726 research outputs found
Labor Income and Risky Assets under Market Incompleteness: Evidence from Italian Data
Theory suggests that uninsurable income risk induces individuals to accumulate assets as a precautionary reserve of value. Most assets, however, bear rate of return risk, that can be diversified only if every asset is traded by a large number of individuals and arbitrage is frictionless. Using Italian micro-data, we find evidence of income and asset risks that affect consumption. Italian households are particularly well insured against illness but not against job losses. Moreover, we detect a positive, yet weak, effect of asset holding on the variability of consumption streams across households.incomplete markets, consumption insurance, precautionary saving, financial markets, equity premium puzzle
Histologic evaluation of bone healing of adjacent alveolar sockets grafted with bovine- and porcine-derived bone: a comparative case report in humans
To evaluate and compare histomorphometrically the bone response to two xenografts, one bovine and the other porcine, grafted in adjacent extraction sockets in a human. In this case report, two adjacent maxillary premolars were extracted, and the sockets were filled with two different xenogeneic bone substitutes (first premolar with bovine bone, and second premolar with porcine bone) to counteract post-extraction volume loss. Following 6 months bone core specimens were harvested during the placement of implants at the regenerated sites. Histomorphometrically, for the bovine xenograft the percentage of newly formed bone (osteoid) was 26.85%, the percentage of the residual graft material was 17.2% and the percentage of connective tissue 48.73%, while for the porcine xenograft, newly formed bone (osteoid) represented 32.19%, residual graft material was 6.57% and non-mineralized connective tissue was 52.99%. Histological results indicated that both biomaterials assessed in this study as grafts for socket preservation technique are biocompatible and osteoconductive. Bovine bone derived demonstrated to be less resorbable than porcine bone derived. Both xenogenic biomaterials did not interfere with the normal bone reparative processe
From Osteoclast Differentiation to Osteonecrosis of the Jaw: Molecular and Clinical Insights
Bone physiology relies on the delicate balance between resorption and formation of its tissue. Bone resorption depends on a process called osteoclastogenesis in which bone-resorbing cells, i.e., osteoclasts, are produced by the differentiation of more undifferentiated progenitors and precursors. This process is governed by two main factors, monocyte colony-stimulating factor (M-CSF) and receptor activator of NFÎșB ligand (RANKL). While the former exerts a proliferating effect on progenitors/precursors, the latter triggers a differentiation effect on more mature cells of the same lineage. Bone homeostasis requires a perfect spaceâtime coordination of the involved signals. When osteoclastogenesis is poorly balanced with the differentiation of the bone forming counterparts, i.e., osteoblasts, physiological bone remodelling can turn into a pathological state, causing the systematic disruption of bone tissue which results in osteopenia or osteolysis. Examples of these conditions are represented by osteoporosis, Pagetâs disease, bone metastasis, and multiple myeloma. Therefore, drugs targeting osteoclastogenesis, such as bisphosphonates and an anti-RANKL monoclonal antibody, have been developed and are currently used in the treatment of such diseases. Despite their demonstrated therapeutic efficacy, these agents are unfortunately not devoid of side effects. In this regard, a condition called osteonecrosis of the jaw (ONJ) has been recently correlated with anti-resorptive therapy. In this review we will address the involvement of osteoclasts and osteoclast-related factors in the pathogenesis of ONJ. It is to be hoped that a better understanding of the biological mechanisms underlying bone remodelling will help in the design a medical therapeutic approach for ONJ as an alternative to surgical procedures.Bone physiology relies on the delicate balance between resorption and formation of its tissue. Bone resorption depends on a process called osteoclastogenesis in which bone-resorbing cells, i.e., osteoclasts, are produced by the differentiation of more undifferentiated progenitors and precursors. This process is governed by two main factors, monocyte colony-stimulating factor (M-CSF) and receptor activator of NFÎșB ligand (RANKL). While the former exerts a proliferating effect on progenitors/precursors, the latter triggers a differentiation effect on more mature cells of the same lineage. Bone homeostasis requires a perfect spaceâtime coordination of the involved signals. When osteoclastogenesis is poorly balanced with the differentiation of the bone forming counterparts, i.e., osteoblasts, physiological bone remodelling can turn into a pathological state, causing the systematic disruption of bone tissue which results in osteopenia or osteolysis. Examples of these conditions are represented by osteoporosis, Pagetâs disease, bone metastasis, and multiple myeloma. Therefore, drugs targeting osteoclastogenesis, such as bisphosphonates and an anti-RANKL monoclonal antibody, have been developed and are currently used in the treatment of such diseases. Despite their demonstrated therapeutic efficacy, these agents are unfortunately not devoid of side effects. In this regard, a condition called osteonecrosis of the jaw (ONJ) has been recently correlated with anti-resorptive therapy. In this review we will address the involvement of osteoclasts and osteoclast-related factors in the pathogenesis of ONJ. It is to be hoped that a better understanding of the biological mechanisms underlying bone remodelling will help in the design a medical therapeutic approach for ONJ as an alternative to surgical procedures
Comparative 16SrDNA Gene-Based Microbiota Profiles of the Pacific Oyster (Crassostrea gigas) and the Mediterranean Mussel (Mytilus galloprovincialis) from a Shellfish Farm (Ligurian Sea, Italy)
The pacific oyster Crassostrea gigas and the Mediterranean mussel Mytilus galloprovincialis are two widely farmed bivalve species which show contrasting behaviour in relation to microbial diseases, with C. gigas being more susceptible and M. galloprovincialis being generally resistant. In a recent study, we showed that different susceptibility to infection exhibited by these two bivalve species may depend on their different capability to kill invading pathogens (e.g., Vibrio spp.) through the action of haemolymph components. Specific microbial-host interactions may also impact bivalve microbiome structure and further influence susceptibility/resistance to microbial diseases. To further investigate this concept, a comparative study of haemolymph and digestive gland 16SrDNA gene-based bacterial microbiota profiles in C. gigas and M. galloprovincialis co-cultivated at the same aquaculture site was carried out using pyrosequencing. Bacterial communities associated with bivalve tissues (hemolymph and digestive gland) were significantly different from those of seawater, and were dominated by relatively few genera such as Vibrio and Pseudoalteromonas. In general, Vibrio accounted for a larger fraction of the microbiota in C. gigas (on average 1.7-fold in the haemolymph) compared to M. galloprovincialis, suggesting that C. gigas may provide better conditions for survival for these bacteria, including potential pathogenic species such as V. aestuarianus. Vibrios appeared to be important members of C. gigas and M. galloprovincialis microbiota and might play a contrasting role in health and disease of bivalve species. Accordingly, microbiome analyses performed on bivalve specimens subjected to commercial depuration highlighted the ineffectiveness of such practice in removing Vibrio species from bivalve tissues
Free response of a gravitational liquid sheet by means of three-dimensional Volume-of-Fluid simulations
The volume-of-fluid (VOF) method is employed to simulate the dynamics of gravitational liquid sheets (curtains) issuing into an initially quiescent gaseous environment
Colecistectomia laparoscopica in situs viscerum inversus totalis: nota di tecnica
The Authors report the case of a patient admitted in Emergency Room for biliary colic. She knew her dextrocardia. ECG and chest X-ray confirmed the dextrocardia. Ultrasonography and CT scan discovered a situs viscerum inversus totalis and cholecystolithiasis responsible of the abdominal colic. Laparoscopic cholecystectomy was performed. The Authors discuss the clinical case and the particular technique used
Vibrio cholerae interactions with Mytilus galloprovincialis hemocytes mediated by serum components
Edible bivalves (e.g., mussels, oysters) can accumulate large amount of bacteria in their tissues and act as passive carriers of pathogens to humans. Bacterial persistence inside bivalves depends, at least in part, on hemolymph anti-bacterial activity that is exerted by both serum soluble factors and phagocytic cells (i.e., the hemocytes). It was previously shown that Mytilus galloprovincialis hemolymph serum contains opsonins that mediate D-mannose-sensitive interactions between hemocytes and Vibrio cholerae O1 El Tor bacteria that carry the mannose-sensitive hemagglutinin (MSHA). These opsonins enhance phagocytosis and killing of vibrios by facilitating their binding to hemocytes. Since V. cholerae strains not carrying the MSHA ligand (O1 classical, non-O1/O139) are present in coastal water and can be entrapped by mussels, we studied whether in mussel serum, in addition to opsonins directed toward MSHA, other components can mediate opsonization of these bacteria. By comparing interactions of O1 classical and non-O1/O139 strains with hemocytes in artificial sea water and serum, it was found that M. galloprovincialis serum contains components that increase by at approximately twofold their adhesion to, association with, and killing by hemocytes. Experiments conducted with high and low molecular mass fractions obtained by serum ultrafiltration indicated that these compounds have molecular mass higher than 5000 Da. Serum exposure to high temperature (80°C) abolished its opsonizing capability suggesting that the involved serum active components are of protein nature. Further studies are needed to define the chemical properties and specificity of both the involved bacterial ligands and hemolymph opsonins. This information will be central not only to better understand V. cholerae ecology, but also to improve current bivalve depuration practices and properly protect human health
gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples
The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA) is a chitin-binding protein involved in V . cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V . cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V . cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR) samples. Overall, the method is sensitive (50 gene copies), highly specific for V . cholerae and failed to amplify strains of the closely-related species Vibrio mimicus . The sensitivity of the assay applied to environmental and stool samples spiked with V . cholerae ATCC 39315 was comparable to that of pure cultures and was of 10 2 genomic units/l for drinking and seawater samples, 10 1 genomic units/g for sediment and 10 2 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V . cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V . cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME) is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies
Pulsed Electro-Magnetic Field (PEMF) Effect on Bone Healing in Animal Models: A Review of Its Efficacy Related to Different Type of Damage
Biophysical energies are a versatile tool to stimulate tissues by generating biopotentials. In particular, pulsed electromagnetic field (PEMF) stimulation has intrigued researchers since the 1970s. To date, many investigations have been carried out in vivo, but a gold standard treatment protocol has not yet been defined. The main obstacles are represented by the complex setting of PEMF characteristics, the variety of animal models (including direct and indirect bone damage) and the lack of a complete understanding of the molecular pathways involved. In the present review the main studies about PEMF stimulation in animal models with bone impairment were reviewed. PEMF signal characteristics were investigated, as well as their effect on molecular pathways and osseous morphological features. We believe that this review might be a useful starting point for a prospective study in a clinical setting. Consistent evidence from the literature suggests a potential beneficial role of PEMF in clinical practice. Nevertheless, the wide variability of selected parameters (frequency, duration, and amplitude) and the heterogeneity of applied protocols make it difficult to draw certain conclusions about PEMF effectiveness in clinical implementation to promote bone healing. Deepening the knowledge regarding the most consistent results reported in literature to date, we believe that this review may be a useful starting point to propose standardized experimental guidelines. This might provide a solid base for further controlled trials, to investigate PEMF efficacy in bone damage conditions during routine clinical practic
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