Allele-specific CRISPR-Cas9 editing of dominant epidermolysis bullosa simplex in human epidermal stem cells

Epidermolysis bullosa simplex (EBS) is a rare skin disease inherited mostly in an autosomal dominant manner. Patients display a skin fragility that leads to blisters and erosions caused by minor mechanical trauma. EBS phenotypic and genotypic variants are caused by genetic defects in intracellular proteins whose function is to provide the attachment of basal keratinocytes to the basement membrane zone and most EBS cases display mutations in keratin 5 (KRT5) and keratin 14 (KRT14) genes. Besides palliative treatments, there is still no long-lasting effective cure to correct the mutant gene and abolish the dominant negative effect of the pathogenic protein over its wild-type counterpart. Here, we propose a molecular strategy for EBS01 patient's keratinocytes carrying a monoallelic c.475/495del21 mutation in KRT14 exon 1. Through the CRISPR-Cas9 system, we perform a specific cleavage only on the mutant allele and restore a normal cellular phenotype and a correct intermediate filament network, without affecting the epidermal stem cell, referred to as holoclones, which play a crucial role in epidermal regeneration.

A ROI-based quantitative pipeline for 18F-FDG PET metabolism and pCASL perfusion joint analysis: Validation of the 18F-FDG PET line

In Mild Cognitive Impairment (MCI), the study of brain metabolism, provided by 18F-FluoroDeoxyGlucose Positron Emission Tomography (18F-FDG PET) can be integrated with brain perfusion through pseudo-Continuous Arterial Spin Labeling Magnetic Resonance sequences (MR pCASL). Cortical hypometabolism identification generally relies on wide control group datasets; pCASL control groups are instead not publicly available yet, due to lack of standardization in the acquisition parameters. This study presents a quantitative pipeline to be applied to PET and pCASL data to coherently analyze metabolism and perfusion inside 16 matching cortical regions of interest (ROIs) derived from the AAL3 atlas. The PET line is tuned on 36 MCI patients and 107 healthy control subjects, to agree in identifying hypometabolic regions with clinical reference methods (visual analysis supported by a vendor tool and Statistical Parametric Mapping, SPM, with two parametrizations here identified as SPM-A and SPM-B). The analysis was conducted for each ROI separately. The proposed PET analysis pipeline obtained accuracy 78 % and Cohen's к 60 % vs visual analysis, accuracy 79 % and Cohen's к 58 % vs SPM-A, accuracy 77 % and Cohen's к 54 % vs SPM-B. Cohen's к resulted not significantly different from SPM-A and SPM-B Cohen's к when assuming visual analysis as reference method (p-value 0.61 and 0.31 respectively). Considering SPM-A as reference method, Cohen's к is not significantly different from SPM-B Cohen's к as well (p-value = 1.00). The complete PET-pCASL pipeline was then preliminarily applied on 5 MCI patients and metabolism-perfusion regional correlations were assessed. The proposed approach can be considered as a promising tool for PET-pCASL joint analyses in MCI, even in the absence of a pCASL control group, to perform metabolism-perfusion regional correlation studies, and to assess and compare perfusion in hypometabolic or normo-metabolic areas.

MesenchymAl stromal cells for Traumatic bRain Injury (MATRIx): a study protocol for a multicenter, double-blind, randomised, placebo-controlled phase II trial

BACKGROUND

Traumatic brain injury (TBI) is a significant cause of death and disability, with no effective neuroprotective drugs currently available for its treatment. Mesenchymal stromal cell (MSC)-based therapy shows promise as MSCs release various soluble factors that can enhance the injury microenvironment through processes, such as immunomodulation, neuroprotection, and brain repair. Preclinical studies across different TBI models and severities have demonstrated that MSCs can improve functional and structural outcomes. Moreover, clinical evidence supports the safety of third-party donor bank-stored MSCs in adult subjects. Building on this preclinical and clinical data, we present the protocol for an academic, investigator-initiated, multicenter, double-blind, randomised, placebo-controlled, adaptive phase II dose-finding study aiming to evaluate the safety and efficacy of intravenous administration of allogeneic bone marrow-derived MSCs to severe TBI patients within 48 h of injury.

METHODS/DESIGN

The study will be conducted in two steps. Step 1 will enrol 42 patients, randomised in a 1:1:1 ratio to receive 80 million MSCs, 160 million MSCs or a placebo to establish safety and identify the most promising dose. Step 2 will enrol an additional 36 patients, randomised in a 1:1 ratio to receive the selected dose of MSCs or placebo. The activity of MSCs will be assessed by quantifying the plasmatic levels of neurofilament light (NfL) at 14 days as a biomarker of neuronal damage. It could be a significant breakthrough if the study demonstrates the safety and efficacy of MSC-based therapy for severe TBI patients. The results of this trial could inform the design of a phase III clinical trial aimed at establishing the efficacy of the first neurorestorative therapy for TBI.

DISCUSSION

Overall, the MATRIx trial is a critical step towards developing an effective treatment for TBI, which could significantly improve the lives of millions worldwide affected by this debilitating condition. Trial Registration EudraCT: 2022-000680-49.

Exoscopic Microsurgery: A Change of Paradigm in Brain Tumor Surgery? Comparison with Standard Operative Microscope

BACKGROUND

The exoscope is a high-definition telescope recently introduced in neurosurgery. In the past few years, several reports have described the advantages and disadvantages of such technology. No studies have compared results of surgery with standard microscope and exoscope in patients with glioblastoma multiforme (GBM).

METHODS

Our retrospective study encompassed 177 patients operated on for GBM (WHO 2021) between February 2017 and August 2022. A total of 144 patients were operated on with a microscope only and the others with a 3D4K exoscope only. All clinical and radiological data were collected. Progression-free survival (PFS) and overall survival (OS) have been estimated in the two groups and compared by the Cox model adjusting for potential confounders (e.g., sex, age, Karnofsky performance status, gross total resection, MGMT methylated promoter, and operator's experience).

RESULTS

IDH was mutated in 9 (5.2%) patients and MGMT was methylated in 76 (44.4%). Overall, 122 patients received a gross total resection, 14 patients received a subtotal resection, and 41 patients received a partial resection. During follow-up, 139 (73.5%) patients experienced tumor recurrence and 18.7% of them received a second surgery. After truncation to 12 months, the median PFS for patients operated on with the microscope was 8.82 months, while for patients operated on with the exoscope it was >12 months. Instead, the OS was comparable in the two groups. The multivariable Cox model showed that the use of microscope compared to the exoscope was associated with lower progression-free survival (hazard ratio = 3.55, 95%CI = 1.66-7.56, p = 0.001).

CONCLUSIONS

The exoscope has proven efficacy in terms of surgical resection, which was not different to that of the microscope. Furthermore, patients operated on with the exoscope had a longer PFS. A comparable OS was observed between microscope and exoscope, but further prospective studies with longer follow-up are needed.

Case Report: Potential role of selective venous sampling for liquid biopsy in complex clinical settings: Three case presentations

Tumor mutation profiling from a blood sample, known as liquid biopsy, is a reality that has already been approved for some cancers. This molecular diagnostic method complements tissue biopsy but is less invasive and therefore more easily applied, especially during tumor evolution. Its use should allow detection of residual disease, evaluation of treatment response or resistance, and selection of targeted treatments. However, implementation of liquid biopsy in routine clinical practice is hindered by unsolved issues, one of which is the scarcity of circulating tumor DNA in blood samples drawn from peripheral veins. To address this problem, we propose minimally invasive selective venous sampling from the region of interest, as used for some hormonal studies and for mapping of endocrine tumors. Intuitively, selective sampling should improve the sensitivity of liquid biopsy by avoiding the dilution of tumor biomarkers that occurs in the peripheral circulation. We report three cases that illustrate the potential utility of selective liquid biopsy in complex clinical settings, providing implications for diagnosis and treatment as well as for monitoring over time, disease localization, identification of drug resistance, and differential diagnosis.

Neural bases of loss aversion when choosing for oneself versus known or unknown others

Despite the ubiquitous interdependence between one's own decisions and others' welfare, and the controversial evidence on the behavioral effect of choosing for others, the neural bases of making decisions for another versus oneself remain unexplored. We investigated whether loss aversion (LA; the tendency to avoid losses over approaching equivalent gains) is modulated by (i) choosing for oneself, other individuals, or both; (ii) knowing or not knowing the other recipients; or (iii) an interaction between these factors. We used fMRI to assess the brain activations associated with choosing whether to accept or reject mixed gambles, either for oneself, for another player, or both, in 2 groups of 28 participants who had or had not briefly interacted with the other players before scanning. Participants displayed higher LA for choices involving their payoff compared with those affecting only the payoff of other, known, players. This "social" modulation of decision-making was found to engage the dorsomedial prefrontal cortex and its inhibitory connectivity to the middle cingulate cortex. This pattern might underpin decision-making for known others via self-other distinction processes associated with dorsomedial prefrontal areas, with this in turn promoting the inhibition of socially oriented responses through the downregulation of the midcingulate node of the empathy network.

Perilesional resection technique of glioblastoma: intraoperative ultrasound and histological findings of the resection borders in a single center experience

INTRODUCTION

The surgical goal in glioblastoma treatment is the maximal safe resection of the tumor. Currently the lack of consensus on surgical technique opens different approaches. This study describes the "perilesional technique" and its outcomes in terms of the extent of resection, progression free survival and overall survival.

METHODS

Patients included (n = 40) received a diagnosis of glioblastoma and underwent surgery using the perilesional dissection technique at "San Gerardo Hospital"between 2018 and 2021. The tumor core was progressively isolated using a circumferential movement, healthy brain margins were protected with Cottonoid patties in a "shingles on the roof" fashion, then the tumorwas removed en bloc. Intraoperative ultrasound (iOUS) was used and at least 1 bioptic sample of "healthy" margin of the resection was collected and analyzed. The extent of resection was quantified. Extent of surgical resection (EOR) and progression free survival (PFS)were safety endpoints of the procedure.

RESULTS

Thirty-four patients (85%) received a gross total resection(GTR) while 3 (7.5%) patients received a sub-total resection (STR), and 3 (7.5%) a partial resection (PR). The mean post-operative residual volume was 1.44 cm³ (range 0-15.9 cm³).During surgery, a total of 76 margins were collected: 51 (67.1%) were tumor free, 25 (32.9%) were infiltrated. The median PFS was 13.4 months, 15.3 in the GTR group and 9.6 months in the STR-PR group.

CONCLUSIONS

Perilesional resection is an efficient technique which aims to bring the surgeon to a safe environment, carefully reaching the "healthy" brain before removing the tumoren bloc. This technique can achieve excellent tumor margins, extent of resection, and preservation of apatient's functions.

The peritumoral brain zone in glioblastoma: where we are and where we are going

Glioblastoma (GBM) is the most aggressive and invasive primary brain tumor. Current therapies are not curative, and patients' outcomes remain poor with an overall survival of 20.9 months after surgery. The typical growing pattern of GBM develops by infiltrating the surrounding apparent normal brain tissue within which the recurrence is expected to appear in the majority of cases. Thus, in the last decades, an increased interest has developed to investigate the cellular and molecular interactions between GBM and the peritumoral brain zone (PBZ) bordering the tumor tissue. The aim of this review is to provide up-to-date knowledge about the oncogenic properties of the PBZ to highlight possible druggable targets for more effective treatment of GBM by limiting the formation of recurrence, which is almost inevitable in the majority of patients. Starting from the description of the cellular components, passing through the illustration of the molecular profiles, we finally focused on more clinical aspects, represented by imaging and radiological details. The complete picture that emerges from this review could provide new input for future investigations aimed at identifying new effective strategies to eradicate this still incurable tumor.

Functional Coherence in Intrinsic Frontal Executive Networks Predicts Cognitive Impairments in Alcohol Use Disorder

Growing evidence highlights the potential of innovative rehabilitative interventions such as cognitive remediation and neuromodulation, aimed at reducing relapses in Alcohol Use Disorder (AUD). Enhancing their effectiveness requires a thorough description of the neural correlates of cognitive alterations in AUD. Past related attempts, however, were limited by the focus on selected neuro-cognitive variables. We aimed to fill this gap by combining, in 22 AUD patients and 18 controls, an extensive neuro-cognitive evaluation and metrics of intrinsic connectivity as highlighted by resting-state brain activity. We addressed an inherent property of intrinsic activity such as intra-network coherence, the temporal correlation of the slow synchronous fluctuations within resting-state networks, representing an early biomarker of alterations in the functional brain architecture underlying cognitive functioning. AUD patients displayed executive impairments involving working-memory, attention and visuomotor speed, reflecting abnormal coherence of activity and grey matter atrophy within default mode, in addition to the attentional and the executive networks. The stronger relationship between fronto-lateral coherent activity and executive performance in patients than controls highlighted possible compensatory mechanisms counterbalancing the decreased functionality of networks driving the switch from automatic to controlled behavior. These results provide novel insights into AUD patients' cognitive impairments, their neural bases, and possible targets of rehabilitative interventions.

Canonical and uncanonical pathogenic germline variants in colorectal cancer patients by next-generation sequencing in a European referral center

BACKGROUND

Despite increasing use of next-generation sequencing (NGS), data concerning the gain in germline pathogenic variants (PVs) remain scanty, especially with respect to uncanonical ones. We aimed to verify the impact of different cancer predisposition genes (CPGs) on colorectal cancer (CRC) in patients referred for genetic evaluation.

MATERIALS AND METHODS

We enrolled for NGS, by Illumina TruSight Cancer panel comprising 94 CPGs, 190 consecutive subjects referred for microsatellite instability (MSI) CRC, polyposis, and/or family history.

RESULTS

Overall, 51 (26.8%) subjects carried 64 PVs; PVs coexisted in 4 (7.8%) carriers. PVs in mismatch repair (MMR) genes accounted for one-third of variant burden (31.3%). Four Lynch syndrome patients (20%) harbored additional PVs (HOXB13, CHEK2, BRCA1, NF1 plus BRIP1); such multiple PVs occurred only in subjects with PVs in mismatch syndrome genes (4/20 versus 0/31; P = 0.02). Five of 22 (22.7%) patients with MSI cancers but wild-type MMR genes harbored PVs in unconventional genes (FANCL, FANCA, ATM, PTCH1, BAP1). In 10/63 patients (15.9%) with microsatellite stable CRC, 6 had MUTYH PVs (2 being homozygous) and 4 exhibited uncanonical PVs (BRCA2, BRIP1, MC1R, ATM). In polyposis, we detected PVs in 13 (25.5%) cases: 5 (9.8%) in APC, 6 (11.8%) with biallelic PVs in MUTYH, and 2 (3.9%) in uncanonical genes (FANCM, XPC). In subjects tested for family history only, we detected two carriers (18.2%) with PVs (ATM, MUTYH).

CONCLUSION

Uncanonical variants may account for up to one-third of PVs, underlining the urgent need of consensus on clinical advice for incidental findings in cancer-predisposing genes not related to patient phenotype.

Association of Microglial Activation With Spontaneous ARIA-E and CSF Levels of Anti-Aβ Autoantibodies

BACKGROUND AND OBJECTIVES

Amyloid-related imaging abnormalities suggestive of vasogenic edema or sulcal effusion (ARIA-E) are the most common adverse events complicating Alzheimer disease (AD) immunotherapy with anti-β-amyloid (Aβ) monoclonal antibodies. ARIA-E can also occur spontaneously in cerebral amyloid angiopathy-related inflammation (CAA-ri), a rare autoimmune encephalopathy associated with increased CSF levels of anti-Aβ autoantibodies. Although the pathophysiologic mechanisms of ARIA-E remain to be fully elucidated, experimental evidence from ex vivo studies suggests that gantenerumab and aducanumab enable microglial activation. However, the in vivo evidence for a direct association between neuroinflammation and ARIA-E in patients with high CSF anti-Aβ (auto)antibody levels has never been demonstrated.

METHODS

The spatial distribution and temporal variations of microglial activation associated with levels of anti-Aβ autoantibodies at (sub)acute presentation of ARIA-E and after corticosteroid therapy were evaluated in a longitudinal case series of patients with CAA-ri, the spontaneous variant of the iatrogenic ARIA-E reported in Aβ-lowering immunotherapy with monoclonal antibodies. Multimodal and multiparametric MRI was used for CAA and ARIA-E severity quantification, according to validated scoring system; CSF testing for anti-Aβ autoantibodies and AD biomarkers; 11C-PK11195 PET for activated microglia.

RESULTS

At (sub)acute presentation, we found focal peaks of microglial activation having a greater spatial colocalization with ARIA-E compared with chronic age-related white matter change imaging abnormalities. The severity of ARIA-E and the magnitude of the associated microglial activation were greater in patients having AD and severe CAA concomitant disease compared with patients having CAA only. CSF anti-Aβ autoantibodies at presentation were high in all patients and markedly decreased at posttreatment follow-up, in parallel with clinical resolution of acute symptoms, reduced ARIA-E severity, and reduced microglial activation.

DISCUSSION

Our findings extend the current notion of ARIA-E by providing the first in vivo 11C-PK11195 PET evidence for an association between microglial activation and the magnitude and severity of ARIA-E in patients with increased CSF concentration of anti-Aβ autoantibodies and comorbid AD and CAA disease. Our results highlight CSF testing for anti-Aβ autoantibodies as a promising diagnostic, prognostic, and therapy response biomarker to help guide future treatment and management decisions in real clinical practice and clinical trials.

Computation of contrast-enhanced perfusion using only two CT scan phases: a proof-of-concept study on abdominal organs

Background

Computed tomography perfusion imaging (CTPI) by repeated scanning has clinical relevance but implies relatively high radiation exposure. We present a method to measure perfusion from two CT scan phases only, considering tissue enhancement, feeding vessel (aortic) peak enhancement, and bolus shape.

Methods

CTPI scans (each with 40 frames acquired every 1.5 s) of 11 patients with advanced hepatocellular carcinoma (HCC) enrolled between 2012 and 2016 were retrospectively analysed (aged 69 ± 9 years, 8/11 males). Perfusion was defined as the maximal slope of the time-enhancement curve divided by the peak enhancement of the feeding vessel (aorta). Perfusion was computed two times, first using the maximum slope derived from all data points and then using the peak tissue enhancement and the bolus shape obtained from the aortic curve.

Results

Perfusion values from the two methods were linearly related (r2 = 0.92, p < 0.001; Bland–Altman analysis bias -0.12). The mathematical model showed that the perfusion ratio of two ROIs with the same feeding vessel (aorta) corresponds to their peak enhancement ratio (r2 = 0.55, p < 0.001; Bland–Altman analysis bias -0.68). The relationship between perfusion and tissue enhancement is predicted to be linear in the clinical range of interest, being only function of perfusion, peak feeding vessel enhancement, and bolus shape.

Conclusions

This proof-of-concept study showed that perfusion values of HCC, kidney, and pancreas could be computed using enhancement measured only with two CT scan phases, if aortic peak enhancement and bolus shape are known.

Altered striatal-opercular intrinsic connectivity reflects decreased aversion to losses in alcohol use disorder

The persistence of addictive behaviours despite their adverse consequences highlights decreased punishment sensitivity as a facet of decision-making impairments in Alcohol Use Disorder (AUD). This attitude departs from the typical loss aversion (LA) pattern, i.e. the stronger sensitivity to negative than positive outcomes, previously associated with striatal and limbic-somatosensory responsiveness in healthy individuals. Consistent evidence highlights decreased LA as a marker of disease severity in AUD, but its neural bases remain largely unexplored. AUD-specific modulations of frontolateral activity by LA were previously related to the higher executive demands of anticipating losses than gains, but the relationship between LA and executive/working-memory performance in AUD is debated. Building on previous evidence of overlapping neural bases of LA during decision-making and at rest, we investigated a possible neural signature of altered LA in AUDs, and its connections with executive skills, in terms of complementary facets of resting-state functioning. In patients, smaller LA than controls, unrelated to executive performance, reflected reduced connectivity within striatal and medial temporal networks, and altered connectivity from these regions to the insular-opercular cortex. AUD-specific loss-related modulations of intrinsic connectivity thus involved structures previously associated both with drug-seeking and with coding the trade-off between appetitive and aversive motivational drives. These findings fit the hypothesis that altered striatal coding of choice-related incentive value, and interoceptive responsiveness to prospective outcomes, enhance neural sensitivity to drug-related stimuli in addictions. LA and its neural bases might prove useful markers of AUD severity and effectiveness of rehabilitation strategies targeting the salience of negative choice outcomes.

Posterior fronto-medial atrophy reflects decreased loss aversion, but not executive impairment, in alcohol use disorder

Decreased punishment sensitivity in alcohol use disorder (AUD) might reflect a reduction in the typical human tendency to overweigh negative choice outcomes compared with equivalent positive ones, that is, 'loss aversion.' While this hypothesis is supported by previous reports of reduced loss aversion in AUD, it is still unknown whether such decreased sensitivity to prospective losses represents a specific facet of altered decision-making or a secondary effect of executive/working-memory impairments. We addressed this issue by assessing whether lower loss aversion in 22 AUD patients compared with 19 healthy controls is explained by their differential executive or working-memory performance and by investigating its neural basis in terms of grey matter density and cortical thickness via voxel- and surface-based morphometry, respectively. A significant decrease of loss aversion in patients, unrelated to their impaired executive/working-memory performance, reflected the reduction of posterior fronto-medial grey matter density and right frontopolar cortical thickness. Rather than their executive deficits, patients' reduced loss aversion reflects the structural damage of the posterior fronto-medial cortex previously associated with solving conflicts at the response level, where earlier functional magnetic resonance imaging (fMRI) studies have shown a 'neural loss aversion' pattern of steeper deactivation for losses than activation for gains, and of the frontopolar cortex in charge of managing competing goals. These findings highlight possible directions for addressing AUD patients' high relapse rate, for example, cognitive-behavioural rehabilitative interventions enhancing the awareness of the adverse outcomes of addiction or neurostimulation protocols targeting the regions processing their salience.

Spontaneous ARIA-like Events in Cerebral Amyloid Angiopathy-Related Inflammation: A Multicenter Prospective Longitudinal Cohort Study

BACKGROUND AND OBJECTIVES

The goal of this work was to investigate the natural history and outcomes after treatment for spontaneous amyloid-related imaging abnormalities (ARIA)-like in cerebral amyloid angiopathy-related inflammation (CAA-ri).

METHODS

This was a multicenter, hospital-based, longitudinal, prospective observational study of inpatients meeting CAA-ri diagnostic criteria recruited through the Inflammatory Cerebral Amyloid Angiopathy and Alzheimer's Disease βiomarkers International Network from January 2013 to March 2017. A protocol for systematic data collection at first-ever presentation and at subsequent in-person visits, including T1-weighted, gradient recalled echo-T2*, fluid-suppressed T2-weighted (fluid-attenuated inversion recovery), and T1 postgadolinium contrast-enhanced images acquired on 1.5T MRI, was used at the 3-, 6-, 12-, and 24-month follow-up. Centralized reads of MRIs were performed by investigators blinded to clinical, therapeutic, and time-point information. Main outcomes were survival, clinical and radiologic recovery, intracerebral hemorrhage (ICH), and recurrence of CAA-ri.

RESULTS

The study enrolled 113 participants (10.6% definite, 71.7% probable, and 17.7% possible CAA-ri). Their mean age was 72.9 years; 43.4% were female; 37.1% were APOEε4 carriers; 36.3% had a history of Alzheimer disease; and 33.6% had a history of ICH. A history of ICH and the occurrence of new ICH at follow-up were more common in patients with cortical superficial siderosis at baseline (52.6% vs 14.3%, p < 0.0001 and 19.3% vs 3.6%, p < 0.009, respectively). After the first-ever presentation of CAA-ri, 70.3% (95% confidence interval [CI] 61.6%-78.5%) and 84.1% (95% CI 76.2%-90.6%) clinically recovered within 3 and 12 months, followed by radiologic recovery in 45.1% (95% CI 36.4%-54.8%) and 77.4% (95% CI 67.7%-85.9%), respectively. After clinicoradiologic resolution of the first-ever episode, 38.3% (95% CI 22.9%-59.2%) had at least 1 recurrence within the following 24 months. Recurrence was more likely if IV high-dose corticosteroid pulse therapy was suddenly stopped compared to slow oral tapering off (hazard ratio 4.68, 95% CI 1.57-13.93; p = 0.006).

DISCUSSION

These results from the largest longitudinal cohort registry of patients with CAA-ri support the transient and potentially relapsing inflammatory nature of the clinical-radiologic acute manifestations of the disease and the effectiveness of slow oral tapering off after IV corticosteroid pulse therapy in preventing recurrences. Our results highlight the importance of differential diagnosis for spontaneous ARIA-like events in β-amyloid-driven diseases, including treatment-related ARIA in patients with Alzheimer disease exposed to immunotherapy drugs.

Perspectives on (A)symmetry of Arcuate Fasciculus. A Short Review About Anatomy, Tractography and TMS for Arcuate Fasciculus Reconstruction in Planning Surgery for Gliomas in Language Areas

Gliomas are brain tumors that are treated with surgical resection. Prognosis is influenced by the extent of resection and postoperative neurological status. As consequence, given the extreme interindividual and interhemispheric variability of subcortical white matter (WM) surgical planning requires to be patient's tailored. According to the “connectionist model,” there is a huge variability among both cortical areas and subcortical WM in all human beings, and it is known that brain is able to reorganize itself and to adapt to WM lesions. Brain magnetic resonance imaging diffusion tensor imaging (DTI) tractography allows visualization of WM bundles. Nowadays DTI tractography is widely available in the clinical setting for presurgical planning. Arcuate fasciculus (AF) is a long WM bundle that connects the Broca's and Wernicke's regions with a complex anatomical architecture and important role in language functions. Thus, its preservation is important for the postoperative outcome, and DTI tractography is usually performed for planning surgery within the language-dominant hemisphere. High variability among individuals and an asymmetrical pattern has been reported for this WM bundle. However, the functional relevance of AF in the contralateral non-dominant hemisphere in case of tumoral or surgical lesion of the language-dominant AF is unclear. This review focuses on AF anatomy with special attention to its asymmetry in both normal and pathological conditions and how it may be explored with preoperative tools for planning surgery on gliomas in language areas. Based on the findings available in literature, we finally speculate about the potential role of preoperative evaluation of the WM contralateral to the surgical site.

Increased pSTS activity and decreased pSTS-mPFC connectivity when processing negative social interactions

We have previously shown that activity and connectivity within and between the action observation and mentalizing brain systems reflect the degree of positive dimensions expressed by social interactions such as cooperativity and affectivity, respectively. Here we aim to extend this evidence by investigating the neural bases of processing negative dimensions of observed interactions, such as competition and affective conflict, possibly representing a benchmark for different pathological conditions. In this fMRI study 34 healthy participants were shown pictures depicting interactions characterized by two crossed dimensions, i.e. positively- vs. negatively- connotated social intentions mainly expressed in terms of motor acts vs. mental states, i.e. cooperative, competitive, affective and conflicting interactions. We confirmed the involvement of the action observation and mentalizing networks in processing intentions mainly expressed through motor acts (cooperative/competitive) vs. mental states (affective/conflicting), respectively. Results highlighted the selective role of the left pSTS/TPJ in decoding social interactions, even when compared with parallel actions by non-interacting individuals. Its right-hemispheric homologue displayed stronger responses to negative than positive social intentions, regardless of their motor/mental status, and decreased connectivity with the medial prefrontal cortex (mPFC) when processing negative interactions. The resulting mPFC downregulation by negative social scenes might reflect an adaptive response to socio-affective threats, via decreased mentalizing when facing negative social stimuli. This evidence on the brain mechanisms underlying the decoding of real complex interactions represents a baseline for assessing both the neural correlates of impaired social cognition, and the effects of rehabilitative treatments, in neuro-psychiatric diseases or borderline conditions such as loneliness.

Fronto-temporal brain activity and connectivity track implicit attention to positive and negative social words in a novel socio-emotional Stroop task

Previous inconsistencies on the effects of implicitly processing positively - vs. negatively - connotated emotional words might reflect the influence of uncontrolled psycholinguistic dimensions, and/or social facets inherent in putative "emotional" stimuli. Based on the relevance of social features in semantic cognition, we developed a socio-emotional Stroop task to assess the influence of social vs. individual (non-social) emotional content, besides negative vs. positive valence, on implicit word processing. The effect of these variables was evaluated in terms of performance and RTs, alongside associated brain activity/connectivity. We matched conditions for several psycholinguistic variables, and assessed a modulation of brain activity/connectivity by trial-wise RT, to characterize the maximum of condition- and subject-specific variability. RTs were tracked by insular and anterior cingulate activations likely reflecting implicit attention to stimuli, interfering with task-performance based on condition-specific processing of their subjective salience. Slower performance for negative than neutral/positive words was tracked by left-hemispheric structures processing negative stimuli and emotions, such as fronto-insular cortex, while the lack of specific activations for positively-connotated words supported their marginal facilitatory effect. The speeding/slowing effects of processing positive/negative individual emotional stimuli were enhanced by social words, reflecting in specific activations of the right anterior temporal and orbitofrontal cortex, respectively. RTs to social positive and negative words modulated connectivity from these regions to fronto-striatal and sensorimotor structures, respectively, likely promoting approach vs. avoidance dispositions shaping their facilitatory vs. inhibitory effect. These results might help assessing the neural correlates of impaired social cognition and emotional regulation, and the effects of rehabilitative interventions.

Microstructural damage of white-matter tracts connecting large-scale networks is related to impaired executive profile in alcohol use disorder

Alcohol Use Disorders (AUD) is associated with negative consequences on global functioning, likely reflecting chronic changes in brain morphology and connectivity. Previous attempts to characterize cognitive impairment in AUD addressed patients' performance in single domains, without considering their cognitive profile as a whole. While altered cognitive performance likely reflects abnormal white-matter microstructural properties, to date no study has directly addressed the relationship between a proxy of patients' cognitive profile and microstructural damage. To fill this gap we aimed to characterize the microstructural damage pattern, and its relationship with cognitive profile, in treatment-seeking AUD patients. Twenty-two AUD patients and 18 healthy controls underwent a multimodal MRI protocol including diffusion tensor imaging (DTI), alongside a comprehensive neurocognitive assessment. We used a principal component analysis (PCA) to identify superordinate components maximally explaining variability in cognitive performance, and whole-brain voxelwise analyses to unveil the neural correlates of AUD patients' cognitive impairment in terms of different white-matter microstructural features, i.e. fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). PCA revealed a basic executive component, significantly impaired in AUD patients, associated with tasks tapping visuo-motor processing speed, attention and working-memory. Within a widespread pattern of white-matter damage in patients, we found diverse types of relationship linking WM microstructure and executive performance: (i) in the whole sample, we observed a linear relationship involving MD/RD metrics within both 'superficial' white-matter systems mediating connectivity within large-scale brain networks, and deeper systems modulating their reciprocal connections; (ii) in AUD patients vs. controls, a performance-by-group interaction highlighted a MD/AD pattern involving two frontal white-matter systems, including the genu of corpus callosum and cingulum bundle, mediating structural connectivity among central executive, salience and default mode networks. Alterations of prefrontal white-matter pathways are suggestive of abnormal structural connectivity in AUD, whereby a defective interplay among large-scale networks underpins patients' executive dysfunction. These findings highlight different directions for future basic and translational research aiming to tailor novel rehabilitation strategies and assess their functional outcomes.

Executive Impairment in Alcohol Use Disorder Reflects Structural Changes in Large-Scale Brain Networks: A Joint Independent Component Analysis on Gray-Matter and White-Matter Features

Alcohol Use Disorder (AUD) entails chronic effects on brain structure. Neurodegeneration due to alcohol toxicity is a neural signature of executive impairment typically observed in AUD, previously related to both gray-matter volume/density and white-matter abnormalities. Recent studies highlighted the role of meso-cortico-limbic structures supporting the salience and executive networks, in which the extent of neurostructural damage is significantly related to patients’ executive performance. Here we aim to integrate multimodal information on gray-matter and white-matter features with a multivariate data-driven approach (joint Independent Component Analysis, jICA), and to assess the relationship between the extent of damage in the resulting neurostructural superordinate components and executive profile in AUD. Twenty-two AUD patients and 18 matched healthy controls (HC) underwent a Magnetic Resonance Imaging (MRI) protocol, alongside clinical and neuropsychological examinations. We ran jICA on five neurostructural features, including gray-matter density and different diffusion tensor imaging metrics. We extracted 12 Independent Components (ICs) and compared the resulting mixing coefficients in patients vs. HC. Finally, we correlated significant ICs with executive and clinical variables. One out of 12 ICs (IC11) discriminated patients from healthy controls and correlated positively both with executive performance in all subjects, and with lifetime duration of alcohol abuse in patients. In line with previous related evidence, this component involved widespread gray-matter and white-matter patterns including key nodes and fiber tracts of salience, default-mode and central executive networks. These findings highlighted the role of multivariate data integration as a valuable approach revealing superordinate hallmarks of neural changes related to cognition in neurological and psychiatric populations.

Patient-derived organoids (PDOs) as a novel in vitro model for neuroblastoma tumours

BACKGROUND

Neuroblastoma (NB) is a paediatric tumour of the sympathetic nervous system. Half of all cases are defined high-risk with an overall survival less than 40% at 5 years from diagnosis. The lack of in vitro models able to recapitulate the intrinsic heterogeneity of primary NB tumours has hindered progress in understanding disease pathogenesis and therapy response.

METHODS

Here we describe the establishment of 6 patient-derived organoids (PDOs) from cells of NB tumour biopsies capable of self-organising in a structure resembling the tissue of origin.

RESULTS

PDOs recapitulate the histological architecture typical of the NB tumour. Moreover, PDOs expressed NB specific markers such as neural cell adhesion molecules, NB84 antigen, synaptophysin (SYP), chromogranin A (CHGA) and neural cell adhesion molecule NCAM (CD56). Analyses of whole genome genotyping array revealed that PDOs maintained patient-specific chromosomal aberrations such as MYCN amplification, deletion of 1p and gain of chromosome 17q. Furthermore, the PDOs showed stemness features and retained cellular heterogeneity reflecting the high heterogeneity of NB tumours.

CONCLUSIONS

We were able to create a novel preclinical model for NB exhibiting self-renewal property and allowing to obtain a reservoir of NB patients' biological material useful for the study of NB molecular pathogenesis and to test drugs for personalised treatments.

Abnormal fronto-striatal intrinsic connectivity reflects executive dysfunction in alcohol use disorders

The neural bases of cognitive impairment(s) in alcohol use disorders (AUDs) have been explained either with the specific involvement of frontal regions mostly affected by alcohol neurotoxic effects, or with a global brain damage underlying different neuro-cognitive alterations. Novel insights into this issue might come from the analysis of resting-state brain activity, representing a baseline level of intrinsic connectivity within and between the networks underlying cognitive performance. We thus addressed the neural bases of cognitive impairment(s) in 22 AUD patients, compared with 18 healthy controls, by coupling resting-state fMRI with an in-depth neuropsychological assessment of the main cognitive domains. We assessed a relationship between AUD patients' cognitive impairment and two complementary facets of intrinsic brain functioning, i.e., intensity of activation and functional network connectivity, related to the strength of connectivity within and between resting-state networks, respectively. Alcoholic patients' decreased cognitive performance involved specifically an executive domain associated with attentional and working-memory tasks. This impairment reflected an abnormal relationship, in patients versus controls, between cognitive performance and the intensity of intrinsic activity in the dorsolateral prefrontal and striatal nodes of the executive control network. Functional connectivity between the same structures was positively correlated with executive performance in the whole sample, but significantly reduced in patients. The present data suggest that AUD patients' executive impairment reflects dysfunctional connectivity between the cortical and subcortical nodes of the networks underlying cognitive control on goal-directed behavior. This evidence provides a baseline for future studies addressing the abnormal neural architecture underlying cognitive impairment in AUDs and the outcome of rehabilitative treatment.

N-MYC and C-MYC Oncogenes Amplification in Medulloblastomas. Evidence of Particularly Aggressive Behavior of a Tumor with C-MYC Amplification

N-myc and c-myc amplification was investigated in 27 medulloblastomas. DNA was extracted from 19 formalin fixed and paraffin embedded tumors and from fresh frozen tumor tissue in 8 other cases. The results showed no evidence of amplification of N-myc oncogene and only 1 case had a 27 fold amplification of c-myc. Cytogenetically, this neoplasm presented numerous double minute chromosomes (DMs). Moreover, it had an unusual rapidly aggressive course with massive cerebrospinal fluid dissemination unresponsive to intrathecal chemotherapy. Our results indicate a low incidence of N-myc and c-myc gene amplification in medulloblastomas, suggesting that the oncogenic mechanism in these neoplasms is not closely related to DNA gene amplification. C-myc amplification, although not frequently observed, may however provide a growth advantage for medulloblastoma cells in vivo, favoring their rapid dissemination. Medulloblastomas with c-myc activation may represent a subgroup of tumors with a more aggressive behavior.

Primary mediastinal large B-cell lymphoma: Outcome of a series of pediatric patients treated with high-dose methotrexate and cytarabine plus anti-CD20

Between 2007 and 2013, 13 children diagnosed with primary mediastinal large B-cell lymphoma (PMLBL) were treated according to a modified version of AIEOP (Associazione Italiana Ematologia Oncologia Pediatrica) LNH-97 protocol based on high-dose methotrexate, anthracyclines, and addition of anti-CD20. Ten patients achieved a continuous complete remission with front-line therapy. The overall 5-year survival was 91.7%, and event-free survival was 83.9%, with only one patient dying of progressive disease. Despite the few cases, these results demonstrate that this therapy, which includes anti-CD20, given in a multicenter setting, is feasible with acceptable toxicity in children with PMLBL.

The alcoholic brain: neural bases of impaired reward-based decision-making in alcohol use disorders

Neuroeconomics is providing insights into the neural bases of decision-making in normal and pathological conditions. In the neuropsychiatric domain, this discipline investigates how abnormal functioning of neural systems associated with reward processing and cognitive control promotes different disorders, and whether such evidence may inform treatments. This endeavor is crucial when studying different types of addiction, which share a core promoting mechanism in the imbalance between impulsive subcortical neural signals associated with immediate pleasurable outcomes and inhibitory signals mediated by a prefrontal reflective system. The resulting impairment in behavioral control represents a hallmark of alcohol use disorders (AUDs), a chronic relapsing disorder characterized by excessive alcohol consumption despite devastating consequences. This review aims to summarize available magnetic resonance imaging (MRI) evidence on reward-related decision-making alterations in AUDs, and to envision possible future research directions. We review functional MRI (fMRI) studies using tasks involving monetary rewards, as well as MRI studies relating decision-making parameters to neurostructural gray- or white-matter metrics. The available data suggest that excessive alcohol exposure affects neural signaling within brain networks underlying adaptive behavioral learning via the implementation of prediction errors. Namely, weaker ventromedial prefrontal cortex activity and altered connectivity between ventral striatum and dorsolateral prefrontal cortex likely underpin a shift from goal-directed to habitual actions which, in turn, might underpin compulsive alcohol consumption and relapsing episodes despite adverse consequences. Overall, these data highlight abnormal fronto-striatal connectivity as a candidate neurobiological marker of impaired choice in AUDs. Further studies are needed, however, to unveil its implications in the multiple facets of decision-making.

Characterization of children with FLT3-ITD acute myeloid leukemia: a report from the AIEOP AML-2002 study group

Recurrent molecular markers have been routinely used in acute myeloid leukemia (AML) for risk assessment at diagnosis, whereas their post-induction monitoring still represents a debated issue. We evaluated the prognostic value and biological impact of minimal residual disease (MRD) and of the allelic ratio (AR) of FLT3-internal-tandem duplication (ITD) in childhood AML. We retrospectively screened 494 children with de novo AML for FLT3-ITD mutation, identifying 54 harboring the mutation; 51% of them presented high ITD-AR at diagnosis and had worse event-free survival (EFS, 19.2 versus 63.5% for low ITD-AR, <0.05). Forty-one percent of children with high levels of MRD after the 1st induction course, measured by a patient-specific real-time-PCR, had worse EFS (22.2 versus 59.4% in low-MRD patients, P<0.05). Next, we correlated these parameters with gene expression, showing that patients with high ITD-AR or persistent MRD had characteristic expression profiles with deregulated genes involved in methylation and acetylation. Moreover, patients with high CyclinA1 expression presented an unfavorable EFS (20.3 versus 51.2% in low CyclinA1 group, P<0.01). Our results suggest that ITD-AR levels and molecular MRD should be considered in planning clinical management of FLT3-ITD patients. Different transcriptional activation of epigenetic and oncogenic profiles may explain variability in outcome among these patients, for whom novel therapeutic approaches are desirable.

Calcineurin and GSK-3 inhibition sensitizes T-cell acute lymphoblastic leukemia cells to apoptosis through X-linked inhibitor of apoptosis protein degradation

The calcineurin (Cn)-nuclear factor of activated T cells signaling pathway is critically involved in many aspects of normal T-cell physiology; however, its direct implication in leukemogenesis is still ill-defined. Glycogen synthase kinase-3β (GSK-3β) has recently been reported to interact with Cn in neuronal cells and is implicated in MLL leukemia. Our biochemical studies clearly demonstrated that Cn was able to interact with GSK-3β in T-cell acute lymphoblastic leukemia (T-ALL) cells, and that this interaction was direct, leading to an increased catalytic activity of GSK-3β, possibly through autophosphorylation of Y216. Sensitivity to GSK-3 inhibitor treatment correlated with altered GSK-3β phosphorylation and was more prominent in T-ALL with Pre/Pro immunophenotype. In addition, dual Cn and GSK-3 inhibitor treatment in T-ALL cells promoted sensitization to apoptosis through proteasomal degradation of X-linked inhibitor of apoptosis protein (XIAP). Consistently, resistance to drug treatments in primary samples was strongly associated with higher XIAP protein levels. Finally, we showed that dual Cn and GSK-3 inhibitor treatment in vitro and in vivo is effective against available models of T-ALL, indicating an insofar untapped therapeutic opportunity.

Focal nodular hyperplasia of the liver: an emerging complication of hematopoietic SCT in children

Hepatic focal nodular hyperplasia (FNH) is a nonmalignant condition rarely affecting children previously treated for cancer, especially those who received hematopoietic SCT (HSCT). Some aspects of its pathogenesis still remain unclear and a strong association with specific risk factors has not yet been identified. We report here a single institution's case series of 17 patients who underwent HSCT and were diagnosed with FNH, analyzing retrospectively their clinical features and the radiological appearance of their hepatic lesions. We aimed to compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) and to explore the role of transient elastography (FibroScan) to evaluate the degree of hepatic fibrosis in FNH patients. Our analysis showed an association of FNH with age at transplant ⩽12 years (hazard ratio (HR) 9.10); chronic GVHD (HR 2.99); hormone-replacement therapy (HR 4.02) and abdominal radiotherapy (HR 4.37). MRI proved to be a more accurate diagnostic tool compared with US. Nine out of 12 patients who underwent FibroScan showed hepatic fibrosis. Our study points out that FNH is an emerging complication of HSCT, which requires a lifelong surveillance to follow its course in cancer patients.

Lymphocytes subsets reference values in childhood

Immunophenotyping of blood lymphocyte subsets and activation markers is a basic tool in the diagnostic process of primary immunodeficiency diseases, its use becoming more and more widespread as the knowledge about these illnesses increases. However, the availability of reliable reference values, which need to be age-matched for the pediatric population, is a pre-requisite for the reliable interpretation of immunophenotyping data. Aim of this study is to analyze the lymphocyte subsets and activation markers distribution in children aged 0-18 years referring to the University Hospital of Padova and to create age-matched reference values expressed by percentiles, thus providing a valuable guideline for the interpretation of the immunophenotype.

Validation of flow cytometric phospho-STAT5 as a diagnostic tool for juvenile myelomonocytic leukemia

To diagnose juvenile myelomonocytic leukemia (JMML) is sometimes challenging, because around 10% of patients lack molecular abnormalities affecting Ras-MAPK (mitogen-activated protein kinase) pathway and other diseases such as cytomegalovirus infection can mimic clinical signs of JMML. In order to validate a phospho-specific flow cytometry assay assessing phospho-signal transducer and activator of transcription factor 5 (p-STAT5) as a new diagnostic tool for JMML, we examined 22 samples from children with JMML and 47 controls. CD33+/CD34+ cells from 22 patients with JMML showed hyperphosphorylation of STAT5 induced by sub-saturating doses of granulocyte-macrophage colony-stimulating factor (GM-CSF). Using a training set of samples (11 JMML and 23 controls), we identified a threshold for p-STAT5-positive after stimulation with 0.1 ng/ml GM-CSF (17.17%) that discriminates JMML from controls. This threshold was validated in an independent series (11 JMML, 24 controls and 7 cases with diseases other than JMML) where we demonstrated that patients with JMML could be distinguished from other subjects with a sensitivity of 91% (confidence interval (CI) 59–100%) and a specificity of 87% (CI 70–96%). Positive and negative predictive values were 71% (CI 42–92%) and 96% (CI 82–100%), respectively. In conclusion, flow cytometric p-STAT5 profiling is a reliable diagnostic tool for identifying patients with JMML and can contribute to consistency of current diagnostic criteria.

Early expression of the fractalkine receptor CX3CR1 in pancreatic carcinogenesis

BACKGROUND

In pancreatic ductal adenocarcinoma (PDAC), fractalkine receptor CX3CR1 contributes to perineural invasion (PNI). We investigated whether CX3CR1 expression occurs early in PDAC and correlates with tumour features other than PNI.

METHODS

We studied CX3CR1 and CX3CL1 expression by immunohistochemistry in 104 human PDAC and coexisting Pancreatic Intraepithelial Neoplasia (PanIN), and in PdxCre/LSL-Kras(G12D) mouse model of PDAC. CX3CR1 expression in vitro was studied by a spheroid model, and in vivo by syngenic mouse graft of tumour cells.

RESULTS

In total, 56 (53.9%) PDAC expressed CX3CR1, 70 (67.3%) CX3CL1, and 45 (43.3%) both. CX3CR1 expression was independently associated with tumour glandular differentiation (P=0.005) and PNI (P=0.01). Pancreatic Intraepithelial Neoplasias were more frequently CX3CR1+ (80.3%, P<0.001) and CX3CL1+ (86.8%, P=0.002) than matched cancers. The survival of PDAC patients was better in those with CX3CR1+ tumour (P=0.05). Mouse PanINs were also CX3CR1(+) and -CL1(+). In vitro, cytokines significantly increased CX3CL1 but not CX3CR1 expression. Differently, CX3CR1 was upregulated in tumour spheroids, and in vivo only in well-differentiated tumours.

CONCLUSION

Tumour differentiation, rather than inflammatory signalling, modulates CX3CR1 expression in PanINs and PDAC. CX3CR1 expression pattern suggests its early involvement in PDAC progression, outlining a potential target for interfering with the PanIN transition to invasive cancer.

Improvement of the accuracy of noise measurements by the two-amplifier correlation method

We present a novel method for device noise measurement, based on a two-channel cross-correlation technique and a direct "in situ" measurement of the transimpedance of the device under test (DUT), which allows improved accuracy with respect to what is available in the literature, in particular when the DUT is a nonlinear device. Detailed analytical expressions for the total residual noise are derived, and an experimental investigation of the increased accuracy provided by the method is performed.

Distinguishable neurofunctional effects of task practice and item practice in picture naming: a BOLD fMRI study in healthy subjects

Practice of language tasks results in improved performance and BOLD signal changes. We distinguish changes correlated with repeated exposure to a picture naming task, from changes associated with naming specific items trained during practice. Task practice affected trained and untrained items, yielding left-sided BOLD deactivations in extrastriate, prefrontal and superior temporal areas (consistent with their putative role in perceptual priming, articulatory planning and phonological lexical retrieval, respectively). Item practice effects were restricted to trained words. There was deactivation in left posterior fusiform (supporting its role in accessing structural object representations), anterior cingulate and left insular/inferior frontal cortices (consistent with their role in processing low-frequency words). Central precuneus and posterior cingulate were hyperactivated (consistent with their putative role in episodic memory for trained items, probably due to functional connections with language areas). In healthy subjects, naming practice modifies stored linguistic representations, but mostly affects ease of access to trained words.

Postoperative radiotherapy (RT) with or without chemotherapy (CT) in anaplastic astrocitoma (AA) patients

e13046

Background: Although the evidence for the benefit of adding temozolamide (TMZ) to RT is limited to glioblastoma patients (pts), there is currently an increased tendency toward a combined RT + TMZ approach also in AA patients. Methods: We report in this study the survival outcome of 2 groups of pts, treated at in 2 different periods at our institution with RT after surgery ± CT. GROUP A (years 1984-2001): pts treated with surgery followed by RT; GROUP B (YEARS 2004-2009): pts treated with surgery followed by radical RT and CT according to the STUPP’s protocol; Results: Data were retrospectively collected on a consecutive series: GROUP A: 17 pts: 10 Males (M), 7 Females (F); median age 50 years (range: 31-65). Ten out of 17 pts received radical surgery and 7 subtotal surgery. All were treated with postoperative RT, median dose 5082 cGy (range: 2160-6300). The mean time between surgery and beginning of RT was 44.7 days (range 20-87). GROUP B: 17 pts: 10 M, 7 F; median age 44 years (25-72). Eleven out 17 pts received radical surgery and 6 subtotal surgery. All were treated with postoperative RT, median dose 5800 cGy (range: 4000-600). The mean time between surgery and beginning of RT was 56.3 days (range 26-111). All patients received TMZ 75 mg/mq for a median of 6 weeks (range 3-7), followed by adjuvant treatment with TMZ (200 mg/mq) for a median of 5 cycles (range 0-13). At a median follow-up of 45 mos , the median OS was 29.1 mos for the group A and 49,1 mos for the group B. Among pts treated with RT + CT after surgery, median OS was significantly longer (p= 0.03), compared to those treated with only RT after surgery. Conclusions: The limited sample sizes of 2 groups and differences such as the median RT dose and the median time between surgery and RT, does not allow any conclusion. However, our data suggest that the combined RT-CT treatment is feasible in AA pts after surgery and may possibly contribute to a prolonged control of disease. These suggestions should be explored in a prospective randomized trial.

Wnt activation promotes neuronal differentiation of glioblastoma

One of the biggest challenges in tumour research is the possibility to reprogram cancer cells towards less aggressive phenotypes. In this study, we reprogrammed primary Glioblastoma multiforme (GBM)-derived cells towards a more differentiated and less oncogenic phenotype by activating the Wnt pathway in a hypoxic microenvironment. Hypoxia usually correlates with malignant behaviours in cancer cells, but it has been recently involved, together with Wnt signalling, in the differentiation of embryonic and neural stem cells. Here, we demonstrate that treatment with Wnt ligands, or overexpression of β-catenin, mediate neuronal differentiation and halt proliferation in primary GBM cells. An hypoxic environment cooperates with Wnt-induced differentiation, in line with our finding that hypoxia inducible factor-1α (HIF-1α) is instrumental and required to sustain the expression of β-catenin transcriptional partners TCF-1 and LEF-1. In addition, we also found that Wnt-induced GBM cell differentiation inhibits Notch signalling, and thus gain of Wnt and loss of Notch cooperate in the activation of a pro-neuronal differentiation program. Intriguingly, the GBM sub-population enriched of cancer stem cells (CD133⁺ fraction) is the primary target of the pro-differentiating effects mediated by the crosstalk between HIF-1α, Wnt, and Notch signalling. By using zebrafish transgenics and mutants as model systems to visualize and manipulate in vivo the Wnt pathway, we confirm that Wnt pathway activation is able to promote neuronal differentiation and inhibit Notch signalling of primary human GBM cells also in this in vivo set-up. In conclusion, these findings shed light on an unsuspected crosstalk between hypoxia, Wnt and Notch signalling in GBM, and suggest the potential to manipulate these microenvironmental signals to blunt GBM malignancy.

Rare frequencey of point mutations for codon 12, 13 and 61 of ras gene in italian neuroblastoma

Single point mutations of ras oncogenes are found in many tumors and contribute to the pathogenesis of the cancer. The product of the ras gene, p21 protein, was found expressed in several neuroblastoma tissues. However, the role of ras gene in this tumor has yet to be clarified. To contribute to the understanding of the ras activation, 79 fresh biopsies of neuroblastoma were studied to investigate the possibility that ras would be activated by point mutation. Analysis of H-ras and N-ras was performed by means of PCR and SSO, while K-ras mutations were detected by multiplex-ASPCR. None of the neuroblastomas examined showed H- or K-ras activation, while N-ras mutations were demonstrated in only three patients (3,7%). N-myc oncogene is amplified in a substantial number of patients with neuroblastoma. N-myc amplification was studied by Southern blot technique. N-myc amplification was demonstrated in 13.2% of patients less than 1 year of age at diagnosis and 23% of older children. Two of the patients (one stage I and one stage IVs) with N-ras mutation and without N-myc amplification had a good outcome, while the third (stage IVs) with N-myc amplification had a poor prognosis. These results suggest that ras activation is a rare event in both amplified and non-amplified neuroblastoma tumors and that N-ras activation was not involved in the clinical outcome of these patients. Moreover, our data suggest that p21 expression is induced by a post-transcriptional activation.

Frontal terminations for the inferior fronto-occipital fascicle: anatomical dissection, DTI study and functional considerations on a multi-component bundle

The anatomy and functional role of the inferior fronto-occipital fascicle (IFOF) remain poorly known. We accurately analyze its course and the anatomical distribution of its frontal terminations. We propose a classification of the IFOF in different subcomponents. Ten hemispheres (5 left, 5 right) were dissected with Klingler's technique. In addition to the IFOF dissection, we performed a 4-T diffusion tensor imaging study on a single healthy subject. We identified two layers of IFOF. The first one is superficial and antero-superiorly directed, terminating in the inferior frontal gyrus. The second is deeper and consists of three portions: posterior, middle and anterior. The posterior component terminates in the middle frontal gyrus (MFG) and dorso-lateral prefrontal cortex. The middle component terminates in the MFG and lateral orbito-frontal cortex. The anterior one is directed to the orbito-frontal cortex and frontal pole. In vivo tractography study confirmed these anatomical findings. We suggest that the distribution of IFOF fibers within the frontal lobe corresponds to a fine functional segmentation. IFOF can be considered as a "multi-function" bundle, with each anatomical subcomponent subserving different brain processing. The superficial layer and the posterior component of the deep layer, which connects the occipital extrastriate, temporo-basal and inferior frontal cortices, might subserve semantic processing. The middle component of the deep layer could play a role in a multimodal sensory-motor integration. Finally, the anterior component of the deep layer might be involved in emotional and behavioral aspects.