Bioimpedancemetry for the assessment of periodontal tissue inflammation: a numerical feasibility study

In dentistry possible inflammatory episodes of oral cavity can be very frequent (periodontitis, mucositis, peri-implantitis) and they can have serious consequences. Indeed, peri-implantitis is still the principal cause of implant failure. Impedance values of biological tissues are related to the physiological/pathological state of the tissue itself. In fact, an inflamed site exhibits an impedance value lower than that of the corresponding healthy tissue. Based on these observations, the aim of this work is to determine if impedancemetric measurements are able to provide information about the inflammatory state of tissues. A numerical 3D model has been realized to simulate the measurement conditions present in the event of inflammation around a dental implant. The aim is to understand if it is possible to determine the presence of an inflamed tissue and to locate its site, so that the treatment could be specifically focused in that specific area. A simplified geometry reproducing the implant has been realized in order to validate the numerical model by means of experimental measurements. The obtained results are satisfactorily accurate, so the model can be considered reliable. Therefore, multiple simulations have been run on the original model to carry out a parametric study in terms of different conductivity values, different volumes of inflamed tissues and different measurement frequencies. The advantages and limits of such a method have been shown to properly define the main constraints for the system design.     

Co-culture of dedifferentiated and primary human chondrocytes obtained from cadaveric donor enhance the histological quality of repair tissue: an in-vivo animal study

To compare the quality of the repair tissue in three-dimensional co-culture of human chondrocytes implanted in an in vivo model. Six cadaveric and five live human donors were included. Osteochondral biopsies from the donor knees were harvested for chondrocyte isolation. Fifty percent of cadaveric chondrocytes were expanded until passage-2 (P2) while the remaining cells were cryopreserved in passage-0 (P0). Fresh primary chondrocytes (P0f) obtained from live human donors were co-cultured. Three-dimensional constructs were prepared with a monolayer of passage-2 chondrocytes, collagen membrane (Geistlich Bio-Gide^®), and pellet of non-co-cultured (P2) or co-cultured chondrocytes (P2 + P0c, P2 + P0f). Constructs were implanted in the subcutaneous tissue of athymic mice and left for 3 months growth. Safranin-O and Alcian blue staining were used to glycosaminoglycan content assessment. Aggrecan and type-II collagen were evaluated by immunohistochemistry. New-formed tissue quality was evaluated with an adaptation of the modified O’Driscoll score. Histological quality of non-co-cultured group was 4.37 (SD ±4.71), while co-cultured groups had a mean score of 8.71 (SD ±3.98) for the fresh primary chondrocytes and 9.57 (SD ±1.27) in the cryopreserved chondrocytes. In immunohistochemistry, Co-culture groups were strongly stained for type-II and aggrecan not seen in the non-co-cultured group. It is possible to isolate viable chondrocytes from cadaveric human donors in samples processed in the first 48-h of dead. There is non-significant difference between the numbers of chondrocytes isolated from live or cadaveric donors. Cryopreservation of cadaveric primary chondrocytes does not alter the capability to form cartilage like tissue. Co-culture of primary and passaged chondrocytes enhances the histological quality of new-formed tissue compared to non-co-cultured cells.     

Managed Wildfire Effects on Forest Resilience and Water in the Sierra Nevada

Fire suppression in many dry forest types has left a legacy of dense, homogeneous forests. Such landscapes have high water demands and fuel loads, and when burned can result in catastrophically large fires. These characteristics are undesirable in the face of projected warming and drying in the western US. Alternative forest and fire treatments based on managed wildfire—a regime in which fires are allowed to burn naturally and only suppressed under defined management conditions—offer a potential strategy to ameliorate the effects of fire suppression. Understanding the long-term effects of this strategy on vegetation, water, and forest resilience is increasingly important as the use of managed wildfire becomes more widely accepted. The Illilouette Creek Basin in Yosemite National Park has experienced 40 years of managed wildfire, reducing forest cover by 22%, and increasing meadow areas by 200% and shrublands by 24%. Statistical upscaling of 3300 soil moisture observations made since 2013 suggests that large increases in wetness occurred in sites where fire caused transitions from forests to dense meadows. The runoff ratio (ratio of annual runoff to precipitation) from the basin appears to be increasing or stable since 1973, compared to declines in runoff ratio for nearby, unburned watersheds. Managed wildfire appears to increase landscape heterogeneity, and likely improves resilience to disturbances, such as fire and drought, although more detailed analysis of fire effects on basin-scale hydrology is needed.     

Gastrointestinal stromal tumors (GIST): Facing cell death between autophagy and apoptosis

Autophagy and apoptosis are 2 fundamental biological mechanisms that may cooperate or be antagonistic, although both are involved in deciding the fate of cells in physiological or pathological conditions. These 2 mechanisms coexist simultaneously in cells and share common upstream signals and stimuli. Autophagy and apoptosis play pivotal roles in cancer development. Autophagy plays a key function in maintaining tumor cell survival by providing energy during unfavorable metabolic conditions through its recycling mechanism, and supporting the high energy requirement for metabolism and growth. This review focuses on gastrointestinal stromal tumors and cell death through autophagy and apoptosis, taking into account the involvement of both of these processes in tumor development and growth and as mechanisms of drug resistance. We also focus on the crosstalk between autophagy and apoptosis as an emerging field with major implications for the development of novel therapeutic options.     

IgG,IgA, and lysozyme in Martina Franca donkey jennies and their foals

Because immune transfer from jenny to donkey foal is mostly unknown, the aim of the present study was to evaluate, from 5 days before to 10 days after foaling, immunoglobulin (Ig)G, IgA, and lysozyme peripartal concentrations in serum and mammary secretions of 10 healthy, spontaneously foaling Martina Franca jennies and in serum of their mature, viable, healthy foals, in the first 10 days after birth. The results showed that, in jennies, mammary secretion of IgG levels (ranging between 16 and 75 mg/mL) and IgA (0.9–2 mg/mL), and IgG (6.8–13.5 mg/mL) and IgA (0.5–2.4 mg/mL) serum concentrations were not different along the time of study. Also, IgG concentrations in serum of foals did not show significant differences although a high level was observed at 12 hours after birth (8 mg/mL), and IgA concentrations in serum of foals did not show any significant difference, although a high level was observed at 12 hours after birth (1.2 mg/mL). Lysozyme increased significantly at Day 2 after parturition in mammary secretions of jennies (551.9 μg/mL) and at 12 hours in serum of foals (25.9 μg/mL). The study demonstrated that the pattern of passive immune transfer in donkey foals seems to be similar to that reported for the horse foal, with IgG predominating IgA in serum and mammary secretions of the jenny and also in serum of foals. The most significant early increase in foals' serum concerns lysozyme, which probably plays an important role in the innate immunity of the donkey foal in the first challenging hours after birth.     

Crenulations of the hinge plate of pectinoideans

Checa, A.G., Esteban‐Delgado, F.J. and Salas, C. 2010. Crenulations of the hinge plate of pectinoideans. —Acta Zoologica (Stockholm) 92 : 344–354. Crenulations are a succession of micron‐sized elongated ridges and troughs with a general dorsoventral pseudo‐labyrinthine pattern that are present on the hinge plate of most pectinoideans. The crenulations of opposing valves are complementary and interpenetrate in a hinge‐like fashion. They are also imprinted in the dorsal mantle, although there is evidence that the mantle adheres only at the ridges, but not at the troughs. Those mantle areas that secrete the ridges contain cells that are richer in structures, indicating an active metabolism than those facing the troughs. Crenulations are formed because the dorsal mantle expands allometrically along the anteroposterior direction. The excess length is accommodated by creasing. Crenulations initiate at the anterior and posterior ends of the hinge plate as shallow spheruliths, which increase in height with time until the mantle on both sides detaches from the shell areas forming the neighbouring troughs. A contact differentiation of the mantle into actively and passively secreting bands follows. This genetic model explains the general pattern as well as the changes in the morphology of crenulations that occur during growth. Crenulations are secondary postlarval structures unrelated to the provinculum. Their presence in the earliest pectinoideans makes crenulations a plesiomorphic character of the group.