Effects of Early Functional Loading on Maintenance of Free Autogenous Bone Graft and Implant Osseointegration: An Experimental Study in Dogs

Purpose: The aim of the present study was to investigate the healing, integration, and maintenance of autogenous onlay bone grafts and implant osseointegration either loaded in the early or the delayed stages. Materials and Methods: A total of 5 male clogs received bilateral blocks of onlay bone grafts harvested from the contralateral alveolar ridge of the mandible. On one side, the bone block was secured by 3 dental implants (3.5 mm x 13.0 mm, Osseospeed; Astra Tech AB, Molndal, Sweden). Two implants at the extremities of the graft were loaded 2 clays after installation by abutment connection and prosthesis (simultaneous implant placement group); the implant in the middle remained unloaded and served as the control. On the other side, the block was fixed with 2 fixation screws inserted in the extremities of the graft. Four weeks later, the fixation screws were replaced with 3 dental implants. The loading procedure (delayed implant placement group) was performed 2 clays later, as described for the simultaneous implant placement sites. The animals were sacrificed 12 weeks after the grafting procedure. Implant stability was measured through resonance frequency analysis. The bone volume and density were assessed on computed tomography. The bone to implant contact and bone area in a region of interest were evaluated on histologic slides. Results: The implant stability quotient showed statistical significance in favor of the delayed loaded grafts (P=.001). The bone-to-implant contact (P=.008) and bone area in a region of interest (P=0.005) were significantly greater in the delayed group. Nevertheless, no difference was found in terms of graft volume and density between the early loaded and delayed-loaded approaches. Conclusions: The protocol in which the implant and bone graft were given delayed loading allows for effective quality of implant osseointegration and stabilization, with healing and remodeling occurring in areas near the implant resulting in denser bone architecture. (C) 2010 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Sing 68:825-832, 2010

Impact of maintenance of Macrobrachium rosenbergii de Man, 1879 (Crustacea, Decapoda, Palaemonidae) broodstock on the water used in culture ponds

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

Isolation and maintenance of symbiotic fungi of ants in the tribe Attini (Hymenoptera: Formicidae)

O isolamento e a manutenção de fungos basidiomicetos simbiontes de formigas da tribo Attini tem sido dificultado pela baixa velocidade de crescimento desses fungos, bem como pela presença de muitos microrganismos que vivem na superfície do material que as formigas mantêm no interior nos ninhos como substrato para o crescimento dos seus fungos simbiontes. No presente trabalho nós descrevemos um método que aumenta em mais de sete vezes a eficiência de isolamento desses fungos, quando comparada àquela obtida por procedimentos tradicionais. Ninhos subterrâneos de formigas atíneas dos gêneros Atta, Acromyrmex, Trachymyrmex e Mycetarotes foram localizados e deles foram coletadas amostras contendo fungos simbiontes e formigas, que foram transportadas para o laboratório, onde as formigas foram capazes de limpar a cultura do fungo e estimular o seu crescimento. em seguida, porções dos micélios foram assepticamente coletadas e transferidas para meio Yeast Nitrogen Base contendo glicose e cloranfenicol. Para facilitar a manutenção dos isolados em culturas de laboratório, diferentes nutrientes foram analisados para a elaboração de um meio de cultivo complexo, que possibilitou aumentar a velocidade de crescimento dos fungos e estocá-los por longos períodos. O método foi aplicado com sucesso para os fungos simbiontes de todos os gêneros de formigas estudados, gerando, assim, um procedimento extremamente útil para a formação e manutenção de uma coleção representativa de diferentes fungos simbiontes de formigas da tribo Attini.

A survey for maintenance of virulent newcastle disease virus-free area in poultry production in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs on the production of reactive oxygen species by activated rat neutrophils

The release of reactive oxygen specie (ROS) by activated neutrophil is involved in both the antimicrobial and deleterious effects in chronic inflammation. The objective of the present investigation was to determine the effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) on the production of ROS by stimulated rat neutrophils. Diclofenac (3.6 µM), indomethacin (12 µM), naproxen (160 µM), piroxicam (13 µM), and tenoxicam (30 µM) were incubated at 37ºC in PBS (10 mM), pH 7.4, for 30 min with rat neutrophils (1 x 10(6) cells/ml) stimulated by phorbol-12-myristate-13-acetate (100 nM). The ROS production was measured by luminol and lucigenin-dependent chemiluminescence. Except for naproxen, NSAIDs reduced ROS production: 58 ± 2% diclofenac, 90 ± 2% indomethacin, 33 ± 3% piroxicam, and 45 ± 6% tenoxicam (N = 6). For the lucigenin assay, naproxen, piroxicam and tenoxicam were ineffective. For indomethacin the inhibition was 52 ± 5% and diclofenac showed amplification in the light emission of 181 ± 60% (N = 6). Using the myeloperoxidase (MPO)/H2O2/luminol system, the effects of NSAIDs on MPO activity were also screened. We found that NSAIDs inhibited both the peroxidation and chlorinating activity of MPO as follows: diclofenac (36 ± 10, 45 ± 3%), indomethacin (97 ± 2, 100 ± 1%), naproxen (56 ± 8, 76 ± 3%), piroxicam (77 ± 5, 99 ± 1%), and tenoxicam (90 ± 2, 100 ± 1%), respectively (N = 3). These results show that therapeutic levels of NSAIDs are able to suppress the oxygen-dependent antimicrobial or oxidative functions of neutrophils by inhibiting the generation of hypochlorous acid.

The effect of salinization in maintenance of intermittent catheter

O uso de cateter intermitente representa um procedimento muito utilizado em ambiente hospitalar. Este estudo, de natureza experimental, teve como propósito a análise comparativa entre o cateter intermitente, preenchido com solução de heparina 100 U/ml e o preenchido com soro fisiológico 0,9%. Foi realizado um estudo comparativo, avaliando a formação de coágulos e se estes estivessem presentes seriam quantificados. Para tanto, foram utilizados quatro grupos de 7 coelhos, da linhagem Norfolk, sendo realizado acesso venoso em veia auricular conectado ao dispositivo de infusão múltipla. em dois destes grupos, foi usada solução salina; em um grupo, caso fosse encontrada resistência, esta seria forçada; no outro, esta resistência não seria forçada. Nos dois outros grupos, foi usada solução de heparina; em um grupo, caso fosse encontrada resistência, esta seria forçada; no outro esta resistência não seria forçada. O cateter intermitente foi mantido por 72 horas e, a cada 12 horas foi infundida água destilada, simulando a administração de medicamento. Durante o experimento foram observadas as seguintes variáveis: presença da formação de coágulos, comprimento do coágulo, peso fresco do coágulo, peso seco do coágulo, contagem plaquetária e desconforto. Na análise estatística feita pelo método não paramétrico Kruskal-Wallis, com nível de significância de sigma = 5%, não foi encontrada diferença significativa entre os grupos e momentos. Pôde-se constatar a presença de formação de coágulo em todos os grupos independentemente da solução de preenchimento. Concluímos, principalmente, que há necessidade de elaboração de novas normas e rotinas na utilização de cateter intermitente.

Evaluation of Torque Maintenance of Abutment and Cylinder Screws With Morse Taper Implants

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

Evaluation of the Effect of Retightening and Mechanical Cycling on Preload Maintenance of Retention Screws

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

Effect of Misfit on Preload Maintenance of Retention Screws of Implant-Supported Prostheses

The aim of this study was to evaluate the effect of unilateral misfit at different levels on a crown-implant-retention screw system of implant-supported crowns. Hexagon castable UCLA abutments were cast in Co-Cr alloy to fabricate 48 metallic crowns divided into four groups (n = 12). Group A: crowns did not present misfit; Groups B, C and D: crowns were fabricated with unilateral misfit of 50, 100, and 200 mu m, respectively. The crowns were attached by titanium retention screw with 30 N/cm to external hexagonal osseointegrated implants embedded in acrylic resin. After 2 min, the retention screw of each replica was submitted to detorque evaluation by an analogic torque gauge. Three retention screws were used to perform detorque evaluation at each replica and the procedure was repeated twice with each screw. Each group was submitted to 72 detorque measurements. Data were evaluated by ANOVA and Tukey test (P < 0.05). All groups exhibited significant decrease (P < 0.05) in preload and the lowest decrease occurred in Group A. Groups B, C, and D were statistically significant different from Group A (P < 0.05), but there was no statistically significant difference between Groups B and D (P > 0.05). Crowns with unilateral misfit presented higher preload decrease than crowns completely fitted to osseointegrated implants.

Expression of differential genes involved in the maintenance of water balance in human skin by Piptadenia colubrina extract

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

SIRT1 Deacetylase Activity and the Maintenance of Protein Homeostasis in Response to Stress: An Overview

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

Contribution of the Malpighian tubules for the maintenance of symbiotic microorganisms in cephalotes ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Doxorubicin as an antioxidant: Maintenance of myocardial levels of lycopene under doxorubicin treatment

The mechanism of doxorubicin-induced cardiotoxicity remains controversial. Wistar rats (n=96) were randomly assigned to a control (C), lycopene (L), doxorubicin (D), or doxorubicin+lycopene (DL) group. The L and DL groups received lycopene (5 mg/kg body wt/day by gavage) for 7 weeks. The D and DL groups received doxombicin (4 mg/kg body wt intraperitoneally) at 3, 4, 5, and 6 weeks and were killed at 7 weeks for analyses. Myocardial tissue lycopene levels and total antioxidant performance (TAP) were analyzed by HPLC and fluorometry, respectively. Lycopene metabolism was determined by incubating H-2(10)-lycopene with intestinal mucosa postmitochondrial fraction and lipoxygenase and analyzed with HPLC and APCI mass spectroscopy. Myocardial tissue lycopene levels in DL and L were similar. TAP adjusted for tissue protein were higher in myocardium of D than those of C (P=0.002). Lycopene metabolism study identified a lower oxidative cleavage of lycopene in D as compared to those of C. Our results showed that lycopene was not depleted in myocardium of lycopene-supplemented rats treated with doxorubicin and that higher antioxidant capacity in myocardium and less oxidative cleavage of lycopene in intestinal mucosa of doxorubicin-treated rats suggest an antioxidant role of doxombicin rather than acting as a prooxidant. (c) 2007 Elsevier B.V. All rights reserved.