The workload and plasma ion concentration in a training match session of high-goal (elite) polo ponies

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

Autogenous transplantation of rib cartilage preserved in glycerol, after removal of the perichondrium, to the malar process of rats--a histological study (Part I).

Seventy-two male albino rats received autogenous transplants of glycerol-preserved rib cartilage into the malar process. The animals were divided into two groups which received preserved cartilage with or without perichondrium. The implants were well tolerated and removal of the perichondrium enhanced the rate of resorption and bone replacement of the material.

Allogeneic transplants of rib cartilage preserved in 98% glycerol or 70% alcohol into the malar process of rats: a comparative histological study.

A comparative study was made of two methods of cartilage preservation, 98% glycerol and 70% alcohol. Rib cartilage was treated by either of these methods and transplanted into the malar process of rats. Cartilage grafts preserved by both methods were equally well tolerated. Resorption and bone substitution were similar in both groups after 120 days, although resorption was greater for the alcohol-preserved cartilage up until day 30. The possible reduction in antigenicity by the 98% glycerol did not produce any difference of behavior from the cartilage preserved in 70% alcohol.

Cryopreservation of equine embryos with glycerol plus sucrose and glycerol plus 1,2-propanediol.

Six or 7-day-old equine embryos were divided into 4 groups; Group 1, n = 15, Day 7 embryos destined for immediate transfer; Group 2, n = 15, Day 6 embryos destined for deep-freezing with glycerol plus sucrose as cryoprotectant; Group 3, n = 10, Day 6 embryos destined for deep-freezing with glycerol plus 1,2-propanediol as cryoprotectant and Group 4, n = 3, fresh embryos destined for ultrastructural analysis. All the frozen/thawed embryos were transferred to recipient mares, except 3 embryos in Group 3 that were subjected to ultrastructural analysis. After thawing the cryoprotectants were removed by successive dilutions in PBS + 15% v:v fetal calf serum (FCS) containing decreasing concentrations of the cryoprotectants. Pregnancy was diagnosed ultrasonographically in 53.3%, 13.3% and 0% of the mares in Groups 1, 2 and 3 respectively. Ultrastructural analysis showed differences between frozen/thawed and fresh embryos. In the former, embryonic cells were deformed and showed dilation of the intercellular and perivitelline spaces, a decrease of desmosome number in the junctional complexes, few microvilli on the apical surface of the trophectoderm and an almost total absence of pinocytotic vesicles. Most of the mitochondria showed regions containing dilation and irregularities on the cristae, which appeared electron-dense. The results obtained with Groups 2 and 3 embryos showed that the cryoprotectants employed were not effective in protecting the embryos against damage during freezing and thawing. Indeed, the ultrastructural changes observed in the Group 3 embryos explained the absence of any established pregnancies in this group of mares.

Pre-concentration of Cd(II), Cr(III), Cu(II) and Ni(II) on a column packed with free carboxymethylcellulose (CMCH)

Carboxymethylcellulose packed in to a glass column was used to pre-concentrate metallic cations from aqueous solutions. The pre-concentrated metal cations are directly eluted from the column using 5.0 mL of 1.0 mol L -1 hydrochloric acid. The optimum pre-concentration conditions are given (glass column, 16 cm length, 0.80 cm i.d., stationary phase height of 12 cm, flow-rate, 1.5 mL min -1). The recuperation efficiency achieved is greater than 95%, while the enrichment factor is 10 for 50 mL of solution (0.50 mg L -1 each).

Calcium hydroxide root canal sealers: Evaluation of pH, calcium ion concentration and conductivity

The calcium hydroxide ionization of four root canal sealers (Sealapex, CRCS, Sealer 26, and Apexit) was studied by measuring conductivity and pH and by conducting atomic absorption spectrophotometry. Samples 6 mm in diameter and 15 mm long were prepared from these sealers. After setting and 48 h storage in a desiccator, five samples of each material were placed in 50 mL distilled water and analysed after 0,1,2,4, 6 and 24 h and 5, 15 and 30 days. The results showed that Sealapex was the root canal sealer showing the highest pH, ionic calcium and total calcium values (P<0.05) throughout the experimental period, followed by CRCS, Apexit and Sealer 26.

Measuring fluoride concentration in mineral waters in the Araraquara region, Brazil

It has been shown that people of all ages can benefit from the topical and systemic effects of water fluoridation. However, the increase in consumption of bottled water, either to substitute for or supplement consumption of water from public sources, has implications for safe fluoride supplementation. Taking that into consideration, in 1995 we analyzed the fluoride content in 31 commercial brands of mineral water in the region of Araraquara, state of Sao Paulo, Brazil. Fluoride concentration as determined by our analysis was compared to the concentration of fluoride specified on each label. Only 25% of the products studied listed the fluoride concentration on their labels. In addition, among 31 mineral water brands, 26 listed the date when the chemical analysis to determine chemical composition had been performed. Of these, 20 had not been put through the annual chemical analysis determined by Brazilian law. Based on these results, if the mineral waters tested had been the only source of drinking water, fluoride supplementation would have been necessary in 69% of the samples analyzed. In the case of children up to 6 years of age who use products containing fluoride, such as topical gels, mouthwashes or toothpastes, supplementation should be recommended only if commercially bottled water is the only source of water used, not only for drinking but for cooking as well.

Effect of in concentration in the starting solution on the structural and electrical properties of ZnO films prepared by the pyrosol process at 450°C

Undoped and indium-doped Zinc oxide (ZnO) solid films were deposited by the pyrosol process at 450°C on glass substrates from solutions where In/Zn ratio was 2, 5, and 10 at.%. Electrical measurements performed at room temperature show that the addition of indium changes the resistance of the films. The resistivities of doped films are less than non-doped ZnO films by one to two orders of magnitude depending on the dopant concentration in the solution. Preferential orientation of the films with the c-axis perpendicular to the substrate was detected by X-ray diffraction and polarized extended X-ray absorption fine structures measurements at the Zn K edge. This orientation depends on the indium concentration in the starting solution. The most textured films were obtained for solutions where In/Zn ratio was 2 and 5 at.%. When In/Zn = 10 at.%, the films had a nearly random orientation of crystallites. Evidence of the incorporation of indium in the ZnO lattice was obtained from extended X-ray absorption fine structures at the In and Zn K edges. The structural analysis of the least resistive film (Zn/In = 5 at.%) shows that In substitutes Zn in the wurtzite structure. © 2000 Elsevier Science B.V. All rights reserved.

Growth of Dendrobium nobile Lindl. as related with nutrient concentration in the growing media

Dendrobium nobile orchids were grown for three years in different substrates (tree fern fiber, blocks of pressed coconut bark, bark of Eucalyptus grandis, mixtures with coconut bark blocks and eucalyptus bark and mixtures with the latter materials and charcoal. Plant growth increased with higher concentrations of S (up to 1.6 g/kg), Cu (up to 46 mg/kg) and Zn (up to 147 mg/kg), and decreased with higher concentrations of Ca (up to 13.2 g/kg), Mg (up to 6.6 g/kg) and B (up to 19 mg/kg). High Mo (up to 5.3 mg/kg) caused a more intense loss of leaves after planting. Relations between nutrient concentrations also affected plant growth. With exception of eucalyptus bark, all growing media under study were suitable for plant growth.

Effects of nitrate concentration on larval development of the giant river prawn, Macrobrachium rosenbergii

The effect of nitrate concentration on giant river prawn, Macrobrachium rosenbergii, larvae was investigated. Survival rate, weight gain, and larval development were evaluated for different concentrations of nitrate in three experiments. The experiments were divided i n to two phases. In the first phase, larvae from stages I through VIII were analysed, while in the second phase larvae from stage VIII through post-larvae metamorphosis were analysed. Oxygen consumption was also determined for zoea I, II, and VIII exposed to 0, 700, and 1,000 mg/L of nitrate-N. No effect was observed for concentrations up to 180 mg/L NO3-N (experiments I and II), and nitrate levels as 1,000 mg/L NO3-N did not affect survival in the first phase of the third experiment. On the other hand, larval stage index (LSI) and weight gain decreased as nitrate-N concentration increased from 0 to 1,000 mg/L. In the second phase, survival and metamorphosis rate decreased as nitrate concentration increased, according to a linear model. The effect of nitrate levels on weight gain followed a curvilinear pattern. Larval respiration decreased in the water where nitrate was added, but only during stage II. The results demonstrated that nitrate presents extremely low toxicity for giant river prawn larvae, and data were related to the levels of nitrate that usually occur in larviculture systems also discussed. Therefore, nitrate is not a limiting factor for giant river prawn larviculture. © 2003 by The Haworth Press, Inc. All rights reserved.

Determination of Cu, Ni and Pb in Aqueous Medium by FAAS after Pre-Concentration on 2-Aminothiazole Modified Silica Gel

This work describes the synthesis and characterization of 2-aminothiazole modified silica gel (SiAT), and the results of a study of the adsorption and pre-concentration (in batch and using a flow-injection system coupled to an absorption atomic spectrometer) of Cu(II), Ni(II) and Pb(II) in aqueous medium. The adsorption capacities for each metal ions in mmol g -1 were: Cu(II)= 1.18, Ni(II)= 1.15 and Pb(II)= 1.10. The results obtained in the flow experiments showed a recovery of practically 100% of the metal ions adsorbed in a mini-column packed with 100 mg of SiAT, using 100 μL of 2.0 mol L -1 HCl solution as eluent. The sorption-desorption of the metal ions made possible the application of a flow-injection system for the pre-concentration and quantification by FAAS of metal ions at trace level in natural water samples digested and not digest by an oxidizing UV photolysis.

Solubilization of proteins from human lymph node tissue and two-dimensional gel storage.

In the present study, we compared six different solubilization buffers and optimized two-dimensional electrophoresis (2-DE) conditions for human lymph node proteins. In addition, we developed a simple protocol for 2-D gel storage. Efficient solubilization was obtained with lysis buffers containing (a) 8 M urea, 4% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), 40 mM Tris base, 65 mM DTT (dithiothreitol) and 0.2% carrier ampholytes; (b) 5 M urea, 2 M thiourea, 2% CHAPS, 2% SB 3-10 (N-decyl-N,N-dimethyl-3-ammonio-1-propanesulfonate), 40 mM Tris base, 65 mM DTT and 0.2% carrier ampholytes or (c) 7 M urea, 2 M thiourea, 4% CHAPS, 65 mM DTT and 0.2% carrier ampholytes. The optimal protocol for isoelectric focusing (IEF) was accumulated voltage of 16,500 Vh and 0.6% DTT in the rehydration solution. In the experiments conducted for the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), best results were obtained with a doubled concentration (50 mM Tris, 384 mM glycine, 0.2% SDS) of the SDS electrophoresis buffer in the cathodic reservoir as compared to the concentration in the anodic reservoir (25 mM Tris, 192 mM glycine, 0.1% SDS). Among the five protocols tested for gel storing, success was attained when the gels were stored in plastic bags with 50% glycerol. This is the first report describing the successful solubilization and 2D-electrophoresis of proteins from human lymph node tissue and a 2-D gel storage protocol for easy gel handling before mass spectrometry (MS) analysis.

Analysis of fluoride concentration in mother's milk substitutes

The aim of the present study was to determine the fluoride concentration in some brands of mother's milk substitutes and evaluate the possibility of developing dental fluorosis by consuming these products. The products, all powdered, were divided into 3 groups: infant formulae (group I, n = 7), milk-based (group M, n = 8) and soy-based (group 8, n = 3). Samples from 3 cans of different batches of each brand were reconstituted in deionized water and analyzed using the specific electrode method, after hexamethyldisiloxane (HMDS) facilitated diffusion. The fluoride content (mg F/L) of the products ranged from 0.044 to 0.326 (I), 0.014 to 0.045 (M) and 0.253 to 0.702 (S). There was significant difference in the fluoride content of cans from distinct batches (p < 0.05) in most of the brands. The reconstitution of all products in water with optimal fluoride concentration for consumption during the mineralization phase of the primary teeth could result in daily fluoride intake above 0.07 mg F/kg body weight/day. Therefore, the consumption of these products, especially when reconstituted with optimally fluoridated water, could increase the risk of developing dental fluorosis.

Influence of temperature and concentration on thermophysical properties of yellow mombin (Spondias mombin, L.)

Thermal conductivity, thermal diffusivity, and density of yellow mombin juice were determined at 8.8-49.4 °Brix and at temperature from 0.4 to 77.1 °C. Apparent viscosity was also measured between 7.8 and 30 °Brix and at temperature from 0 to 60 °C. Yellow mombin juice was produced from fruits of two different batches and the concentration process was performed using a roto evaporator or a rising film evaporator, single effect, with recirculation, under vacuum, to obtain concentrated juice. In order to obtain different concentrations, concentrated juice was diluted with distilled water. Multiple regression analysis was performed to fit thermal conductivity, thermal diffusivity and density experimental data obtaining a good fit. Arrhenius and power law relationships were proposed to fit apparent viscosity as a function of temperature and juice concentration at typical shear rates found during processing. The rheological parameters together with experimental values of pressure loss in tube flow were used to calculate friction factors, which were compared to those resulting from theoretical equation.

Aspectos toxicológicos do bissulfito e outros agentes tóxicos sobre a síntese de glicerol-3-fosfato desidrogenase citoplasmá tica de levedura de panificação

The synthesis of intracellular glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) in baker's yeast was investigated in submerged culture supplied with glucose or glycerol as sole carbon sources. Inhibitors of the glycolytic pathway, Krebs cycle and respiratory chain did not stimulate glycerol-3-phosphate dehydrogenase synthesis when added in low concentrations in up 7.5 × 10 -5 mol/L. The repression exercised by glucose on the synthesis of glycerol-3-phosphate dehydrogenase in YP-glucose medium was reduced by the addition of fermentation products and of sodium bisulfite. Synthesis of the enzyme was raised 22-110%. However, in YP-glycerol medium, the addition of 0.06% (w/v) sodium bisulfite reduced (29%) the synthesis of the enzyme, while 0.012% (v/v) acetaldehyde stimulated the synthesis of glycerol-3-phosphate dehydrogenase by 12%.