Regeneração natural do componente arbóreo após a mortalidade de um maciço de taquara em um fragmento de floresta ombrófila mista em Lages - SC

The present study aimed to analyze the floristic and structural descriptors of tree species natural regeneration in a forest sector with synchronized bamboo (Merostachys multiramea Hackel) die-off (CT) and an adjacent area with continuous canopy cover (ST) in an araucaria forest fragment in the municipality of Lages, Santa Catarina state. A total of 14, 5x5m, plots (six plots in CT sector and eight in ST sector) were allocated, where all tree species regenerative individual with circumference at breast height smaller than 15cm and height higher than 25cm was measured (diameter at soil level) and identified. The richest families were: Myrtaceae (nine), Solanaceae (six) and Aquifoliaceae (four). The Shannon Diversity Index in ST and CT sectors were respectively 2.73 and 2.31. The species with the highest importance values in CT sector were Solanum variabile, Piptocarpha angustifolia, Mimosa scabrella, Jacaranda puberula and Solanum pseudoquina. In ST sector, the species with highest importance values were Myrsine lorentziana, Casearia decandra, Cinnamodendron dinisii, Drimys brasiliensis and Ilex paraguariensis. The results showed that the synchronized bamboo die-off influenced the spatial variation in the floristic and structural descriptors of the tree species natural regeneration.

Clinical outcomes following regenerative therapy of non-contained intrabony defects using a deproteinized bovine bone mineral combined with either enamel matrix derivative or collagen membrane

BACKGROUND The purpose of this study is to compare clinical outcomes in the treatment of deep non-contained intrabony defects (i.e., with ≥70% 1-wall component and a residual 2- to 3-wall component in the most apical part) using deproteinized bovine bone mineral (DBBM) combined with either enamel matrix protein derivative (EMD) or collagen membrane (CM). METHODS Forty patients with multiple intrabony defects were enrolled. Only one non-contained defect per patient with an intrabony depth ≥3 mm located in the interproximal area of single- and multirooted teeth was randomly assigned to the treatment with either EMD + DBBM (test: n = 20) or CM + DBBM (control: n = 20). At baseline and after 12 months, clinical parameters including probing depth (PD) and clinical attachment level (CAL) were recorded. The primary outcome variable was the change in CAL between baseline and 12 months. RESULTS At baseline, the intrabony component of the defects amounted to 6.1 ± 1.9 mm for EMD + DBBM and 6.0 ± 1.9 mm for CM + DBBM sites (P = 0.81). The mean CAL gain at sites treated with EMD + DBBM was not statistically significantly different (P = 0.82) compared with CM + DBBM (3.8 ± 1.5 versus 3.7 ± 1.2 mm). No statistically significant difference (P = 0.62) was observed comparing the frequency of CAL gain ≥4 mm between EMD + DBBM (60%) and CM + DBBM (50%) or comparing the frequency of residual PD ≥6 mm between EMD + DBBM (5%) and CM + DBBM (15%) (P = 0.21). CONCLUSION Within the limitations of the present study, regenerative therapy using either EMD + DBBM or CM + DBBM yielded comparable clinical outcomes in deep non-contained intrabony defects after 12 months.

Clinical and radiographic outcomes of a combined resective and regenerative approach in the treatment of peri-implantitis: a prospective case series

AIM To assess the clinical and radiographic outcomes applying a combined resective and regenerative approach in the treatment of peri-implantitis. MATERIALS AND METHODS Subjects with implants diagnosed with peri-implantitis (i.e., pocket probing depth (PPD) ≥5 mm with concomitant bleeding on probing (BoP) and ≥2 mm of marginal bone loss or exposure of ≥1 implant thread) were treated by means of a combined approach including the application of a deproteinized bovine bone mineral and a collagen membrane in the intrabony and implantoplasty in the suprabony component of the peri-implant lesion, respectively. The soft tissues were apically repositioned allowing for a non-submerged healing. Clinical and radiographic parameters were evaluated at baseline and 12 months after treatment. RESULTS Eleven subjects with 11 implants were treated and completed the 12-month follow-up. No implant was lost yielding a 100% survival rate. At baseline, the mean PPD and mean clinical attachment level (CAL) were 8.1 ± 1.8 mm and 9.7 ± 2.5 mm, respectively. After 1 year, a mean PPD of 4.0 ± 1.3 mm and a mean CAL of 6.7 ± 2.5 mm were assessed. The differences between the baseline and the follow-up examinations were statistically significant (P = 0.001). The mucosal recession increased from 1.7 ± 1.5 at baseline to 3.0 ± 1.8 mm at the 12-month follow-up (P = 0.003). The mean% of sites with BoP+ around the selected implants decreased from 19.7 ± 40.1 at baseline to 6.1 ± 24.0 after 12 months (P = 0.032). The radiographic marginal bone level decreased from 8.0 ± 3.7 mm at baseline to 5.2 ± 2.2 mm at the 12-month follow-up (P = 0.000001). The radiographic fill of the intrabony component of the defect amounted to 93.3 ± 13.0%. CONCLUSION Within the limits of this study, a combined regenerative and resective approach for the treatment of peri-implant defects yielded positive outcomes in terms of PPD reduction and radiographic defect fill after 12 months.

A regenerative link in the ionic fluxes through the weaver potassium channel underlies the pathophysiology of the mutation

The homozygous weaver mouse displays neuronal degeneration in several brain regions. Previous experiments in heterologous expression systems showed that the G protein-gated inward rectifier K+ channel (GIRK2) bearing the weaver pore-region GYG-to-SYG mutation (i) is not activated by Gβγ subunits, but instead shows constitutive activation, and (ii) is no longer a K+-selective channel but conducts Na+ as well. The present experiments on weaverGIRK2 (wvGIRK2) expressed in Xenopus oocytes show that the level of constitutive activation depends on intracellular Na+ concentration. In particular, manipulations that decrease intracellular Na+ produce a component of Na+-permeable current activated via a G protein pathway. Therefore, constitutive activation may not arise because the weaver mutation directly alters the gating transitions of the channel protein. Instead, there may be a regenerative cycle of Na+ influx through the wvGIRK2 channel, leading to additional Na+ activation. We also show that the wvGIRK2 channel is permeable to Ca2+, providing an additional mechanism for the degeneration that characterizes the weaver phenotype. We further demonstrate that the GIRK4 channel bearing the analogous weaver mutation has properties similar to those of the wvGIRK2 channel, providing a glimpse of the selective pressures that have maintained the GYG sequence in nearly all known K+ channels.

Commercialisation of regenerative human tissue : Regulation and reform in Australia and England, Wales and Northern Ireland

The commercialisation of therapeutic products containing regenerative human tissue is regulated by the common law, statute and ethical guidelines in Australia and England, Wales and Northern Ireland. This article examines the regulatory regimes in these jurisdictions and considers whether reform is required to both support scientific research and ensure conformity with modern social views on medical research and the use of human tissue. The authors consider the crucial role of informed consent in striking the balance between the interests of researchers and the interests of the public.