ABSTRACT
We present here the clinical and molecular data of two patients with acromegaly treated with octreotide LAR after non-curative surgery, and who presented different responses to therapy. Somatostatin receptor type 2 and 5 (SSTR2 and SSTR5), and aryl hydrocarbon receptor-interacting protein (AIP) expression levels were analyzed by qPCR. In both cases, high SSTR2 and low SSTR5 expression levels were detected; however, only one of the patients achieved disease control after octreotide LAR therapy. When we analyzed AIP expression levels of both cases, the patient whose disease was controlled after therapy exhibited AIP expression levels that were two times higher than the patient whose disease was still active. These two cases illustrate that, although the currently available somatostatin analogs bind preferentially to SSTR2, some patients are not responsive to therapy despite high expression of this receptor. This difference could be explained by differences in post-receptor signaling pathways, including the recently described involvement of AIP. Arq Bras Endocrinol Metab. 2012;56(8):501-6.
Apresentamos os dados clínicos e moleculares de dois pacientes com acromegalia tratados com octreotide LAR após cirurgia não curativa, com diferentes respostas a essa terapia medicamentosa. As expressões do receptor de somatostatina tipo 2 e 5 (SSTR2 e SSTR5) e da proteína de interação com o receptor aril hidrocarbono (AIP) foram analisadas por qPCR. Em ambos os casos, foi encontrada uma expressão elevada de SSTR2 e baixa do SSTR5. No entanto, o controle da doença foi obtido após tratamento com octreotide LAR em apenas um dos pacientes. Quando analisamos a expressão do AIP em ambos os casos, o paciente cuja doença foi controlada após a terapia medicamentosa apresentou uma expressão duas vezes maior do que a do paciente não controlado com o tratamento. Conclui-se que esses dois casos ilustram que, embora os análogos de somatostatina atualmente disponíveis se liguem preferencialmente ao SSTR2, alguns pacientes não respondem ao tratamento, apesar de uma elevada expressão desse receptor. Isso poderia ser explicado por alterações nas vias de sinalização pós-receptor, incluindo o envolvimento recentemente descrito da AIP. Arq Bras Endocrinol Metab. 2012;56(8):501-6.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Acromegaly/drug therapy , Antineoplastic Agents, Hormonal/therapeutic use , Drug Resistance, Neoplasm , Intracellular Signaling Peptides and Proteins/metabolism , Octreotide/therapeutic use , Pituitary Neoplasms/drug therapy , Acromegaly/metabolism , Pituitary Neoplasms/metabolism , Receptors, Somatostatin/metabolismABSTRACT
OBJECTIVES: Idiopathic central precocious puberty and its postponement with a (gonadotropin-releasing hormone) GnRH agonist are complex conditions, the final effects of which on bone mass are difficult to define. We evaluated bone mass, body composition, and bone remodeling in two groups of girls with idiopathic central precocious puberty, namely one group that was assessed at diagnosis and a second group that was assessed three years after GnRH agonist treatment. METHODS: The precocious puberty diagnosis and precocious puberty treatment groups consisted of 12 girls matched for age and weight to corresponding control groups of 12 (CD) and 14 (CT) girls, respectively. Bone mineral density and body composition were assessed by dual X-ray absorptiometry. Lumbar spine bone mineral density was estimated after correction for bone age and the mathematical calculation of volumetric bone mineral density. CONEP: CAAE-0311.0.004.000-06. RESULTS: Lumbar spine bone mineral density was slightly increased in individuals diagnosed with precocious puberty compared with controls; however, after correction for bone age, this tendency disappeared (CD = -0.74 + 0.9 vs. precocious puberty diagnosis = -1.73 + 1.2). The bone mineral density values of girls in the precocious puberty treatment group did not differ from those observed in the CT group. CONCLUSION: There is an increase in bone mineral density in girls diagnosed with idiopathic central precocious puberty. Our data indicate that the increase in bone mineral density in girls with idiopathic central precocious puberty is insufficient to compensate for the marked advancement in bone age observed at diagnosis. GnRH agonist treatment seems to have no detrimental effect on bone mineral density.
Subject(s)
Adolescent , Child , Female , Humans , Young Adult , Body Composition/physiology , Bone Density/physiology , Gonadotropin-Releasing Hormone/agonists , Puberty, Precocious/drug therapy , Puberty, Precocious/pathology , Absorptiometry, Photon , Age Factors , Body Mass Index , Body Composition/drug effects , Bone Density/drug effects , Case-Control Studies , Reference Values , Statistics, Nonparametric , Treatment OutcomeABSTRACT
INTRODUCTION: Central diabetes insipidus (DI) characterized by polyuria, polydipsia and inability to concentrate urine, has different etiologies including genetic, autoimmune, post-traumatic, among other causes. Autosomal dominant central DI presents the clinical feature of a progressive decline of arginine-vasopressin (AVP) secretion. OBJECTIVE: In this study, we characterized the clinical features and sequenced the AVP-NPII gene of seven long-term follow-up patients with idiopathic central DI in an attempt to determine whether a genetic cause would be involved. METHODS: The diagnosis of central DI was established by fluid deprivation test and hyper-tonic saline infusion. For molecular analysis, genomic DNA was extracted and the AVP-NPII gene was amplified by polymerase chain reaction and sequenced. RESULTS: Sequencing analysis revealed a homozygous guanine insertion in the intron 2 (IVS2 +28 InsG) of the AVP-NPII gene in four patients, which represents an alternative gene assembly. No mutation in the code region of the AVP-NPII gene was found. CONCLUSIONS: The homozygous guanine insertion in intron 2 (IVS2 +28 InsG) is unlikely to contribute to the AVP-NPII gene modulation in DI. In addition, the etiology of idiopathic central DI in children may not be apparent even after long-term follow-up, and requires continuous etiological surveillance.
INTRODUÇÃO: O diabetes insípido (DI) central, caracterizado por poliúria, polidipsia e inabilidade em concentrar a urina, apresenta diferentes etiologias, incluindo causas genética, autoimune, pós-traumática, entre outras. O DI central autossômico dominante apresenta a característica clínica de falência progressiva da secreção da arginina-vasopressina (AVP). OBJETIVO: No presente estudo, caracterizou-se a apresentação clínica e sequenciou-se o gene AVP-NPII de sete pacientes com DI central idiopático seguidos de longa data na tentativa de determinar se uma causa genética estava envolvida na etiologia. MÉTODOS: O diagnóstico do DI central foi estabelecido por meio do teste de jejum hídrico e infusão de salina hipertônica. Para a realização da análise molecular, o DNA genômico foi extraído e o gene AVP-NPII foi amplificado pela reação em cadeia da polimerase e, posteriormente, sequenciado. RESULTADOS: A análise do sequenciamento do gene AVP-NPII revelou uma inserção em homozigose de uma guanina no íntron 2 (IVS2 +28 InsG) em quatro pacientes, correspondendo a um arranjo alternativo do gene. Nenhuma mutação da região codificadora do gene AVP-NPII foi encontrada. CONCLUSÕES: A inserção em homozigose de uma guanina no íntron 2 (IVS2 +28 InsG) provavelmente não contribui na modulação do gene AVP-NPII no DI. Adicionalmente, a etiologia do DI central idiopático em crianças pode não se tornar evidente mesmo após um longo período de seguimento, necessitando de contínua vigilância da etiologia.