957 resultados para insulin-like growth factor
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Context: Abnormal FGFR4 expression has been detected in pituitary tumors, especially in larger and invasive adenomas. In addition, the FGFR4 functional polymorphism G388R has been associated with poor outcome in several human malignancies. Then, we hypothesized that FGFR4 expression and genotype could be markers of adverse outcome of Cushing`s disease after transsphenoidal surgery. Objectives: The objective was to investigate whether there is an association between the postoperative outcome of Cushing`s disease (remission/recurrence) and the FGFR4 G388R genotype or the FGFR4 expression in corticotrophinomas. Design and Patients: Clinical, hormonal, and pathological data of 76 patients who underwent the first transsphenoidal surgery were retrospectively reviewed. All patients were genotyped for G388R polymorphism. FGFR4 expression was assessed by real-time PCR in 18 corticotrophinomas. Main Outcome Measures: The outcome measures included the FGFR4 G388R genotype and FGFR4 expression in postoperative remission and recurrence of Cushing`s disease. Results: Homozygosis for FGFR4 glycine (Gly(388)) allele was associated with reduced disease-free survival, in the univariate analysis (hazard ratio of 6.91; 95% confidence interval of 1.14-11.26; P = 0.028). Male gender (P = 0.036), lack of pathology confirmation (P = 0.009), and cortisol levels more than 2 mu g/dl in the early postoperative period (P < 0.001) were also significant predictors of Cushing`s disease recurrence in the univariate analysis. FGFR4 overexpression was found in 44% of the corticotrophinomas, and it was associated with lower postoperative remission rate (P = 0.009). Conclusions: Our data suggest that homozygosis for FGFR4 Gly(388) allele and FGFR4 overexpression are associated with higher frequency of postoperative recurrence and persistence of Cushing`s disease, respectively. (J Clin Endocrinol Metab 95: E271-E279, 2010)
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While conventional antidepressants benefit many patients with major depressive disorder (MDD), as much as eight to 12 weeks can elapse before significant improvements in depressive symptoms are seen. Treatments that act more rapidly in MDD are urgently needed. Sleep deprivation (SD) has been shown to produce a rapid antidepressant response within one day in 50-60% of patients with MDD; thus, identifying its antidepressant mechanism may contribute to the development of antidepressants that act more rapidly. The present study evaluated the effects of 39 h of SD on mood, as well as on plasma levels of brain derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in patients with MDD. After a drug-free period of at least two weeks, 11 patients (6 males, 5 females; ages 25-62) who met DSM-IV criteria for MDD underwent total SD. Plasma samples for BDNF and VEGF assays were collected on Days 1 (baseline) and 2. The six-item Hamilton Rating Scale for Depression (HAMD-6) was the primary outcome measure. HAMD-6 scores decreased significantly after SD (Day 2). SD was negatively correlated with change in HAMD-6 score and change in VEGF levels, indicating that as depression scores decreased following SD, VEGF plasma levels increased. In contrast, SD did not alter plasma BDNF concentrations, nor was an association found between BDNF levels and clinical improvement on the HAMD-6. These results suggest that SD is associated with mood-related changes in plasma VEGF levels, but not plasma BDNF levels. Further studies using larger sample sizes are needed to confirm these preliminary findings. Published by Elsevier Inc.
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Background and objective: Vascular endothelial growth factor (VEGF) is known to increase vascular permeability and promote angiogenesis. It is expressed in most types of pleural effusions. However, the exact role of VEGF in the development of pleural effusions has yet to be determined. The anti-VEGF mAb, bevacizumab, has been used in the treatment of cancer to reduce local angiogenesis and tumour progression. This study describes the acute effects of VEGF blockade on the expression of inflammatory cytokines and pleural fluid accumulation. Methods: One hundred and twelve New Zealand rabbits received intrapleural injections of either talc or silver nitrate. In each group, half the animals received an intravenous injection of bevacizumab, 30 min before the intrapleural agent was administered. Five animals from each subgroup were sacrificed 1, 2, 3, 4 or 7 days after the procedure. Twelve rabbits were used to evaluate vascular permeability using Evans`s blue dye. Pleural fluid volume and cytokines were quantified. Results: Animals pretreated with anti-VEGF antibody showed significant reductions in pleural fluid volumes after talc or silver nitrate injection. IL-8 levels, vascular permeability and macroscopic pleural adhesion scores were also reduced in the groups that received bevacizumab. Conclusions: This study showed that bevacizumab interferes in the acute phase of pleural inflammation induced by silver nitrate or talc, reinforcing the role of VEGF as a key mediator in the production of pleural effusions. The results also suggest that bevacizumab should probably be avoided in patients requiring pleurodesis.
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OBJECTIVE: Investigate the effects of antenatal steroids and tracheal occlusion on pulmonary expression of vascular endothelial growth factor receptors in rats with nitrofen-induced congenital diaphragmatic hernia. STUDY DESIGN: Fetuses were exposed to nitrofen at embryonic day 9.5. Subgroups received dexamethasone or were operated on for tracheal occlusion, or received combined treatment. Morphologic variables were recorded. To analyze vascular endothelial growth factor receptor 1 and vascular endothelial growth factor receptor 2 expression, we performed Western blotting and immunohistochemistry. Morphologic variables were analyzed by analysis of variance and immunohistochemistry by Kruskal-Wallis test. RESULTS: Congenital diaphragmatic hernia decreased body weight, total lung weight, and lung-to-body weight ratio. Tracheal occlusion increased total lung weight and lung-to-body weight ratio (P < .05). Fetuses with congenital diaphragmatic hernia had reduced vascular endothelial growth factor receptor 1 and vascular endothelial growth factor receptor 2 expression, whereas steroids and tracheal occlusion increased their expression. Combined treatment increased expression of receptors, but had no additive effect. CONCLUSION: Vascular endothelial growth factor signaling disruption may be associated with pulmonary hypertension in congenital diaphragmatic hernia. Tracheal occlusion and steroids provide a pathway for restoring expression of vascular endothelial growth factor receptors.
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P>Objective Congenital hypogonadotropic hypogonadism with anosmia (Kallmann syndrome) or with normal sense of smell is a heterogeneous genetic disorder caused by defects in the synthesis, secretion and action of gonadotrophin-releasing hormone (GnRH). Mutations involving autosomal genes have been identified in approximately 30% of all cases of hypogonadotropic hypogonadism. However, most studies that screened patients with hypogonadotropic hypogonadism for gene mutations did not include gene dosage methodologies. Therefore, it remains to be determined whether patients without detected point mutation carried a heterozygous deletion of one or more exons. Measurements We used the multiplex ligation-dependent probe amplification (MLPA) assay to evaluate the potential contribution of heterozygous deletions of FGFR1, GnRH1, GnRHR, GPR54 and NELF genes in the aetiology of GnRH deficiency. Patients We studied a mutation-negative cohort of 135 patients, 80 with Kallmann syndrome and 55 with normosmic hypogonadotropic hypogonadism. Results One large heterozygous deletion involving all FGFR1 exons was identified in a female patient with sporadic normosmic hypogonadotropic hypogonadism and mild dimorphisms as ogival palate and cavus foot. FGFR1 hemizygosity was confirmed by gene dosage with comparative multiplex and real-time PCRs. Conclusions FGFR1 or other autosomal gene deletion is a possible but very rare event and does not account for a significant number of sporadic or inherited cases of isolated GnRH deficiency.
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Epidermal growth factor (EGF) plays an important role in cancer. A functional single nucleotide polymorphism (SNP) in the 5`-untranslated region of the EGF gene (+61 A>G) may influence its expression and contribute to cancer predisposition and aggressiveness. Aiming to investigate the role of EGF +61 A>G in the susceptibility to glioma and its prognosis, we performed a case-control study with 165 patients and 200 healthy controls from Brazil. Comparisons of genotype distributions and allele frequencies did not reveal any significant differences between the groups. The mean overall survival was 9.2 months for A/A, 8.2 months for A/G, and 7.7 months for GIG. When survival curves were plotted we found that the +61G allele is associated with poor overall survival (p=0.023) but not with disease-free survival (p=0.527). Our data suggest that, although there is no association between the EGF +61 A>G genotype and glioma susceptibility, this SNP is associated with shorter overall survival of glioma patients in the Brazilian population. Nevertheless, future studies utilizing a larger series are essential for a definitive conclusion. (Int J Biol Markers 2009; 24: 277-81)
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Background: Angiogenesis has been shown as an important process in hematological malignancies. It consists in endothelial proliferation, migration, and tube formation following pro-angiogenic factors releasing, specially the vascular endothelial growth factor (VEGF), which angiogenic effect seems to be dependent on nitric oxide (NO). We examined the association among functional polymorphism in these two angiogenesis related genes: VEGF (-2578C>A, -1154G>A, and -634G>C) and NOS3 (-786T>C, intron 4 b>a, and Glu298Asp) with prognosis of childhood acute lymphoblastic leukemia (ALL). Methods: The genotypes were determined and haplotypes estimated in 105 ALL patients that were divided in 2 groups: high risk (HR) and low risk of relapse (LR) patients. In addition, event-free survival curves according to genotypes were assessed. Results: The group HR compared to the LR showed a higher frequency of the alleles -2578C and -634C and the haplotype CGC for VEGF (0.72 vs. 0.51, p<0.008; 0.47 vs. 0.26, p<0.008; and 42.1 vs. 14.5, p<0.006; respectively) and a lower frequency of the haplotype CbGlu (0.4 vs. 8.8, p<0.006), for NOS3. Conclusion: Polymorphisms of VEGF and NOS3 genes are associated with high risk of relapse, therefore may have a prognostic impact in childhood ALL. (C) 2010 Elsevier B.V. All rights reserved.
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Glioma is the most frequent and malignant primary human brain tumor with dismal prognosis despite multimodal therapy. Resveratrol and quercetin, two structurally related and naturally occurring polyphenols, are proposed to have anticancer effects. We report here that resveratrol and quercetin decreased the cell number in four glioma cell lines but not in rat astrocytes. Low doses of resveratrol (10 mu M) or quercetin (25 mu M) separately had no effect on apoptosis induction, but had a strong effect on caspase 3/7 activation when administered together. Western blot analyses showed that resveratrol (10 mu M) and quercetin (25 mu M) caused a reduction in phosphorylation of Akt, but this reduction was not sufficient by itself to mediate the effects of these polyphenols. Most important, resveratrol and quercetin chronically administered presented a strong synergism in inducing senescence-like growth arrest. These results suggest that the combination of polyphenols can potentialize their antitumoral activity, thereby reducing the therapeutic concentration needed for glioma treatment. (Cancer Sci 2009; 100: 1655-1662).
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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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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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Strong vascular endothelial growth factor-C (VEGF-C) expression has been correlated to occurrence of lymph-node metastases in patients with oral squamous cell carcinoma (OSCC). The incidence of occult lymph-node metastasis remains a decisive factor in the prognosis of patients with early OSCC. The aim of this study was to evaluate VEGF-C expression as a predictor of occult lymph-node metastasis in OSCC. Eighty-seven patients with primary OSCC arising in the tongue or floor of mouth, clinically T1N0M0 or T2N0M0, with (pN+) and without (pN0) occult lymph-node metastases were analyzed for VEGF-C expression by malignant cells. Occult lymph-node metastases (pN+) were detected in 22% of the 64 patients who were submitted to elective neck dissection. No statistically significant difference was found between OSCC with and without occult lymph-node metastasis in regard to VEGF-C immunoexpression by malignant cells and clinicopathologic features. Independently of VEGF-C expression, lymph-node metastasis (PN+) was the most significant prognostic factor for overall survival of patients with OSCC (p = 0.030). These findings indicate that isolated VEGF-C expression by malignant cells is not of predictive value for occult lymph-node metastasis in the early stages of OSCC.
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There is considerable evidence showing that the neurodegenerative processes that lead to sporadic Parkinson`s disease (PD) begin many years before the appearance of the characteristic motor symptoms and that impairments in olfactory, cognitive and motor functions are associated with time-dependent disruption of dopaminergic neurotransmission in different brain areas. Midkine is a 13-kDa retinoic acid-induced heparin-binding growth factor involved in many biological processes in the central nervous system such as cell migration, neurogenesis and tissue repair. The abnormal midkine expression may be associated with neurochemical dysfunction in the dopaminergic system and cognitive impairments in rodents. Here, we employed adult midkine knockout mice (Mdk(-/-)) to further investigate the relevance of midkine in dopaminergic neurotransmission and in olfactory, cognitive and motor functions. Mdk(/-) mice displayed pronounced impairments in their olfactory discrimination ability and short-term social recognition memory with no gross motor alterations. Moreover, the genetic deletion of midkine decreased the expression of the enzyme tyrosine hydroxylase in the substantia nigra reducing partially the levels of dopamine and its metabolites in the olfactory bulb and striatum of mice. These findings indicate that the genetic deletion of midkine causes a partial loss of dopaminergic neurons and depletion of dopamine, resulting in olfactory and memory deficits with no major motor impairments. Therefore, Mdk(-/-) mice may represent a promising animal model for the study of the early stages of PD and for testing new therapeutic strategies to restore sensorial and cognitive processes in PD.
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Transforming growth factor beta1 treatment of keratinocytes results in a suppression of differentiation, an induction of extracellular matrix production, and a suppression of growth. In this study we utilized markers specific for each of these functions to explore the signaling pathways involved in mediating these transforming-growth-factor-beta1-induced activities. In the first instance, we found that the induction of extracellular matrix production (characterized by 3TP-Lux reporter activity) was induced in both keratinocytes and a keratinocyte-derived carcinoma cell line, SCC25, in a dose-dependent manner. Furthermore, transforming growth factor beta1 also suppressed the differentiation-specific marker gene, transglutaminase type 1, in both keratinocytes and SCC25 cells. In contrast, transforming growth factor beta1 inhibited proliferation of keratinocytes but did not cause growth inhibition in the SCC25 cells. Transforming-growth-factor-beta1-induced growth inhibition of keratinocytes was characterized by decreases in DNA synthesis, accumulation of hypophosphorylated Rb, and the inhibition of the E2F:Rb-responsive promoter, cdc2, and an induction of the p21 promoter. When the negative regulator of transforming growth factor beta1 signaling, SMAD7, was overexpressed in keratinocytes it could prevent transforming-growth-factor-beta1-induced activation of the 3TP-Lux and the p21 promoter. SMAD7 could also prevent the suppression of the transglutaminase type 1 by transforming growth factor beta1 but it could not inhibit the repression of the cdc2 promoter. These data indicate that the induction of 3TP-Lux and p21 and the suppression of transglutaminase type 1 are mediated by a different proximate signaling pathway to that regulating the suppression of the cdc2 gene. Combined, these data indicate that the regulation of transforming growth factor beta1 actions are complex and involve multiple signaling pathways.