A novel approach to simulate gene-environment interactions in complex diseases

Background: Complex diseases are multifactorial traits caused by both genetic and environmental factors. They represent the major part of human diseases and include those with largest prevalence and mortality (cancer, heart disease, obesity, etc.). Despite a large amount of information that has been collected about both genetic and environmental risk factors, there are few examples of studies on their interactions in epidemiological literature. One reason can be the incomplete knowledge of the power of statistical methods designed to search for risk factors and their interactions in these data sets. An improvement in this direction would lead to a better understanding and description of gene-environment interactions. To this aim, a possible strategy is to challenge the different statistical methods against data sets where the underlying phenomenon is completely known and fully controllable, for example simulated ones. Results: We present a mathematical approach that models gene-environment interactions. By this method it is possible to generate simulated populations having gene-environment interactions of any form, involving any number of genetic and environmental factors and also allowing non-linear interactions as epistasis. In particular, we implemented a simple version of this model in a Gene-Environment iNteraction Simulator (GENS), a tool designed to simulate case-control data sets where a one gene-one environment interaction influences the disease risk. The main aim has been to allow the input of population characteristics by using standard epidemiological measures and to implement constraints to make the simulator behaviour biologically meaningful. Conclusions: By the multi-logistic model implemented in GENS it is possible to simulate case-control samples of complex disease where gene-environment interactions influence the disease risk. The user has full control of the main characteristics of the simulated population and a Monte Carlo process allows random variability. A knowledge-based approach reduces the complexity of the mathematical model by using reasonable biological constraints and makes the simulation more understandable in biological terms. Simulated data sets can be used for the assessment of novel statistical methods or for the evaluation of the statistical power when designing a study

Cerebellopontine angle pilocytic astrocytoma in adults: a systematic review

Background: In adults, the cerebellopontine angle (CPA) pilocytic astrocytoma (PA) is very rare. This tumor has radiological features similar to those of a vestibular schwannoma in the few cases reported in the literature. Methods: In this study, we conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol and scrutinized all original studies pertaining to pontocerebellar angle PA in adult patients. We conducted an analysis of the clinical, radiological, and molecular components of all eligible articles. We have also reported a case involving a 67-year-old male individual in whom the PA exhibited radiological characteristics similar to an epidermoid cyst. Results: After the screening phase, we found four cases of PA of the pontocerebellar angle. Three cases were identified that resembled vestibular schwannoma; however, in our case, the tumor resembled an epidermoid cyst. These uncommon tumors exhibit distinctive histological patterns and molecular characteristics (adenosine triphosphate dependent helicase (ATP- dependent helicase)+, Isocitrate dehydrogenase 1-), rendering them a potential differential diagnosis for glioblastoma (GBM). Conclusion: The CPA PA has rarely been found in adult patients and should be considered in the differential diagnosis of vestibular schwannoma and epidermoid cysts. In these rare cases, the histological characteristics of PA are significant for the differential diagnosis of GBM. © 2024 Published by Scientific Scholar on behalf of Surgical Neurology International

Intracranial meningioma in elderly patients. Retrospective multicentric risk and surgical factors study of morbidity and mortality

With the increasing life expectancy, a large number of intracranial meningiomas (IM) have been identified in elderly patients. There is no general consensus regarding the management for IMs nor studies regarding the outcome of older patients undergoing meningioma surgery. We aimed to determine whether preoperative variables and postoperative clinical outcomes differ between age groups after meningioma surgery. We analyzed data from all patients who had undergone IM surgery from our departments. The final cohort consisted of 340 patients affected by IM with ASA class I-II: 188 in the young group (<65) and 152 in the elderly. The two subgroups did not present significant differences concerning biological characteristics of tumor, localization, diameters, lesion and edema volumes and surgical radicality. Despite these comparable data, elderly presented with a significantly lower Karnofsky Performance status value on admission and remained consistently lower during the follow-up. We establish instead that there is no intrinsic correlation to the presence of IM and no significant increased risk of complications or recurrence in elderly patients, but rather only an increased risk of reduced performance status with mortality related to the comorbidity of the patient, primarily cardiovascular disease, and an intrinsic frailty of the aged population

Risk of Recurrence of Chronic Subdural Hematomas After Surgery: A Multicenter Observational Cohort Study

background: chronic subdural Hematoma (CSDH) is a common condition in the elderly population. recurrence rates after surgical evacuation range from 5 to 30%. factors predicting recurrence remain debated and unclear. objective: to identify factors associated with increased risk of recurrence. methods: cases of CSDHs that underwent surgical treatment between 2005 and 2018 in the neurosurgery units of two major Italian hospitals were reviewed. data extracted from a prospectively maintained database included demographics, laterality, antithrombotic therapy, history of trauma, corticosteroid therapy, preoperative and postoperative symptoms, type of surgical intervention, use of surgical drain, and clinical outcomes. results: a total of 1313 patients was analyzed. the overall recurrence rate was 10.1%. the risk of recurrence was not significantly different between patients with unilateral or bilateral CSDH (10.4 vs. 8.8%, p = 0.39). The risk of recurrence was higher in patients that underwent surgical procedure without postoperative drainage (16.1 vs. 5.4%, p < 0.01). no relationship was found between recurrence rates and therapy with antithrombotic drugs (p = 0.97). the risk of recurrence was increasingly higher considering craniostomy, craniectomy, and craniotomy (9.3, 11.3, and 18.9%, respectively, p = 0.013). Lower recurrence rates following dexamethasone therapy were recorded (p = 0.013). conclusion: no association was found between the risk of recurrence of CSDH after surgical evacuation and age, use of antithrombotic medication, or laterality. burr-hole craniostomy was found to be associated with lower recurrence rates, when compared to other surgical procedures. placement of surgical drain and dexamethasone therapy were significantly associated with reduced risk of recurrence of CSDHs

RET/PTC3 translocation in a rare hemorrhagic brain metastasis of papillary thyroid cancer post Chernobyl radiation affects vessels ultrastructure

Abstract Background Slow progression and good prognosis are the usual characteristics of papillary thyroid carcinoma (PTC). The presence of brain metastases (0.4–1.2%) is suggestive of a worse prognosis. RET/PTC rearrangements were particularly prevalent in PTCs developed after Chernobyl nuclear accident. Case description A 50-year-old woman born in Slovakia, exposed to radiation resulting from the accident at the Chernobyl nuclear power plant, affected since 2017 by papillary thyroid cancer and in therapy at our hospital, experimented cerebral hemorrhagic metastasis. Biopsy analyses revealed a RET/PTC3 rearrangement, so our aim was to find possible morphological relation between hemorrhagic metastasis and RET/PTC3 translocation. Results Immunohistochemical analysis showed diffuse and intense positivity for VEGF in endothelial cells of the neoplasm’ vascular network. Transmission electron microscopy images showed vessels with unorganized pattern and uneven diameters. In particular, metastasis endothelial cells (MECs) showed irregular shape and size, thickened cytoplasm and swelling of endoplasmic reticulum. MECs organized in irregular monolayers or multiple layers, surrounded by a thickened but unstructured extracellular matrix. Absence of strong junctional complexes among MECs resulted in a further weakened vessels wall. Conclusion RET/PTC3 translocation causes VEGF overexpression via STAT3 signaling cascade and the increased amount of VEGF adds to the greater amount of VEGFRs expressed by MECs. Our ultrastructural investigation show that this condition creates a massive growth of altered vessels prone to bleeding. The clinical significance of our study consists in alert oncologist and surgeons on possible arising of hemorrhagic brain metastases in patients with PTC and RET/PTC3 translocation exposed to ionizing radiation as people living in areas caught up in Chernobyl or Fukushima disasters

Primary Cauda Equina Lymphoma Mimicking Meningioma

Background: Spinal cord lymphomas represent a minority of extranodal lymphomas and often pose diagnostic challenges by imitating primary spinal tumors or inflammatory/infective lesions. This paper presents a unique case of primary cauda equina lymphoma (PCEL) and conducts a comprehensive review to delineate the clinical and radiological characteristics of this rare entity. Case Report: A 74-year-old male presented with progressive paresthesia, motor weakness, and symptoms indicative of cauda equina syndrome. Neurological examination revealed paraparesis and sphincter dysfunction. Imaging studies initially suggested an intradural meningioma. However, surgical intervention revealed a diffuse large B-cell lymphoma infiltrating the cauda equina. Findings: A systematic review of the pertinent literature identified 18 primary cauda equina lymphoma cases. These cases exhibited diverse clinical presentations, treatments, and outcomes. The mean age at diagnosis was 61.25 years for women and 50 years for men, with an average follow-up of 16.2 months. Notably, 35% of patients were alive at 18 months, highlighting the challenging prognosis associated with PCEL. Discussion: Primary spinal cord lymphomas, especially within the cauda equina, remain rare and diagnostically complex due to their nonspecific clinical manifestations. The review highlights the need to consider spinal cord lymphoma in patients with neurological symptoms, even without a history of systemic lymphoma. Diagnostic Approaches: Magnetic resonance imaging (MRI) serves as the primary diagnostic tool but lacks specificity. Histopathological examination remains the gold standard for definitive diagnosis. The review underscores the importance of timely biopsy in suspected cases to facilitate accurate diagnosis and appropriate management. Management and Prognosis: Current management involves biopsy and chemotherapy; however, optimal treatment strategies remain ambiguous due to the rarity of PCEL. Despite aggressive therapeutic interventions, prognosis remains poor, emphasizing the urgency for enhanced diagnostic and treatment modalities. Conclusions: Primary cauda equina lymphoma poses diagnostic and therapeutic challenges, necessitating a high index of suspicion in patients with atypical spinal cord symptoms. Collaborative efforts between neurosurgical, oncological, and infectious diseases teams are imperative for timely diagnosis and management. Advancements in diagnostic precision and therapeutic options are crucial for improving patient outcomes

Advancements in Telomerase-Targeted Therapies for Glioblastoma: A Systematic Review

Glioblastoma (GBM) is a primary CNS tumor that is highly lethal in adults and has limited treatment options. Despite advancements in understanding the GBM biology, the standard treatment for GBM has remained unchanged for more than a decade. Only 6.8% of patients survive beyond five years. Telomerase, particularly the hTERT promoter mutations present in up to 80% of GBM cases, represents a promising therapeutic target due to its role in sustaining telomere length and cancer cell proliferation. This review examines the biology of telomerase in GBM and explores potential telomerase-targeted therapies. We conducted a systematic review following the PRISMA-P guidelines in the MEDLINE/PubMed and Scopus databases, from January 1995 to April 2024. We searched for suitable articles by utilizing the terms "GBM", "high-grade gliomas", "hTERT" and "telomerase". We incorporated studies addressing telomerase-targeted therapies into GBM studies, excluding non-English articles, reviews, and meta-analyses. We evaluated a total of 777 records and 46 full texts, including 36 studies in the final review. Several compounds aimed at inhibiting hTERT transcription demonstrated promising preclinical outcomes; however, they were unsuccessful in clinical trials owing to intricate regulatory pathways and inadequate pharmacokinetics. Direct hTERT inhibitors encountered numerous obstacles, including a prolonged latency for telomere shortening and the activation of the alternative lengthening of telomeres (ALT). The G-quadruplex DNA stabilizers appeared to be potential indirect inhibitors, but further clinical studies are required. Imetelstat, the only telomerase inhibitor that has undergone clinical trials, has demonstrated efficacy in various cancers, but its efficacy in GBM has been limited. Telomerase-targeted therapies in GBM is challenging due to complex hTERT regulation and inadequate inhibitor pharmacokinetics. Our study demonstrates that, despite promising preclinical results, no Telomerase inhibitors have been approved for GBM, and clinical trials have been largely unsuccessful. Future strategies may include Telomerase-based vaccines and multi-target inhibitors, which may provide more effective treatments when combined with a better understanding of telomere dynamics and tumor biology. These treatments have the potential to be integrated with existing ones and to improve the outcomes for patients with GBM

Cortical atrophy in chronic subdural hematoma from ultra-structures to physical properties

Several theories have tried to elucidate the mechanisms behind the pathophysiology of chronic subdural hematoma (CSDH). However, this process is complex and remains mostly unknown. In this study we performed a retrospective randomised analysis comparing the cortical atrophy of 190 patients with unilateral CSDH, with 190 healthy controls. To evaluate the extent of cortical atrophy, CT scan images were utilised to develop an index that is the ratio of the maximum diameter sum of 3 cisterns divided by the maximum diameter of the skull at the temporal lobe level. Also, we reported, for the first time, the ultrastructural analyses of the CSDH using a combination of immunohistochemistry methods and transmission electron microscopy techniques. Internal validation was performed to confirm the assessment of the different degrees of cortical atrophy. Relative Cortical Atrophy Index (RCA index) refers to the sum of the maximum diameter of three cisterns (insular cistern, longitudinal cerebral fissure and cerebral sulci greatest) with the temporal bones' greatest internal distance. This index, strongly related to age in healthy controls, is positively correlated to the preoperative and post-operative maximum diameter of hematoma and the midline shift in CSDH patients. On the contrary, it negatively correlates to the Karnofsky Performance Status (KPS). The Area Under the Receiver Operating Characteristics (AUROC) showed that RCA index effectively differentiated cases from controls. Immunohistochemistry analysis showed that the newly formed CD-31 positive microvessels are higher in number than the CD34-positive microvessels in the CSDH inner membrane than in the outer membrane. Ultrastructural observations highlight the presence of a chronic inflammatory state mainly in the CSDH inner membrane. Integrating these results, we have obtained an etiopathogenetic model of CSDH. Cortical atrophy appears to be the triggering factor activating the cascade of transendothelial cellular filtration, inflammation, membrane formation and neovascularisation leading to the CSDH formation