Publications by authors named "Amir Samii"

The estimation of rupture risk in Unruptured Intracranial Aneurysm (UIA) constitutes a major area of clinical interest due to the significant morbidity and mortality rates associated with aneurysm rupture. Classic clinical models based on factors such as size and location have demonstrated limited predictive accuracy, with small aneurysms being capable of rupture and larger ones remaining stable. Recent advances in Artificial Intelligence (AI) now allow the development of more sophisticated models that integrate both geometric and hemodynamic variables, including wall shear stress (WSS) and blood flow dynamics.

View Article and Find Full Text PDF

Autophagy is a cellular degradation process that plays a crucial role in maintaining metabolic homeostasis under conditions of stress or nutrient deprivation. This process involves sequestering, breaking down, and recycling intracellular components such as proteins, organelles, and cytoplasmic materials. Autophagy also serves as a mechanism for eliminating pathogens and engulfing apoptotic cells.

View Article and Find Full Text PDF

Objective: Chronic subdural hematoma (CSDH) is frequently met in neurosurgical practice and often need urgent surgical treatment in case of neurological deterioration. Different surgical approaches to evacuate CSDH are described in the literature. In our experience, an external drainage system is crucial in order to avoid recurrences.

View Article and Find Full Text PDF

Background: The diverse and complex attributes of cancer have made it a daunting challenge to overcome globally and remains to endanger human life. Detection of critical cancer-related gene alterations in solid tumor samples better defines patient diagnosis and prognosis, and indicates what targeted therapies must be administered to improve cancer patients' outcome.

Materials And Methods: To identify genes that have aberrant expression across different cancer types, differential expressed genes were detected within the TCGA datasets.

View Article and Find Full Text PDF

Indications Corridor And Limits Of Exposure: The retrosigmoid intradural suprameatal approach is mostly indicated for tumors in the cerebellopontine angle extending toward the Meckel cave and supratentorial regions, most frequently meningiomas and schwannomas. This approach was first established by the senior author in 1982.

Anatomic Essentials Need For Preoperative Planning And Assessment: Nervous structures: cranial nerves III to XII, cerebellum, and brainstem.

View Article and Find Full Text PDF

Background: This meta-analysis aimed to provide a comprehensive assessment of the association between Methylenetetrahydrofolate reductase () gene polymorphisms, specifically C677T and A1298C, and the susceptibility to myocardial infarction (MI).

Methods: A systematic literature search was conducted in MEDLINE, Web of Science, and Scopus until April 2023 to identify studies investigating the relationship between gene polymorphisms (C677T and A1298C) and the risk of MI.

Results: The analysis included 66 studies involving 16,860 cases and 20,403 controls for the C677T polymorphism and 18 studies comprising 3162 cases and 3632 controls for the A1298C polymorphism.

View Article and Find Full Text PDF
Article Synopsis
  • Pathogenic variants in the POLE and POLD1 genes are linked to an inherited condition, polymerase proofreading-associated polyposis, which increases the risk of colorectal cancer and other tumors, including gliomas.
  • Whole-exome sequencing of glioma patients revealed that 16% carried rare deleterious POLE/POLD1 variants, with significant features indicating defective DNA proofreading and a correlation with tumor characteristics.
  • Glioblastoma patients with these variants had a notably shorter average overall survival of 21 months, and these genetic variants might also make glioma patients more responsive to immunotherapy and warrant ongoing surveillance for other cancer risks.
View Article and Find Full Text PDF

Angiogenesis is an essential process in the growth, development, and transition of tumors from dormancy to proliferating state. Resveratrol (RSV), as a natural polyphenolic compound, is claimed to be effective in regulating angiogenesis. This study aimed to evaluate the impact of RSV onthe angiogenesis process in HUVECs (human umbilical vein endothelial cells) alone and co-cultured with Jurkat cells.

View Article and Find Full Text PDF

Rare bleeding disorders (RBDs), including factor (F) I, FII, FV, FVII, combined FV and FVIII (CF5F8), FXI, FXIII and vitamin-K dependent coagulation factors (VKCF) deficiencies, are a heterogeneous group of hemorrhagic disorder with a variable bleeding tendency. RBDs are due to mutation in underlying coagulation factors genes, except for CF5F8 and VKCF deficiencies. FVII deficiency is the most common RBD with >330 variants in the F7 gene, while only 63 variants have been identified in the F2 gene.

View Article and Find Full Text PDF

Background: Doxorubicin (DOX)-induced cardiotoxicity appears to be a growing concern for extensive use in acute lymphoblastic leukemia (ALL). The new combination treatment strategies, therefore might be an effective way of decreasing its side effects as well as improving efficacy. AMG232 (KRT-232) is a potential MDM-2 inhibitor, increasing available p53 through disturbing p53-MDM-2 interaction.

View Article and Find Full Text PDF

We conducted a two-center retrospective survey on standard MRI features including apparent diffusion coefficient mapping (ADC) of diffuse midline gliomas H3 K27M-mutant (DMG) compared to midline glioblastomas H3 K27M-wildtype (midGBM-H3wt). We identified 39 intracranial DMG and 18 midGBM-H3wt tumors. Samples were microscopically re-evaluated for microvascular proliferations and necrosis.

View Article and Find Full Text PDF

Gastrointestinal bleeding (GIB) is serious, intractable, and potentially life-threatening condition. There is considerable heterogeneity in GIB phenotypes among congenital bleeding disorders (CBDs), making GIB difficult to manage. Although GIB is rarely encountered in CBDs, its severity in some patients makes the need for a comprehensive and precise assessment of underlying factors and management approaches imperative.

View Article and Find Full Text PDF

Purpose: The entity 'diffuse midline glioma, H3 K27M-mutant (DMG)' was introduced in the revised 4th edition of the 2016 WHO classification of brain tumors. However, there are only a few reports on magnetic resonance imaging (MRI) of these tumors. Thus, we conducted a retrospective survey focused on MRI features of DMG compared to midline glioblastomas H3 K27M-wildtype (mGBM-H3wt).

View Article and Find Full Text PDF

Glioblastoma multiforme (GBM) is the most malignant brain tumor with patient mortality rate close to 100%, 5-yr survival rate of ∼5%, and a median survival of 14 mo. GBMs have notorious histomorphologic and molecular heterogeneities thus giving hope for development of future personalized therapies. We describe here a case of a 48-yr-old male patient with three-nodular GBM.

View Article and Find Full Text PDF

The genetic basis of brain tumor development is poorly understood. Here, leukocyte DNA of 21 patients from 15 families with ≥ 2 glioma cases each was analyzed by whole-genome or targeted sequencing. As a result, we identified two families with rare germline variants, p.

View Article and Find Full Text PDF

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant central nervous system tumor predominantly occurring in infants that may also arise in older children and adults. Rare secondary AT/RT developing from other tumors such as pleomorphic xanthoastrocytoma (PXA) are on record, but AT/RT presenting with molecular features of PXA have not been described. Here, we report 3 malignant central nervous system tumors in children (10, 13, and 18 y old).

View Article and Find Full Text PDF

Craniotomes have shown to be fast and precise in performing bone flaps. Nevertheless, in everyday practice, the neurosurgeon can experience breakage of the blade and other complications like dural tears during cutting of the bone. We developed a test procedure for craniotomies and used it to compare two blade types.

View Article and Find Full Text PDF

Background: We investigated the added value of combining information from direction-encoded color (DEC) maps with high-resolution structural magnetic resonance imaging scans (T1-weighted images [T1WIs]) to improve the identification of regions of interest (ROIs) for fiber tracking during preoperative planning for patients with brain tumors.

Methods: The dataset included 42 patients with gliomas and 10 healthy subjects from the Human Connectome Project. For identification of the ROIs, we combined the structural information from high-resolution T1WIs and the directional information from DEC maps.

View Article and Find Full Text PDF

Small RNA sequencing by Illumina's Next Generation technology has revolutionized the transcriptome analysis by facilitating massive parallel sequencing of RNA molecules at low cost. Illumina's Next Generation RNA sequencing is ideal for profiling small RNA (microRNAs, snoRNAs, and piRNAs) libraries in the identification of novel biomarkers for better clinical diagnosis. This method offers significant advantages when compared to microarray analysis with the ability to identify novel transcripts, higher sensitivity, specificity, and detection of rare and low-abundance transcripts.

View Article and Find Full Text PDF

Regulation of hematopoietic stem and progenitor cells (HSPCs) self-renewal, expansion, and differentiation is an inevitable process for normal hematopoiesis in the bone marrow (BM) niche, where leukemia cells are born, proliferate and occupy the microenvironment. External mediators such as extracellular vesicles (EVs) shed from leukemia cells, are one of the most important cell to cell communicators, and leading to phenotype and genotype modification and subsequently, fate of the cell. This review highlights recent evidences about the possible roles of leukemia derived-EVs on maintenance, proliferation, and death of HSPCs in a same microenvironment as leukemia cells.

View Article and Find Full Text PDF

Objective: In this study we present the nature and characteristic of the fluctuation of blood oxygen level-dependent (BOLD) signals measured from brain tumors.

Methods: Supratentorial astrocytomas, which were neither operated nor previously managed with chemotherapy or radiotherapy, were segmented, and the time series of the BOLD signal fluctuations were extracted. The mean (across patients) power spectra were plotted for the different World Health Organization tumor grades.

View Article and Find Full Text PDF

Objective: Measuring functional connectivity (FC) and resting state networks (RSNs) using resting state functional magnetic resonance imaging is a method of preoperative planning in patients with brain tumors. However, the baseline FC and RSNs are altered in patients with brain tumors. In this study, we examined changes in inter-network FC in patients with brain tumors.

View Article and Find Full Text PDF

Excessive video gaming has a number of psychological and social consequences. In this study, we looked at possible changes in gray and white matter and asked whether these changes are correlated to psychological measures. Twentynine players of violent videogames (mean daily playing time 4.

View Article and Find Full Text PDF

Objective: Many neurosurgeons prefer conservative treatments in the elderly because of higher rates of mortality and morbidity after surgery. We aim to evaluate safety and efficacy of surgery in elderly patients with frontobasal and suprasellar meningiomas with a simple operative procedure, the frontolateral approach.

Methods: Retrospective analysis was made in consecutive patients with meningiomas operated via frontolateral approach.

View Article and Find Full Text PDF