines than those of mice. Moreover, human Purkinje cells had a higher dendritic complexity than mouse Purkinje cells and usually emitted 2-3 main dendritic trunks instead of one. Intrinsic electro-responsiveness was similar between the two species, but model simulations revealed that the dendrites could process ~6.5 times (n = 51 vs. n = 8) more input patterns in human Purkinje cells than in mouse Purkinje cells. Thus, while human Purkinje cells maintained spike discharge properties similar to those of rodents during evolution, they developed more complex dendrites, enhancing computational capacity.

Outcome of elderly patients undergoing awake-craniotomy for tumor resection.

BACKGROUND: Awake-craniotomy allows maximal tumor resection, which has been associated with extended survival. The feasibility and safety of awake-craniotomy and the effect of extent of resection on survival in the elderly population has not been established. The aim of this study was to compare surgical outcome of elderly patients undergoing awake-craniotomy to that of younger patients. METHODS: Outcomes of consecutive patients younger and older than 65 years who underwent awake-craniotomy at a single institution between 2003 and 2010 were retrospectively reviewed. The groups were compared for clinical variables and surgical outcome parameters, as well as overall survival. RESULTS: A total of 334 young (45.4 ± 13.2 years, mean ± SD) and 90 elderly (71.7 ± 5.1 years) patients were studied. Distribution of gender, mannitol treatment, hemodynamic stability, and extent of tumor resection were similar. Significantly more younger patients had a better preoperative Karnofsky Performance Scale score (>70) than elderly patients (P = 0.0012). Older patients harbored significantly more high-grade gliomas (HGG) and brain metastases, and fewer low-grade gliomas (P < 0.0001). No significantly higher rate of mortality, or complications were observed in the elderly group. Age was associated with increased length of stay (4.9 ± 6.3 vs. 6.6 ± 7.5 days, P = 0.01). Maximal extent of tumor resection in patients with HGG was associated with prolonged survival in the elderly patients. CONCLUSIONS: Awake-craniotomy is a well-tolerated and safe procedure, even in elderly patients. Gross total tumor resection in elderly patients with HGG was associated with prolonged survival. The data suggest that favorable prognostic factors for patients with malignant brain tumors are also valid in elderly patients.

Non-invasive assessment of normal and impaired iron homeostasis in the brain.

Strict iron regulation is essential for normal brain function. The iron homeostasis, determined by the milieu of available iron compounds, is impaired in aging, neurodegenerative diseases and cancer. However, non-invasive assessment of different molecular iron environments implicating brain tissue's iron homeostasis remains a challenge. We present a magnetic resonance imaging (MRI) technology sensitive to the iron homeostasis of the living brain (the r1-r2* relaxivity). In vitro, our MRI approach reveals the distinct paramagnetic properties of ferritin, transferrin and ferrous iron ions. In the in vivo human brain, we validate our approach against ex vivo iron compounds quantification and gene expression. Our approach varies with the iron mobilization capacity across brain regions and in aging. It reveals brain tumors' iron homeostasis, and enhances the distinction between tumor tissue and non-pathological tissue without contrast agents. Therefore, our approach may allow for non-invasive research and diagnosis of iron homeostasis in living human brains.

Reversible freezing of gait caused by dural arteriovenous fistula and congestion of the globus pallidus.

BACKGROUND: Freezing of gait (FOG) is defined as an episodic inability to generate effective stepping in the absence of any known cause other than parkinsonism or high-level gait disorders. METHODS: We present a 59-year-old male with acute, progressive episodes of FOG. Imaging studies revealed a dural arteriovenous fistula (DAVF) associated with edema of the globus pallidus interna (GPi). Cerebral angiography confirmed the diagnosis of DAVF and demonstrated an occluded straight sinus and a retrograde blood flow of deep cerebral veins. RESULTS: After endovascular closure of the DAVF, a major improvement of FOG was observed concomitant with striking near resolution of GPi congestion. CONCLUSIONS: This reversal of the clinical course, correlated with changes in imaging studies, suggests a major role of the GPi in the pathology of FOG.

Convection-enhanced delivery catheter placements for high-grade gliomas: complications and pitfalls.

Convection-enhanced delivery (CED) of compounds into brain tumors reportedly circumvents the blood brain barrier. CED intends to increase drug delivery to malignant cells, reaching high local therapeutic concentration and decreasing or eliminating systemic side effects. Clinical experience and published data on catheter placement (CP) surgery are scarce. We propose practical and technical guidelines for planning CED based on our experience. We retrospectively analyzed the medical charts and relevant neuroimages of 25 patients following the insertion of 64 CED catheters. The patients were enrolled in at least one of four clinical trials using CED for treating recurrent glioblastoma multiforme in our institution between 2003-2006. Intra- and postoperative complications related to CP surgery and the difficulties and pitfalls of planning were evaluated. There were 29 CP surgeries. Forty-four peritumoral brain tissue catheters were inserted in 16 CP surgeries following tumor resection in 16 patients, and 20 catheters were placed into the tumor in 13 procedures in 10 patients. The lesions were in or near eloquent brain tissue areas in 13 of all CP surgeries. Complications included increased edema (31%), infection (6.9%), bleeding (6.9%) and seizures (13.8%). Significant neurological deterioration occurred in 4 patients (13.8%). Difficulties in adhering to CP surgery guidelines included lesion site (superficial, mesial temporal lobe, proximity to CSF spaces), proximity to eloquent cortical areas, tissue density that interfered with the trajectory, and technical limitations of stereotactic instruments. CED procedures for high-grade gliomas may be associated with surgical morbidity. Adherence to guidelines might be difficult because of lesion site and complicated by brain and tumor tissue characteristics. This should be considered while planning clinical trials that use convection-based technology.

[18F]-FDHT PET/CT as a tool for imaging androgen receptor expression in high-grade glioma.

BACKGROUND: G lioblastoma (GBM) is associated with poor overall survival. Recently, we showed that androgen receptor (AR) protein is overexpressed in 56% of GBM specimens and AR antagonists induced dose-dependent death in several GBM cell lines and significantly reduced tumor growth and prolonged the lifespan of mice implanted with human GBM. 16ß-18F-fluoro-5α-dihydrotestosterone ([18F]-FDHT) is a positron emission tomography (PET) tracer used to detect AR expression in prostate and breast cancers. This study was aimed at exploring the ability of [18F]-FDHT-PET to detect AR expression in high-grade gliomas. METHODS: Twelve patients with suspected high-grade glioma underwent a regular workup and additional dynamic and static [18F]-FDHT-PET/CT. Visual and quantitative analyses of [18 F]-FDHT kinetics in the tumor and normal brain were performed. Mean and maximum (max) standardized uptake values (SUVs) were determined in selected volumes of interest. The patients had surgery or biopsy after PET/CT. AR protein was analyzed in the tumor samples by western blot. Fold change in AR expression was calculated by densitometry analysis. Correlation between imaging and AR protein samples was determined. RESULTS: In six of the 12 patients, [18 F]-FDHT uptake was significantly higher in the tumor than in the normal brain. These patients also had increased AR protein expression within the tumor. Pearson correlation coefficient analysis for the tumor-to-control normal brain uptake ratio in terms of SUVmean versus AR protein expression was positive and significant (R = 0.84; P = .002). CONCLUSION: [18 F]-FDHT-PET/CT could identify increased AR expression in high-grade glioma.

The combination of granulocyte colony-stimulating factor and stem cell factor significantly increases the number of bone marrow-derived endothelial cells in brains of mice following cerebral ischemia.

Granulocyte colony-stimulating factor (G-CSF) induces proliferation of bone marrow-derived cells. G-CSF is neuroprotective after experimental brain injury, but the mechanisms involved remain unclear. Stem cell factor (SCF) is a cytokine important for the survival and differentiation of hematopoietic stem cells. Its receptor (c-kit or CD117) is present in some endothelial cells. We aimed to determine whether the combination of G-CSF/SCF induces angiogenesis in the central nervous system by promoting entry of endothelial precursors into the injured brain and causing them to proliferate there. We induced permanent middle cerebral artery occlusion in female mice that previously underwent sex-mismatched bone marrow transplantation from enhanced green fluorescent protein (EGFP)-expressing mice. G-CSF/SCF treatment reduced infarct volumes by more than 50% and resulted in a 1.5-fold increase in vessel formation in mice with stroke, a large percentage of which contain endothelial cells of bone marrow origin. Most cells entering the brain maintained their bone marrow identity and did not transdifferentiate into neural cells. G-CSF/SCF treatment also led to a 2-fold increase in the number of newborn cells in the ischemic hemisphere. These findings suggest that G-CSF/SCF treatment might help recovery through induction of bone marrow-derived angiogenesis, thus improving neuronal survival and functional outcome.

When a Root Is the Cause of Infection.

BACKGROUND: Sinorhizobium meliloti is a phytobacterium found in the root nodules of plants, where it is involved in fixing nitrogen for delivery to the roots in exchange for a photosynthate carbon source. There have been no reported cases of S. meliloti infection in humans. We conducted a retrospective review of clinical records and diagnostic tests. CASE DESCRIPTION: An 81-year-old woman who presented to the emergency department with a 1-day history of progressive decline in her level of consciousness following a head injury and deep scalp laceration. Her medical history was significant for a ventriculoperitoneal shunt due to normal pressure hydrocephalus. Imaging studies revealed hydrocephalus and a tear in the shunt catheter. Cerebrospinal fluid analysis was not suggestive for meningitis. Cerebrospinal fluid culture revealed an unfamiliar organism, identified as S. meliloti following sequencing of its entire genome, which was considered a contaminant. The patient subsequently developed peritonitis, and the same pathogen was detected in the peritoneal fluid, suggesting distal shunt infection. Symptoms resolved after shunt removal and antibiotic treatment. Thorough history taking revealed that the patient had fallen and struck her head against a flowerpot. CONCLUSIONS: S. meliloti is a phytopathogen that should not be easily disregarded as a contaminant when isolated from human sterile fluids or tissues. Aggressive management including removal of infected hardware, if present, is required to ensure resolution of infection. It emphasizes the importance of thorough history taking.