Dynamics of bone healing after osteotomy with piezosurgery or conventional drilling - histomorphometrical, immunohistochemical, and molecular analysis

Background: Piezosurgery is an osteotomy system used in medical and dental surgery. Many studies have proven clinical advantages of piezosurgery in terms of quality of cut, maneuverability, ease of use, and safety. However, few investigations have tested its superiority over the traditional osteotomy systems in terms of dynamics of bone healing. Therefore, the aim of this study was to evaluate the dynamics of bone healing after osteotomies with piezosurgery and to compare them with those associated to traditional bone drilling.Methods: One hundred and ten rats were divided into two groups with 55 animals each. The animals were anesthetized and the tibiae were surgically exposed to create defects 2 mm in diameter by using piezosurgery (Piezo group) and conventional drilling (Drill group). Animals were sacrificed at 3, 7, 14, 30 and 60 days post-surgery. Bone samples were collected and processed for histological, histomorphometrical, immunohistochemical, and molecular analysis. The histological analysis was performed at all time points (n = 8) whereas the histomorphometrical analysis was performed at 7, 14, 30 and 60 days post-surgery (n = 8). The immunolabeling was performed to detect Vascular Endothelial Growth Factor (VEGF), Caspase-3 (CAS-3), Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), and Osteocalcin (OC) at 3, 7, and 14 days (n = 3). For the molecular analysis, animals were sacrificed at 3, 7 and 14 days, total RNA was collected, and quantification of the expression of 21 genes related to BMP signaling, Wnt signaling, inflammation, osteogenenic and apoptotic pathways was performed by qRT-PCR (n = 5).Results: Histologically and histomorphometrically, bone healing was similar in both groups with the exception of a slightly higher amount of newly formed bone observed at 30 days after piezosurgery (p < 0.05). Immunohistochemical and qRT-PCR analyses didn't detect significant differences in expression of all the proteins and most of the genes tested.Conclusions: Based on the results of our study we conclude that in a rat tibial bone defect model the bone healing dynamics after piezosurgery are comparable to those observed with conventional drilling. © 2013 Esteves et al.; licensee BioMed Central Ltd.

Ultrasound-assisted extraction of Na and K from swine feed and its application in a digestibility assay: A green analytical procedure

The study is aimed to evaluate the efficiency of ultrasound-assisted extraction (UAE) as a simple strategy focused on sample preparation for metal determination in biological samples. The extraction of sodium and potassium extraction was carried out from swine feed followed by determination of the concentration of these metals by flame atomic emission spectrometry (FAES). The experiment was performed to cover the study of the variables influencing the extraction process and its optimal conditions (sample mass, particle size, acid concentration, sonication time and ultrasound power); the determination of these analytical characteristics and method validation using certified reference material; and the analysis of pre-starter diets. The optimal conditions established conditions were as follows: mass: 100 mg, particle size:<60 μm, acid concentration: 0.10 mol L-1 HCl, sonication time: 50 s and ultrasound power: 102 W. The proposed method (UAE) was applied in digestibility assays of those nutrients present in different piglet pre-starter feeds and their results proved to be compatible with those obtained from mineralized samples (P < 0.05). The ultrasound extraction method was demonstrated to be an excellent alternative for handless sampling and operational costs and the method also has the advantage of does not generating toxic residues that may negatively affect human health and contaminate the environment. © 2013 Elsevier B.V. All rights reserved.

National trade operations and procedure guide: Antigua and Barbuda: preliminary draft

Includes bibliography

National trade operations and procedure guide: Bahamas: preliminary draft

Includes bibliography

National trade operations and procedure guide: Barbados: preliminary draft

Includes bibliography

Guía nacional de procedimientos y operaciones de comercio: Cuba = Trade operation and procedure national guide: Cuba

Guia de procedimientos y operaciones comerciales de Cuba sobre el regimen de importaciones y exportaciones, tratados multilaterales y acuerdos de integracion, ferias nacionales e internacionales. Incluye lista de organismos que intervienen directamente en el comercio exterior.

National trade operations and procedure guide: Dominica

Includes bibliography

National trade operations and procedure guide: Guyana: preliminary draft

Includes bibliography

National trade operations and procedure guide: Jamaica: preliminary draft

Includes bibliography

National trade operations and procedure guide: Montserrat

Includes bibliography

National trade operations and procedure guide: Netherlands Antilles

Includes bibliography

National trade operations and procedure guide: St. Christopher (St. Kitts)

Includes bibliography

National trade operations and procedure guide: Saint Lucia

Includes bibliography