Publications by authors named "Aleksandr Vasilyev"

The dynamics of the diffraction peak shape during pulsed heat load on mosaic single-crystal tungsten were measured at the `Plasma' scattering station on the eighth beamline of the VEPP-4 synchrotron radiation source at the Budker Institute of Nuclear Physics. The observed evolution of the diffraction peak shape agrees with theoretical predictions based on calculations of deformation caused by pulsed heating. Three clearly distinguishable stages of the diffraction-peak evolution were found, correlating with the evolution of temperature and deformation distributions.

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Acute Kidney Injury (AKI) is a common medical condition with a high mortality rate. With the repair abilities of the kidney, it is possible to restore adequate kidney function after supportive treatment. However, a better understanding of how nephron cell death and repair occur on the cellular level is required to minimize cell death and to enhance the regenerative process.

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Mustn1 is a small nuclear protein that is involved in the development and regeneration of the musculoskeletal system. Previous work established a role for Mustn1 in myogenic and chondrogenic differentiation. In addition, recent evidence suggests a potential role for Mustn1 in cilia function in zebrafish.

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New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis.

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Several evolutionary theories have been proposed to explain the adaptation of the long giraffe neck; however, few studies examine the fossil cervical vertebrae. We incorporate extinct giraffids, and the okapi and giraffe cervical vertebral specimens in a comprehensive analysis of the anatomy and elongation of the neck. We establish and evaluate 20 character states that relate to general, cranial and caudal vertebral lengthening, and calculate a length-to-width ratio to measure the relative slenderness of the vertebrae.

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Objectives: Innate immune dysfunction after major burn injuries increases the susceptibility to organ failure. Lipid mediators of inflammation resolution, e.g.

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The zebrafish pronephric tubule consists of proximal and distal segments and a collecting duct. The proximal segment is subdivided into the neck, proximal convoluted tubule (PCT) and proximal straight tubule (PST) segments. The distal segment consists of the distal-early (DE) and distal-late (DL) segments.

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Dysregulation of the actin cytoskeleton in podocytes represents a common pathway in the pathogenesis of proteinuria across a spectrum of chronic kidney diseases (CKD). The GTPase dynamin has been implicated in the maintenance of cellular architecture in podocytes through its direct interaction with actin. Furthermore, the propensity of dynamin to oligomerize into higher-order structures in an actin-dependent manner and to cross-link actin microfilaments into higher-order structures has been correlated with increased actin polymerization and global organization of the actin cytoskeleton in the cell.

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Acute kidney injury is common and has a high mortality rate, and no effective treatment exists other than supportive care. Using cell culture models, we previously demonstrated that exocyst Sec10 overexpression reduced damage to renal tubule cells and speeded recovery and that the protective effect was mediated by higher basal levels of mitogen-activated protein kinase (MAPK) signaling. The exocyst, a highly-conserved eight-protein complex, is known for regulating protein trafficking.

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Acute kidney injury (AKI) is a common and significant medical problem. Despite the kidney's remarkable regenerative capacity, the mortality rate for the AKI patients is high. Thus, there remains a need to better understand the cellular mechanisms of nephron repair in order to develop new strategies that would enhance the intrinsic ability of kidney tissue to regenerate.

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Glutamylation is a functionally important tubulin posttranslational modification enriched on stable microtubules of neuronal axons, mitotic spindles, centrioles, and cilia. In vertebrates, balanced activities of tubulin glutamyl ligase and cytoplasmic carboxypeptidase deglutamylase enzymes maintain organelle- and cell type-specific tubulin glutamylation patterns. Tubulin glutamylation in cilia is regulated via restricted subcellular localization or expression of tubulin glutamyl ligases (ttlls) and nonenzymatic proteins, including the zebrafish TPR repeat protein Fleer/Ift70.

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Inflammatory responses to infection and injury must be restrained and negatively regulated to minimize damage to host tissue. One proposed mechanism involves enzymatic inactivation of the pro-inflammatory mediator leukotriene B4, but it is difficult to dissect the roles of various metabolic enzymes and pathways. A primary candidate for a regulatory pathway is omega oxidation of leukotriene B4 in neutrophils, presumptively by CYP4F3A in humans and CYP4F18 in mice.

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Chordoma is a malignant tumor thought to arise from remnants of the embryonic notochord, with its origin in the bones of the axial skeleton. Surgical resection is the standard treatment, usually in combination with radiation therapy, but neither chemotherapeutic nor targeted therapeutic approaches have demonstrated success. No animal model and only few chordoma cell lines are available for preclinical drug testing, and, although no druggable genetic drivers have been identified, activation of EGFR and downstream AKT-PI3K pathways have been described.

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Formation of a functional renal network requires the interconnection of two epithelial tubes: the nephron, which arises from kidney mesenchyme, and the collecting system, which originates from the branching ureteric epithelium. How this connection occurs, however, is incompletely understood. Here, we used high-resolution image analysis in conjunction with genetic labeling of epithelia to visualize and characterize this process.

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Organ development leads to the emergence of organ function, which in turn can impact developmental processes. Here we show that fluid flow-induced collective epithelial migration during kidney nephron morphogenesis induces cell stretch that in turn signals epithelial proliferation. Increased cell proliferation was dependent on PI3K signaling.

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The zebrafish has emerged as a powerful model to study organ development and regeneration. It has a number of advantages over other vertebrate model systems. The embryo can be kept transparent throughout embryonic development, which allows direct visualization of the developing organs.

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Mutations in polycystin1 (PKD1) account for the majority of autosomal dominant polycystic kidney disease (ADPKD). PKD1 mutations are also associated with vascular aneurysm and abdominal wall hernia, suggesting a role for polycystin1 in extracellular matrix (ECM) integrity. In zebrafish, combined knockdown of the PKD1 paralogs pkd1a and pkd1b resulted in dorsal axis curvature, hydrocephalus, cartilage and craniofacial defects, and pronephric cyst formation at low frequency (10-15%).

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Collective cell migration is emerging as a significant component of many biological processes including metazoan development, tissue maintenance and repair and tumor progression. Different contexts dictate different mechanisms by which migration is guided and maintained. In vascular endothelia subjected to significant shear stress, fluid flow is utilized to properly orient a migrating group of cells.

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Tissue organization in epithelial organs is achieved during development by the combined processes of cell differentiation and morphogenetic cell movements. In the kidney, the nephron is the functional organ unit. Each nephron is an epithelial tubule that is subdivided into discrete segments with specific transport functions.

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The kidney and vasculature are intimately linked both functionally and during development, when nephric and blood/vascular progenitor cells occupy adjacent bands of mesoderm in zebrafish and frog embryos. Developmental mechanisms that underlie the differentiation of kidney versus blood/vascular lineages remain unknown. The odd skipped related1 (osr1) gene encodes a zinc-finger transcription factor that is expressed in the germ ring mesendoderm and subsequently in the endoderm and intermediate mesoderm, prior to the expression of definitive kidney or blood/vascular markers.

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We report the case of a 48-year-old woman presenting with recurrent uterine leiomyosarcoma (LMS) associated with right iliac vein and inferior vena cava (IVC) invasion and left lower lobe pulmonary tumor embolus. Because the prognosis and treatment differ from that of thrombotic pulmonary emboli, the differentiating imaging characteristics of intravascular tumor embolism are reviewed. To our knowledge, only two other cases of intravenous uterine leiomyosarcomatosis have been described in the existing literature, and this is the first reported case of the entity with associated intravascular tumor embolism.

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