Articolele autorului Viorel Pais
Link la profilul stiintific al lui Viorel Pais

Intercellular communication by extracellular vesicles with emphasis on the roles of cordocytes in the human brain. An ultrastructural study

We describe in this work the presence of extracellular vesicles (EVs) along different cell types, especially cordocytes, in various clinical conditions of the human brain (atherothrombotic disease, cerebral tumors, hygroma durae matris, intracerebral cysts, Moyamoya disease and parenchymatous hematoma) using transmission electron microscopy (TEM). EVs, illustrated as exosomes and microvesicles, were causally related to cell-to-cell communication,

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From precursor/stem cells to cordocytic phenotypes in the skin

This cytohistopathological study was performed to have a better knowledge of the continuum of cellular events, from mesenchymal stem cells to mature cordocytic phenotypes with their morphological heterogeneity and multiple functions in the human skin. We used light microscopy, as well as transmission and scanning electron microscopy to study multiple tissue fragments obtained by skin biopsy from post-burn tissue, surrounding superficial temporal

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The vascular stem cell niches and their significance in the brain

AIM: This cytohistopathological study was performed for a better knowledge of phenotypes derived from pluripotent stem cells, as well as for precise location of stem cells within the vascular niche in the brain. METHODS: We used light and transmission electron microscopy to demonstrate the presence of stem cells in the vascular wall of microvessels in the cerebral and cerebellar cortex, pia mater (considered by us a cordocytic-vascular tissue), adventitia

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Cordocytes-stem cells cooperation in the human brain with emphasis on pivotal role of cordocytes in perivascular areas of broken and thrombosed vessels

This study is based on data analysis by light and transmission electron microscopy of the surgical cases in cerebral tumors, cerebrovascular malformations, thromboses in the carotid system, and other injuries such as perivascular hemorrhage. We examined cortical arteries and veins, perivascular areas with old hematic masses, vasculogenic foci, and broken large vessels. We identified, characterized, and compared both undifferentiated cells and well-differentiated

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Apoptosis, paraptosis, necrosis, and cell regeneration in posttraumatic cerebral arteries

This study is to understand the nature and functional significance of the activated cell death programs and rehabilitation signs during late vascular changes after brain injury. We used light and transmission electron microscopy to describe changes of cells within the vascular endothelium and tunica media of the cortical arteries four weeks after craniocerebral traumatism. Within tunica media of the posttraumatic damaged artery, apoptotic and paraptotic

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Ultrastructural patterns of the activated cell death programs in the human brain

The authors analyzed by transmission electron microscopy (TEM) neurosurgical samples obtained from patients with cerebral tumors, neurotrauma, cerebral ischemia, Moyamoya disease, encephalitis, etc. Their observations concern a variety of dying cell types by different programmed death pathways, including apoptosis, paraptosis, autophagy, autoschizis, programmed necrosis, as well as combined and coexisting forms. This ample work pointed out not only

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Expertiza urmelor de natura piloasa prin microscopie electronica
Early and late coexistence of apoptosis and paraptosis in perivascular vasculogenic focuses and posttraumatic cerebral arteries, and their pathophysiologic significance

Introduction. This study is to understand the nature and functional significance of the activated cell death programs during events of the postnatal vasculogenesis and late changes after neurotrauma. Methods. We used light and transmission electron microscopy to describe changes of the cells in vasculogenic focuses and dying cells in the damaged arteries. Results. Vasculogenic focuses were composed of a nondifferentiated cell population including

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Multifaceted intracranial neuroprotection by means of the ultimate intelligent and efficient defender: the interstitial cell. A new cytodynamic perspective

Introduction. This study is to understand the full role of the ICs of the human cerebral arteries, because their function is now scarcely known. Methods. We used light, transmission and scanning electron microscopy to describe distribution, morphology and cell interaction regarding ICs identified in the brain in clinical conditions after surgery. Results. We observed ICs located along the arterial surface as well as on the cortical surface with different

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Atlas de patologie cerebro-vasculara