Composite suture material based on polylactide accelerates the healing of surgical wounds in in vivo experiment.

In laboratory conditions, composite sutures based on polylactide (PLA) containing chitin nanofibrils modified with polyethylene glycol (CN-PEG) and poviargol (silver nanoparticles stabilized with poly(N-vinylpyrrolidone)) were obtained, studied, and used as a prototype. Surgical sutures threads with the addition of CN-PEG have stable mechanical properties both in air and in a buffer simulating the environment of a living organism. The yield strength of oriented threads decreased by an average of 15%, whereas for non-oriented threads the decrease was 3-4 times.

The Pattern of Granuloma Formation in the Liver of Rats as a Reflection of the Mechanism of Internalization of Submicron Silicon Particles.

A morphological analysis of the liver of Wistar rats was performed 2 months after a single intravenous injection of porous silicon particles of different sizes (60-80, 250-300, and 500-600 nm; 2 mg/ml, 1 ml). Histological, immunohistochemical, and electron microscopic methods showed the development of CD68 granulomas in all experimental groups. Injection of 60-80-nm porous silicon particles led to the formation of single large granulomas (>2000 μm), while 500-600-nm nanoparticles caused the formation of numerous smaller granulomas.

Properties of Resorbable Conduits Based on Poly(L-Lactide) Nanofibers and Chitosan Fibers for Peripheral Nerve Regeneration.

New tubular conduits have been developed for the regeneration of peripheral nerves and the repair of defects that are larger than 3 cm. The conduits consist of a combination of poly(L-lactide) nanofibers and chitosan composite fibers with chitin nanofibrils. In vitro studies were conducted to assess the biocompatibility of the conduits using human embryonic bone marrow stromal cells (FetMSCs).

Morphological Analysis of the Respiratory Tract of Rats after Parenteral Administration of Silicon Dioxide Nanoparticles.

Morphological analysis of the respiratory tract of Wistar rats was performed after a single parenteral administration of 12-nm silicon dioxide nanoparticles (1 ml, 2 mg/ml, intravenously) was performed. On day 21 and in 2, 4, and 6 months after the administration of nanoparticles, the development of macrophage infiltration in the interstitium of the respiratory tract was demonstrated by histological and immunohistochemical methods. The pool of alveolar macrophages increased in 4 months after administration (p=0.

[Experience with using cyanoacrylate glue in endovascular treatment of varicose veins].

The method of cyanoacrylate-mediated obliteration of subcutaneous veins is known to be an alternative to thermal endovascular obliteration and eliminates the need for tumescent anaesthesia. This technique is based on glue-induced damage to the venous intima, followed by immune response according to the delayed-type hypersensitivity principle. The authors report herein their first experience with using cyanoacrylate-mediated embolization in treatment of patients presenting with varicose veins.

The Spatial Organization of the Intranuclear Structures of Human Brain Dopaminergic Neurons.

We studied the intranuclear localization of protein nucleophosmin (B23) and ubiquitin in the dopaminergic neurons of human substantia nigra (n = 6, age of 25-87 years) using immunohistochemistry and confocal laser microscopy. Intranuclear ubiquitin-immunopositive bodies that morphologically correspond to Marinesco bodies were found to be present in substantia nigra dopaminergic (tyrosine hydroxylase-immunopositive) neurons but absent in non-dopaminergic neurons. The number of bodies varied from 0 to 6 per cell nucleus.

[Immunohistochemical characteristics of the substantia nigra neurons of the human].

Aim: To determine the cytochemical characteristics of unchanged neurons of the human substantia nigra using a wide range of immunocytochemical markers some of which (glutamate decarboxylase-65, PGP 9.5, non-phosphorylated neurofilament proteins, alpa-tubulin) have never been used for study of human dopaminergic neurons.

Material And Methods: Fragments of human midbrain (17 men and women, aged from 28 to 78 years) from the archives of the Department of General and Specific Morphology of the Institute of Experimental Medicine were used.

Immunohistochemical demonstration of specific antigens in the human brain fixed in zinc-ethanol-formaldehyde.

Tissue fixation is critical for immunohistochemistry. Recently, we developed a zinc-ethanol-formalin fixative (ZEF), and the present study was aimed to assess the applicability of the ZEF for the human brain histology and immunohistochemistry and to evaluate the detectability of different antigens in the human brain fixed with ZEF. In total, 11 antigens were tested, including NeuN, neuron-specific enolase, GFAP, Iba-1, calbindin, calretinin, choline acetyltransferase, glutamic acid decarboxylase (GAD65), tyrosine hydroxylase, synaptophysin, and α-tubulin.

[GAP-43 and its proteolytic fragment in spinal cord cells of rats with experimental autoimmune encephalomyelitis].

The regenerative capacity of the Central Nervous System (CNS) is a key factor implicated in the pathogenesis of neurodegenerative diseases. In the present study, the regenerative capacity of the CNS is considered using one of the markers of regeneration, Growth Associated Protein-43 (GAP-43) and its proteolytic fragment GAP-43-3 in the Experimental Autoimmune Encephalomyelitis (EAE) animal model of multiple sclerosis. The EAE on Wistar rats was characterized as an adequate model of multiple sclerosis, with typical clinical (pares and paralysis) and morphological (infiltration of spinal cord and deformation of motoneurons) disorders.

[Glial fibrillary acidic protein: the component of intermediate filaments in the vertebrate brain astrocytes].

Glial fibrillary acidic protein (GFAP) refers to the type III intermediate filament proteins and is the essential component of the cytoskeleton in astrocytes of all vertebrates. This review presents current data on the molecular organization of GFAP in a comparative aspect. The results of most relevant studies using immunocytochemical labeling of the protein are summarized.

[Catecholaminergic neurons of mammalian brain and neuromelanin].

Brain catecholaminergic neurons belong to the most extensively studied populations of nerve cells. Presence of a pigment neuromelanin in their cytoplasm is a specific morphological feature of these neurons in many mammalian species. Elucidation of the role of neuromelanin is of importance for comparative neurobiology, as it is absent in neurons of another neurotransmitter systems and, moreover, even in catecholaminergic neurons of some laboratory animals, which limits the possibility of experimental verification of existing hypotheses of its functions under physiological and pathological conditions.

[Neuroglobin distribution in the human cerebellar cortex (an immunohistochemical study)].

Neuroglobin is a recently discovered heme-containing protein located predominantly in the mammalian brain. This paper for the first time presents the data on neuroglobin distribution in human cerbellum using immunohistochemistry. Neuroglobin immunoreactivity in the cerebellum was found in all the cases studied (n = 7), although its intensity varied.

[INTRANUCLEAR UBIQUITIN-IMMUNOPOSITIVE STRUCTURES OF THE HUMAN SUBSTANTIA NIGRA NEURONS].

Marinesco bodies were discovered in the human substantia nigra neurons in 1902. However, relationships these intranuclear inclusions with other cell nuclear structures remains obscured yet. The aim of the present study was to investigate morphological and cytochemical peculiarities of these ubiquitin-immunopositive intranuclear bodies in neurons of the human substantia nigra and the character of their relationships with the nucleolus using light microscopy, immunocytochemistry, and confocal laser microscopy.

[Method for simultaneous visualization of mast cells and nerve terminals in the rodent thymus].

The purpose of this study was to develop the method for the simultaneous visualization of mast cells (MCs) and nerve terminals, based on generally accepted techniques of histochemical identification of MCs with alcian blue and immunohistochemical detection of synaptophysin. The protocol presented allows simultaneous identification of mast cells and nerve terminals in the sections of paraffin-embedded thymus of laboratory mammals with high selectivity and good reproducibility. The method can be used for both visualization of spatial relationship between MCs and nerve terminals and independent research of the innervation of mammalian internal organs.

[Subependymal microgliocytes of the third ventricle of the brain].

The goal of the study was to identify the subependymal microglial cells of the III ventricle of the rat brain and to determine their structural characteristics. The sections of the brain of intact Wistar (n = 3) and Sprague-Dawley (n = 3) male rats were studied using the methods of immunocytochemistry and confocal laser microscopy. Subependymal microglia of the III ventricle was found to be a constantly present cell population.

[Diagnostic potential of the histochemical methods used in histological studies of the heart].

The authors proposed a number of immunohistochemical markers to be used in histological diagnostic studies of the heart and protocols for their identification that extend the possibilities for the estimation of the heart function in case of pathological changes and sudden cardiac death.

[Advantages and disadvantages of zink-ethanol-formaldehyde as a fixative for immunocytochemistry and confocal laser microscopy].

The paper presents an analysis of authors' results obtained using fixation of various tissues in zink-ethanol-formaldehyde (ZEF). It was found that fixation in ZEF, in comparison with other methods of fixation, allowed to achieve higher sensitivity of immunocytochemical reaction for a large number of antigens studied and, in many cases, to avoid heat unmasking of antigens. It also provided high resolution of the images obtained using the fluorescent and confocal laser microscopy.

[NeuN nuclear protein in neurons of human brain substantia nigra].

The expression of NeuN protein was examined immunocytochemically in the neurons of human substantia nigra (n=14, age: 27-78 years). Some of substantia nigra neurons demonstrated weak NeuN immunopositive reaction, while the others were NeuN-immunonegative. In general, NeuN immunocytochemical reaction in neurons of human substantia nigra was expressed much weaker than in the nucleus rubrum neurons located in the same sections.

[Microglia detection in the brain preparations after long-term storage in formalin].

Relatively simple protocol for identification of microgliocytes in archived material is proposed. A novel variant is based on preparation processing with the use of polyclonal antibodies against Iba-1 protein. The proposed approach includes antigen heat unmasking in a modified citrate buffer and prolonged incubation of the sections with the primary antibodies at high temperature.

[Method of immunocytochemical demonstration of cholinergic neurons in the central nervous system of laboratory animals].

A protocol of immunocytochemical demonstration of choline acetyltransferase (ChAT), a key enzyme of acetylcholine synthesis, in paraffin sections of the brain of some laboratory animals, is presented. The method is simple, gives fairly reproducible results and allows for demonstration of ChAT in neurons, nerve fibers, and terminals in preparations of at least three species of laboratory animals including rat, rabbit, and cat. Different kinds of fixation (10% formalin, 4% paraformaldehyde, or zinc-ethanol-formaldehyde) were found suitable for immunocytochemical visualization of ChAT, however, optimal results were obtained with the application of zinc-ethanol-formaldehyde

[Neuromelanin in neurons of substantia nigra lacking tyrosine hydroxylase].

The distribution of tyrosine hydroxylase (TH), a key enzyme of catecholamine synthesis, was studied immunocytochemically in the neurons of substantia nigra in the human brain (n=7), and localization of neuromelanin in these cells was determined. The evidence indicating the existence of three types of neurons in substantia nigra was obtained, including the neurons containing both TH and neuromelanin, neurons containing only neuromelanin, and neurons expressing neither TH, nor neuromelanin. Presence of a population of neuromelanin-containing neurons lacking TH (which make up 7-30% of the cells) is discussed considering the participation of catecholamines and TH in neuromelanin synthesis.