44 research outputs found
A Narrow Internal Auditory Canal with Duplication in a Patient with Congenital Sensorineural Hearing Loss
A narrow internal auditory canal (IAC) with duplication is a rare anomaly of the temporal bone. It is associated with congenital sensorineural hearing loss. Aplasia or hypoplasia of the vestibulocochlear nerve may cause the hearing loss. We present an unusual case of an isolated narrow IAC with duplication that was detected by a CT scan. In this case, the IAC was divided by a bony septum into an empty stenotic inferoposterior portion and a large anterosuperior portion containing the facial nerve that was clearly delineated on MRI
In Vivo Isolation and Characterization of Stem Cells with Diverse Phenotypes Using Growth Factor Impregnated Biomatrices
BACKGROUND: The stimulation to differentiate into specific cell types for somatic stem cells is largely due to a series of internal and external signals coming from the microenvironment that surrounds the stem cell. Even though intensive research has been made, the basic mechanisms of plasticity and/or the molecules regulating stem cells proliferation and differentiation are not completely determined. Potential answers concerning the problems could be derived from the studies of stem cells in culture. METHODOLOGY/PRINCIPLE FINDINGS: We combine a new procedure (using the matrigel biopolymer supplemented with a selected cytokine/growth factor) with classic techniques such as light, confocal and electron microscopy, immunohistochemistry and cell culture, to perform an analysis on stem cells involved in the leech (Hirudo medicinalis) repair tissues. The leech has a relative anatomical simplicity and is a reliable model for studying a variety of basic events, such as tissue repair, which has a striking similarity with vertebrate responses. Our data demonstrate that the injection of an appropriate combination of the matrigel biopolymer supplemented with a selected cytokine/growth factor in the leech Hirudo medicinalis is a remarkably effective tool for isolating a specific cell population in vivo. A comparative analysis of biopolymer in vivo sorted stem cells indicates that VEGF recruited cells of a hematopoietic/endothelial phenotype whereas MCP-1/CCL2 isolated cells that were of an early myeloid lineage. CONCLUSION: Our paper describes, for the first time, a method allowing not only the isolation of a specific cell population in relation to the cytokine utilized but also the possibility to culture a precise cell type whose isolation is otherwise quite difficult. This approach could be broadly applied to isolate stem cells of diverse origins based on the recruitment stimuli employed
Identification, Isolation and Expansion of Myoendothelial Cells Involved in Leech Muscle Regeneration
Adult skeletal muscle in vertebrates contains myoendothelial cells that express both myogenic and endothelial markers, and which are able to differentiate into myogenic cells to contribute to muscle regeneration. In spite of intensive research efforts, numerous questions remain regarding the role of cytokine signalling on myoendothelial cell differentiation and muscle regeneration. Here we used Hirudo medicinalis (Annelid, leech) as an emerging new model to study myoendothelial cells and muscle regeneration. Although the leech has relative anatomical simplicity, it shows a striking similarity with vertebrate responses and is a reliable model for studying a variety of basic events, such as tissue repair. Double immunohistochemical analysis were used to characterize myoendothelial cells in leeches and, by injecting in vivo the matrigel biopolymer supplemented with the cytokine Vascular Endothelial Growth Factor (VEGF), we were able to isolate this specific cell population expressing myogenic and endothelial markers. We then evaluated the effect of VEGF on these cells in vitro. Our data indicate that, similar to that proposed for vertebrates, myoendothelial cells of the leech directly participate in myogenesis both in vivo and in vitro, and that VEGF secretion is involved in the recruitment and expansion of these muscle progenitor cells
The main actors involved in parasitization of Heliothis virescens larva
At the moment of parasitization by another insect, the host Heliothis larva is able to defend itself by the activation of humoral and cellular defenses characterized by unusual reactions of hemocytes in response to external stimuli. Here, we have combined light and electron microscopy, staining reactions, and immunocytochemical characterization to analyze the activation and deactivation of one of the most important immune responses involved in invertebrates defense, i.e., melanin production and deposition. The insect host/parasitoid system is a good model to study these events. The activated granulocytes of the host insect are a major repository of amyloid fibrils forming a lattice in the cell. Subsequently, the exocytosed amyloid lattice constitutes the template for melanin deposition in the hemocel. Furthermore, cross-talk between immune and neuroendocrine systems mediated by hormones, cytokines, and neuromodulators with the activation of stress-sensoring circuits to produce and release molecules such as adrenocorticotropin hormone, alpha melanocyte-stimulating hormone, and neutral endopeptidase occurs. Thus, parasitization promotes massive morphological and physiological modifications in the host insect hemocytes and mimics general stress conditions in which phenomena such as amyloid fibril formation, melanin polymerization, pro-inflammatory cytokine production, and activation of the adrenocorticotropin hormone system occur. These events observed in invertebrates are also reported in the literature for vertebrates, suggesting that this network of mechanisms and responses is maintained throughout evolution
Cytokine Impregnated Biomatrix: A New Tool to Study Multi-Wall Carbon Nanotubes Effects on Invertebrate Immune Cells
The novel features of engineered nanoparticles, such as multi-wall carbon nanotubes (MWCNTs) are impressive and attractive for technology, however they dissolved in water and accumulate in soils through the application of sewage sludge, accidental spills, and deposition from the air, agrochemicals or soil remediation. Given that several studies have revealed that chronic exposure to these nanomaterials products through the ingestion of drinking water, inhalation and dermal contact may harbour potential risks to human health, risk assessment of this nanomaterials in the aquatic environment are becoming essential. Here we propose a freshwater invertebrate, the leech Hirudo medicinalis, as a model to assess the effects MWCNTs on the immune system by means of in vivo and in vitro experiments. For this study, we used a consolidated experimental approach based on injection in the body wall of the leech of the biomatrice Matrigel (MG), added with a specific macrophage chemoattractant, the cytokine Allograft inflammatory factor-1 (AIF-1) and/or with MWCNTs. MG sponges analysis show the presence of a larger number of cells positive for both CD68 and HmAIF-1, specific monocyte-macrophage markers. Ultrastructural analysis suggests that MWCNTs may be internalized by phagocytosis but they seem also to be able to pierce cell membranes during cells migration.
Cells extracted from MG were also used for in vitro treatment with MWCNTs at different concentration (2.5, 5, 10, 25, 50 and 100 \ub5g/ml) for 24 h to study cell morphology changes and production of amyloid fibrils in order to encapsulate
the foreign bodies. Our results, not only confirm the ability of MWCNTs in inducing a potent inflammatory response, but highlight rapid colorimetric assays that can be successfully used as sensitive tools for aquatic pollution biomonitoring
Hirudo medicinalis: a new model system for testing activators and inhibitors of angiogenesis
9nonenoneDE EGUILEOR M.; A. GRIMALDI; TETTAMANTI G.; FERRARESE R.; CONGIU T.; PROTASONI M.; PERLETTI G.; VALVASSORI R.; LANZAVECCHIA GDE EGUILEOR, MAGDA ANNA; Grimaldi, Annalisa; Tettamanti, Gianluca; Ferrarese, Roberto; Congiu, Terenzio; Protasoni, Marina; Perletti, Gianpaolo; Valvassori, Roberto; Lanzavecchia, G
Structural and biochemical analysis of the parasite Gordius villoti (Nematomorpha, Gordiacea) cuticle
The cuticle of the nematomorpha Gordius villoti is a proteinaceous extracellular structure that covers the body during the endoparasitic life in the hemocoelic cavity of insect hosts, and of the free-living adult animals. The ultrastructure of the cuticle has a complex spatial organization with several parallel layers of large diameter fibres, interposed thinner fibrous elements and honeycomb-shaped matrix surrounding the fibers. When adult isolated cuticles were partially solubilized by several compounds, the structure revealed a strong insolubility and the main fibers were always observable. HPLC and spectrophotometric assays carried out to investigate the presence of tyrosine cross-linking, indicated such a mechanism as a key-element in the hardening process of the cuticle. Such data strongly suggest that the Gordius cuticle contains dityrosine compounds, whose formation is probably mediated by endogenous peroxidase activity. (C) 2000 Harcourt Publishers Ltd
La valutazione come agente di miglioramento. Il monitoraggio del Progetto Scuolinsieme
What is the impact that funded projects can have on school organization and student outcomes? How can it be monitored? Does monitoring detect impacts or is it itself a source of impact? It is possible to provide teachers with methodologies and tools capable of increasing their self-assessment possibilities? The article intends to provide some answers to these questions, describing - in a nutshell - the monitoring of the Scuolinsieme project, a set of interventions financed by the Fondazione per la Scuola della Compagnia di San Paolo, applied in 34 lower secondary schools from 2017 to 2020. Starting from a brief description of the interventions and of the system of indicators used, a monitoring strategy is presented. This strategy not only aims to detect the effects of the interventions themselves but intends to impact them, in concert with the planning and training actions. The first results highlight a positive effect of the intervention on the practices implemented by teachers and in their awareness of being the main agents of school improve- ment. This is possible if the teachers are appropriately supported by external experts who help to bring out the potential present in the school.Qual è l’impatto che i progetti finanziati possono avere sull’organizzazione scolastica e sugli esiti degli studenti? Come può essere monitorato? Il monitoraggio rileva gli impatti o è esso stesso fonte di impatto? Può fornire ai docenti metodologie e strumenti in grado di incrementarne le possibilità di autovalutazione? L’articolo intende fornire alcune risposte a questi interrogativi, descrivendo - in estrema sintesi - il monitoraggio del progetto Scuolinsieme, un insieme di interventi finanziati dalla Fondazione per la Scuola della Compagnia di San Paolo, applicati in 34 Istituti secondari di primo grado dal 2017 al 2020. Partendo da una sintetica descrizione degli interventi e del sistema di indicatori utilizzato, viene presentata una strategia di monitoraggio che non mira solo a rilevare gli effetti degli interventi stessi ma ad impattare su questi, di concerto con le azioni progettuali e formative. Dalle prime analisi dei dati emergono esiti promettenti associabili a tale approccio, soprattutto per quanto riguarda le pratiche messe in atto dagli insegnanti e la consapevolezza di poter essere essi stessi i principali agenti del miglioramento scolastico, a patto che vengano opportuna- mente supportati da esperti esterni che li aiutino a far emergere le potenzialità insite nell’istituto