RESUMO
Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn1.4Pt0.9Pd0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.
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AIM: To examine whether Positron Emission Tomography Response Criteria in Solid Tumours (PERCIST) is useful to predict tumour response and prognosis of patients with oesophageal cancer who received neoadjuvant chemoradiotherapy (NACRT) followed by surgery. MATERIALS AND METHODS: This multicentre retrospective study included 60 patients with oesophageal cancer who underwent 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (18F-FDG-PET/CT) before and after NACRT prior to surgery from January 2007 and June 2016. The correlation between pathological response and PERCIST was assessed by χ2 test. The prognostic significance was assessed by the Kaplan-Meier method and Cox regression analysis. RESULTS: There were 30 responders and 30 non-responders pathologically. The complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), and progressive metabolic disease (PMD) were seen in 22, 29, seven, and two patients, respectively. There was a significant correlation between pathological response and PERCIST (p<0.001). Forty patients showed eventual progression, and 20 patients were alive without progression between the start of NACRT and last clinical follow-up (median follow-up period; 27 months [range, 3-107]). Pathological stage and PERCIST were significant for progression-free survival (PFS; p=0.044 and 0.006, respectively) and also significant for overall survival (OS; p=0.009 and 0.001, respectively) at univariate analysis. Pathological lymph node staging was also significant for OS at univariate analysis (p=0.018). At multivariate analysis, PERCIST remained significant and independent for PFS (hazard ratio [HR]: 1.59, p=0.046) and OS (HR: 1.82, p=0.008). CONCLUSION: PERCIST may be useful for predicting tumour response and prognosis of patients with oesophageal cancer who received NACRT.
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Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/terapia , Tomografia por Emissão de Pósitrons , Adulto , Idoso , Quimiorradioterapia , Neoplasias Esofágicas/patologia , Feminino , Fluordesoxiglucose F18 , Humanos , Japão , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Valor Preditivo dos Testes , Prognóstico , Compostos Radiofarmacêuticos , Estudos RetrospectivosRESUMO
The ultrastructural characteristics and immunolocalization of in vivo bound immunoglobulin G (IgG) in skin affected by anti-p200 pemphigoid have not been elucidated. To give insight into the mechanism of blister formation we report a new case of anti-p200 pemphigoid, studied with stage-oriented morphological analysis and immunoelectron microscopy. Skin biopsy specimens were evaluated ultrastructurally and histologically with immunohistochemistry. By observing the nonblister site, the blister edge and centre of the blister, we determined that neutrophil infiltration increases gradually at the dermoepidermal junction in association with the destruction of type IV collagen. Ultrastructurally, many neutrophils were observed under the lamina densa, with vacuole formation in the dermis. At the periphery of the blister, the lamina densa became fragmented and was observed either at the roof or the floor of the blister. At the centre of the blister, the lamina densa was mainly observed at the blister floor. Postembedding immunoelectron microscopy demonstrated that the IgG, bound in vivo, localized at the lamina lucida, while the area beneath the hemidesmosomes was spared. Together with the early involvement of neutrophils and the destruction of the basal lamina, we suggest that the binding of autoantibodies to the nonhemidesmosomal lamina lucida may induce inflammation with neutrophils, resulting in blister formation.
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Autoanticorpos/imunologia , Membrana Basal/imunologia , Imunoglobulina G/metabolismo , Neutrófilos/imunologia , Penfigoide Bolhoso/imunologia , Idoso , Membrana Basal/ultraestrutura , Vesícula/imunologia , Vesícula/patologia , Humanos , Imuno-Histoquímica , Laminina/imunologia , Masculino , Microscopia Eletrônica , Microscopia de Fluorescência , Infiltração de Neutrófilos , Neutrófilos/patologia , Penfigoide Bolhoso/patologiaRESUMO
Development of endocrine cells in the endoderm involves Atonal and Achaete/Scute-related basic helix-loop-helix (bHLH) proteins. These proteins also serve as neuronal determination and differentiation factors, and are antagonized by the Notch pathway partly acting through Hairy and Enhancer-of-split (HES)-type proteins. Here we show that mice deficient in Hes1 (encoding Hes-1) display severe pancreatic hypoplasia caused by depletion of pancreatic epithelial precursors due to accelerated differentiation of post-mitotic endocrine cells expressing glucagon. Moreover, upregulation of several bHLH components is associated with precocious and excessive differentiation of multiple endocrine cell types in the developing stomach and gut, showing that Hes-1 operates as a general negative regulator of endodermal endocrine differentiation.
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Proteínas de Drosophila , Glândulas Endócrinas/embriologia , Endoderma , Sequências Hélice-Alça-Hélice , Proteínas de Homeodomínio/fisiologia , Proteínas Repressoras , Sequência de Aminoácidos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Diferenciação Celular , Proteínas de Ligação a DNA/metabolismo , Glândulas Endócrinas/citologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Proteínas de Insetos/metabolismo , Intestinos/patologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Pâncreas/embriologia , Pâncreas/patologia , Pâncreas/fisiopatologia , Proteínas/metabolismo , Receptores Notch , Transdução de Sinais , Estômago/patologia , Fatores de Transcrição HES-1RESUMO
BACKGROUND: We previously reported that bone marrow (BM) was a homing site for gastric cancer (GC) cells leading to haematogenous metastases. There has been little study that microRNAs regulated pathways in malignant cells or host cells in BM, and thereby regulated the progression of GC. METHODS: Both microRNA microarray and gene expression microarray analyses of total RNA from BM were conducted, comparing five early and five advanced GC patients. We focused on miR-144-ZFX axis as a candidate BM regulator of GC progression and validated the origin of the microRNA expression in diverse cell fractions (EpCAM(+)CD45(-), EpCAM(-)CD45(+), and CD14(+)) by magnetic-activated cell sorting (MACS). RESULTS: Quantitative reverse-transcriptase (RT)-PCR analysis validated diminished miR-144 expression in stage IV GC patients with respect to stage I GC patients (t-test, P=0.02), with an inverse correlation to ZFX (ANOVA, P<0.01). Luciferase reporter assays in five GC cell lines indicated their direct binding and validated by western blotting. Pre-miR144 treatment and the resultant repression of ZFX in GC cell lines moderately upregulated their susceptibility to 5-fluorouracil chemotherapy. In MACS-purified BM fractions, the level of miR-144 expression was significantly diminished in disseminated tumour cell fraction (P=0.0005). Diminished miR-144 expression in 93 cases of primary GC indicated poor prognosis. CONCLUSION: We speculate that disseminated cancer cells could survive in BM when low expression of miR-144 permits upregulation of ZFX. The regulation of the miR-144-ZFX axis in cancer cells has a key role in the indicator of the progression of GC cases.
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Medula Óssea/metabolismo , Fatores de Transcrição Kruppel-Like/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Medula Óssea/patologia , Progressão da Doença , Perfilação da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Células Neoplásicas Circulantes , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Neoplasias Gástricas/patologiaRESUMO
Eosinophilia is recognized as a poor prognostic factor in patients with cutaneous T-cell lymphoma (CTCL). We report a case of folliculotropic mycosis fungoides (FMF) presenting with multiple ulcerative nodular lesions and persistent eosinophilia. Severe facial lesions resulted in a leonine appearance. On histopathological examination, nodular infiltration of large CD30+ large cells was seen. When the previous biopsy specimens were reviewed, marked folliculotropism with atypical lymphocytes was identified in previous specimens 20 years before the blastic transformation. CC chemokine receptor 3 was expressed in tumour cells, whereas CXC chemokine receptor 3 was negative. Expression of interleukin (IL)-5 was detected in a few mononuclear lymphoid cells. This case demonstrates that T helper (Th)2-polarized tumour cells may produce Th2 cytokines including IL-5, which suggests that cytokines and chemokines may contribute to persistent eosinophilia and to recruitment of eosinophils into tumour lesions in advanced FMF.
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Eosinofilia/diagnóstico , Neoplasias Faciais/diagnóstico , Fácies , Micose Fungoide/diagnóstico , Neoplasias Cutâneas/diagnóstico , Adulto , Eosinofilia/patologia , Neoplasias Faciais/patologia , Evolução Fatal , Humanos , Linfoma Anaplásico de Células Grandes/diagnóstico , Linfoma Anaplásico de Células Grandes/patologia , Masculino , Micose Fungoide/patologia , Neoplasias Cutâneas/patologiaRESUMO
An in vitro study in which isolated prothoracic glands of the Bombyx silkworm were cultured has provided definite evidence that the prothoracic gland is the site where molting hormone is synthesized. The hormone behaved very similarly to free ecdysone on thin-layer chromatography. Analysis by liquid chromatography and mass fragmentography revealed that the hormone is identical with alpha-ecdysone.
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AIM: To examine the utility of 2'-[18F]-fluoro-2'-deoxy-D-glucose positron emission tomography (FDG-PET) for detecting multiple primary cancers (MPC) in patients with hypopharyngeal cancer (HPC). PATIENTS, METHODS: Seventy patients with HPC underwent FDG-PET to determine the staging. Routine clinical examinations were carried out, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), and oesophagealgastroduodenoscopy (EGDS). The detection rate of synchronous and metachronous cancer was calculated based on FDG-PET alone or FDG-PET combined with clinical routine examination. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy were used to diagnose oesophageal cancer using FDG-PET. RESULTS: Of the 70 patients, 12 (17.1%) had 15 synchronous tumours, and 2 of the 58 remaining patients (3.4%) had metachronous tumours. Oesophageal cancer was discovered most frequently: superficial type (n=6), advanced type (n=4). On a per-patient basis, 11 of 12 patients (91.6%) were diagnosed with synchronous tumours, and on a per-lesion basis, 12 of 15 lesions (80.0%) were detected by FDG-PET. The sensitivity, specificity, accuracy, PPV, and NPV of FDG-PET regarding oesophageal cancer were 70%, 100%, 95.7%, 100%, and 95.2% respectively. Three of the six superficial types were positive on FDG-PET. Both of the metachronous tumour lesions were detected by FDG-PET. CONCLUSION: FDG-PET is useful for estimating the MPC in HPC patients. Since 3 of 10 synchronous oesophageal cancer were missed with PET alone, a combination with EGDS should be considered to exclude synchronous oesophageal cancer.
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Fluordesoxiglucose F18 , Neoplasias Hipofaríngeas/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Feminino , Humanos , Neoplasias Hipofaríngeas/patologia , Neoplasias Laríngeas/diagnóstico por imagem , Neoplasias Laríngeas/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/diagnóstico por imagem , Neoplasias Orofaríngeas/patologia , Tomografia por Emissão de Pósitrons/métodos , Radiografia , Compostos RadiofarmacêuticosRESUMO
Ovarian tumors of low malignant potential (LMP) appear to be intermediate between adenomas and ovarian carcinomas. Such tumors are often associated with a significantly better prognosis than for ovarian carcinomas. However, a subset of LMPs can progress and become lethal even in patients with early-stage disease. In order to seek sensitive diagnostic tools to monitor patients after surgical therapy, we performed a genome-wide scan for LOH in 37 early-stage mucinous LMPs using 91 polymorphic microsatellite markers at an average interval of 50 cM across all of the human chromosomes and 25 LOH markers reported to be associated with ovarian carcinoma. Fractional allelic loss (FAL) values were calculated as (loci scored with LOH)/(total informative loci) for each sample. With respect to tumor recurrence, high FAL values were more frequent in recurrent tumors than in non-recurrent tumors. Using the screening markers, FAL values for recurrent tumors were significantly higher than for non-recurrent tumors (19.8% vs 6.3%, respectively, p < 0.0001). Similar results were obtained using the hotspot markers (22.2% vs 7.1%, respectively, p < 0.0001). A significant correlation between FAL values obtained using screening markers and those based on hotspot markers was observed (R = 0.460, p = 0.003). Our findings suggest that a specific type of genetic instability (i.e., chromosomal instability, CIN) may exist in mucinous LMPs, and that this instability may indicate tumors with an aggressive biological nature. Therefore, FAL values may represent a new biomarker for risk prediction in early-stage mucinous LMP tumors.
Assuntos
Adenocarcinoma Mucinoso/genética , Perda de Heterozigosidade , Repetições de Microssatélites , Recidiva Local de Neoplasia/genética , Neoplasias Ovarianas/genética , Adenocarcinoma Mucinoso/patologia , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Neoplasias Ovarianas/patologia , Análise de SobrevidaAssuntos
Transportadores de Ânions Orgânicos , Osteoartropatia Hipertrófica Primária , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Povo Asiático/genética , População do Leste Asiático , Japão , Transportadores de Ânions Orgânicos/genética , Osteoartropatia Hipertrófica Primária/genética , Osteoartropatia Hipertrófica Primária/diagnósticoRESUMO
Mammalian hairy and Enhancer of split homolog 1 (HES1), a basic helix-loop-helix factor gene, is expressed in retinal progenitor cells, and its expression decreases as differentiation proceeds. Retinal progenitor cells infected with HES1-transducing retrovirus did not differentiate into mature retinal cells, suggesting that persistent expression of HES1 blocks retinal development. In contrast, in the retina of HES1-null mutant mice, differentiation was accelerated, and rod and horizontal cells appeared prematurely and formed abnormal rosette-like structures. Lens and cornea development was also severely disturbed. Furthermore, in the mutant retina, bipolar cells extensively died, and finally disappeared. These studies provide evidence that HES1 regulates differentiation of retinal neurons and is essential for eye morphogenesis.
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Diferenciação Celular , Olho/crescimento & desenvolvimento , Expressão Gênica , Proteínas de Homeodomínio/fisiologia , Neurônios/citologia , Retina/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Vetores Genéticos , Sequências Hélice-Alça-Hélice , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Endogâmicos ICR , Morfogênese , Técnicas de Cultura de Órgãos , Ratos , Retina/metabolismo , Retroviridae/genética , Células-Tronco/citologia , Células-Tronco/metabolismo , Fatores de Transcrição HES-1 , TransfecçãoRESUMO
This study examined the status of KRAS and BRAF mutations, in relation to extracellular signal-regulated protein kinase (ERK) activation in 58 ovarian carcinomas to clarify the clinicopathological and prognostic significance of KRAS/BRAF mutations. Somatic mutations of either KRAS or BRAF were identified in 12 (20.6%) out of 58 ovarian carcinomas. The frequency of KRAS/BRAF mutations in conventional serous high-grade carcinomas (4.0% : 1/25) was significantly lower than that in the other histological type (32.3% : 10/31). Phosphorylated ERK1/2 (p-ERK1/2) expression was identified in 18 (38.2%) out of 45 ovarian carcinomas. KRAS/BRAF mutation was significantly correlated with International Federation of Gynecology and Obstetrics (FIGO) stage I, II (P<0.001), and p-ERK1/2 (P<0.001). No significant correlations between KRAS/BRAF mutations or p-ERK1/2 expression and overall survival were found in patients with ovarian carcinoma treated with platinum and taxane chemotherapy (P=0.2460, P=0.9339, respectively). Next, to clarify the roles of ERK1/2 activation in ovarian cancers harbouring KRAS or BRAF mutations, we inactivated ERK1/2 in ovarian cancer cells using CI-1040. Cl-1040 is a compound that selectively inhibits MAP kinase kinase (MEK), an upstream regulator of ERK1/2, and thus prevents ERK1/2 activation. Profound growth inhibition and apoptosis were observed in CI-1040-treated cancer cells with mutations in either KRAS or BRAF in comparison with the ovarian cancer cells containing wild-type sequences. This was evident in both in vitro and in vivo studies. The findings in this study indicate that an activated ERK1/2 pathway is critical to tumour growth and survival of ovarian cancers with KRAS or BRAF mutations. Furthermore, they suggest that the CI-1040-induced phenotypes depend on the mutational status of KRAS and BRAF in ovarian cancers. Therefore, ovarian cancer patients with KRAS or BRAF mutations may benefit from CI-1040 treatment.
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Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Animais , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células , Ativação Enzimática , Feminino , Humanos , Camundongos , Camundongos Nus , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Mutação/genética , Neoplasias Ovarianas/patologia , Fosforilação , Prognóstico , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Especificidade por Substrato , Taxa de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/metabolismoRESUMO
Alkylating agents have strong leukemogenic potential. There are a number of recent acute myeloid leukemia (t-AML) cases related to previous paclitaxel exposure. These leukemias tend to be of aggressive subtypes with long-latency periods. Unlike previously reported cases, the present case was of the secondary acute megakaryoblastic myeloid leukemia (AML M7) subtype. Additionally, it did not harbor a translocation in chromosome 19. A 73-year-old woman was diagnosed with t-AML M7 with antecedent myelodysplasia. Leukemia followed a second induction of paclitaxel- and carboplatin-based chemotherapy for recurrent ovarian cancer. Her second induction began 25 months after completion of her first course of chemotherapy. The increased incidence of postpaclitaxel leukemia suggests a probable role for paclitaxel as a leukemogenic agent. It highlights the importance of assessing for leukemia risk factors prior to beginning paclitaxel therapy.
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Carboplatina/uso terapêutico , Leucemia Mieloide Aguda/induzido quimicamente , Leucemia Mieloide Aguda/complicações , Síndromes Mielodisplásicas/induzido quimicamente , Síndromes Mielodisplásicas/complicações , Neoplasias Ovarianas/tratamento farmacológico , Paclitaxel/uso terapêutico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/sangue , Feminino , Humanos , Cariotipagem , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/patologia , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/patologiaRESUMO
In Japan, organ donation has been still limited because of the strict donor criteria. The aim of this study was to show the effectiveness of pancreas transplantation (PTx) by analyzing the outcomes even under poor donor conditions. Thirty-six cases of PTx (32 simultaneous pancreas and kidney transplantations [SPK], 4 pancreas after kidney transplantations) performed during the last 8 years were examined especially for donor characteristics. Mean donor age of 41.4 +/- 11.9 years was considerably older compared with that in the United States and Europe; donors aged over 40 years comprised 67% of the total. According to the criteria described by Kapur, 29 cases (81%) in our series would be considered marginal. Thus, to increase blood supply into the pancreatic head, the gastroduodenal artery (GDA) was anastomosed using donor artery to common hepatic artery or iliac Y graft. These procedures were performed in 16 of the 24 cases in which there was liver procurement. Eventually, 34 cases (94%) preserved GDA continuity. Mean total cold ischemic time of pancreatic grafts was 12 hours 15 minutes. Of 214 registrants, 17 patients on the waiting list for SPK died of diabetic complications. To date, patient survival remains 100% with a mean follow-up period of 33 months. Pancreas graft survivals at 1, 3, and 5 years posttransplantation were 92%, 80%, and 80%, respectively. In contrast, kidney survivals were 91%, 91%, and 91%, respectively. The integrity of the pancreas head and duodenum by preservation of the GDA continuity might have decreased the risk associated with the marginal donors.
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Sobrevivência de Enxerto , Transplante de Pâncreas/métodos , Transplante de Pâncreas/estatística & dados numéricos , Doadores de Tecidos/estatística & dados numéricos , Artérias/cirurgia , Morte Encefálica , Nefropatias Diabéticas/cirurgia , Humanos , Japão , Falência Renal Crônica/cirurgia , Transplante de Rim/estatística & dados numéricos , Procedimentos de Cirurgia Plástica , Sistema de Registros , Alocação de Recursos , Transplante/estatística & dados numéricosRESUMO
BACKGROUND: Pleomorphic rhabdomyosarcoma (RMS) of gynecologic origin is an exceedingly rare, highly malignant tumor. Only a few cases have been reported in the last decades. CASE REPORT: A 60-year-old postmenopausal woman presented with a high LDH level of unknown origin. Ultimately, she was diagnosed with pleomorphic RMS. She underwent total hysterectomy, bilateral salpingo-oophorectomy, left pelvic and paraaortic lymphadenectomy and partial omentectomy. Surgery was followed by systemic chemotherapy and pelvic irradiation. Unfortunately, the patient did not respond to treatment. Her disease course correlated with the fluctuation of plasma LDH levels. Ultimately she died within 20 months of the diagnosis. CONCLUSION: It is important to have better insight and to set a standard multimodal treatment for adult RMS. In addition, plasma LDH levels can be considered as a prognostic marker for RMS, particularly in advanced stage.
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L-Lactato Desidrogenase/sangue , Rabdomiossarcoma/patologia , Neoplasias Uterinas/patologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Pessoa de Meia-Idade , Rabdomiossarcoma/sangue , Rabdomiossarcoma/fisiopatologia , Neoplasias Uterinas/sangue , Neoplasias Uterinas/fisiopatologiaRESUMO
In an attempt to delineate the mechanism and the site of action of cyproheptadine and dopaminergic agonists as well as hormones including thyrotropin-releasing hormone (TRH) and hydrocortisone, the effects of these substances on ACTH secretion from corticotroph adenoma cells in culture were examined. Dispersed cells of pituitary adenomas obtained at surgery from four patients with Nelson's syndrome and one subject with Cushing's disease formed a monolayer and actively secreted ACTH into the medium. When TRH (0.1 microM) was added to the medium, a significant increase in ACTH secretion was demonstrated by adenoma cells from two patients who responded to TRH preoperatively. Moreover, a dose-response relationship between TRH concentrations and ACTH secretion was observed. Incubation of cells with cyproheptadine (1 or 0.1 microM) resulted in a significant decrease in ACTH release, and inhibited stimulation produced by TRH in one experiment. This effect of cyproheptadine was blocked when equimolar concentrations of serotonin was coincubated, whereas serotonin by itself did not affect ACTH secretion. Dopamine (0.1 microM) lowered ACTH accumulation in the medium, which was blocked by the addition of haloperidol. When hydrocortisone was added to the culture, dose-dependent suppression of ACTH secretion was demonstrated. TRH at an equimolar concentration reversed this effect, but, failed to overcome the inhibition induced by a higher concentration of hydrocortisone in cells from one adenoma studied. Cultured normal corticotrophs obtained from a patient with metastatic breast cancer, on the other hand, did not show any response to these substances, except for hydrocortisone. We suggest that TRH, cyproheptadine, dopamine affect ACTH secretion in patients with ACTH-producing pituitary adenomas by their direct action on the adenoma.
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Hormônio Adrenocorticotrópico/metabolismo , Síndrome de Cushing/fisiopatologia , Ciproeptadina/farmacologia , Dopamina/farmacologia , Síndrome de Nelson/fisiopatologia , Neoplasias Hipofisárias/fisiopatologia , Hormônio Liberador de Tireotropina/farmacologia , Adenoma/fisiopatologia , Células Cultivadas , Humanos , Hidrocortisona/farmacologia , Taxa Secretória/efeitos dos fármacosRESUMO
To determine the mechanism and the site of action of catecholamines as well as hormones including thyrotropin-releasing hormone (TRH)1 and somatostatin on pituitary hormone release in patients with acromegaly and in normal subjects, the effects of these substances on growth hormone (GH) and prolactin (PRL) secretion from adenomatous and nonadenomatous human pituitary cells in culture were examined. When dopamine (0.01-0.1 microM) or bromocriptine (0.01-0.1 microM) was added to the culture media, a significant inhibition of GH and PRL secretion from adenoma cells from acromegalic patients was observed. This inhibition was blocked by D2 receptor blockade with metoclopramide or sulpiride, but not by D1 receptor blockade. Similarly, dopamine suppressed GH and PRL release by nonadenomatous pituitary cells in a dose-dependent manner, which was again blocked by D2 receptor blockade. The minimum effective concentration of dopamine required for a significant inhibition of PRL secretion (0.01 microM) was lower than that for GH release (0.1 microM). Norepinephrine, likewise, caused a suppression of PRL secretion from adenomatous and nonadenomatous pituitary cells. This effect was blocked by sulpiride, phentolamine, however, was ineffective. When TRH was added to the media, both GH and PRL secretion were enhanced in adenoma cells, while only the stimulation of PRL release was observed in nonadenomatous pituitary cells. Coincubation of TRH and dopamine resulted in variable effects on GH and PRL secretion. Somatostatin consistently lowered GH and PRL secretion in both adenomatous and nonadenomatous pituitary cells and completely blocked the TRH-induced stimulation of GH and PRL secretion from adenoma cells. Opioid peptides (1 microM) failed to affect hormone release. These results suggest that no qualitative difference in GH and PRL responses to dopaminergic agonists or to somatostatin exists between adenoma cells of acromegalic patients and normal pituitary cells, and that the direct effect of catecholamines on GH and PRL secretion from human pituitary cells is mediated mainly through dopamine receptor activation.
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Adenoma/metabolismo , Norepinefrina/farmacologia , Neoplasias Hipofisárias/metabolismo , Somatostatina/farmacologia , Hormônio Liberador de Tireotropina/farmacologia , Acromegalia/metabolismo , Adulto , Bromocriptina/farmacologia , Células Cultivadas , Dopamina/farmacologia , Endorfinas/farmacologia , Feminino , Hormônio do Crescimento/biossíntese , Hormônio do Crescimento/metabolismo , Haloperidol/farmacologia , Humanos , Levodopa/farmacologia , Masculino , Pessoa de Meia-Idade , Hipófise/metabolismo , Prolactina/metabolismoRESUMO
To determine whether atrial natriuretic factor (ANF) is a circulating hormone in men, a radioimmunoassay suitable for the estimation of ANF in human plasma was developed and the nature of plasma ANF was characterized. Plasma ANF was extracted before radioimmunoassay by affinity chromatography on a column of ANF antibody-coupled agarose. When plasma ANF extract was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with the radioimmunoassay of the eluted gel slices for ANF, almost all of the ANF activities ran in the 3,000-mol-wt area, while three peaks of ANF were observed in human atrial tissue extract, molecular weights of which corresponded to 14,000, 6,000, and 3,000, respectively. Reversed-phase high performance liquid chromatography of atrial tissue extract resolved multiple forms of ANF. In contrast, one major peak was observed in human plasma extract, and its retention time coincided with that of synthetic human alpha-atrial natriuretic polypeptide. When 500 ml of 0.9% saline was infused into six healthy subjects over 45 min, plasma levels of ANF were unequivocally elevated. The mean plasma ANF concentrations rose from the baseline (23.0 +/- 2.5 pg/ml, mean +/- SEM, n = 6) to the peak (41.8 +/- 4.9 pg/ml, mean +/- SEM) at 75 min postinfusion. No significant change in plasma ANF, on the other hand, was found in the control group. These results suggest that ANF is a circulating hormone in men and is secreted in response to isotonic volume expansion.