Simplified drug efficacy evaluation system for vasopressin neurodegenerative disease using mouse disease-specific induced pluripotent stem cells.

Familial neurohypophyseal diabetes insipidus (FNDI) is a degenerative disorder in which vasopressin-secreting neurons degenerate over time due to the production of mutant proteins. We have demonstrated therapeutic effects of chemical chaperones in an FNDI mouse model, but the complexity and length of this evaluation were problematic. In this study, we established disease-specific mouse induced pluripotent stem cells (iPSCs) from FNDI-model mice and differentiated vasopressin neurons that produced mutant proteins. Fluorescence immunostaining showed that chemical chaperones appeared to protect vasopressin neurons generated from iPSCs derived from FNDI-model mice. Although KCL stimulation released vasopressin hormone from vasopressin neurons generated from FNDI-derived iPSCs, vasopressin hormone levels did not differ significantly between baseline and chaperone-added culture. Semi-quantification of vasopressin carrier protein and mutant protein volumes in vasopressin neurons confirmed that chaperones exerted a therapeutic effect. This research provides fundamental technology for creating in vitro disease models using human iPSCs and can be applied to therapeutic evaluation of various degenerative diseases that produce abnormal proteins.

Neurophysin I is an analytically robust surrogate biomarker for oxytocin.

Oxytocin is a pleiotropic neuropeptide that plays roles in biological processes ranging from birth, lactation, and social bonding to immune function, cardiovascular repair, and regulation of appetite. Although measurements of endogenous oxytocin concentrations have been performed for more than 50 years, the ability to measure oxytocin accurately poses notable challenges. One potential solution for overcoming these challenges involves measurement of oxytocin's carrier molecule - neurophysin I (NP-1) - as a surrogate biomarker. NP-1 is secreted in equimolar concentrations with oxytocin but has a longer half-life, circulates in higher concentrations, and can be measured using a sandwich immunoassay. We report experiments that 1) analytically validate a commercially available NP-1 sandwich immunoassay for use with human plasma and urine samples, 2) confirm the specificity of this assay, based on detection of NP-1 in plasma from wild-type but not oxytocin knockout mice, 3) demonstrate that NP-1 concentrations are markedly elevated in late pregnancy, consistent with studies showing substantial increases in plasma oxytocin throughout gestation, and 4) establish strong correlation between NP-1 and plasma oxytocin concentrations when oxytocin is measured in extracted (but not non-extracted) plasma. The NP-1 assay used in this study has strong analytical properties, does not require time-intensive extraction protocols, and the assay itself can be completed in < 2 h (compared to 16-24 h for a competitive oxytocin immunoassay). Our findings suggest that much like copeptin has become a useful surrogate biomarker in studies of vasopressin, measurements of NP-1 have similar potential to advance oxytocin research.

Small cell lung cancer associated with multiple paraneoplastic syndromes / Cáncer de pulmón de células pequeñas asociado a múltiples síndromes paraneoplásicos

Abstracts We report the case of a patient presenting with multiple severe electrolyte disturbances who was subsequently found to have small cell lung cancer. Upon further evaluation, she demonstrated three distinct paraneoplastic processes, including the syndrome of inappropriate antidiuretic hormone, Fanconi syndrome, and an inappropriate elevation in fibroblast growth factor-23 (FGF23). The patient underwent one round of chemotherapy, but she was found to have progressive disease. After 36 days of hospitalization, the patient made the decision to enter hospice care and later she expired.

Resumen Se reporta el caso de una paciente que ingresó al hospital para evaluación de múltiples trastornos electrolíticos y, posteriormente, se le hizo el diagnóstico de cáncer de pulmón de células pequeñas. Tras la evaluación médica, se detectaron tres síndromes paraneoplásicos: síndrome de secreción inadecuada de hormona antidiurética, síndrome de Fanconi y elevación inapropiada del factor 23 de crecimiento de fibroblastos. Se le administró quimioterapia sin éxito, por lo cual se decidió darle tratamiento paliativo y, un tiempo después, falleció.

Autoimmune central diabetes insipidus in a patient with ureaplasma urealyticum infection and review on new triggers of immune response

Diabetes insipidus is a disease in which large volumes of dilute urine (polyuria) are excreted due to vasopressin (AVP) deficiency [central diabetes insipidus (CDI)] or to AVP resistance (nephrogenic diabetes insipidus). In the majority of patients, the occurrence of CDI is related to the destruction or degeneration of neurons of the hypothalamic supraoptic and paraventricular nuclei. The most common and well recognized causes include local inflammatory or autoimmune diseases, vascular disorders, Langerhans cell histiocytosis (LCH), sarcoidosis, tumors such as germinoma/craniopharyngioma or metastases, traumatic brain injuries, intracranial surgery, and midline cerebral and cranial malformations. Here we have the opportunity to describe an unusual case of female patient who developed autoimmune CDI following ureaplasma urealyticum infection and to review the literature on this uncommon feature. Moreover, we also discussed the potential mechanisms by which ureaplasma urealyticum might favor the development of autoimmune CDI.

Clinical features and molecular analysis of arginine-vasopressin neurophysin II gene in long-term follow-up patients with idiopathic central diabetes insipidus / Apresentação clínica e análise molecular do gene da arginina-vasopressina neurofisina II de pacientes com diabetes insípido central idiopático com longo seguimento

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.