Effect of follicle size on mRNA expression in cumulus cells and oocytes of Bos indicus: an approach to identify marker genes for developmental competence

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of Ag additions on the activation energy for the reverse eutectoid reaction in Cu-Al alloys

The eutectoid transformation may be defined as a solid-state diffusion-controlled decomposition process of a high-temperature phase into a two-phase lamellar aggregate behind a migrating boundary on cooling below the eutectoid temperature. In substitutional solid solutions, the eutectoid reaction involves diffusion of the solute atoms either through the matrix or along the boundaries or ledges. The effect of Ag on the non-isothermal kinetics of the reverse eutectoid reaction in the Cu-9 mass%Al, Cu-10 mass%Al, and Cu-11 mass%Al alloys were studied using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The activation energy for this reaction was obtained using the Kissinger and Ozawa methods. The results indicated that Ag additions to Cu-Al alloys interfere on the reverse eutectoid reaction, increasing the activation energy values for the Cu-9 mass%Al and Cu-10 mass%Al alloys and decreasing these values for the Cu-11 mass%Al alloy for additions up to 6 mass%Ag. The changes in the activation energy were attributed to changes in the reaction solute and in Ag solubility due to the increase in Al content.

The effect of alpha-tocopherol on the oxidative cleavage of beta-carotene

Two cleavage pathways of beta-carotene have been proposed, one by central cleavage and the other by random (excentric) cleavage. The central cleavage pathway involves the metabolism of beta-carotene at the central double bond (15, 15') to produce retinal by beta-carotene 15, 15'-dioxygenase (E.C.888990988). The random cleavage of beta-carotene produces beta-apo-carotenoids, but the mechanism is not clear. To understand the various mechanisms of beta-carotene cleavage, beta-carotene was incubated with the intestinal postmitochondrial fractions of 10-week-old male rats for 1 h and cleavage products of beta-carotene were analyzed using reverse-phase, high-performance liquid chromatography (HPLC). We also studied the effects of alpha-tocopherol and NAD(+)/NADH on beta-carotene cleavage. In addition to beta-carotene, we used retinal and beta-apo-14'-carotenoic acid as substrates in these incubations. Beta-apo-14'-carotenoic acid is the two-carbon longer homologue of retinoic acid. In the presence of alpha-tocopherol, beta-carotene was converted exclusively to retinal, whereas in the absence of alpha-tocopherol, both retinal and beta-apo-carotenoids were formed. Retinoic acid was produced from both retinal and beta-apo-14'-carotenoic acid incubations only in the presence of NAD(+). Our data suggest that in the presence of an antioxidant such as alpha-tocopherol, beta-carotene is converted exclusively to retinal by central cleavage. In the absence of an antioxidant, beta-carotene is cleaved randomly by enzyme-related radicals to produce beta-apo-carotenoids, and these beta-apo-carotenoids can be oxidized further to retinoic acid via retinal. (C) 2000 Elsevier B.V.

Biocompatibility of denture base acrylic resins evaluated M culture of L929 cells. Effect of polymerisation cycle and postpoymerisation treatments

Objective: the purpose of this study was to evaluate the effect of two post-polymerisation treatments and different cycles of polymerisation on the cytotoxicity of two denture base resins.Materials and methods: the resins tested were Lucitone 550 and QC 20. Discs of resins were fabricated following the manufacturer's instructions. Lucitone 550 was processed by long cycle or short cycle. The resin QC 20 was processed by reverse cycle or normal cycle. The specimens were divided into groups: (i) post-polymerised in microwave for 3 min at 500 W; (ii) post-polymerised in water-bath at 55 degrees C for 60 min and (iii) without post-polymerisation. Eluates were prepared by placing three discs into a sterile glass vial with 9 ml of Eagle's medium and incubated at 37 degrees C for 24 hours. L929 cells were seeded into 96 3 well culture plates and DNA synthesis was assessed by H-thymidine incorporation assay.Results: the results were submitted to two-way ANOVA and Tukey HSD test. QC 20 specimens polymerised by the normal cycle and submitted to microwave post-polymerisation were graded as moderately cytotoxic. Similar results were observed for Lucitone 550 processed by long cycle without post-polymerisation. The other experimental groups were graded as not cytotoxic. After water-bath post-polymerisation, specimens of Lucitone 550 processed by long cycle produced significantly lower inhibition of DNA synthesis than the other groups.Conclusion: the long cycle increased the cytotoxicity of Lucitone 550 and water-bath post-polymerisation reduced the cytotoxicity of Lucitone 550 processed by long cycle.

AMINO-ACID-SEQUENCE OF TSTX-V, AN ALPHA-TOXIN FROM TITYUS-SERRULATUS SCORPION-VENOM, AND ITS EFFECT ON K+ PERMEABILITY OF BETA-CELLS FROM ISOLATED RAT ISLETS OF LANGERHANS

Highly purified Tityustoxin V (TsTX-V), an alpha-toxin isolated from the venom of the Brazilian scorpion Tityus serrulatus, was obtained by ion exchange chromatography on carboxymethylcellulose-52. It was shown to be homogeneous by reverse phase high performance liquid chromatography, N-terminal sequencing (first 39 residues) of the reduced and alkylated protein and by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and tricine. Following enzymatic digestion, the complete amino acid sequence (64 residues) was determined. The sequence showed higher homology with the toxins from the venoms of the North African than with those of the North and South American scorpions. Using the rate of Rb-86(+) release from depolarized rat pancreatic beta-cells as a measure of K+ permeability changes, TsTX-V (5.6 mu g/ml) was found to increase by 2.0-2.4-fold the rate of marker outflow in the presence of 8.3 mM glucose. This effect was persistent and slowly reversible, showing similarity to that induced by 100 mu-M veratridine, an agent that increases the open period of Na+ channels, delaying their inactivation. It is suggested that, by extending the depolarized period, TsTX-V indirectly affects beta-cell voltage-dependent K+ channels, thus increasing K+ permeability.

Inhibitory effect of PGE(2) on the killing of Paracoccidioides brasiliensis by human monocytes can be reversed by cellular activation with cytokines

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

The effect of CpG-ODN on antigen presenting cells of the foal

Background: Cytosine-phosphate-guanosine oligodeoxynucleotide (CpG-ODN) has been used successfully to induce immune responses against viral and intracellular organisms in mammals. The main objective of this study was to test the effect of CpG-ODN on antigen presenting cells of young foals. Methods: Peripheral blood monocytes of foals (n = 7) were isolated in the first day of life and monthly thereafter up to 3 months of life. Adult horse (n = 7) monocytes were isolated and tested once for comparison. Isolated monocytes were stimulated with IL-4 and GM-CSF (to obtain dendritic cells, DC) or not stimulated (to obtain macrophages). Macrophages and DCs were stimulated for 14-16 hours with either CpG-ODN, LPS or not stimulated. The stimulated and non-stimulated cells were tested for cell surface markers (CD86 and MHC class II) using flow cytometry, mRNA expression of cytokines (IL-12, IFNα, IL-10) and TLR-9 using real time quantitative RT-PCR, and for the activation of the transcription factor NF-κB p65 using a chemiluminescence assay. Results: The median fluorescence of the MHC class II molecule in non-stimulated foal macrophages and DCs at birth were 12.5 times and 11.2 times inferior, respectively, than adult horse cells (p = 0.009). That difference subsided at 3 months of life (p = 0.3). The expression of the CD86 co-stimulatory molecule was comparable in adult horse and foal macrophages and DCs, independent of treatment. CpG-ODN stimulation induced IL-12p40 (53 times) and IFNα (23 times) mRNA expression in CpG-ODN-treated adult horse DCs (p = 0.078), but not macrophages, in comparison to non-stimulated cells. In contrast, foal APCs did not respond to CpG-ODN stimulation with increased cytokine mRNA expression up to 3 months of age. TLR-9 mRNA expression and NF-kB activation (NF-kB p65) in foal DCs and macrophages were comparable (p > 0.05) to adult horse cells. Conclusion: CpG-ODN treatment did not induce specific maturation and cytokine expression in foal macrophages and DCs. Nevertheless, adult horse DCs, but not macrophages, increased their expression of IL-12 and IFNα cytokines upon CpG-ODN stimulation. Importantly, foals presented an age-dependent limitation in the expression of MHC class II in macrophages and DCs, independent of treatment. © 2007 Flaminio et al; licensee BioMed Central Ltd.

Mutagenic effect of native species of the Brazilian Cerrado with anti-ulcerogenic activity

Neea theifera Oerted (Nyctaginaceae), Guapira noxia Linn. (Nyctaginaceae) and Hancornia speciosa Gomes (Apocynaceae) are plant species found in Brazilian Cerrado used popularly for the treatment of gastric ulcers. Here they are assessed for mutagenic activity by analysis of the reverse mutations induced in Salmonella typhimurium strains TA100, TA98, TA102 and TA97a, by extracts of the plants, with and without metabolic activation. Methanol and chloroform extracts of N. theifera and G. noxia and methanolic and aqueous extracts of H. speciosa were tested at five different concentrations. It was found that only the methanolic extract of H. speciosa exhibited a positive mutagenic effect, on strains TA98 and TA100 in the absence of metabolic activation. The phytochemical analysis of the species suggested that condensed tannins are the main compounds responsible for the observed effect.

The effect of laminin-1-doped nanoroughened implant surfaces: Gene expression and morphological evaluation

Aim. This study aimed to observe the morphological and molecular effect of laminin-1 doping to nanostructured implant surfaces in a rabbit model. Materials and Methods. Nanostructured implants were coated with laminin-1 (test; dilution, 100 g/mL) and inserted into the rabbit tibiae. Noncoated implants were used as controls. After 2 weeks of healing, the implants were removed and subjected to morphological analysis using scanning electron microscopy (SEM) and gene expression analysis using the real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results. SEM revealed bony tissue attachment for both control and test implants. Real-time RT-PCR analysis showed that the expression of osteoblast markers RUNX-2, osteocalcin, alkaline phosphatase, and collagen I was higher (1.62-fold, 1.53-fold, 1.97-fold, and 1.04-fold, resp.) for the implants modified by laminin-1 relative to the control. All osteoclast markers investigated in the study presented higher expression on the test implants than controls as follows: tartrate-resistant acid phosphatase (1.67-fold), calcitonin receptor (1.35-fold), and ATPase (1.25-fold). The test implants demonstrated higher expression of inflammatory markers interleukin-10 (1.53-fold) and tumour necrosis factor-α (1.61-fold) relative to controls. Conclusion. The protein-doped surface showed higher gene expression of typical genes involved in the osseointegration cascade than the control surface. © 2012 Humberto Osvaldo Schwartz-Filho et al.

In vitro transdentinal effect of low-level laser therapy

Low-level laser therapy (LLLT) has been used for the treatment of dentinal hypersensitivity. However, the specific LLL dose and the response mechanisms of these cells to transdentinal irradiation have not yet been demonstrated. Therefore, this study evaluated the transdentinal effects of different LLL doses on stressed odontoblast-like pulp cells MDPC-23 seeded onto the pulpal side of dentin discs obtained from human third molars. The discs were placed in devices simulating in vitro pulp chambers and the whole set was placed in 24-well plates containing plain culture medium (DMEM). After 24 h incubation, the culture medium was replaced by fresh DMEM supplemented with either 5% (simulating a nutritional stress condition) or 10% fetal bovine serum (FBS). The cells were irradiated with doses of 15 and 25 J cm-2 every 24 h, totaling three applications over three consecutive days. The cells in the control groups were removed from the incubator for the same times as used in their respective experimental groups for irradiation, though without activating the laser source (sham irradiation). After 72 h of the last active or sham irradiation, the cells were evaluated with respect to succinic dehydrogenase (SDH) enzyme production (MTT assay), total protein (TP) expression, alkaline phosphatase (ALP) synthesis, reverse transcriptase polymerase chain reaction (RT-PCR) for collagen type 1 (Col-I) and ALP, and morphology (SEM). For both tests, significantly higher values were obtained for the 25 J cm-2 dose. Regarding SDH production, supplementation of the culture medium with 5% FBS provided better results. For TP and ALP expression, the 25 J cm-2 presented higher values, especially for the 5% FBS concentration (Mann-Whitney p < 0.05). Under the tested conditions, near infrared laser irradiation at 25 J cm -2 caused transdentinal biostimulation of odontoblast-like MDPC-23 cells. © 2013 Astro Ltd.

Effect of Dental Surface Treatment with Nd:YAG and Er:YAG Lasers on Bond Strength to Recently Bleached Dentin

The objective of this study was to evaluate the effect of surface treatment with Er:YAG and Nd:YAG lasers on resin composite bond strength to recently bleached dentin. A total of 120 bovine incisors were distributed into two groups: C- without bleaching; and B- bleached with 35% hydrogen peroxide. Each group was divided into three subgroups: N- without laser treatment; Nd- Nd:YAG laser irradiation; and Er- Er:YAG laser irradiation. The adhesive system (Adper Single Bond 2) was applied and composite build-ups were constructed with Filtek Supreme (3M/ESPE). The teeth were sectioned to obtain dentin-resin sticks (1x1mm(2)) and tested by microtensile bond testing. The bond strength values in group B, subgroup N (16.1 +/- 3.5MPa) presented no significant difference compared with group B, subgroup Er (14.7 +/- 6.1MPa). Group C, subgroup N (26.8 +/- 7.4MPa) presented no significant difference compared with group B, subgroup Nd (28.8 +/- 5.6MPa). Group C, subgroup Nd (36.1 +/- 7.9MPa) presented a significant increase in bond strength compared with the other groups. The Er:YAG laser did not influence the bond strength of bleached specimens, and the use of the Nd:YAG laser on bleached specimens was able to reverse the immediate effects of bleaching, obtaining bond strength values similar to those of the control group.

Effect of mechanical cycling on screw torque in external hexagon implants with and without platform switching

This in vitro study evaluated the effect of mechanical cycling on the torque of retaining screw in external hexagon implants with platform switching (PS), regular platform (RP) and wide platform (WP). A total of 30 specimens were equally divided into 3 groups: PS, PR and WP. Each specimen was prepared with implants: 3.75 x 10 mm for RP group and 5.0x10 mm for PS and WP groups and its respective abutment with 32 Ncm torque. All groups were subjected to 106 cycles with 100 N (corresponding to about 40 months of chewing). The results were obtained with the reverse torque of each specimen and data were evaluated using ANOVA and Tukey test (p<0.05). The PS group showed statistically significant difference in screw removal torque (30.06±5.42) compared with RP (23.75±2.76) and WP (21.32±3.53) (p<0.05) groups; the RP and WP groups showed no statistically significant difference between them. It was concluded that the PS group showed higher reverse torque value, suggesting lower susceptibility of the abutment screw loosening.

Effect of lithium on behavioral disinhibition induced by electrolytic lesion of the median raphe nucleus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sunflower Oil Supplementation Has Proinflammatory Effects and Does Not Reverse Insulin Resistance in Obesity Induced by High-Fat Diet in C57BL/6Mice

High consumption of polyunsaturated fatty acids, such as sunflower oil has been associated to beneficial effects in plasma lipid profile, but its role on inflammation and insulin resistance is not fully elucidated yet. We evaluated the effect of sunflower oil supplementation on inflammatory state and insulin resistance condition in HFD-induced obese mice. C57BL/ 6 male mice (8 weeks) were divided in four groups: (a) control diet (CD), (b) HFD, (c) CD supplemented with n-6 (CD + n-6), and (d) HFD supplemented with n-6 (HFD + n-6). CD + n-6 and HFD + n-6 were supplemented with sunflower oil by oral gavage at 2 g/ Kg of body weight, three times per week. CD and HFD were supplemented with water instead at the same dose. HFD induced whole andmuscle-specific insulin resistance associated with increased inflammatory markers in insulin-sensitive tissues andmacrophage cells. Sunflower oil supplementation was not efficient in preventing or reducing these parameters. In addition, the supplementation increased pro-inflammatory cytokine production by macrophages and tissues. Lipid profile, on the other hand, was improved with the sunflower oil supplementation in animals fed HFD. In conclusion, sunflower oil supplementation improves lipid profile, but it does not prevent or attenuate insulin resistance and inflammation induced by HFD in C57BL/ 6 mice.

Comparative Studies of the (Anti) Mutagenicity of Baccharis dracunculifolia and Artepillin C by the Bacterial Reverse Mutation Test

Baccharis dracunculifolia is a plant native from Brazil, commonly known as 'Alecrim-do-campo' and 'Vassoura' and used in alternative medicine for the treatment of inflammation, hepatic disorders and stomach ulcers. Previous studies reported that artepillin C (ArtC, 3-{4-hydroxy-3,5-di(3-methyl-2-butenyl)phenyl}-2(E)-propenoic acid), is the main compound of interest in the leaves. This study was undertaken to assess the mutagenic effect of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE: 11.4-182.8 mu g/plate) and ArtC (0.69-10.99 mu g/plate) by the Ames test using Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, and to compare the protective effects of Bd-EAE and ArtC against the mutagenicity of a variety of direct and indirect acting mutagens such as 4-nitro-O-phenylenediamine, sodium azide, mitomycin C, benzo[a]pyrene, aflatoxin B1, 2-aminoanthracene and 2-aminofluorene. The mutagenicity test showed that Bd-EAE and ArtC did not induce an increase in the number of revertant colonies indicating absence of mutagenic activity. ArtC showed a similar antimutagenic effect to that of Bd-EAE in some strains of S. typhimurium, demonstrating that the antimutagenic activity of Bd-EAE can be partially attributed to ArtC. The present results showed that the protective effect of whole plant extracts is due to the combined and synergistic effects of a complex mixture of phytochemicals, the total activity of which may result in health benefits.