C60 adduct with L-arginine as a promising nanomaterial for treating cerebral ischemic stroke.

The work aimed to investigate the biocompatibility and biological activity of the water-soluble fullerene adduct C60-Arg. It was found that the material is haemocompatible, is not cyto- and genotoxic, possesses pronounced antioxidant activity. Additionally, this paper outlines the direction of application of water-soluble fullerene adducts in the creation of neuroprotectors. It has been suggested that a putative mechanism of the protective action of the C60-Arg adduct is associated with its antioxidant properties, the ability to penetrate the blood-brain barrier, and release nitrogen monoxide as a result of the catabolism of L-arginine residues, which promote vascular relaxation. The action of the C60-Arg adduct was compared with the action of such an antioxidant as Edaravone, which is approved in Japan for the treatment of ischemic and haemorrhagic strokes.

Neutrophils Mediate Pulmonary Artery Thrombosis In Situ.

Pulmonary embolism is a life-threatening condition, which can result in respiratory insufficiency and death. Blood clots occluding branches of the pulmonary artery (PA) are traditionally considered to originate from thrombi in deep veins (usually in legs). However, growing evidence suggests that occlusion of the vessels in the lungs can develop without preceding deep vein thrombosis (DVT). In this work, we used an inferior vena cava (IVC) complete ligation model of DVT in Wistar rats to explore the possibility and mechanisms of PA thrombosis under the conditions where all routes of thrombotic mass migration from peripheral veins are blocked. We demonstrate that rats both with normal and reduced neutrophil counts developed thrombi in the IVC, although, neutropenia caused a substantial decrease in thrombus size and a shift from fresh fibrin toward mature fibrin and connective tissue inside the thrombus. Massive fibrin deposition was found in the PA branches in the majority of DVT rats with normal neutrophil counts, but in none of the neutropenic animals. Neutrophil ablation also abolished macroscopic signs of lung damage. Altogether, the results demonstrate that thrombi in the lung vasculature can form in situ by mechanisms that require local neutrophil recruitment taking place in the DVT setting.

Development of neurochemical labeling in the intermediolateral nucleus of cats' spinal cord.

NeuN is a neuron-specific nuclear protein expressed in most mature neuronal cell types, with some exceptions. These exceptions are known mainly for the brain but not for the spinal cord or the spinal visceral networks for which only scarce information is available. One of the most defined visceral structures in the spinal cord is the sympathetic intermediolateral nucleus located within the thoracolumbar segments. We investigated the NeuN staining in the intermediolateral nucleus and compared it with the staining for two neurochemical markers of visceral neurons: nitric oxide synthase and calcium-binding protein calretinin in adult cats and in kittens aged 0, 14, and 35 days. A clear NeuN-immunonegativity was obtained for intermediolateral neurons labeled for nitric oxide synthase for both adult cats and kittens. In contrast, a matched immunopositivity for the NeuN and calretinin was obtained, showing an age-dependent degree of this colocalization, which was high in newborn kittens, decreased on postnatal 14 and 35 days and persisted at a moderate level up to adulthood. Perhaps our data displayed a heterogeneity of the intermediolateral neurons.

25-Year Storage of Human Choroid Plexus in Methyl Salicylate Preserves Its Antigen Immunoreactivity.

OBJECTIVE: Immunohistochemical investigation of archival histological material is a serious problem, since long-term storage of biological tissues, most often in formalin, leads to a loss of antigenic properties. However, the biological material can also be stored in the clearing agent methyl salicylate. The aim of this study was to assess the antigenicity of the human choroid plexus after extra long-term storage in methyl salicylate. MATERIAL AND METHOD: The study was performed on samples of fixed human choroid plexus (occasionally with attached neighboring pineal gland) stored in either methyl salicylate or paraffin blocks for 25 years. Chromogenic and fluorescence immunohistochemistry of vimentin, GFAP, type IV collagen, ß-catenin, α-smooth muscle actin, von Willebrand factor, CD68, mast cell tryptase, TMEM119, and synaptophysin was carried out. RESULTS: The storage of human choroid plexus in methyl salicylate for 25 years does not impair its histomorphology and preserves the properties of all the antigens assessed, which makes their immunohistochemical visualization possible using both light and fluorescence microscopy. Additionally, we found that long-term storage of human choroid plexus in methyl salicylate does not cause an increase in autofluorescence. CONCLUSION: Methyl salicylate can be recommended as a medium for long-term storage of biological tissue, as it provides excellent brain tissue preservation and retains its antigenic properties for up to 25 years.

Changes in cytoplasmic and extracellular neuromelanin in human substantia nigra with normal aging.

Neuromelanin (NM) is a dark polymer pigment produced in certain populations of catecholaminergic neurons in the brain. It is present in various areas of the human brain, most often in the substantia nigra (SN) pars compacta and the locus coeruleus, the main centers of dopaminergic and noradrenergic innervation, respectively. Interest in NM has revived in recent years due to the alleged link between NM and the particular vulnerability of neuromelanin-containing neurons to neurodegeneration. The aim of this work was to study the structural, cytochemical, and localization features of cytoplasmic and extracellular neuromelanin in the human SN pars compacta during normal aging. Sections of human SN from young/middle-aged adults (25 to 51 years old, n=7) and older adults (60 to 78 years old, n=5), all of which had no neurological disorders, were stained histochemically for metals (Perls' reaction, Mayer's hematoxylin) and immunohistochemically for tyrosine hydroxylase (TH) and Iba-1. It was shown that dopaminergic neurons in SN pars compacta differ in the amount of neuromelanin and the intensity of TH-immunoreactivity. The number of neuromelanin-containing neurons with decreased TH-immunoreactivity positively correlates with age. Extracellular NM is present in SN pars compacta in both young/middle-aged and older adults. The number of extracellular NM accumulations increases with aging. Cytoplasmic and extracellular NM are predominantly not stained using histochemical methods for detecting metals in people of all ages. We did not detect the appearance of amoeboid microglia in human SN pars compacta with aging, but we found an age-related increase in microglial phagocytic activity. The absence of pronounced microgliosis, as well as a pronounced loss of neuromelanin-containing neurons, indicate the absence of neuroinflammation in human SN pars compacta during normal aging.