Nardin Samuel

• University of Toronto

Li-Fraumeni syndrome (LFS) is an autosomal dominantly inherited cancer predisposition syndrome associated with germline mutations of the TP53 tumor suppressor gene. TP53 mutation carriers are susceptible to a wide range of cancers that occur at strikingly earlier age of onset than their sporadic counterparts. The lifetime cancer risk in TP53 mutati...

Background: Postoperative follow-up of non-functioning pituitary adenomas (NFAs) occasionally detects residual or recurrent disease. Subsequent treatment options range from continued follow-up, to re-resection or radiotherapy. To better understand current practice patterns on this topic, we surveyed neurosurgeons and radiation oncologists in Canada...

OBJECTIVE Although surgery is the mainstay of treatment for most pituitary adenomas, post-operative radiotherapy has been shown to be beneficial in improving tumour control and recurrence-free survival. However, due to the potential complications of with radiotherapy, the role of adjuvant radiotherapy in the setting of pituitary adenomas remains un...

Background: Although surgery is the mainstay of treatment for most pituitary adenomas, post-operative radiotherapy has been shown to be of benefit in improving tumor control and recurrence-free survival. To understand potential side effects of radiotherapy we performed a systematic review and meta-analysis to determine the efficacy and safety of po...

Objective Although surgery is the mainstay of treatment for most pituitary adenomas, postoperative radiotherapy has been shown to be of benefit in improving tumor control and recurrence-free survival. However, due to the potential complications and long-term side effects associated with radiotherapy, the role of postoperative radiotherapy in the se...

Objective: Despite the increasing prominence of stereotactic radiosurgery (SRS) in treating intracranial and spinal pathologies, there is currently a dearth of exposure to this modality in neurosurgical residency. To address this gap, the aim of this study is to assess neurosurgery educators' views regarding the current state of SRS exposure, and...

Glioblastoma Following Ischemic Stroke - Naif M. Alotaibi, Nardin Samuel, Alireza Mansouri, Romina Nejad, R. Loch Macdonald

Mutations in the TP53 tumor suppressor gene are the most common genetic aberrations across all human cancers. Germline TP53 mutations are also the hallmark genetic event in Li-Fraumeni syndrome (LFS), a highly penetrant human cancer susceptibility syndrome, conferring a predisposition to developing early-onset breast cancer, leukemias, bone and sof...

Background: The importance of videos in social media communications in the context of healthcare and neurosurgery is becoming increasingly recognized. However, to date, there has not yet been a systematic analysis of these neurosurgery-related communications. Accordingly, this study was aimed at characterizing the online video content pertaining to...

OBJECTIVE Patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) (World Federation of Neurosurgical Societies Grade IV or V) are often considered for decompressive craniectomy (DC) as a rescue therapy for refractory intracranial hypertension. The authors performed a systematic review and meta-analysis to assess the impact of DC on funct...

Germline polymorphic variants in cancer predisposition genes such as TP53 have been shown to impact the risk of pre-menopausal cancer. Accordingly, the aim of this study was to assess the spectrum of polymorphisms in TP53 and its negative regulatory gene, MDM2 (SNP309:T>G) in patients with pre-menopausal breast cancer. Our findings in a cohort of 4...

Background Acquired Chiari malformations (ACM) and associated syringomyelia secondary to space-occupying lesions can cause neurological deficits independent of or in combination with the offending mass. Although type I CM are traditionally treated with posterior fossa decompression, optimal surgical management of ACM and associated syringomyelia re...

Background The diagnosis of a ruptured or unruptured brain aneurysm has a significant impact on patients’ quality of life and their psychosocial wellbeing. As a result, patients and caregivers may resort to social media platforms for support and education. The aim of this report is to evaluate the current use of social media and the online communic...

Background: The primary objective of the present study was to examine the drug approval process and the time to approval (tta) for cancer drugs by 3 major international regulatory bodies-Health Canada, the U.S. Food and Drug Administration (fda), and the European Medicines Agency (ema)-and to explore differences in the drug approval processes that...

Purpose: Although the link between mutant TP53 and human cancer is unequivocal, a significant knowledge gap exists in clinically actionable molecular targets in Li-Fraumeni syndrome (LFS), a highly penetrant cancer predisposition syndrome associated with germline mutations in TP53. This study surveyed the epigenome to identify functionally and cli...

Objective: The aim of this study is to better understand perspectives of patients with persistent postoperative neuropathic pain (PPNP) and assess perceptions of the ethical issues surrounding their structural spinal surgeon also performing spinal cord stimulation (SCS). Methods: Semistructured face-to-face interviews with 20 neurosurgical spine...

Introduction: The aim of this study is to better understand patients' perspectives of persistent postoperative neuropathic pain (PPNP) and assess perceptions of the ethical issues surrounding implantation of neuromodulators, such as spinal cord stimulators (SCS), to treat PPNP in medically refractory patients. Methods: Semistructured face-to-fac...

OBJECTIVE The objective of this study was to identify clinically relevant predictors of progression-free survival and functional outcomes in patients who underwent surgery for intramedullary spinal cord tumors (ISCTs). METHODS An institutional spinal tumor registry and billing records were reviewed to identify adult patients who underwent resectio...

Highlights •This report explores our Division’s preliminary experience with social media and investigates the possible factors that contribute to high reach and engagement among users in the online neurosurgical community. •The majority of Facebook users (83%) were 18 to 34 years old. •Posts containing photos or videos were significantly higher in...

microRNA-34A is a critical component of the p53 network and expression of miR- 34A is down-regulated by promoter hypermethylation or focal deletions in numerous human cancers. Although miR-34A deregulation may be an important driver in cancer, the endogenous role of this microRNA in cellular homeostasis is not well characterized. To address this kn...

OBJECT Neurosurgical patients bear a varying degree of anxiety when confronted with having to undergo surgery or even visit with a neurosurgeon in consultation. Previous studies have suggested that patient perceptions can heavily influence the patient-physician encounter. Accordingly, a better understanding of these perceptions can marshal our know...

The Canadian Society of Clinician Investigators (CSCI) and Clinical Investigator Trainee Association of Canada/Association des cliniciens-chercheurs en formation du Canada (CITAC/ACCFC) annual general meeting (AGM) was held in Toronto during November 21-24, 2015 for the first time in conjunction with the University of Toronto Clinician-Investigator...

INTRODUCTION: Li-Fraumeni Syndrome (LFS) is a cancer predisposition syndrome that confers a high lifetime risk of developing malignancies, including pre-menopausal breast cancer. Over 80% of LFS patients harbor germline mutations of the TP53 tumor suppressor gene. OBJECTIVE: We sought to determine if the spectrum of TP53 variants, as well as global...

Spinal cord herniation is a relatively rare but increasingly recognized clinical entity, with fewer than 200 cases reported in the literature to date. The etiology of this condition remains unknown, and surgery is used as the primary treatment to correct the herniation and consequent spinal cord compromise. Some patients without clinical progressio...

s: AACR Special Conference: Cancer Susceptibility and Cancer Susceptibility Syndromes; January 29-February 1, 2014; San Diego, CA Aim: Li-Fraumeni Syndrome (LFS) is a cancer predisposition syndrome that confers a high lifetime risk of developing malignancies, including pre-menopausal breast cancer. Although many families with classic LFS phenotype...

Germline TP53 mutations are observed in ∼80% of patients with Li-Fraumeni syndrome (LFS) and a lesser frequency of patients meeting the revised Chompret criteria. A variety of studies are being conducted exploring the role of genetic modifiers on p53 function and their impact in refining the genotype:phenotype correlation of the TP53:LFS relationsh...

The clinical management of familial cancer begins with recognition of patterns of cancer occurrence suggestive of genetic susceptibility in a proband or pedigree, to enable subsequent investigation of the underlying DNA mutations. In this regard, next-generation sequencing of DNA continues to transform cancer diagnostics, by enabling screening for...

Aim: The therapeutic care of cancer patients is significantly impacted by timely access to drugs that improve survival and overall patient outcomes. The key objective of this study was to examine the drug approval process and time to approval (TTA) by three international regulatory bodies–Health Canada, United States Food and Drug Administration (F...

Primary brain tumors cumulatively represent the most common solid tumors of childhood and are the leading cause of cancer related death in this age group. Traditionally, molecular findings and histological analyses from biopsies of resected tumor tissue have been used for diagnosis and classification of these diseases. However, there is a dearth of...

This study used an integrated analysis of copy number, gene expression, and RNA interference screens for identification of putative driver genes harbored in somatic copy number gains in pancreatic ductal adenocarcinoma (PDAC). Somatic copy number gain data on 60 PDAC genomes were extracted from public data sets to identify genomic loci that are rec...

Background: Sequencing of cancer genomes has become a pivotal method for uncovering and understanding the deregulated cellular processes driving tumor initiation and progression. Whole-genome sequencing is evolving toward becoming less costly and more feasible on a large scale; consequently, thousands of tumors are being analyzed with these techno...

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related mortality in the United States. PDAC presents with the worst prognosis of all solid tumors and the 5-year survival rate for patients with advanced PDAC is only 2%. Current chemotherapies fail to attenuate the aggressiveness of this disease and as such, novel thera...

Current standard therapies for pancreatic ductal adenocarcinoma have failed to attenuate the aggressiveness of this disease or confer notable improvements in survival. Previous molecular research into pancreatic cancers, along with advances in sequencing technologies, have identified many altered genes in patients with pancreatic cancer and reveale...

A community pharmacist is frequently the first healthcare professional who is asked to give advice regarding medication use during pregnancy. As 50% of pregnancies are unplanned, a woman often discovers she is pregnant while already taking a medication and visits a pharmacy which is easily accessible, to enquire if she has harmed her baby by this a...

During the H1N1 influenza pandemic in 2009, The Motherisk Program, a counselling service providing teratology information, received many calls from pregnant women inquiring about the safety of the H1N1 vaccine. We wished to explore pregnant women's perception of risk and the factors associated with deciding whether or not to receive the vaccine. Pr...

It is known that lipid membranes become, typically, less susceptible to solubilization with increasing temperature so that more detergent is needed to start and complete their conversion to mixed micelles. Qualitatively, this can be explained by the fact that thermal chain disordering and headgroup dehydration render the spontaneous curvature of th...