155 resultados para CORTICOTROPIN-RELEASING FACTOR
Resumo:
This study evaluates the mRNA expression profile of genes TIMP1, TIMP2, MMP2 and MMP9 in diagnostic bone marrow samples from 134 consecutive ALL children by real-time quantitative PCR. A significant association was observed between higher expression levels of MMP9 and low risk group and absence of extramedullary infiltration and higher expression levels of TIMP2 and MMP2 with T-ALL. TIMP1 gene expression values higher than the median were associated with a significantly lower 5-year event free-survival in univariable (P = 0.04) and multivariable analysis (P = 0.01). Our data address new information in the complex interaction of the migration/adhesion genes and childhood ALL. (c) 2009 Elsevier Ltd. All rights reserved.
Increased plasma levels of brain derived neurotrophic factor (BDNF) after multiple sclerosis relapse
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Brain derived neurotrophic factor (BDNF) has been related to neuroprotection in a series of central nervous system diseases, although its role in multiple sclerosis (MS) was only partially investigated. In this work, we aimed to evaluate the plasma levels of BDNF from 29 MS patients and 24 control subjects. MS patients had decreased levels of BDNF in comparison with healthy controls. BDNF levels increased significantly after MS relapse. Our results provide some evidence for the involvement of BDNF in the pathogenesis of MS and suggest a role for this neurotrophin during the recovery of acute demyelinating inflammatory lesion. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
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Background: The tumor necrosis factor (TNF) gene is located within the highly polymorphic major histocompatibility complex region, exhibiting the -308 CA promoter region polymorphism and six microsatellites (TNFa-f) spanning the region nearby the TNF locus. Objective: In the present Study, we evaluated the frequency of -308 CA and TNFa-e polymorphisms and respective haplotypes (in chromosomal sequence: TNFd-TNFe-308GA-TNFc-TNFa-TNFb), in 222 patients with AIDS, 52 of whom exhibited cytomegalovirus retinitis, and in 202 healthy HIV-negative individuals. Method: TNF microsatellite and single nucleotide polymorphism typings were performed by PCR followed by polyacrylamide gel electrophoresis. Results: The TNF-308A allele and the 4-3-C-2-7-1 haplotype were associated with susceptibility to AIDS, whereas the TNFb4 allele and the 3-3-C-1-11-4 haplotype were associated with protection against AIDS development. The TNFc2 allele and the 4-1-G-2-2-1 haplotype, which contains the TNFc2 allele, were associated with cytomegalovirus retinitis. Conclusion: This study highlights that polymorphic sites spanning the region nearby the TNF locus are associated with AIDS per se and with cytomegalovirus retinitis in AIDS patients. (C) 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Resumo:
Vascular endothelial growth factor (VEGF) is relevant for normal pregnancy, and abnormalities in VEGF functions are associated with hypertensive disorders of pregnancy. Because there are few studies on how VEGF genetic polymorphisms affect susceptibility to pre-eclampsia (PE), and no studies on how they affect susceptibility to gestational hypertension (GH), we compared VEGF genotype and haplotype distributions in normotensive and hypertensive pregnancies. Genotypes and haplotypes for VEGF polymorphisms (C-2578A, G-1154A and G-634C) were determined in 303 pregnant women (108 healthy pregnant, HP; 101 with GH and 94 with PE). When white and non-white pregnant women were considered together, no significant differences were found in the distributions of VEGF genotypes or haplotypes (P > 0.05) in the three groups. However, with only white subjects, significant differences were found in genotypes distributions for two (C-2578A and G-634C) VEGF polymorphisms (both P < 0.05) between the HP and the PE groups. Importantly, the haplotype including the variants C-2578, G-1154 and C-634, which is associated with higher VEGF gene expression, was less common in the PE group compared with the HP group (4% versus 16%; P = 0.0047). However, we found no significant differences in VEGF haplotypes distributions when the HP and GH groups were compared (P > 0.05). These findings suggest a protective effect for the `C-2578, G-1154 and C-634` haplotype against the development of PE, but no major effects of VEGF gene variants on susceptibility to GH.
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There is evidence that several fibroblast growth factors (FGFs) are involved in growth and development of the corpus luteum (CL), but many FGFs have not been investigated in this tissue, including FGF10. The objective of this study was to determine if FGF10 and its receptor (FGFR2B) are expressed in the CL. Bovine CL were collected from an abattoir and classed as corpus hemorrhagica (stage 1), developing (stage 11), developed (stage 111), and regressed (stage IV) CL. Expression of FGF10 and FGFR2B mRNA was measured by reverse transcription-polymerase chain reaction (RT-PCR). Both genes were expressed in bovine CL, and FGF10 expression did not differ between stages of CL development. FGF10 protein was localized to large and small luteal cells by immunohistochemistry. FGFR2B expression was approximately threefold higher in regressed compared to developing and developed CL (P < 0.05). To determine if FGF10 and FGFR2B expression is regulated during functional luteolysis, cattle were injected with PGF2 alpha and CL collected at 0, 0.5, 2, 4, 12, 24, 48, and 64 hr thereafter (n = 5 CL/time point), and mRNA abundance was measured by real-time RT-PCR. FGF10 mRNA expression did not change during functional luteolysis, whereas FGFR2B mRNA abundance decreased significantly at 2, 4, and 12 hr after PGF2a, and returned to pretreatment levels for the period 24-64 hr post-PGF2 alpha. These data suggest a potential role for FGFR2B signaling during structural luteolysis in bovine CL.
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There is evidence that fibroblast growth factors (FGFs) are involved in the regulation of growth and regression of the corpus luteum (CL). However, the expression pattern of most FGF receptors (FGFRs) during CL lifespan is still unknown. The objective of the present study was to determine the pattern of expression of `B` and `C` splice variants of FGFRs in the bovine CL. Bovine CL were collected from an abattoir and classed as corpora hemorrhagica (Stage I), developing (Stage II), developed (Stage III) or regressed (Stage IV) CL. Expression of FGFR mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction and FGFR protein was localised by immunohistochemistry. Expression of mRNA encoding the `B` and `C` spliced forms of FGFR1 and FGFR2 was readily detectable in the bovine CL and was accompanied by protein localisation. FGFR1C and FGFR2C mRNA expression did not vary throughout CL lifespan, whereas FGFR1B was upregulated in the developed (Stage III) CL. FGFR3B, FGFR3C and FGFR4 expression was inconsistent in the bovine CL. The present data indicate that FGFR1 and FGFR2 splice variants are the main receptors for FGF action in the bovine CL.
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Contents This study aimed to evaluate the effect of the exogenous recombinant bovine somatotropin (rbST) on plasma concentrations of insulin-like growth factor I (IGF-I), insulin and semen quality of bulls. Twenty bulls (Aberdeen Angus and Brangus) were divided by breed into two groups. Placebo group was injected with NaCl 0.9% (s.c.) and treatment group with rbST (s.c., 500 mg) at days 0 and 14 of the experiment. Immediately after semen collection, blood samples were taken on days 0, 14, 28, 42 and 56 of the experiment. Semen was also collected on day 70 of the experiment. Evaluation of sperm motility was performed at pre-freezing and post-thawing stage, whereas assessment of sperm membrane integrity was performed after freezing and thawing. Analysis of data revealed that the effect of treatment and treatment-by-collection day on plasma concentrations of IGF-I and insulin was not significant. However, mean plasma concentrations of IGF-I and insulin were affected (p < 0.0001) by days of blood sampling. Effect of treatment and treatment-by-collection day on motility of spermatozoa was similar (p > 0.05) at pre-freezing and post-thawing stage. Intactness of plasmalemma and tail membrane of spermatozoa at post-thawing stage was higher (p < 0.05) in rbST-treated group than in control. In conclusion, rbST did not affect plasma concentrations of IGF-I and insulin, however, it did improve post-thaw sperm membrane integrity.
Resumo:
Two experiments were conducted to investigate the effects of equine chorionic gonadotropin (eCG) at progestin removal and gonadotropin-releasing hormone (GnRH) at timed artificial insemination (TA!) on ovarian follicular dynamics (Experiment 1) and pregnancy rates (Experiment 2) in suckled Nelore (Bos indicus) cows. Both experiments were 2 x 2 factorials (eCG or No eCG, and GnRH or No GnRH), with identical treatments. In Experiment 1, 50 anestrous cows, 134.5 +/- 2.3 d postpartum, received a 3 mg norgestomet ear implant se, plus 3 mg norgestomet and 5 mg estradiol valerate im on Day 0. The implant was removed on Day 9, with TAI 54 h later. Cows received 400 IU eCG or no further treatment on Day 9 and GnRH (100 mu g gonadorelin) or no further treatment at TAI. Treatment with eCG increased the growth rate of the largest follicle from Days 9 to 11 (means +/- SEM, 1.53 +/- 0.1 vs. 0.48 +/- 0.1 mm/d; P < 0.0001), its diameter on Day 11(11.4 +/- 0.6 vs. 9.3 +/- 0.7 mm; P = 0.03), as well as ovulation rate (80.8% vs. 50.0%, P = 0.02), whereas GnRH improved the synchrony of ovulation (72.0 +/- 1.1 VS. 71.1 +/- 2.0 h). In Experiment 2 (n = 599 cows, 40 to 120 d postpartum), pregnancy rates differed (P = 0.004) among groups (27.6%, 40.1%, 47.7%, and 55.7% for Control. GnRH, eCG, and eCG + GnRH groups). Both eCG and GnRH improved pregnancy rates (51.7% vs. 318%, P = 0.002; and 48.0% vs 37.6%, P = 0.02, respectively), although their effects were not additive (no significant interaction). In conclusion, eCG at norgestomet implant removal increased the growth rate of the largest follicle (LF) from implant removal to TAI, the diameter of the LF at TAI, and rates of ovulation and pregnancy rates. Furthermore, GnRH at TAI improved the synchrony of ovulations and pregnancy rates in postpartum Nelore cows treated with a norgestomet-based TAI protocol. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
The continuum of folliculogenesis begins in the fetal ovary with the differentiation of the oogonia and their isolation within the primordial follicles. Primordial follicle activation is an enigmatic process, whereby some follicles enter the growing pool to become primary follicles, thereby embarking on an irreversible progression towards ovulation or atresia. This process is under the coordinated regulation of factors from the oocyte itself, as well as from the somatic cells of the ovary, in particular the theca and granulosa cells, which are structural components of the follicle. These two influences provide the principal stimuli for the growth of the follicle to the late preantral or early antral stage of development. The endocrine effects of the gonadotrophins FSH and LH are essential to the continued progression of the follicle and most atresia can be attributed to the failure to receive or process the gonadotrophin signals. The peri-ovulatory state has received intensive investigation recently, demonstrating a coordinated role for gonadotrophins, steroids, epidermal growth factor family proteins and prostaglandins. Thus, a complex programme of coordinated interaction of governing elements from both germ and somatic cell sources is required for successful follicle development.
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Two experiments evaluated the effects of the first GnRH injection of the 5-d timed artificial insemination (AI) program on ovarian responses and pregnancy per AT (P/AI), and the effect of timing of the final GnRH to induce ovulation relative to AT on P/AI. In experiment 1, 605 Holstein heifers were synchronized for their second insemination and assigned randomly to receive GnRH on study d 0 (n = 298) or to remain as untreated controls (n = 307). Ovaries were scanned on study d 0 and 5. All heifers received a controlled internal drug-release (CIDR) insert containing progesterone on d 0, a single injection of PGF(2 alpha),, and removal of the CIDR on d 5, and GnRH concurrent with timed AT on d 8. Blood was analyzed for progesterone at AI. Pregnancy was diagnosed on d 32 and 60 after AI. Ovulation on study d 0 was greater for GnRH than control (35.4 vs. 10.6%). Presence of a new corpus luteum (CL) at PGF(2 alpha),, injection was greater for GnRH than for control (43.1 vs. 20.8%), although the proportion of heifers with a CL at PGF(2 alpha) did not differ between treatments and averaged 87.1%. Progesterone on the day of AT was greater for GaRH than control (0.50 +/- 0.07 vs. 0.28 +/- 0.07 ng/mL). The proportion of heifers at AI with progesterone <0.5 ng/mL was less for GURH than for control (73.8 vs. 88.2%). The proportion of heifers in estrus at AI did not differ between treatments and averaged 66.8%. Pregnancy per AI was not affected by treatment at d 32 or 60 (GnRH = 52.5 and 49.8% vs. control = 54.1 and 50.0%), and pregnancy loss averaged 6.0%. Responses to GnRH were not influenced by ovarian status on study d 0. In experiment 2, 1,295 heifers were synchronized for their first insemination and assigned randomly to receive a CIDR on d 0, PGF(2 alpha) and removal of the CIDR on d 5, and either GnRH 56 h after PGF(2 alpha) and AI 16 h later (OVS56, n = 644) or GnRH concurrent with AI 72 h after PGF(2 alpha) (COS72; n = 651). Estrus at AI was greater for COS72 than for OVS56 (61.4 vs. 47.5). Treatment did not affect P/AI on d 32 in heifers displaying signs of estrus at AI, but COS72 improved P/AI compared with OVS56 (55.0 vs. 47.6%) in those not in estrus at AI. Similarly, P/AI on d 60 did not differ between treatments for heifers displaying estrus, but COS72 improved P/AI compared with OVS56 (53.0 vs. 44.7%) in those not in estrus at AI. Administration of GnRH on the first day of the 5-d timed AI program resulted in low ovulation rate and no improvement in P/AI when heifers received a single PGF(2 alpha) injection 5 d later. Moreover, extending the proestrus by delaying the finAI GnRH from 56 to 72 h concurrent with AI benefited fertility of dairy heifers that did not display signs of estrus at insemination following the 5-d timed AI protocol.
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Menadione is a naphthoquinone used as a vitamin K source in animal feed that can generate reactive oxygen species (ROS) and cause apoptosis. Here, we examined whether menadione reduces development of preimplantation bovine embryos in a ROS-dependent process and tested the hypothesis that actions of menadione would be reduced by insulin-like growth factor-1 (IGF-1). Menadione caused a concentration-dependent decrease in the proportion of embryos that became blastocysts. All concentrations tested (1, 2.5, and 5.0 mu M) inhibited development. Treatment with 100 ng/ml IGF-1 reduced the magnitude of the anti-developmental effects of the two lowest menadione concentrations. Menadione also caused a concentration-dependent increase in the percent of cells positive for the TUNEL reaction. The response was lower for IGF-1-treated embryos. The effects of menadione were mediated by ROS because (1) the anti-developmental effect of menadione was blocked by the antioxidants dithiothreitol and Trolox and (2) menadione caused an increase in ROS generation. Treatment with IGF-1 did not reduce ROS formation in menadione-treated embryos. In conclusion, concentrations of menadione as low as 1.0 mu M can compromise development of bovine preimplantation embryos to the blastocyst stage of development in a ROS-dependent mechanism. Anti-developmental actions of menadione can be blocked by IGF-1 through effects downstream of ROS generation.
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Transforming growth factor-beta (TGF-beta) is a multifunctional growth factor that has several biological effects in vivo including control of cell growth and differentiation, cell migration, lineage determination, motility, adhesion, apoptosis, and synthesis and degradation of extracellular matrix, and TGF-beta plays an important role in regulating tissue repair and regeneration. Our study analyzed the participation of TGF-beta 1, -beta 2, and -beta 3 in the different stages of morphogenesis and differentiation of human developing dental organ using immunobistochemistry. The maxillae and mandibles of 10 human embryos ranging from 8 to 23 weeks of gestation were employed, according to the approval of the ethical committee. Our study revealed that the TGF-beta subunits-beta 1, beta 2, and beta 3 were present in the various stages of tooth development, but the expression varied according to the differentiation stage, tissue, and TGF-beta subunit. Our results indicated that TGF-beta 1 is closely related to differentiation of enamel organ and initiation of matrix secretion, TGF-beta 2 to cellular differentiation, and TGF-beta 3 to mineral maturation matrix.
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This study evaluated the effect of the C-factor and dentin preparation method (DPM) in the bond strength (BS) of a mild self-etch adhesive; the study also observed the SEM superficial aspects of the corresponding smear layer. For purposes of this study, 25 molars (n=5) were used in a bond strength test. The molars were divided into two parts (buccal and lingual): one part received a Class V cavity (C-factor=3) and the other received a flat surface (C-factor=0) with the same bur type (coarse diamond or carbide bur and fine diamond or carbide bur), both within the same dentin depth. Five teeth were prepared with wet 60-grit and 600-grit SiC papers. After restoration with Clearfil SE Bond, microtensile beans (0.8 mm(2)) were prepared and tested after 24 hours in a universal testing machine (0.5 mm/minute). An additional two teeth for each DPM were prepared for SEM evaluation of the smear layer superficial aspects. The BS values were submitted to one-way ANOVA, considering only the DPM (flat surfaces) and two-way ANOVA (C-Factor x DPM, considering only burs) with p=0.05. Although the DPM in the flat surfaces was not significant, the standard deviations of carbide bur-prepared specimens were markedly lower. The BS was significantly lower in cavities. The fine carbide bur presented the most favorable smear layer aspect. It was concluded that different dentin preparation methods could not prevent the adverse effect in bond strength of a high C-factor. A coarse cut carbide bur should be avoided prior to a mild self-etch adhesive, because it adversely affected bond strength. In contrast, a fine cut carbide bur provided the best combination: high bond strength with low variability, which suggests a more reliable bond strength performance.
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The stress intensity factor threshold (K(IO)) is related to the stress level at which cracks start to grow stably, causing the weakening of porcelain prostheses during their use. The values of K(IO) of seven dental porcelains (with and without reinforcing leucite crystal, KAlSi(2)O(6)) stored in air (22 degrees C, 60% relative humidity) and artificial saliva (37 degrees C) were determined by measuring the crack growth velocity of radial cracks generated at the corner of Vickers indentations. The results of K(IO) were correlated with the leucite content, fracture toughness (K(Ic)), and chemical composition of the porcelains. It was observed that K(IO) increased with the increase of leucite content (only for the leucite-based porcelains) and with the increase of K(Ic). The increase in Al(2)O(3) content or the decrease in the alkali oxide (K(2)O and Na(2)O) content of the material`s glassy matrix tended to increase the K(IO) values. Storage media (air and saliva) did not significantly affect the K(IO) of porcelains tested, indicating that the control parameter of K(IO) value was not the water content of the storage media.
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Paracoccidioidomycosis, the major systemic mycosis in Latin America, is caused by fungus Paracoccidioides brasiliensis. To analyze the influence of inducible nitric oxide synthase (iNOS) in this disease, iNOS-deficient (iNOS(-/-)) and wild-type (WT) mice were infected intravenously with P. brasiliensis 18 isolate. We found that, unlike WT mice, iNOS(-/-) mice did not control fungal proliferation, and began to succumb to infection by day 50 after inoculation of yeast cells. Typical inflammatory granulomas were found in WT mice, while, iNOS(-/-) mice presented incipient granulomas with intense inflammatory process and necrosis. Additionally, splenocytes from iNOS(-/-) mice did not produce nitric oxide, however, their proliferative response to Con-A was impaired, just like infected WT mice. Moreover, infected iNOS(-/-) mice presented a mixed pattern of immune response, releasing high levels of both Th1 (IL-12, IFN-gamma and TNF-alpha) and Th2 (IL-4 and IL-10) cytokines. These data suggest that the enzyme iNOS is a resistance factor during paracoccidioidomycosis by controlling fungal proliferation, by influencing cytokines production, and by appeasing the development of a high inflammatory response and consequently formation of necrosis. However, iNOS-derived nitric oxide seems not being the unique factor responsible for immunosuppression observed in infections caused by P. brasiliensis. (c) 2008 Elsevier Masson SAS. All rights reserved.