GFAP serves as a structural element of tunneling nanotubes between glioblastoma cells and could play a role in the intercellular transfer of mitochondria.

Tunneling nanotubes (TNTs) are long F-actin-positive plasma membrane bridges connecting distant cells, allowing the intercellular transfer of cellular cargoes, and are found to be involved in glioblastoma (GBM) intercellular crosstalk. Glial fibrillary acid protein (GFAP) is a key intermediate filament protein of glial cells involved in cytoskeleton remodeling and linked to GBM progression. Whether GFAP plays a role in TNT structure and function in GBM is unknown. Here, analyzing F-actin and GFAP localization by laser-scan confocal microscopy followed by 3D reconstruction (3D-LSCM) and mitochondria dynamic by live-cell time-lapse fluorescence microscopy, we show the presence of GFAP in TNTs containing functional mitochondria connecting distant human GBM cells. Taking advantage of super-resolution 3D-LSCM, we show the presence of GFAP-positive TNT-like structures in resected human GBM as well. Using H2O2 or the pro-apoptotic toxin staurosporine (STS), we show that GFAP-positive TNTs strongly increase during oxidative stress and apoptosis in the GBM cell line. Culturing GBM cells with STS-treated GBM cells, we show that STS triggers the formation of GFAP-positive TNTs between them. Finally, we provide evidence that mitochondria co-localize with GFAP at the tip of close-ended GFAP-positive TNTs and inside receiving STS-GBM cells. Summarizing, here we found that GFAP is a structural component of TNTs generated by GBM cells, that GFAP-positive TNTs are upregulated in response to oxidative stress and pro-apoptotic stress, and that GFAP interacts with mitochondria during the intercellular transfer. These findings contribute to elucidate the molecular structure of TNTs generated by GBM cells, highlighting the structural role of GFAP in TNTs and suggesting a functional role of this intermediate filament component in the intercellular mitochondria transfer between GBM cells in response to pro-apoptotic stimuli.

Long term follow up in 183 high grade meningioma: A single institutional experience.

INTRODUCTION: Meningiomas are usually considered benign lesions, however a proportion of them shows a more aggressive behavior, defined high-grade meningiomas (HGM). Effective medical treatments are lacking, especially at the time of recurrence. METHODS: Through a retrospective analysis, we examined epidemiological, diagnostic, therapeutic, recurrence information and survival data of HGM treated at our institution between 2010 and 2018. RESULTS: 183 patients (105 females and 78 males), with median age of 58 years (25-88), were included; 168 were atypical, 12 anaplastic, 3 rhabdoid. Overall, m-PFS was 4.2 years, and m-OS was 10.3 years. Gross-total resection had a 5-year survival rate of 95% compared with subtotal/partial resection (86% and 67%) (p = 0.002). Higher expression of Ki-67/MIB-1 seems associated with higher risk of death (HR:1.06 with 95% CI, 1.00-1.12, p = 0.03). No statistically significant differences were seen in survival between the group managed with a wait-and-see strategy vs the group treated with RT while a difference on PFS was seen (4.1 years vs 5.2 years p = 0.03). After second recurrence, the most employed treatments were systemic therapies with a very limited effect on disease control. CONCLUSIONS: Data confirmed the aggressive behavior of HGM. The extent of resection seems to correlate with a favorable outcome regardless histological subtypes. The role of RT remains controversial, with no statistically significant impact on OS but a possible role on PFS. Recurrent HGM remains the real challenge, to date no chemotherapies are able to achieve disease control. Future research should focus on biological/molecular predictors in order to achieve a patient-tailored treatment.

Liposomal cytarabine in neoplastic meningitis from primary brain tumors: a single institutional experience.

Neoplastic meningitis (NM) is diagnosed in 1-2 % of patients with primary brain tumors. Standard treatment of NM includes single-agent or combination chemotherapy, with compounds such as methotrexate, thiotepa, and cytarabine (Ara-C) or its injectable, sustained-release formulation Depocyte(®). In this Report, we reported the data of efficacy and tolerability of an intrathecal Depocyte(®) regimen for patients presenting with NM from primary brain tumors. We described 12 patients with NM confirmed at magnetic resonance imaging (MRI) and with a positive cerebrospinal fluid (CSF) cytology. Patients were treated with repeated courses of intrathecal Depocyte(®) (once every 2 weeks for 1 month of induction therapy and as consolidation therapy on a monthly base in responding patients). Twelve patients (10 males and 2 females) were treated by our Institution. The diagnosis of primitive brain tumor was medulloblastoma in six patients, germinoma in two patients, pylocitic astrocytomas with spongioblastic aspects, teratocarcinoma, meningeal melanoma, and ependimoma in the other four patients. The total number of Depocyte(®) cycles ranged from one to nine. In 7/12 patients, there was clinical and/or radiological response after Depocyte(®), and the toxicity was moderate and transient, mainly due to the lumbar puncture procedure. In the two patients with germinoma, we observed a normalization of MRI Imaging and negativization of CSF with disappearance of the tumor cells. OS was 180 days (range 20-300, CI 95 %).

Hemodynamic instability after extracranial carotid stenting.

OBJECTIVE: Hemodynamic instability (hypertension, hypotension and bradycardia) is a well-known complication of carotid endarterectomy. Carotid angioplasty and stenting (CAS) is becoming a valuable alternative treatment for patients with severe carotid stenosis and increased surgical risk. CAS implies instrumentation of the carotid bulb, so baroceptor dysfunction may provoke hemodynamic instability. The aim of this work was to calculate the incidence of this complication and to detect factors to predict it. METHODS: Medical records and angiograms of 51 consecutive patients submitted to CAS for severe atherosclerotic stenosis (40 cases) or postsurgical restenosis (11 cases) were retrospectively reviewed in order to detect the occurrence of intra- and post-procedural hypertension (systolic blood pressure >160 mmHg), hypotension (systolic blood pressure <90 mmHg) and bradycardia (heart rate <60 beats/min). The relationship between clinical, procedural and angiographic factors and the occurrence of hemodynamic instability was assessed with univariate and multivariate analysis (logistic regression). RESULTS: Transient mild systolic post-procedural hypertension occurred in five cases (10%); preprocedural hypertension, asymptomatic stenosis and ipsilateral post-surgical restenosis predicted this. Hypotension with bradycardia also occurred in five cases (10%), one with neurological sequelae. Transient periprocedural bradycardia occurred in 19 cases (37%). Severe bradycardia without hypotension arose in one case only. Factors predicting post-procedural hypotension included the presence of a fibrous plaque and the ratio between the pre- and post-stenting diameter of the internal carotid artery. Peri-procedural bradycardia predicted post-procedural bradycardia. None of these factors were confirmed by multivariate analysis as a significant prognostic predictor. CONCLUSION: Mild systolic hypertension may occur after CAS, but is resolved by medical treatment. Prolonged hypotension and bradycardia may also arise and this can be dangerous because it may cause neurological deterioration due to hypoperfusion. These complications cannot be predicted by clinical, procedural, and angiographic factors.

Prevalence of some markers of the hepatitis B virus in a blood donor population.

Investigations were made for anti-HBs and anti-HBe antibodies, markers of hepatitis B virus, in a population of HBsAg negative blood donors, but exhibiting high serum transaminase (ALT) values. 25.9% of this population was found to be positive for at least one type of marker antibody. The samples found to be positive only for anti-HBe were examined for anti-HBc antibodies. These donors were re-examined over a period of time until the anti-HBs antibodies disappeared. Further studies will have to be carried out in order to verify whether those samples of blood found to be positive for anti-HBc and/or anti-HBe are really infecting. The advisability of a systematic ALT activity check in all blood donors is stressed.

[Observations about the use of different types of enzymes in immunohistological diagnosis of autoimmune diseases. Comparative study with indirect immunofluorescence technique (author's transl)]. / Osservazioni sull'impiego di differenti tipi di enzimi nella diagnostica immunoistologica delle malattie autoimmuni. Valutazione comparativa con la tecnica dell'immunofluorescenza indiretta.

The Authors have evaluated the use of anti-human immunoglobulins conjugated with peroxidase, alkaline-phosphatase, glucose-oxidase as a diagnostic tool for assaying autoantibodies. A comparison study was done using the classical indirect immunofluorescence technique. Immunoenzymatic techniques, of minor cost compared to immunofluorescence, have revealed a better appreciation of global and particular structure of the tissue in examination. From the three enzymes examined peroxidase revealed itself as first choice, because, other than having on overlapping sensitivity to immunofluorescence, it can allow a further ultrastructural study.

Prevalence of HBeAg, anti-HBe and Dane particle-associated DNA polymerase activity in asymptomatic carriers of HBsAg.

HBeAg/anti-HBe and Dane particle-associated DNA polymerase activity were detected in serum samples from 358 HBsAg asymptomatic carriers found during normal routine screening of 11,200 blood donors (HBsAg prevalence 3.1%). Since virus specific DNA polymerase activity and HBeAg seem to be associated in some way with hepatitis B virus infectivity and liver damage, 5% of the HBsAg carriers examined, as detected by the presence of HBeAg, and 9.5%, as shown by DNA polymerase activity, can be expected to have liver damage and a potential risk of transmitting hepatitis B to contacts. On the other hand, 48% of subjects were theoretically healthy and non-infective because of the presence of anti-HBe in their blood. The differentiation of groups of asymptomatic HBsAg carriers, on the basis of these serological markers, may have important clinical and epidemiological implications.