938 resultados para PITUITARY ADENOMA
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Basal cell adenoma is a benign epithelial neoplasm with a uniform histologic appearance dominated by basaloid cells. Those cells may be distributed in various arrangements as solid, trabecular, tubular and membranous. Canalicular adenoma is also a benign neoplasm composed by columnar cells arranged in branching and interconnecting cords of single or double cell thick rows. There is some disagreement among investigators about whether canalicular adenoma should be included within the basal cell adenoma histologic spectrum. In the present study we compared the expression of cytokeratins (CK), vimentin and muscle-specific actin, utilizing immunohistochemical technique, in three cases diagnosed as basal cell adenomas predominantly of the solid type, and three cases of canalicular adenomas. The results obtained showed a distinct immunoprofile for both neoplasms. Solid areas of basal cell adenomas did not stain for any of the tested antibodies; only when there was tubular differentiation, those structures expressed CKs 7, 8, 14, and 19 in luminal cells and vimentin in non-luminal cells. On the other hand, canalicular adenomas strongly expressed CKs 7 and 13. The panel of antibodies utilized supports the separation of the two entities. © 2001 Elsevier Science Ltd.
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The effects of breed and of recombinant bovine somatotropin (rbST) treatment on growth hormone gene expression were studied in young bulls. The experiment was completely randomized in a [2 × 2]-factorial arrangement, using two levels of rbst (0 or 250 mg/animal/14 days), and two breed groups (Nelore and Simmental x Nelore crossbred). A CDNA encoding Bos indicus growth hormone was cloned and sequenced for use as a probe in Northern and dot blot analyses. Compared to the Bos taurus structural gene, the Bos indicus CDNA was found to begin 21 bases downstream from the transcription initiation site and had only two discrepancies (C to T at position 144-His and T to C at position 354-Phe), without changes in the polypeptide sequence. However, two amino acid substitutions were found for Bubalus spp., which belong to the same tribe. The rbst treatment did not change any of the characteristics evaluated (body and pituitary gland weights, growth hormone MRNA expression level). Crossbred animals had significantly higher body weight and heavier pituitaries than Nelore cattle. Pituitary weight was proportional to body weight in both breed groups. Growth hormone MRNA expression in the pituitary was similar (P>0.075) for both breed and hormonal treatment groups, but was 31.9% higher in the pure Nelore group, suggesting that growth hormone gene transcription regulation differs among these breeds.
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OBJECTIVES: Pleomorphic adenomas are the most frequent type of epithelial salivary gland neoplasms, and their malignant counterpart, the carcinoma in pleomorphic adenomas, is much less common. Beta-catenin is a cell adhesion molecule associated with the invasion and metastasis of carcinomas of the head and neck, esophagus. The objective of this study was to detect the expression of beta-catenin in pleomorphic adenomas, carcinomas in pleomorphic adenomas and normal salivary glands to discuss its role in the development of these two lesions. STUDY DESIGN: The expression of beta-catenin (BD Transduction Laboratories) was analyzed by immunohistochemistry in formalin-fixed, paraffin embedded specimens by the avidin-biotin-peroxidase complex method in 16 pleomorphic adenomas (12 from minor salivary glands), 3 carcinomas in pleomorphic adenomas (all from palate) and 10 normal salivary glands as control group (5 from major and 5 from minor salivary glands). RESULTS: All cases of glands, adenomas and carcinomas in pleomorphic adenomas have membranous and cytoplasmic immunostaining. Nuclear beta-catenin immunostaining was not observed. The antibody presented a fine granular arrangement in the cytoplasm and cellular membrane of duct and acinic cells. Higher beta-catenin index rates were seen mainly in salivary gland ducts and in ductal structures in the adenomas and carcinomas in pleomorphic adenomas. There was protein loss in pleomorphic adenomas and cytoplasmic accumulation in carcinoma in pleomorphic adenomas. CONCLUSIONS: The present study showed participation of the loss of beta-catenin adhesion molecule in the development of pleomorphic adenoma, and that the cytoplasmic accumulation of the molecule takes part in the malignant transformation of the pleomorphic adenoma into carcinoma in pleomorphic adenoma.
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Craniopharyngiomas and germ cell tumors (GCT) may affect the pituitary-hypothalamic region during childhood. Although different in origin, their clinical and radiological features may be similar. In this article we present a 5-year-old girl with clinical and radiological findings (computer tomography calcification) that were initially considered as craniopharyngioma. However clinical outcome, blood and cerebral spinal fluid tumoral markers, and results from anatomopathology and immunohistochemistry disclosed a mixed GCT. This case report highlights that some clinical features and radiological findings of pituitary-hypothalamic tumors may be misdiagnosed as craniopharyngioma mainly when there is a mature teratoma with cartilaginous tissue differentiation. Copyright© ABE&M.
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The objective was to evaluate when the LH reserve was re-established in postpartum Nellore (Bos indicus) cows by evaluating the response of the hypothalamic-pituitary axis responsiveness to exogenous GnRH or estradiol benzoate (EB). Additionally, we tested the influence of dietary supplementation (SUPL) and calf removal (CR) on the duration of postpartum anestrus. Ninety multiparous lactating Nellore cows were randomly assigned to eight groups. The EB and GnRH groups received 1.0 mg EB (N = 7), and 50 μg lecireline (N = 16), respectively. Additional cows were given the same hormones, and subjected to either nutritional supplementation (EB-SUPL, N = 9; GnRH-SUPL, N = 16), or calf removal at 72 hours after calving (EB-CR, N = 4; GnRH-CR, N = 13). The remaining two groups were the LH (12.5 mg, N = 14) and control groups (saline, N = 11). Hormones were administered weekly from 7 (±5) days postpartum to first ovulation (detection of a CL during a weekly ultrasonographic examination). Blood samples were collected just before and 2 hours (GnRH, LH, and control groups) or 18 hours (EB groups) after hormone or saline (control) administration. Ovulation occurred as early as 15 days postpartum in the GnRH group. The mean ± SEM intervals (days) from calving to first ovulation were EB, 87.7 ± 4.2; EB-CR, 20.3 ± 1.2; EB-SUPL, 60.3 ± 3.2; GnRH, 40.4 ± 2.1; GnRH-CR, 21.0 ± 1.1; GnRH-SUPL, 26.4 ± 1.1; LH, 35.6 ± 1.1; and control, 60.9 ± 2.1. We concluded that there was sufficient LH in the pituitary gland (of Nellore cows) from the second week postpartum to induce ovulation in response to exogenous GnRH. Additionally, calf removal and nutritional supplementation reduced, by 2 to 4 weeks, the interval from calving to an LH increase and ovulation induced by GnRH or EB. © 2013.
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Objective: To compare cost-effectiveness between pituitary down-regulation with a GnRH agonist (GnRHa) short regimen on alternate days and GnRH antagonist (GnRHant) multidose protocol on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcome. Design: Prospective, randomized. Setting: A private center. Patient(s): Patients were randomized into GnRHa (n = 48) and GnRHant (n = 48) groups. Intervention(s): GnRHa stimulation protocol: administration of triptorelin on alternate days starting on the first day of the cycle, recombinant FSH (rFSH), and recombinant hCG (rhCG) microdose. GnRHant protocol: administration of a daily dose of rFSH, cetrorelix, and rhCG microdose. Main Outcome Measure(s): ICSI outcomes and treatment costs. Result(s): A significantly lower number of patients underwent embryo transfer in the GnRHa group. Clinical pregnancy rate was significantly lower and miscarriage rate was significantly higher in the GnRHa group. It was observed a significant lower cost per cycle in the GnRHa group compared with the GnRHant group ($5,327.80 ± 387.30 vs. $5,900.40 ± 472.50). However, mean cost per pregnancy in the GnRHa was higher than in the GnRHant group ($19,671.80 ± 1,430.00 vs. $11,328.70 ± 907.20). Conclusion(s): Although the short controlled ovarian stimulation protocol with GnRHa on alternate days, rFSH, and rhCG microdose may lower the cost of an individual IVF cycle, it requires more cycles to achieve pregnancy. Clinical Trial Registration Number: NCT01468441. © 2013 by American Society for Reproductive Medicine.
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Two experiments were performed using the aromatase inhibitor (AI) letrozole (100mg/kg) to promote sex change, from female-to-male, in protogynous dusky grouper. One experiment was performed during the breeding season (spring) and the other at the end of the breeding season (summer). During the spring, AI promoted sex change after 9weeks and the sperm produced was able to fertilize grouper oocytes. During the summer, the sex change was incomplete; intersex individuals were present and sperm was not released by any of the animals. Sex changed gonads had a lamellar architecture; cysts of spermatocytes and spermatozoa in the lumen of the germinal compartment. In the spring, after 4weeks, 11ketotestosterone (11KT) levels were higher in the AI than in control fish, and after 9weeks, coincident with semen release, testosterone levels increased in the AI group, while 11KT returned to the initial levels. Estradiol (E2) levels remained unchanged during the experimental period. Instead of decreasing throughout the period, as in control group, 17 α-OH progesterone levels did not change in the AI-treated fish, resulting in higher values after 9weeks when compared with control fish. fshβ and lhβ gene expression in the AI animals were lower compared with control fish after 9weeks. The use of AI was effective to obtain functional males during the breeding season. The increase in androgens, modulated by gonadotropins, triggered the sex change, enabling the development of male germ cells, whereas a decrease in E2 levels was not required to change sex in dusky grouper. © 2013 Elsevier Inc.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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We investigated the effects of adenosine on prolactin (PRL) secretion from rat anterior pituitaries incubated in vitro. The administration of 5-N- methylcarboxamidoadenosine (MECA), an analog agonist that preferentially activates A2 receptors, induced a dose-dependent (1 nM to 1 µM) increase in the levels of PRL released, an effect abolished by 1,3-dipropyl-7-methylxanthine, an antagonist of A2 adenosine receptors. In addition, the basal levels of PRL secretion were decreased by the blockade of cyclooxygenase or lipoxygenase pathways, with indomethacin and nordihydroguaiaretic acid (NDGA), respectively. The stimulatory effects of MECA on PRL secretion persisted even after the addition of indomethacin, but not of NDGA, to the medium. MECA was unable to stimulate PRL secretion in the presence of dopamine, the strongest inhibitor of PRL release that works by inducing a decrease in adenylyl cyclase activity. Furthermore, the addition of adenosine (10 nM) mimicked the effects of MECA on PRL secretion, an effect that persisted regardless of the presence of LiCl (5 mM). The basal secretion of PRL was significatively reduced by LiCl, and restored by the concomitant addition of both LiCl and myo-inositol. These results indicate that PRL secretion is under a multifactorial regulatory mechanism, with the participation of different enzymes, including adenylyl cyclase, inositol-1-phosphatase, cyclooxygenase, and lipoxygenase. However, the increase in PRL secretion observed in the lactotroph in response to A2 adenosine receptor activation probably was mediated by mechanisms involving regulation of adenylyl cyclase, independent of membrane phosphoinositide synthesis or cyclooxygenase activity and partially dependent on lipoxygenase arachidonic acid-derived substances.
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In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 µM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 µM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 µM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 µM cyclopentyltheophylline, a specific A1 receptor antagonist (1 µM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 µM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 µM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 µM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 µM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Objective: The present study aimed at evaluating the PROP1 and HESX1 genes in a group of patients with septo-optic dysplasia (SOD) and pituitary hormone deficiency (combined – CPHD; isolated GH deficiency – GHD). Eleven patients with a clinical and biochemical presentation consistent with CPHD, GHD or SOD were evaluated. Subjects and methods: In all patients, the HESX1 gene was analyzed by direct sequence analysis and in cases of CPHD the PROP1 gene was also sequenced. Results: A polymorphism (1772 A > G; N125S) was identified in a patient with SOD. We found three patients carrying the allelic variants 27 T > C; A9A and 59 A > G; N20S in exon 1 of the PROP1 gene. Mutations in the PROP1 and HESX1 genes were not identified in these patients with sporadic GHD, CPHD and SOD. Conclusion: Genetic alterations in one or several other genes, or non-genetic mechanisms, must be implicated in the pathogenic process.
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Canalicular adenoma is an uncommon benign tumour that generally arises in the minor salivary glands of individuals over 60 years old. This study illustrates a case of canalicular adenoma in a 70-year-old female, presenting as two distinct asymptomatic nodules in the upper lip. Immunohistochemistry analysis was performed. Clinical features, management, histology and immunoprofile from this case and from the literature are discussed.
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Studies on the environmental consequences of stress are relevant for economic and animal welfare reasons. We recently reported that long-term heat stressors (31 +/- 1 degrees C and 36 +/- 1 degrees C for 10 h/d) applied to broiler chickens (Gallus gallus domesticus) from d 35 to 42 of life increased serum corticosterone concentrations, decreased performance variables and the macrophage oxidative burst, and produced mild, multifocal acute enteritis. Being cognizant of the relevance of acute heat stress on tropical and subtropical poultry production, we designed the current experiment to analyze, from a neuroimmune perspective, the effects of an acute heat stress (31 +/- 1 degrees C for 10 h on d 35 of life) on serum corticosterone, performance variables, intestinal histology, and peritoneal macrophage activity in chickens. We demonstrated that the acute heat stress increased serum corticosterone concentrations and mortality and decreased food intake, BW gain, and feed conversion (P < 0.05). We did not find changes in the relative weights of the spleen, thymus, and bursa of Fabricius (P > 0.05). Increases in the basal and the Staphylococcus aureus-induced macrophage oxidative bursts and a decrease in the percentage of macrophages performing phagocytosis were also observed. Finally, mild, multifocal acute enteritis, characterized by the increased presence of lymphocytes and plasmocytes within the lamina propria of the jejunum, was also observed. We found that the stress-induced hypothalamic-pituitary-adrenal axis activation was responsible for the negative effects observed on chicken performance and immune function as well as for the changes in the intestinal mucosa. The data presented here corroborate with those presented in other studies in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.