Bone Regeneration in Implant Dentistry: Role of Mesenchymal Stem Cells

This chapter focuses on a review of the activity of non-embryonic mesenchymal stem cells used to regenerate jaw bones in dentistry. Recent research of non-embryonic stem cells provides new possibilities for noninvasively obtaining new autologous bone from stem cells provided by various tissues from the same patient. Disaggregation of biologic tissue harvested from the patients during surgery permits extraction of stem cells from a small sample of connective tissue obtained from the patient’s lingual mucosa or from the postextraction surgical site where the endosseous implant will be inserted

Differences between panoramic and Cone Beam-CT in the surgical evaluation of lower third molars

The aim of this study was to evaluate the ability to identify the contiguity between the root of the mandibular third molar and the mandibular canal (MC) in panoramic radiographs compared with Cone Beam-CT. Panoramic radiographs of 326 third molars and CBCT radiographs of 86 cases indicated for surgery and considered at risk were evaluated. The following signs were assessed in panoramic radiographs as risk factors: radiolucent band, loss of MC border, change in MC direction, MC narrowing, root narrowing, root deviation, bifid apex, superimposition, and contact between the root third molar and the MC. Radiographic signs associated with absence of MC cortical bone are: radiolucent band, loss of MC border, change in MC direction, and superimposition. The number of risk factors was significantly increased with an increasing depth of inclusion. CBCT revealed a significant association between the absence of MC cortical bone and a lingual or interradicular position of the MC. In cases in which panoramic radiographs do not exclude contiguity between the MC and tooth, careful assessment the signs and risks on CBCT radiographs is indicated for proper identification of the relationships between anatomic structures

Remediación de efluentes provenientes de feedlots mediante el uso de plantas acuáticas

Feedlots have increased in several regions of Argentina, particularly in the Pampas. The absence of adequate treatments of the effluents produced in these establishments creates serious problems to the society. Phytoremediation can be defined as inexpensive and environmentally sustainable strategy used to remove pollutants by plants. The aim of this study was to evaluate the remediation potential of two macrophyte species (Eichhornia crassipes and Hydrocotyle ranunculoides) on a feedlot effluent. This effluent was treated with these species for 31 days. Control and macrophyte treatments decreased dissolved inorganic nitrogen (DIN), Kjeldahl nitrogen (Kj N), biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved salts (TDS), total phosphorus (TP), Pb, Zn and Cr levels. At macrophyte treatments, relatively constant pH levels were kept and decreased EC and TDS values were obtained compared to control, mitigating the release of contaminants and potential greenhouse gases to the atmosphere. Moreover, significant increases in biomass were obtained, being higher in E. crassipes. The results allow concluding that the presence of aquatic plants increases the removal rates of nutrients, organic matter and heavy metals from wastewater in approximately 10-17 days for a feedlot effluent with high organic load.En diversas regiones de la Argentina, en particular en la región Pampeana, se han incrementado los sistemas de engorde a corral (feedlots). La ausencia de tratamientos adecuados de los efluentes producidos por estos establecimientos crea severos problemas para la sociedad. El uso de plantas nativas para la remediación de sistemas contaminados es una tecnología de muy bajo costo y ambientalmente sustentable. El objetivo de este estudio fue evaluar el potencial de remediación de dos especies de plantas acuáticas (Eichhornia crassipes e Hydrocotyle ranunculoides) sobre un efluente de feedlot. Este efluente fue tratado con estas especies durante 31 días. Tanto el tratamiento control como los tratamientos con macrófitas disminuyen los niveles de nitrógeno inorgánico disuelto, nitrógeno Kjeldahl, demanda bioquímica de oxígeno, demanda química de oxígeno, sales totales disueltas (STD), fósforo total, Pb, Zn y Cr. El uso de macrófitas mantuvo relativamente constante los niveles de pH, disminuyendo CE y STD respecto del control, pudiendo mitigar la liberación de contaminantes hacia la atmósfera. Además se alcanzaron incrementos significativos de biomasa, siendo mayores en E. crassipes. Los resultados permiten concluir que la presencia de plantas acuáticas incrementan las tasas de remoción de nutrientes, material orgánico y metales pesados en aproximadamente 10-17 días desde un efluente con alta carga orgánica.Fil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (Argentina). Instituto de Microbiología y Zoología Agrícola. Laboratorio de Transformación de ResiduosFil: Arreghini, Silvana. Universidad de Buenos Aires. Facultad de AgronomíaFil: Serafini, Roberto José María. Universidad de Buenos Aires. Facultad de AgronomíaFil: Bres, Patricia Alina. Instituto Nacional de Tecnología Agropecuaria (Argentina). Instituto de Microbiología y Zoología Agrícola. Laboratorio de Transformación de ResiduosFil: Crespo, Diana Elvira. Instituto Nacional de Tecnología Agropecuaria (Argentina). Instituto de Microbiología y Zoología Agrícola. Laboratorio de Transformación de ResiduosFil: Fabrizio de Iorio, Alicia Rosa. Universidad de Buenos Aires. Facultad de Agronomí

Remediación de efluentes provenientes de feedlots mediante el uso de plantas acuáticas

Feedlots have increased in several regions of Argentina, particularly in the Pampas. The absence of adequate treatments of the effluents produced in these establishments creates serious problems to the society. Phytoremediation can be defined as inexpensive and environmentally sustainable strategy used to remove pollutants by plants. The aim of this study was to evaluate the remediation potential of two macrophyte species (Eichhornia crassipes and Hydrocotyle ranunculoides) on a feedlot effluent. This effluent was treated with these species for 31 days. Control and macrophyte treatments decreased dissolved inorganic nitrogen (DIN), Kjeldahl nitrogen (Kj N), biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved salts (TDS), total phosphorus (TP), Pb, Zn and Cr levels. At macrophyte treatments, relatively constant pH levels were kept and decreased EC and TDS values were obtained compared to control, mitigating the release of contaminants and potential greenhouse gases to the atmosphere. Moreover, significant increases in biomass were obtained, being higher in E. crassipes. The results allow concluding that the presence of aquatic plants increases the removal rates of nutrients, organic matter and heavy metals from wastewater in approximately 10-17 days for a feedlot effluent with high organic load.Feedlots have increased in several regions of Argentina, particularly in the Pampas. The absence of adequate treatments of the effluents produced in these establishments creates serious problems to the society. Phytoremediation can be defined as inexpensive and environmentally sustainable strategy used to remove pollutants by plants. The aim of this study was to evaluate the remediation potential of two macrophyte species (Eichhornia crassipes and Hydrocotyle ranunculoides) on a feedlot effluent. This effluent was treated with these species for 31 days. Control and macrophyte treatments decreased dissolved inorganic nitrogen (DIN), Kjeldahl nitrogen (Kj N), biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved salts (TDS), total phosphorus (TP), Pb, Zn and Cr levels. At macrophyte treatments, relatively constant pH levels were kept and decreased EC and TDS values were obtained compared to control, mitigating the release of contaminants and potential greenhouse gases to the atmosphere. Moreover, significant increases in biomass were obtained, being higher in E. crassipes. The results allow concluding that the presence of aquatic plants increases the removal rates of nutrients, organic matter and heavy metals from wastewater in approximately 10-17 days for a feedlot effluent with high organic load

Nanofeatured Titanium Surfaces for Dental Implantology: Biological Effects, Biocompatibility, and Safety

Nanotechnology enables the control and modification of the chemical and topographical characteristics of materials of size less than 100 nm, down to 10 nm. The goal of this review is to discuss the role of titanium substrates as nanoscale surface modification tools for improving various aspects of implantology, including osseointegration and antibacterial properties. Techniques that can impart nanoscale topographical features to endosseous implants are described. Since the advent of nanotechnology, cellular specific functions, such as adhesion, proliferation, and differentiation, have been better understood. By applying these technologies, it is possible to direct cellular responses and improve osseointegration. Conversely, modulating surface features by nanotechnology could have the effect of decreased bacterial colonization

Role of Plasma Membrane Caveolae/Lipid Rafts in VEGF-Induced Redox Signaling in Human Leukemia Cells

Caveolae/lipid rafts are membrane-rich cholesterol domains endowed with several functions in signal transduction and caveolin-1 (Cav-1) has been reported to be implicated in regulating multiple cancer-associated processes, ranging from tumor growth to multidrug resistance and angiogenesis. Vascular endothelial growth factor receptor-2 (VEGFR-2) and Cav-1 are frequently colocalized, suggesting an important role played by this interaction on cancer cell survival and proliferation. Thus, our attention was directed to a leukemia cell line (B1647) that constitutively produces VEGF and expresses the tyrosine-kinase receptor VEGFR-2. We investigated the presence of VEGFR-2 in caveolae/lipid rafts, focusing on the correlation between reactive oxygen species (ROS) production and glucose transport modulation induced by VEGF, peculiar features of tumor proliferation. In order to better understand the involvement of VEGF/VEGFR-2 in the redox signal transduction, we evaluated the effect of different compounds able to inhibit VEGF interaction with its receptor by different mechanisms, corroborating the obtained results by immunoprecipitation and fluorescence techniques. Results here reported showed that, in B1647 leukemia cells, VEGFR-2 is present in caveolae through association with Cav-1, demonstrating that caveolae/lipid rafts act as platforms for negative modulation of VEGF redox signal transduction cascades leading to glucose uptake and cell proliferation, suggesting therefore novel potential targets

Fermentation of Vaccinium floribundum Berries with Lactiplantibacillus plantarum Reduces Oxidative Stress in Endothelial Cells and Modulates Macrophages Function

Accumulating evidence suggests that high consumption of natural antioxidants promotes health by reducing oxidative stress and, thus, the risk of developing cardiovascular diseases. Similarly, fermentation of natural compounds with lactic acid bacteria (LAB), such as Lactiplantibacillus plantarum, enhances their beneficial properties as regulators of the immune, digestive, and cardiovascular system. We investigated the effects of fermentation with Lactiplantibacillus plantarum on the antioxidant and immunomodulatory effects of Pushgay berries (Vaccinium floribundum, Ericaceae family) in human umbilical vein endothelial cells (HUVECs) and macrophage cell line RAW264.7. Polyphenol content was assayed by Folin-Ciocalteu and HPLC-MS/MS analysis. The effects of berries solutions on cell viability or proliferation were assessed by WST8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt and Lactate dehydrogenase (LDH) release, Trypan blue exclusion test, and Alamar blue assay. Antioxidant activity was evaluated by a cell-based chemiluminescent probe for the detection of intracellular H2O2 production in HUVECs. Heme oxygenase-1 (HO-1) expression levels were investigated by RT-qPCR. Glutathione reductase (GR), glutathione peroxidase (Gpx), superoxide dismutase (SOD), and catalase (CAT) activities, as markers of intracellular antioxidant defense, were evaluated by spectrophotometric analysis. The immunomodulatory activity was examined in RAW 264.7 by quantification of inducible nitric oxide synthase (iNOS) and Tumor Necrosis Factor-alpha (TNF alpha) by RT-qPCR. Data showed that fermentation of Pushgay berries (i) enhances the content of quercetin aglycone, and (ii) increases their intracellular antioxidant activity, as indicated by the reduction in H2O2-induced cell death and the decrease in H2O2-induced HO-1 gene expression in HUVECs treated for 24 h with fermented berries solution (10 mu g/mL). Moreover, treatment with Pushgay berries for 72 h (10 mu g/mL) promotes cells growth in RAW 264.7, and only fermented Pushgay berries increase the expression of iNOS in the same cell line. Taken together, our results show that LAB fermentation of Pushgay berries enhances their antioxidant and immunomodulatory properties

Study of the effects of different biomaterials on osteogenic differentiation of oral-periosteal cells

Bone regeneration is currently one of the most important challenges for regenerative medicine and it is considered an ideal clinical strategy in the maxillo-facial area [1]. Bone resorption of alveolar crest occurring after tooth extraction leads to several risks for future treatments, including dental implants. For this reason, alveolar ridge preservation (ARP) has become a key component of contemporary clinical dentistry. Several clinical techniques and bone substitute materials can be used to fill the socket after tooth extraction. For all of them, the principle aim is to keep the shape and the size of the bone socket of the extracted tooth allowing inserting the dental implants [2]. The goal of our study was to compare different biocompatible scaffolds based on PLGA (Fisiograft®), Bioglass (Activioss®) and collagen (Sombrero®) in an in vitro model of tissue engineering for dental applications. The cells used in our study derived from Periosteum obtained from four different patients that underwent socket preservation selected by the School of Dentistry of the University of Pavia, previous informed consent. We created bio-complexes constituted by mesenchymal-periosteal cells seeded on different types of biomaterials and we performed adhesion, morphological, proliferative and bone differentiation analyses at different time points (7, 14 and 28 days of culture) in proliferative and osteogenic conditions. Bone differentiation was evaluated by qRT-PCR on genes involved in osteoblast development, like BMP-2, Osteocalcin and Periostin. Our results demonstrated that Sombrero® enhanced adhesion and proliferation of periosteal cells, as highlighted by Haematoxylin-Eosin staining and XTT test (3 and 7 days). Long-term studies (14 and 28 days) demonstrated that periosteal differentiation is about the same among the different materials tested. From these preliminary studies we can conclude that it could be advantageous the clinical use of both collagenic and PLGA scaffolds in order to ameliorate initial colonization and subsequent mechanical support in maxillo-bone regeneration. This work was supported by grant from NATO 2016 (“RAWINTS” (G-984961): RApid Skin Wound healing by INtegrated Tissue engineering and Sensing)

Conexões Afirmativas - oficinas com estudantes de escolas públicas

A presente ação de extensão é desenvolvida pelo grupo PET Conexões Políticas Públicas de Juventude da Universidade Federal do Rio Grande do Sul (UFRGS). O grupo tem como temática principal as Ações Afirmativas, e realiza oficinas em escolas públicas de Ensino Médio priorizando a interação com estudantes da periferia de Porto Alegre. Objetiva a construção de um espaço de divulgação e diálogo entre estudantes da Universidade e de escolas públicas, problematizando e socializando temáticas como as ações afirmativas, políticas de ingresso e permanência no Ensino Superior, bem como dos direitos da juventude à educação pública