Calcitonin in bone-guided regeneration of mandibles in ovariectomized rats: densitometric, histologic and histomorphometric analysis

The aim of the present study was to investigate bone promotion in surgical defects created in the mandible of normal and ovariectomized female rats using calcitonin associated with a polytetrafluoroethylene barrier. The 100 female rats were divided into four groups: control (C), control treated with calcitonin (CM), ovariectomized control (OV) and ovariectomized treated with calcitonin (OVM). A circumscribed bone defect 4 mm in diameter was created in the region of the mandibular angle, and covered with the barrier. Groups CM and OVM received 2 IU/kg of synthetic salmon calcitonin intramuscularly three times a week. The animals were killed 3, 7, 14, 21 and 28 days after surgery. The bone defects were submitted to densitometric, histologic and histomorphometric analysis. Groups C and CM showed higher levels of bone formation after 7 days compared to the OV and OVM groups. A significant difference was observed between groups C and OV at 3-14 days. The OV group presented slower bone regeneration of the surgical bone defect created in the mandibular angle than group C. Synthetic salmon calcitonin accelerated regeneration of the bone defect in the mandibles of OVM animals similarly to group C, and also increased the formation of new bone during the regeneration process in CM.

Homeopathic treatment for bone regeneration: experimental study

Aim and method: The objective of this research was to study the effect of homeopathic treatment with Plumbum metallicum (Plumbum met.) on mandibular bone repair in rats.Materials and methods: We analyzed the mandibles of 60 male rats, approximately 3-month-old, randomly divided into three groups of 20 animals each: control, treated with calcitonin, and treated with a homeopathic medicine. A circumscribed bone defect measuring 4 mm in diameter was made in the mandible and covered with a pollytetrafluorethylene (PTFE) barrier. The group treated with calcitonin received 2 IU/kg intramuscularly three times a week; the group treated with Plumbum met. 30c received three drops in water every day. The animals were sacrificed after 7,14,21 and 28 days. The mandibles were removed and submitted to histologic and histomorphometric analyses.Results: Data were analyzed statistically by two-way ANOVA and by the Tukey test. The interaction effect (ANOVA, F df(6; 48) = 4.64; p = 0.001 < 0.05) indicated that the relationship between treatments was not the same at each time of sacrifice. Although statistical analysis of the histomorphometric data showed a similar results for the treated and control groups. But histological analysis showed complete filling of the surgical defect throughout its extent was only for the group treated with Plumbum met.Conclusion: The study demonstrated that for repair of surgical defects in rat mandibles Plumbum met. 30c and control did not differ significantly in histomorphometric terms. Homeopathy (2009) 98, 92-96.

Immunolocalization of bone morphogenetic protein 2 during the early healing events after guided bone regeneration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Calcium sulfate and PTFE nonporous barrier for regeneration of experimental bone defects

The aim of the study was to evaluate the possibility to obtain guided bone regeneration with two types of physical barriers (calcium sulfate and PTFE nonporous barrier) in surgical defects created in rat parietal bones. In the right parietal bone the calcium sulfate barrier filled out the whole defect and in the left parietal bone the barrier of PTFE was positioned in the floor and externally to the surgical defect. After 7, 14, 30 and 45 days four animals were sacrificed in each period and the bone containing the defects were submitted to the microscopic analysis. The results of the study revealed that the PTFE barrier was more effective for bone regeneration in shallow transcortical defects compared to the calcium sulfate. However, additional experiments are necessary to determine if calcium sulfate would be successful in other bone defects types or the use of the material under another consistence could complement the results obtained in this work.

Influence of the Solvent Evaporation Rate on the Crystalline Phases of Solution-Cast Poly(Vinylidene Fluoride) Films

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Voltammetric sensing of the fuel dye marker Solvent Blue 14 by screen-printed electrodes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A simple electroanalytical method for the analysis of the dye solvent orange 7 in fuel ethanol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemometrics in fuel science: demonstration of the feasibility of chemometrics analyses applied to physicochemical parameters to screen solvent tracers in Brazilian commercial gasoline

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Guided bone regeneration with subperiosteal implants of PTFE and hydroxyapatite physical barriers in rats

A regeneração periodontal e do rebordo ósseo utilizando barreiras físicas são procedimentos bem estabelecidos em cirurgias reconstrutivas. As características do biomaterial e o desenho da membrana empregados na regeneração tecidual guiada desempenham um papel importante na obtenção de bons resultados. O objetivo deste estudo experimental histológico foi comparar o uso de dois tipos de barreiras físicas na regeneração óssea guiada em defeitos criados na tíbia de ratos. Quinze animais foram divididos em três grupos: grupo I (barreira não-porosa de politetrafluoretileno), grupo II (blocos de hidroxiapatita de coral) e grupo III (controle que não recebeu nenhuma barreira). A análise histológica demonstrou várias quantidades de osso neoformado com ambos os tipos de barreiras. A barreira de politetrafluoretileno mostrou melhores resultados do que a hidroxiapatita. Os resultados deste estudo sugerem que a regeneração óssea pode ser conseguida com a técnica de submersão da barreira física.

Correlation between solvation of peptide-resins and solvent properties

The solvation properties of model resin and peptide-resins measured in ca. 30 solvent systems correlated better with the sum of solvent electron acceptor (AN) and electron donor (DN) numbers, in 1:1 proportion, than with other solvent polarity parameters. The high sensitivity of the (AN+DN) term to detect differentiated solvation behaviors of peptide-resins, taken as model of heterogeneous and complex solutes, seems to be in agreement with the previously proposed two-parameter model, where the sum of the Lewis acidity and Lewis basicity characters of solvent are proposed for scaling solvent effect. Besides these physicochemical aspects regarding solute-solvent interactions, important implications of this study for the solid phase peptide synthesis were also observed. Each class of peptide-resin displayed a specific salvation profile that was dependent on the amount and the nature of the resin-bound peptide sequence. Plots of resin swelling versus solvent (AN+DN) values allowed the visualization of a maximum salvation region characteristic for each class of resin. This strategy facilitates the selection of solvent systems for optimal solvation conditions of peptide chains in every step of the entire synthesis cycle. Moreover, only the AN and DN concepts allow the understanding of rules for solvation/shrinking of peptide-resins when in homogeneous or in heterogeneous mixed solvents.

The energy landscape for solvent dynamics in electron transfer reactions: A minimalist model

Energy fluctuations of a solute molecule embedded in a polar solvent are investigated to depict the energy landscape for solvation dynamics. The system is modeled by a charged molecule surrounded by two layers of solvent dipolar molecules with simple rotational dynamics. Individual solvent molecules are treated as simple dipoles that can point toward or away from the central charge (Ising spins). Single-spin-flip Monte Carlo kinetics simulations are carried out in a two-dimensional lattice for different central charges, radii of outer shell, and temperatures. By analyzing the density of states as a function of energy and temperatures, we have determined the existence of multiple freezing transitions. Each of them can be associated with the freezing of a different layer of the solvent. (C) 2002 American Institute of Physics.

Low power laser radiation at 685 nm stimulates stem-cell proliferation rate in Dugesia tigrina during regeneration

Today's scientific interest in tissue engineering for organ transplantations and regeneration from stem cells, allied with recent observations on biostimulation of tissues and cells by laser radiation, stands as a strong motivation for the present work, in which we examine the effects of the low power laser radiation onto planarians under regenerative process. To investigate those effects, a number of 60 amputated worms were divided in three study groups: a control group and two other groups submitted to daily 1 and 3 min long laser treatment sections at similar to 910 W/m(2) power density. A 685 nm diode laser with 35 mW optical power was used. Samples were sent to histological analysis at the 4th, the 7th and the 15th (lays after amputation. A remarkable increase in stem cells counts for the fourth day of regeneration was observed when the regenerating worms was stimulated by the laser radiation. Our findings encourage further research works on the influence of optical radiation onto stem cells and tissue regeneration. (c) 2005 Elsevier B.V. All rights reserved.