Towards Aptamer-Targeted Drug Delivery to Brain Tumors: The Synthesis of Ramified Conjugates of an EGFR-Specific Aptamer with MMAE on a Cathepsin B-Cleavable Linker.

Targeted delivery of chemotherapeutic agents is a well-established approach to cancer therapy. Antibody-drug conjugates (ADCs) typically carry toxic payloads attached to a tumor-associated antigen-targeting IgG antibody via an enzyme-cleavable linker that releases the drug inside the cell. Aptamers are a promising alternative to antibodies in terms of antigen targeting; however, their polynucleotide nature and smaller size result in a completely different PK/PD profile compared to an IgG.

Experimental Reconstruction of the Optic Nerve with a Sural Nerve Graft: An in Vivo Experimental Study.

Background: Neurosurgical interventions and trauma are common causes of damage to the optic nerve. This determines the relevance of research for solutions aimed at restoration of the nerve's anatomical integrity, electrical conductivity, and subsequently - restoration of its function. Restore a damaged (cut) optic nerve using n.

Perifocal Zone of Brain Gliomas: Application of Diffusion Kurtosis and Perfusion MRI Values for Tumor Invasion Border Determination.

(1) Purpose: To determine the borders of malignant gliomas with diffusion kurtosis and perfusion MRI biomarkers. (2) Methods: In 50 high-grade glioma patients, diffusion kurtosis and pseudo-continuous arterial spin labeling (pCASL) cerebral blood flow (CBF) values were determined in contrast-enhancing area, in perifocal infiltrative edema zone, in the normal-appearing peritumoral white matter of the affected cerebral hemisphere, and in the unaffected contralateral hemisphere. Neuronavigation-guided biopsy was performed from all affected hemisphere regions.

Magnetic resonance relaxometry in quantitative imaging of brain gliomas: A literature review.

Magnetic resonance (MR) relaxometry is a quantitative imaging method that measures tissue relaxation properties. This review discusses the state of the art of clinical proton MR relaxometry for glial brain tumors. Current MR relaxometry technology also includes MR fingerprinting and synthetic MRI, which solve the inefficiencies and challenges of earlier techniques.

Radiochemical Synthesis of 4-[F]FluorobenzylAzide and Its Conjugation with EGFR-Specific Aptamers.

Central nervous system tumors related to gliomas are of neuroectodermal origin and cover about 30% of all primary brain tumors. Glioma is not susceptible to any therapy and surgical attack remains one of the main approaches to its treatment. Preoperative tumor imaging methods, such as positron emission tomography (PET), are currently used to distinguish malignant tissue to increase the accuracy of glioma removal.

Sensitivity of three-dimensional time-of-flight 3.0 ​T magnetic resonance angiography in visualizing the number and course of lenticulostriate arteries in patients with insular gliomas.

Background: Neurosurgical resection of insular gliomas is complicated by the possibility of iatrogenic injury to the lenticulostriate arteries (LSAs) and is associated with devastating neurological complications, hence the need to accurately assess the number of LSAs and their relationship to the tumor preoperatively.

Methods: The study included 24 patients with insular gliomas who underwent preoperative 3D-TOF MRA to visualize LSAs. The agreement of preoperative magnetic resonance imaging with intraoperative data in terms of the number of LSAs and their invasion by the tumor was assessed using the Kendall rank correlation coefficient and Cohen's Kappa with linear weighting.

5-ALA-guided tumor resection during awake speech mapping in gliomas located in eloquent speech areas: Single-center experience.

Background: Achieving maximal functionally safe resection of gliomas located within the eloquent speech areas is challenging, and there is a lack of literature on the combined use of 5-aminolevulinic acid (5-ALA) guidance and awake craniotomy.

Objective: The aim of this study was to describe our experience with the simultaneous use of 5-ALA fluorescence and awake speech mapping in patients with left frontal gliomas located within the vicinity of eloquent speech areas.

Materials And Methods: A prospectively collected database of patients was reviewed.

Arterial Spin Labeling Perfusion in Determining the IDH1 Status and Ki-67 Index in Brain Gliomas.

The aim of the study was to evaluate the relationship between tumor blood flow (TBF) measured by the pseudo-continuous arterial spin labeling (PCASL) method and IDH1 mutation status of gliomas as well as Ki-67 proliferative index. Methods. The study included 116 patients with newly diagnosed gliomas of various grades.

Primary Sellar Abscesses: A Systematic Review and 2 Rare Observations.

Background: Abscesses of the chiasmatic-sellar region are quite rare and are often a result of surgical intervention, trauma, or tumor growth. Primary abscesses are extremely rare and represent a group of abscesses the occur because of internal microbial seeding. Primary abscesses are rarely reported.

Prediction of Intraoperative Fluorescence of Brain Gliomas: Correlation between Tumor Blood Flow and the Fluorescence.

Introduction: The prediction of the fluorescent effect of 5-aminolevulinic acid (5-ALA) in patients with diffuse gliomas can improve the selection of patients. The degree of enhancement of gliomas has been reported to predict 5-ALA fluorescence, while, at the same time, rarer cases of fluorescence have been described in non-enhancing gliomas. Perfusion studies, in particular arterial spin labeling perfusion, have demonstrated high efficiency in determining the degree of malignancy of brain gliomas and may be better for predicting fluorescence than contrast enhancement.

A vascular-task response dependency and its application in functional imaging of brain tumors.

Purpose: Preoperative functional MRI (fMRI) is limited by a muted BOLD response caused by abnormal vasoreactivity and resultant neurovascular uncoupling adjacent to malignant brain tumors. We propose to overcome this limitation and more accurately identify eloquent areas adjacent to brain tumors by independently assessing vasoreactivity using breath-holding and incorporating these data into the fMRI analysis.

Methods: Local vasoreactivity using a breath-holding paradigm with the same timing as the functional motor and language tasks was determined in 16 patients (9 glioblastomas, 1 anaplastic astrocytoma, 5 low grade astrocytomas, and 1 metastasis) and 6 healthy control subjects.

Pineal Cyst-Related Aqueductal Stenosis as Cause of Intractable Headaches in Nonhydrocephalic Patients.

Background: Pineal cysts (PCs) are histologically benign lesions of the pineal gland. Although the majority of PCs are asymptomatic, some cases are ambiguous and accompanied by nonspecific symptoms of variable severity. We suggested that disabling headache in nonhydrocephalic patients with PCs is associated with cerebral aqueduct (CAq) stenosis.

Differentiation of glioma malignancy grade using diffusion MRI.

Modern diffusion MR protocols allow one to acquire the multi-shell diffusion data with high diffusion weightings in a clinically feasible time. In the present work we assessed three diffusion approaches based on diffusion and kurtosis tensor imaging (DTI, DKI), and neurite orientation dispersion and density imaging (NODDI) as possible biomarkers for human brain glioma grade differentiation based on the one diffusion protocol. We used three diffusion weightings (so called b-values) equal to 0, 1000, and 2500s/mm with 60 non-coplanar diffusion directions in the case of non-zero b-values.

Validation of DWI pre-processing procedures for reliable differentiation between human brain gliomas.

Diffusion magnetic resonance imaging (dMRI) is a powerful tool in clinical applications, in particular, in oncology screening. dMRI demonstrated its benefit and efficiency in the localisation and detection of different types of human brain tumours. Clinical dMRI data suffer from multiple artefacts such as motion and eddy-current distortions, contamination by noise, outliers etc.

Use of CT perfusion to discriminate between brain metastases from different primaries.

Thirty-six metastases in 22 patients were studied prospectively using computed tomography perfusion. Regions of interests were drawn around: the enhancing part of the tumor, necrotic central part, periphery, peritumoral edema, and normal white matter. Cerebral blood volume, cerebral blood flow, and mean transit time were calculated for each zone.

Partial disconnection procedure in a patient with bilateral lesions (case report).

Purpose: The method of temporal lobectomy and parietooccipital disconnection has been applied in the treatment of patients with monolateral widespread cortical lesions and with hand motor function intact. There are no data regarding the use of this method in the treatment of patients with bilateral lesions.

Case Report: A case history of a 15-year-old female patient with medically refractory epilepsy is presented.

Quantification of dispersion of Gd-DTPA from the initial area of enhancement into the peritumoral zone of edema in brain tumors.

To evaluate Gd-DTPA contrast enhancement of brain tumors over time and to describe the dispersion of contrast into the zone of peritumoral edema. We performed MR imaging with a dose of 0.4 mmol Gd-DTPA/kg on eleven patients diagnosed with 5 different supratentorial tumors.

Diffusion tensor tractography of the motor white matter tracts in man: Current controversies and future directions.

The anatomy of the brain is extremely complex, and certain, even large structures, such as the corticospinal tract (CST), remain poorly understood. Diffusion tractography provides an opportunity to explore the white matter tracts in a fundamentally new way. In the current paper, we show how this technique has already added to our understanding of the anatomy of the CST.