124 resultados para Alginate Bead


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Background: Canine hip dysplasia (HD) is characterized by hip joint laxity and subluxation. It is the most common cause of osteoarthritis in dogs, especially in larger breeds. Its management includes nutritional supplements, nonsteroidal anti-inflammatory drugs, physical therapy, acupuncture or surgical procedures. Implantation of gold beads in acupuncture points and trigger points around a joint has been used in the treatment of osteoarthritis in dogs for at least 30 years. Gold bead implants(GBI) acts as continuous acupuncture stimulation and trigger point treatment in canine HD with long lasting results. Electrophysiological investigations of trigger points reveal dysfunctional muscle spindles which indicate that the electrical activity of active loci arises from extrafusal motor endplates.Case: This is a report on the use of acupuncture and GBI for bilateral HD in a nine year old female German Shepherd. The patient has a HD non-responsive to anti-inflammatory drugs and was unable to stand up or walk by its own. Radiographs showed marked dysplasia, significant subluxation with the femoral head partly out of a shallow acetabulum and massive secondary arthritic bone changes, mainly on the right side. The animal was submitted to eight acupuncture sessions with seven days interval. After the first acupuncture session the use of NSAID was interrupted. After eight weeks the dog was considered rehabilitated and underwent GBI in acupoints and trigger points as maintenance treatment. During the one-year follow-up period the improvement remained unchanged with no need of analgesics.Discussion: It has been suggested that acupuncture or GBI can treat the chronic pain resulting from osteoarthritis induced by HD. According to AP theory, GBI is permanent and long-lasting acupoint stimulation. Moreover, the method is inexpensive, quick and easy to perform, with no postoperative pain or need of exercise restriction. Although gold is extremely corrosion-resistant, the surface of the gold implants stimulates a reaction from the immune system causing an oxidative liberation of gold ions with anti-inflammatory actions. It is well known that gold ions are effective inhibitors of the respiratory burst of neutrophils and monocytes and the proliferation of lymphocytes. These findings suggest that gold implantation, on a local scale, mimics the anti-inflammatory and pain-relieving effect of drugs with chemically bound gold ions. The relatively slow speed of the process results in a limited liberation of gold ions securing that they are taken up almost exclusively by cells close to the implant. The nine year old female German shepherd had a positive response to acupuncture with pain relieve and locomotor rehabilitation. For the nine year old female German shepherd previous acupuncture sessions to GBI resulted in no post-implant worsening period. Indeed, the association acupuncture/GBI does not have the anti-inflammatory drugs undesirable effects and brings long lasting results. In conclusion, GBI therefore should be considered for canine HD when conservative or medical treatments fail to give the desired effect.

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The response surface methodology as a tool for assessing the production of alginate and polyhydroxybutirate by Azotobacter vinelandii. Alginate is a polysaccharide extracted from cell walls of brown algae and used in the food, pharmaceuticals and biotech industries. Production is concentrated on the cultivation of brown seaweed, but several bacteria of the genus Pseudomonas and Azotobacter produce alginate. The chemical structure of alginates produced by algae is similar to those synthesized by A. vinelandii. The bacteria also produce intracellular polymers such as polyhydroxybutyrate (PHB), known as bioplastic. This work studied the simultaneous alginate and PHB production by A. vinelandii using sucrose and different parameters of fermentation in an orbital shaker. The optimal values for the production of these compounds were determined by the MSR. The first experiment was a 2(6-2) factorial design. The second was based on significant variables of the first, resulting in a full 3(3-0) factorial design. From the first to the second, an increase was observed in the PHB productivity from 12 to 45 mg g(-1) cell h(-1) and alginate from 100 to 1,600 mg g(-1) of cell h(-1). The productivity of both compounds was in the maximum incubation temperature of 62 degrees C, in the shortest time of incubation (18h) and the sucrose concentration, 11 g L(-1). In both experiments the PHB extracted presented purity of 94%.

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Due to an increasing interest, a vast number of biodegradable polymers have been obtained recently. Polymers naturally produced, such as cellulose, starch, chitosan and alginate, represent biodegradable materials, with low toxicity and low cost. Among polysaccharides, chitosan has been of great interest of the industrial and academic research, due to its special qualities of biodegradability and biocompatibility and, on the other hand, to the versatility of its use in several physical forms and products. A significant growth in the development of new dosage forms capable to deliver the drug in a controlled and targeted way has been observed in these last years. Such pharmaceutical forms search, mainly, the reduction of the dose administered and of the administration frequency, the reduction of adverse side effects and, consequently, a better patient compliance. The present paper describes the use of chitosan in pharmaceutical products, especially in drug controlled delivery systems.

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In this study, the aim was to measure the concentration of fluoride ions in dental alginates and the quantity released from alginate molds immersed in milliQ water, 0.1N hydrochloric acid and artificial saliva. Two separate lots of each of seven brands of alginate commercially available in Brazil were analyzed: Avagel, Deguprint, Hydrogum, Orthoprint, Jeltrate, Jeltrate Plus and Jeltrate Chromatic. Fluoride was measured in each sample by direct potentiometry, using the combined fluoride-ion selective electrode. The brands with the highest fluoride concentrations were Hydrogum (7052.87 μg/g), Jeltrate Plus (6519.68 μg/g) and Orthoprint (6218.18 μg/g). Only in Hydrogum and Jeltrate were different fluoride concentrations found in lots one and two. The various materials showed differences in the amount of fluoride released from the molds into the immersion medium, the mean concentration being highest in Hydrogum and Orthoprint, in all three media. The immersion medium also influenced the release of fluoride, which was lower in saliva than in water and highest in acid. Considering that the concentrations of fluoride found in the alginates tested were high and that various sources of exposure to fluoride exist, there is a need for constant monitoring of alginates intended for dental use.

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Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4mL concentrated HCI:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them.

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Alginate or irreversible hydrocolloid is one the most accepted and frequently employed impression materials in dental practice. Substances like zinc, cadmium, lead silicate and fluorides, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. Some brands of alginate have been reported to contain potentially toxic fluorides and metals such as cadmium, lead and zinc silicates, either singly or combined. Consequently, special care should be taken while preparing of these materials. It is necessary to monitor potentially toxic chemicals and metals in the alginates continually to avoid contamination of dental professionals and patients. In this review, alginates used in dentistry are analyzed for potential toxicity.

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The Laboratory of Industrial Biotechnology at the Biological Sciences Department in Sao Paulo State University, Brazil is working to improve the technologies involved with isomaltulose production. The study evaluated enzymatic reaction parameters with the goal of improving isomaltulose production which is grown with a medium of 1% cane molasses and 0.5% yeast extract thereby using calcium alginate, glutaraldehyde and polyethyleneimine. The best results were obtained using P. rubrum immobilized pellets in calcium alginate with 705 and 60% sucrose solution. The developed technology apparently allows the reuse of the cell-containing enzymes more times compared to conventional technologies, which ultimately results in decreased costs. The researchers are also involved in alcohol and biopolymer production and seeking interested industrial collaborators.

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The interface formed between the metal and the porcelain of laser-welded Ni-Cr-Mo alloy was studied on a metallurgical basis. The characterization was carried out by using optical microscope, electron scan microscopy and X-ray dispersive spectroscopy techniques and mechanical three-point flexion tests, in the laser-welded region, with and without porcelain. The union of the porcelain with the alloy is possible only after the oxidation of the metallic surface and the subsequent application of a bonding agent known as opaque. The porcelain applied to the base metal and weld bead showed different behaviours - after the flexion test, the base metal showed cracks, while that in the weld bead broke away completely. It was noted that the region subjected to laser welding had lower adherence to the porcelain than the base metal region, due to microstructural refinement of the weld bead. These results can be shown by the X-ray dispersive spectroscopy carried out on the regions studied. The flexion tests demonstrated that the Ni-Cr-Mo alloy subject to laser welding had significant alterations in its mechanical properties after application of the porcelain.

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Intense inflammatory response and an anti-angiogenic state have been implicated in the pathogenesis of preeclampsia. Here, we investigated this hypothesis evaluating the serum concentrations of CXCL10/IP-10, sFlt-1, and PlGF in women with early-onset preeclampsia. CXCL10/IP-10 was measured by Cytometric Bead Array. sFlt-1 and PlGF were measured by automated electrochemiluminescence immunoassay. The median serum concentration of CXCL10/IP-10 was 109.5 pg/mL in preeclamptic women, as compared with 52.28 pg/mL in the controls (P = 0.0028). The mean serum level of sFlt-1 was 13,636 pg/mL in preeclamptic women, as compared with 2020 pg/mL in the controls (P < 0.0001). PlGF levels were significantly lower in women with preeclampsia. © 2011 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

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This study evaluated the influence of tooth embedding media on the accuracy ofan electronic apex locator. The root canal length of 20 human mandibular canines was measured by inserting a 15 K-file into the root canal up to the apical foramen. The distance was measured with a digital caliper. The embedding media evaluated were alginate, saline, floral foam or gauze soaked in saline. Electronic root canal length measurement was performed with Root ZX II. Data were analysed using ANOVA for repeated measurements and Tukey test, at a significance level of 5%. There was no difference between the actual root canal length measurement and the electronic reading recorded with alginate medium. The readings obtained with the other media differed from the actual root canal length measurements. Alginate provided greater accuracy in electronic root canal length determination by Root ZX II than saline, floral foam and gauze.

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The interpretation of the set of radiographs taken during the follow-up period after tooth replantation might pose several difficulties, especially the inability to adequately reproduce the projection geometry of the exposures. This article describes a method for the geometric standardization of intraoral radiographs using a custom-made apparatus comprising a film-holder attached to an occlusal splint for the long-term follow up of dentoalveolar trauma. The method was applied in a patient who suffered an avulsion of the maxillary central incisors and had the teeth replanted after 4 h in saline storage. Endodontic treatment started 7 days after the trauma with changes of a calcium hydroxide intracanal medication every 15 days in the first 2 months and thereafter at 30-day intervals for 8 months. Root canal filling was carried out after this period. The radiographic exposures taken at the follow-up visits were standardized to identify the possible alterations during the repair process, such as root resorptions. A maxillary arch impression was made with alginate, and the model was cast in stone for fabrication of an acetate occlusal splint. The custom-made apparatus used for standardization of the radiographic exposures was fabricated by fixing a Rinn X-C-P film-holder and a 5-mm-long piece of 0.7-mm orthodontic wire to the occlusal splint with autopolymerized acrylic resin. Radiographs were taken at 4-month intervals, starting 10 months after replantation up to 76 months. The images were digitized and analysed using the Digora system. The length of the central incisors was determined to verify the reproduction of the projection geometry of the exposures and the orthodontic wire served to assess accuracy during length estimations in the radiographs. The method described in this article for geometric standardization of intraoral radiographs provided a consistent reproduction of the geometric exposure parameters, being indicated for use in the radiographic follow up of cases of dentoalveolar trauma. © 2012 John Wiley & Sons A/S.

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Fungus-growing ants associate with multiple symbiotic microbes, including Actinobacteria for production of antibiotics. The best studied of these bacteria are within the genus Pseudonocardia, which in most fungus-growing ants are conspicuously visible on the external cuticle of workers. However, given that fungus-growing ants in the genus Atta do not carry visible Actinobacteria on their cuticle, it is unclear if this genus engages in the symbiosis with Pseudonocardia. Here we explore whether improving culturing techniques can allow for successful isolation of Pseudonocardia from Atta cephalotes leaf-cutting ants. We obtained Pseudonocardia from 9 of 11 isolation method/colony component combinations from all 5 colonies intensively sampled. The most efficient technique was bead-beating workers in phosphate buffer solution, then plating the suspension on carboxymethylcellulose medium. Placing these strains in a fungus-growing ant-associated Pseudonocardia phylogeny revealed that while some strains grouped with clades of Pseudonocardia associated with other genera of fungus-growing ants, a large portion of the isolates fell into two novel phylogenetic clades previously not identified from this ant-microbe symbiosis. Our findings suggest that Pseudonocardia may be associated with Atta fungus-growing ants, potentially internalized, and that localizing the symbiont and exploring its role is necessary to shed further light on the association.

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Objective: We evaluated whether chronic exposure to immunosuppression in transplant recipients modulate the placental inflammatory cytokine levels associated to gestational tolerance mechanisms. Methods: Serum samples were collected from 12 renal transplanted pregnant under immunosuppressive regimen treatment and 10 healthy women in second/third trimester of gestation. Term placental tissues (decidua and chorionic villi) were also obtained after elective caesarean. Serum IL-1β, IL-6, IL-8, IL-12p70 and TNF-α were measured, as also in placental homogenates, by Cytometric Bead Array (CBA) combined with flow cytometry and, TGF-β and IL-18 were measured by ELISA. Results: Serum levels of IL-6 (p=0.0001) and TNF-α (0.0112) were higher in the 2nd and 3rd trimesters and in decidua the spectrum of increased pro inflammatory cytokines was wider: IL-1β (p=0.0001), IL-6 (p=0.0001), IL-8 (p=0.0001), IL-12p70 (p=0.0001), TGF-β (p=0.0089) and TNF-α (p=0.0002). TGF-β1 was particularly increased in decidual compartment (p=0.001). In the chorionic villous, pro inflammatory profile also were maintained. High IL-1β (p=0.0001), IL-6 (p=0.0001), IL-8 (p=0.0001) and TNF-α (p=0.0001) levels establish a similar pattern to that seem in decidua. Conclusion: Immunosuppressors may impair the immune response, but when associated with pregnancy the cytokine levels seems to shift a proinflammatory profile in placental compartments, which might also impact on the gestational outcomes in transplanted mothers. © 2013 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)