1,721,127 research outputs found
Cell death in the rat thymus: a minireview
No full textDuring the last decades, the literature has clearly established the fundamental role of the thymus in the development of an effective immune system. During thymocyte development and maturation, potentially autoreactive thymocytes are eliminated by a process known as apoptosis or programmed cell death responsible for the negative selection occurring within the thymus. This process is in sharp contrast to other types of cell death referred to as necrosis. Actually, three different types of cell death have been recently observed morphologically in the rat thymus, i.e. necrosis, apoptosis and clustered cell death. Moreover, among the numerous factors influencing thymocyte cell death, particular attention has been paid to hormones, chemicals, biological compounds and physical agents that may influence the type and/or the extent of cell death. Finally, a brief overview has been devoted to the contribution of mitochondria, nitric oxide, glutathione and intracellular levels of cations in addition to the activity of genes as cdk2, p53, Fas and members' of the Bcl2 family in modulating rat thymus cell death
Patologia della matrice extracellulare.
No full textIl capitolo illustra le caratteristiche delle principali componenti della matrice extracellulare ed il loro ruolo in una ampia serie di patologie sia genetiche che acquisite. Inoltre viene analizzato, sia da un punto di vista morfologiche che biomolecolare, il coinvolgimento della matrice nell'invechiamento, durante la riparazione tessutale, nonchè durante l'insorgenza e la progressione tumorale
Citochine.
No full textSono prese in considerazioni le proprietà biologiche delle principali citochine ed il loro ruolo in condizioni fisiologiche e patologich
The Cardiovascular system
No full textThe organization of the extracellular matrix components within the cardiovascular system are descrided with special emphasis to their role in development, aging and disease
A proteomic approach for investigating the aging process; the human fibroblast model.
No full textProteomic analysis of changes in protein expession of fibroblasts aged in vitro or isolated from aging donors highlights some characteristics of the aging process
APOPTOTIC CELL-DEATH IN THE MOUSE LIMB AND ITS SUPPRESSION IN THE HAMMERTOE MUTANT
No full textWe examined the importance of cell death in producing the limb deformity phenotype of the Hammertoe mouse. In order to make this evaluation, we first combined several techniques to verify the reliability of cell death markers in the normal mouse limb. In the normal limb, cell death occurs between Days 10.5 and 15.5 in the anterior, interdigital, and posterior zones. Morphological examination and staining for acid phosphatase or macrophages all reveal regions of cell death by detecting phagocytosis, while in. situ end labeling of DNA defines nuclear degeneration as apoptotic. The phagocytes display surface markers characteristic of macrophages. The Hammertoe mutant shows strongly reduced cell death only in the interdigital region. This result is consistent with the phenotype and suggests that the mutation influences the patterning or control of cell death rather than its mechanism
A morphological Approach to monitor nanoparticle-cell interaction
No full textNanotechnologies may change to the better many sectors of industry, but considerable concern is arising about their side effects and possible risks to human life. The potential toxicity of nanoparticles (NPs) versus cells has to be much more clearly investigated than it has been done to date to define their future role in biological, medical and environmental applications.The present study performed in-vitro standardized cytotoxicity tests using Hematite, Magnetite and Valentinite nanoparticles with 3T3 cells. Biological (XTT and Brd-U assays), morphological (ESEM and TEM) and physical (EDS and x-ray diffraction) investigations were performed to evaluate cell-nanoparticle interaction and physical state after interaction. The results identified a threshold toxic concentration for all NPs, beyond which no cytotoxic effects were detectable by standardized tests. Notwithstanding these results, cytoplasmatic and nuclear translocation was observed and verified also during mitotic phase. The limits of the standardized tests are analyzed and discussed
Pigment epithelial-derived factor: a new player in dermal elastic fibre calcification?
Full text linkPigment epithelium-derived factor (PEDF) is an endogenously produced glycoprotein expressed in several organs during developmental stages and adulthood mainly acting on cell differentiation.(1) In vitro and in vivo studies have demonstrated that PEDF has neurotrophic and antioxidant activities as well as the ability to counteract angiogenesis, tumorigenesis, atherosclerosis, thrombosis and inflammation.(1,2) In addition, PEDF has been also related to bone metabolism, increasing alkaline phosphatase (ALP) expression and promoting osteoblast differentiation.(3) This article is protected by copyright. All rights reserved
Elastic fiber abnormalities in a case of Beals Sindrome
No full textAbnormalieties in dermal and vascular elastic fibers in a patient affected by Beal Syndrome are described at the ultrastrutural level. The tissue-specific involvement of GAGs are also discussed
Scanning electron microscopy of thinned specimens: From multilayers to biological samples
No full textThe rules governing image formation of thin specimens in scanning and scanning transmission electron microscopy at low energy, deduced from the observation of semiconductor multilayers, were validated on specimens defined by a much more complex structure as the biological ones. It is shown that for a suitable specimen thickness it is possible to have, at the same time, backscattered electron images and scanning transmission electron images with a comparable resolution. Moreover, the nonconductive biological samples can be observed without charging effects if they are thin enough to ensure that a significant fraction of the electron beam crosses the specimen
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