Locus Coeruleus-Norepinephrine System: Spheres of Influence and Contribution to the Development of Neurodegenerative Diseases.

Locus coeruleus is a small bilateral nucleus in the brainstem. It is the main source of norepinephrine (noradrenaline) throughout the central nervous system (about 70% of all norepinephrine in the central nervous system), and, as shown in numerous studies, it is involved in regulating a significant number of functions. The detailed study of the functions of the Locus Coeruleus (LC) and its significance in human life became possible only after the development of histofluorescence methods for monoamines in the 1960s. The widespread locus coeruleus-norepinephrine (LC-NE) projection system regulates the entire central nervous system and modulates sensory processing, motor behavior, arousal, and cognitive processes. Damage to the LC and the associated decrease in norepinephrine levels are involved in a wide range of clinical conditions and pathological processes. Although much about the anatomy and physiology of the LC is currently known, its ultimate role in the regulation of behavior, control of the sleep-wake cycle, stress response, and the development of pathological conditions (such as Alzheimer's disease, dementia, depression, suicidal behavior, chronic traumatic encephalopathy, and Parkinson's disease) is not fully understood. Non-invasive visualization of the LC can be used for differential diagnosis, determining the stage of the disease, and predicting its course. Studying the dysfunction of the LC-norepinephrine system, involved in the pathogenesis of various neurological diseases, may ultimately form the basis for the development of new treatment methods based on the pharmacological elevation of norepinephrine levels. In this review, we will attempt to highlight the key points regarding the structure and function of the Locus Coeruleus, as well as outline the main directions and prospects for its study.

A Recent Update on the Epigenetic Repertoire and Chromatin Modifying Therapy in Diabetes Mellitus: A Comprehensive Review.

Several epigenome studies reported the ability of genes to modulate the lipogenic and glucogenic pathways during insulin signaling as well as the other pathways involved in cardiometabolic diseases. Epigenetic plasticity and oxidative stress are interrelated in the pathophysiology of insulin resistance (IR) and cardiometabolic disease conditions. This review aims to ascertain the previous research evidence pertaining to the role of the epigenome and the variations of histone and non-histone proteins during cardiometabolic disease conditions and insulin signaling to develop effective disease-based epigenetic biomarkers and epigenetics-based chromatic therapy. Several public databases, including PubMed, National Library of Medicine, Medline, and google scholar, were searched for the peer-reviewed and published reports. This study delineates the consistent body of evidence regarding the epigenetic alterations of DNA/histone complexes pertinent to oxidative stress, insulin signaling, metabolic cardiomyopathy, and endothelial dysfunction in patients with cardiometabolic diseases. It has been described that both DNA methylation and post-translational histone alterations across visceral and subcutaneous adipose tissue could facilitate gene transcription to modulate inflammation, lipogenesis, and adipogenesis as the complex network of chromatin-modifying enzymatic proteins involved in the defensive insulin signaling across vasculature in patients with cardiometabolic diseases. Resveratrol, vorinostat, trichostatin, and apabetalone are reported to have significant implications as epigenetic modulators. Based on the epigenetic alterations, a wide range of protein/gene markers, such as interleukin-4 (IL-4) and interferon-γ (IFNγ) genes, may be considered as biomarkers in these patients due to their ability to the polarization of immune cells involved in tissue inflammation and atherosclerosis. Hence, it is crucial to unravel the cell-specific epigenetic information to develop individual risk assessment strategies for chromatin-modifying therapies in patients with cardiometabolic diseases.

Cryogenic sequenced layering for the 3D reconstruction of biological objects.

Three-dimensional (3D) visualization is applied throughout many specialities, prompting an important breakthrough in accessibility and modeling of data. Experimental rendering and computerized reconstruction of objects has influenced many scientific achievements, facilitating one of the greatest advancements in medical education since the first illustrated anatomy book changed specialist training forever. Modern medicine relies on detailed, high quality virtual models for educational, experimental and clinical purposes. Almost all current virtual visualization methods rely on object slicing producing serial sections, which can then be digitalized or analyzed manually. The tendency to computerize serial sections roots from convenience, accessibility, decent visualization quality and automation capabilities. Drawbacks of serial section imaging is tissue damage occurring within each consequent sectioning. To utilize the important aspects of real-life object reconstruction, and maintain integrity of biological structures, we suggest a novel method of low-temperature layering of objects for digitization and computerized virtual reconstruction. Here we show the process of consequent imaging of each novel layer of a biological object, which provides a computer with high quality data for virtual reconstruction and creation of a multidimensional real-life model. Our method prevents tissue deformation and biodegradation due to specific methods used in preparation of the biological object. The resulting images can be applied in surgical training, medical education and numerous scientific fields for realistic reconstruction of biological objects.

Anatomical Aspects of the Transnasal Endoscopic Access to the Craniovertebral Junction.

OBJECTIVE: Interest in endoscopic transnasal access has increased with continued technological advances in endoscopic technology. The goals of this study were to review the normal anatomy in transnasal endoscopic neurosurgery and outline the anatomical basis for an expanded surgical approach. Defining anatomical aspects of surgical endoscopy helps guide the surgeon by defining normal anatomy of the access vector. METHODS: This anatomic study was conducted on 15 adult male cadaver specimens using various microsurgical tools and endoscopic instruments and 1 intraoperative case. The vasculature was injected with colored silicone to aid visualization. Different transnasal approach techniques were used, with angles of endoscope access at 0°, 30°, 45°, and 70° accordingly for extensive anatomical mapping. RESULTS: The proximity of critical structures is different in each approach degree. A full understanding of the possible structures to be met during transnasal access is described. As a result of the study, anatomical aspects and important structures were outlined, and a surgical protocol was defined for minimal risk access in respect to normal anatomy of the area. CONCLUSIONS: Thorough knowledge of topographic anatomy of the craniovertebral junction is required for performing minimal-risk surgical intervention in this region. It is important to know all anatomical aspects of the transnasal approach in order to reduce the risk of damage to vital structures. Transnasal endoscopic surgery of the craniovertebral junction is a relatively new direction in neurosurgery; therefore, anatomical studies such as the one described in this article are extremely important for the development of this access method.