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1.
Br J Pharmacol ; 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31652355

RESUMO

BACKGROUND AND PURPOSE: Excessive GABAergic inhibition contributes to cognitive dysfunctions in Down syndrome (DS). Selective negative allosteric modulators (NAMs) of α5-containing GABAA receptors such as α5IA restore learning and memory deficits in Ts65Dn mice modelling DS. This study aimed at testing long-lasting effects of α5IA on in vivo long-term potentiation (LTP) and behavior in Ts65Dn mice. EXPERIMENTAL APPROACH: We performed in vivo long-term potentiation (LTP) recordings for six consecutive days in freely moving Ts65Dn mice and their wild-type littermates, treated with vehicle or α5IA. In parallel, Ts65Dn mice were subjected to various learning and memory tests (Y-maze, Morris water maze or the novel object recognition) up to seven days following one single injection of α5IA or vehicle. KEY RESULTS: We found that LTP could not be evoked in vivo in Ts65Dn mice at the hippocampal CA3-CA1 synapse. However, this deficit was sustainably reversed for at least six consecutive days following a single injection of α5IA. This long-lasting effect of α5IA was also unveiled when assessing working and long-term memory deficits in Ts65Dn mice. CONCLUSION AND IMPLICATIONS: We show for the first time in vivo LTP deficits in Ts65Dn mice. These deficits are restored for at least six days following acute treatment with α5IA and might be the substrate for the long-lasting pharmacological effects of α5IA demonstrated here on spatial working and long-term recognition and spatial memory tasks. Altogether, these results highlight the interest of NAMs of α5-containing GABAA receptors for treating cognitive deficits associated with DS.

2.
Endocrinol. diabetes nutr. (Ed. impr.) ; 66(7): 443-458, ago.-sept. 2019. graf, tab
Artigo em Espanhol | IBECS | ID: ibc-182864

RESUMO

Objetivo: El tratamiento de la diabetes tipo 2 (DM2) es complejo y su propósito es reducir la morbimortalidad, por lo que su manejo tiene que incluir: un control glucémico individualizado precoz (mediante una adecuada educación diabetológica, modificaciones del estilo de vida y tratamiento farmacológico), el control de los factores de riesgo cardiovascular (CV), la detección y tratamiento precoz de las complicaciones y la evaluación de las comorbilidades asociadas. El objetivo fue elaborar un documento para unificar los aspectos necesarios para el abordaje integral de las personas con DM2. Participantes: Miembros del Grupo de trabajo de Diabetes Mellitus de la Sociedad Española de Endocrinología y Nutrición. Métodos: Se realizó una revisión de la evidencia disponible relativa a cada aspecto del manejo de la diabetes: objetivos de control glucémico, dieta y ejercicio, tratamiento farmacológico, tratamiento y control de factores de riesgo, detección de complicaciones y manejo del paciente frágil con DM2. Las recomendaciones se formularon según los grados de evidencia recogidos en los Standards of Medical Care in Diabetes 2018. Tras la formulación de las recomendaciones el documento fue consensuado por los miembros del Grupo de trabajo de Diabetes Mellitus de la Sociedad Española de Endocrinología y Nutrición. Conclusiones: El objetivo de este documento es proporcionar, desde el punto de vista del endocrinólogo clínico, unas recomendaciones prácticas basadas en la evidencia acerca de todos los aspectos necesarios para el abordaje integral de la DM2


Objective: Treatment of type 2 diabetes mellitus (T2DM) is complex and is intended to decrease morbidity and mortality. Management should therefore include adequate diabetes education, lifestyle changes, drug treatment to achieve early blood glucose control and reduction of cardiovascular (CV) risk factors, early detection and treatment of complications, and assessment of associated comorbidities. The objective was to prepare a document including all aspects required for a comprehensive approach to T2DM. Participants: Members of the Diabetes Mellitus Working Group of the Spanish Society of Endocrinology. Methods: The available evidence regarding each aspect of diabetes management (blood glucose control goals, diet and exercise, drug treatment, risk factor management and control, detection of complications, and management of frail patients) was reviewed. Recommendations were formulated based on the grades of evidence stated in the 2018 Standards of Medical Care in Diabetes. Recommendations were discussed and agreed by the working group members. Conclusions: This document is intended to provide evidence-based practical recommendations for comprehensive management of T2DM by clinical endocrinologists


Assuntos
Humanos , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/complicações , Fatores de Risco , Sociedades Médicas/normas , Documentos , Índice Glicêmico , Estilo de Vida , Sociedades Médicas/organização & administração , Estratégias de eSaúde , Exercício/fisiologia
3.
J Bone Miner Res ; 34(12): 2183-2191, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31369697

RESUMO

In adults with X-linked hypophosphatemia (XLH), excess FGF23 impairs renal phosphate reabsorption and suppresses production of 1,25-dihydroxyvitamin D, resulting in chronic hypophosphatemia and persistent osteomalacia. Osteomalacia is associated with poor bone quality causing atraumatic fractures, pseudofractures, delayed fracture healing, and bone pain. Burosumab is a fully human monoclonal antibody against FGF23. UX023-CL304 is an ongoing, open-label, single-arm, phase 3 study investigating the efficacy of subcutaneous burosumab, 1.0 mg/kg administered every 4 weeks, in improving osteomalacia in adults with XLH who have not been treated for at least 2 years before enrollment. The primary endpoint was improvement in osteoid volume/bone volume assessed by transiliac bone biopsies obtained at baseline and week 48. Additional assessments included serum phosphorus, markers of bone turnover, fracture/pseudofracture healing, and safety. Fourteen subjects enrolled, 13 completed 48 weeks, and 11 completed paired biopsies. All osteomalacia-related histomorphometric measures improved significantly at week 48 (mean percent change: osteoid volume/bone volume, -54%, osteoid thickness, -32%, osteoid surface/bone surface, -26%, [median] mineralization lag time, -83%). Mean serum phosphorus concentration averaged across the mid-point of the dose cycle between weeks 0 and 24 was 3.3 mg/dL, a 50% increase from 2.2 mg/dL at baseline. Markers of bone formation and resorption increased at week 48 (least squares [LS] mean increase: P1NP, +77%; CTx, +36%; both p < 0.0001). All subjects had one or more treatment-emergent adverse event (AE). Most AEs were mild to moderate in severity. Two subjects experienced serious AEs (migraine; paresthesia) that were unrelated to treatment and resolved. Eleven subjects had 18 biopsy procedure-related AEs: 14 for pain, two for itch, and one each for headache and bandage irritation. No deaths or incidents of hyperphosphatemia occurred. In conclusion, by normalizing phosphate homeostasis, burosumab significantly improved osteomalacia in adults with XLH, which likely explains the improved fracture healing and amelioration of skeletal complications. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

4.
J Endocr Soc ; 3(7): 1321-1334, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31259293

RESUMO

Context: X-linked hypophosphatemia (XLH) is characterized by excess fibroblast growth factor 23 (FGF23), hypophosphatemia, skeletal abnormalities, and growth impairment. We aimed to understand the burden of disease of XLH across the lifespan. Methods: Responses were collected from adults with XLH and parents/caregivers of a child with XLH in an online survey, including multiple-choice and open-ended questions on demographics, disease manifestations, treatment history, assistive device use, and age-specific patient-reported outcomes (PROs). Results: Data were collected from 232 adults with XLH (mean age, 45.6 years; 76% female) and 90 parents/caregivers of a child with XLH (mean age, 9.1 years; 56% female). Mean age recalled for symptom onset was 3.2 years for adults and 1.3 years for children. When surveyed, nearly all children (99%) and 64% of adults were receiving oral phosphate, active vitamin D, or both. Prior participation in a trial investigating burosumab, a fully human monoclonal antibody against FGF23, was reported in 3% of children and 10% of adults; of these respondents, only one child reported current treatment with burosumab at the time of the survey. Both children and adults reported typical features of XLH, including abnormal gait (84% and 86%, respectively), bowing of the tibia/fibula (72% and 77%), and short stature (80% and 86%). Nearly all adults (97%) and children (80%) reported bone or joint pain/stiffness. Adults reported a history of fractures (n/N = 102/232; 44%), with a mean (SD) age at first fracture of 26 (16) years. Adults reported osteophytes (46%), enthesopathy (27%), and spinal stenosis (19%). Mean scores for PROs evaluating pain, stiffness, and physical function were worse than population norms. Analgesics were taken at least once a week by 67% of adults. Conclusions: Despite the common use of oral phosphate and active vitamin D established in the 1980s, children with XLH demonstrate a substantial disease burden, including pain and impaired physical functioning that persists, as demonstrated by similar responses reported in adults with XLH.

5.
Calcif Tissue Int ; 105(3): 271-284, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31165191

RESUMO

Burosumab, a fully human monoclonal antibody to FGF23, is the only approved treatment for X-linked hypophosphatemia (XLH), a rare genetic disorder characterized by renal phosphate wasting and substantial cumulative musculoskeletal morbidity. During an initial 24-week randomized, controlled trial, 134 adults with XLH received burosumab 1 mg/kg (n = 68) or placebo (n = 66) every 4 weeks. After 24 weeks, all subjects received open-label burosumab until week 48. This report describes the efficacy and safety of burosumab during the open-label treatment period. From weeks 24-48, serum phosphorus concentrations remained normal in 83.8% of participants who received burosumab throughout and were normalized in 89.4% who received burosumab after placebo. By week 48, 63.1% of baseline fractures/pseudofractures healed fully with burosumab, compared with 35.2% with burosumab after placebo. In both groups, burosumab was associated with clinically significant and sustained improvement from baseline to week 48 in scores for patient-reported outcomes of stiffness, pain, physical function, and total distance walked in 6 min. Rates of adverse events were similar for burosumab and placebo. There were no fatal adverse events or treatment-related serious adverse events. Nephrocalcinosis scores did not change from baseline by more than one grade at either week 24 or 48. These data demonstrate that in participants with XLH, continued treatment with burosumab is well tolerated and leads to sustained correction of serum phosphorus levels, continued healing of fractures and pseudofractures, and sustained improvement in key musculoskeletal impairments.

6.
Lancet ; 393(10189): 2416-2427, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-31104833

RESUMO

BACKGROUND: X-linked hypophosphataemia in children is characterised by elevated serum concentrations of fibroblast growth factor 23 (FGF23), hypophosphataemia, rickets, lower extremity bowing, and growth impairment. We compared the efficacy and safety of continuing conventional therapy, consisting of oral phosphate and active vitamin D, versus switching to burosumab, a fully human monoclonal antibody against FGF23, in paediatric X-linked hypophosphataemia. METHODS: In this randomised, active-controlled, open-label, phase 3 trial at 16 clinical sites, we enrolled children with X-linked hypophosphataemia aged 1-12 years. Key eligibility criteria were a total Thacher rickets severity score of at least 2·0, fasting serum phosphorus lower than 0·97 mmol/L (3·0 mg/dL), confirmed PHEX (phosphate-regulating endopeptidase homolog, X-linked) mutation or variant of unknown significance in the patient or a family member with appropriate X-linked dominant inheritance, and receipt of conventional therapy for at least 6 consecutive months for children younger than 3 years or at least 12 consecutive months for children older than 3 years. Eligible patients were randomly assigned (1:1) to receive either subcutaneous burosumab starting at 0·8 mg/kg every 2 weeks (burosumab group) or conventional therapy prescribed by investigators (conventional therapy group). Both interventions lasted 64 weeks. The primary endpoint was change in rickets severity at week 40, assessed by the Radiographic Global Impression of Change global score. All patients who received at least one dose of treatment were included in the primary and safety analyses. The trial is registered with ClinicalTrials.gov, number NCT02915705. FINDINGS: Recruitment took place between Aug 3, 2016, and May 8, 2017. Of 122 patients assessed, 61 were enrolled. Of these, 32 (18 girls, 14 boys) were randomly assigned to continue receiving conventional therapy and 29 (16 girls, 13 boys) to receive burosumab. For the primary endpoint at week 40, patients in the burosumab group had significantly greater improvement in Radiographic Global Impression of Change global score than did patients in the conventional therapy group (least squares mean +1·9 [SE 0·1] with burosumab vs +0·8 [0·1] with conventional therapy; difference 1·1, 95% CI 0·8-1·5; p<0·0001). Treatment-emergent adverse events considered possibly, probably, or definitely related to treatment by the investigator occurred more frequently with burosumab (17 [59%] of 29 patients in the burosumab group vs seven [22%] of 32 patients in the conventional therapy group). Three serious adverse events occurred in each group, all considered unrelated to treatment and resolved. INTERPRETATION: Significantly greater clinical improvements were shown in rickets severity, growth, and biochemistries among children with X-linked hypophosphataemia treated with burosumab compared with those continuing conventional therapy. FUNDING: Ultragenyx Pharmaceutical and Kyowa Kirin International.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Raquitismo Hipofosfatêmico Familiar/tratamento farmacológico , Fatores Imunológicos/uso terapêutico , Estatura , Criança , Desenvolvimento Infantil , Pré-Escolar , Raquitismo Hipofosfatêmico Familiar/diagnóstico , Feminino , Humanos , Lactente , Masculino , Índice de Gravidade de Doença , Resultado do Tratamento
7.
Endocrinol Diabetes Nutr ; 66(7): 443-458, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30827909

RESUMO

OBJECTIVE: Treatment of type 2 diabetes mellitus (T2DM) is complex and is intended to decrease morbidity and mortality. Management should therefore include adequate diabetes education, lifestyle changes, drug treatment to achieve early blood glucose control and reduction of cardiovascular (CV) risk factors, early detection and treatment of complications, and assessment of associated comorbidities. The objective was to prepare a document including all aspects required for a comprehensive approach to T2DM. PARTICIPANTS: Members of the Diabetes Mellitus Working Group of the Spanish Society of Endocrinology. METHODS: The available evidence regarding each aspect of diabetes management (blood glucose control goals, diet and exercise, drug treatment, risk factor management and control, detection of complications, and management of frail patients) was reviewed. Recommendations were formulated based on the grades of evidence stated in the 2018 Standards of Medical Care in Diabetes. Recommendations were discussed and agreed by the working group members. CONCLUSIONS: This document is intended to provide evidence-based practical recommendations for comprehensive management of T2DM by clinical endocrinologists.

8.
Bone ; 122: 76-81, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30772600

RESUMO

The Rickets Severity Score (RSS) was used to evaluate X-linked hypophosphatemic rickets (XLH), a genetic disorder mediated by increased circulating FGF23. The reliability of the RSS was assessed using data from a randomized, phase 2 clinical trial that evaluated the effects of burosumab, a fully human anti-FGF23 monoclonal antibody, in 52 children with XLH ages 5 to 12 years. Bilateral knee and wrist radiographs were obtained at baseline, week 40, and week 64. We evaluated the relationships of the RSS to the Radiographic Global Impression of Change (RGI-C), serum alkaline phosphatase (ALP), height Z-score, 6-minute walk test (6MWT) percent predicted, and the Pediatric Orthopedic Society of North America Pediatric Outcomes Data Collection Instrument (POSNA-PODCI). The RSS showed moderate-to-substantial inter-rater reliability (weighted kappa, 0.45-0.65; Pearson correlation coefficient (r), 0.83-0.89) and substantial intra-rater reliability (weighted Kappa, 0.66; r = 0.91). Baseline RSS correlated with serum ALP (r = 0.47). Baseline RSS identified two subgroups (higher [RSS ≥1.5] and lower RSS [RSS <1.5]) that discriminated between subjects with greater and lesser rachitic disease. Higher RSS was associated with more severe clinical features, including impaired growth (Z-score, -2.12 vs -1.44) and walking ability (6MWT percent predicted, 77% vs 86%), more severe self-reported pain (29.9 [more severe] vs 45.3 [less severe]) and less physical function (29.6 [more severe] vs 40.9 [less severe]). During burosumab treatment, greater reductions in RSS corresponded to higher RGI-C global scores (r = -0.65). Improvements in RSS correlated with decreased serum ALP (r = 0.47). These results show the reliability of the RSS in XLH, and demonstrate that higher RSS values are associated with greater biochemical, clinical, and functional impairments in children with XLH.

9.
J Neurosci ; 39(18): 3360-3375, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30755493

RESUMO

In the mature mammalian cochlea, inner hair cells (IHCs) are mainly innervated by afferent fibers that convey sound information to the CNS. During postnatal development, however, medial olivocochlear (MOC) efferent fibers transiently innervate the IHCs. The MOC-IHC synapse, functional from postnatal day 0 (P0) to hearing onset (P12), undergoes dramatic changes in the sensitivity to acetylcholine (ACh) and in the expression of key postsynaptic proteins. To evaluate whether there are associated changes in the properties of ACh release during this period, we used a cochlear preparation from mice of either sex at P4, P6-P7, and P9-P11 and monitored transmitter release from MOC terminals in voltage-clamped IHCs in the whole-cell configuration. The quantum content increased 5.6× from P4 to P9-P11 due to increases in the size and replenishment rate of the readily releasable pool of synaptic vesicles without changes in their probability of release or quantum size. This strengthening in transmission was accompanied by changes in short-term plasticity properties, which switched from facilitation at P4 to depression at P9-P11. We have previously shown that at P9-P11, ACh release is supported by P/Q- and N-type voltage-gated calcium channels (VGCCs) and negatively regulated by BK potassium channels activated by Ca2+ influx through L-type VGCCs. We now show that at P4 and P6-P7, release is mediated by P/Q-, R- and L-type VGCCs. Interestingly, L-type VGCCs have a dual role: they both support release and fuel BK channels, suggesting that at immature stages presynaptic proteins involved in release are less compartmentalized.SIGNIFICANCE STATEMENT During postnatal development before the onset of hearing, cochlear inner hair cells (IHCs) present spontaneous Ca2+ action potentials that release glutamate at the first auditory synapse in the absence of sound stimulation. The IHC Ca2+ action potential frequency pattern, which is crucial for the correct establishment and function of the auditory system, is regulated by the efferent medial olivocochlear (MOC) system that transiently innervates IHCs during this period. We show here that developmental changes in synaptic strength and synaptic plasticity properties at the MOC-IHC synapse upon MOC fiber activation at different frequencies might be crucial for tightly shaping the pattern of afferent activity during this critical period.

10.
Lancet Diabetes Endocrinol ; 7(3): 189-199, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30638856

RESUMO

BACKGROUND: Children with X-linked hypophosphataemia have high concentrations of circulating phosphatonin fibroblast growth factor 23 (FGF23), which causes renal phosphate wasting and hypophosphataemia, rickets, skeletal deformities, and growth impairment. Burosumab, a human monoclonal antibody against FGF23, improves phosphate homoeostasis and rickets in children aged 5-12 years with X-linked hypophosphataemia. We aimed to assess the safety and efficacy of burosumab in younger children with X-linked hypophosphataemia. METHODS: In this open-label, phase 2 trial at three hospitals in the USA, children (aged 1-4 years) with X-linked hypophosphataemia received burosumab (0·8 mg/kg) via subcutaneous injection every 2 weeks for 64 weeks. The dose was increased to 1·2 mg/kg if two consecutive pre-dose serum phosphorus concentrations were below 1·03 mmol/L (3·2 mg/dL), serum phosphorus had increased by less than 0·16 mmol/L (<0·5 mg/dL) from baseline, and a dose of burosumab had not been missed. Participants could continue to receive burosumab for up to an additional 96 weeks during the extension period. Key inclusion criteria were age 1-4 years at the time of informed consent; fasting serum phosphorus concentration of less than 0·97 mmol/L (3·0 mg/dL); serum creatinine 8·8-35·4 µmol/L (0·1-0·4 mg/dL); radiographic evidence of rickets (at least five participants were required to have a Thacher Rickets Severity Score of ≥1·5 at the knee); and a confirmed PHEX mutation or a variant of unknown significance in the patient or direct relative also affected with X-linked hypophosphataemia. Conventional therapy was stopped upon enrolment. The coprimary endpoints were safety and change from baseline to week 40 in fasting serum phosphorus concentrations. Changes in rickets severity from baseline to weeks 40 and 64 (assessed radiographically using Thacher Rickets Severity Score and an adaptation of the Radiographic Global Impression of Change), and recumbent length or standing height, were key secondary outcomes. This trial is registered with ClinicalTrials.gov, number NCT02750618, and is ongoing. FINDINGS: Between May 16, 2016, and June 10, 2016, we enrolled 13 children with X-linked hypophosphataemia. All 13 children completed 64 weeks of treatment and were included in the efficacy and safety analysis; none exceeded 70 weeks of treatment at the time of analysis. Serum phosphorus least squares mean increase from baseline to week 40 of treatment was 0·31 mmol/L (SE 0·04; 95% CI 0·24-0·39; 0·96 mg/dL [SE 0·12]; p<0·0001). All patients had at least one adverse event. 14 treatment-related adverse events, mostly injection site reactions, occurred in five children. One serious adverse event considered unrelated to treatment (tooth abscess) occurred in a child with a history of tooth abscess. All other adverse events were mild to moderate, except a severe food allergy considered unrelated to treatment. No instances of nephrocalcinosis or noteworthy changes in the results of a standard safety chemistry panel emerged. Total Thacher Rickets Severity Score decreased by a least squares mean of -1·7 (SE 0·1; p<0·0001) from baseline to week 40 and by -2·0 (SE 0·1; p<0·0001) by week 64. The Radiographic Global Impression of Change score also indicated significant improvement, with a least squares mean score of +2·3 (SE 0·1) at week 40 and +2·2 (0·1) at week 64 (both p<0·0001). Mean length or standing height Z score was maintained from baseline to week 64. INTERPRETATION: Burosumab had a favourable safety profile, increased serum phosphorus, and improved rickets and prevented early declines in growth in children aged 1-4 years with X-linked hypophosphataemia. These findings could substantially alter the treatment of young children with X-linked hypophosphataemia. FUNDING: Ultragenyx Pharmaceutical and Kyowa Kirin International.

11.
Endocrinol. diabetes nutr. (Ed. impr.) ; 66(1): 62-68, ene. 2019. graf
Artigo em Espanhol | IBECS | ID: ibc-175795

RESUMO

La importante prevalencia y morbimortalidad de la obesidad ha ocasionado un aumento de pacientes sometidos a cirugía bariátrica. Son numerosos los beneficios reportados de la cirugía de la obesidad en distintas esferas de la salud. Sin embargo, no ocurre lo mismo sobre el hueso, donde tiene un impacto negativo. Los mecanismos fisiopatológicos que subyacen en el deterioro del tejido óseo de estos pacientes son complejos y requieren de un estudio en profundidad. El adecuado conocimiento de estos factores permitirá adoptar las herramientas más oportunas para un adecuado abordaje terapéutico


The important prevalence and morbidity of obesity has generated an increase in bariatric surgery. It has a positive effect in obesity-related comorbidities. However, it's detrimental to bone health. The underline pathophysiological mechanisms are complex and heterogeneous. The knowledge of these factors may lead us to develop an adequate therapeutic intervention


Assuntos
Humanos , Cirurgia Bariátrica/métodos , Osso e Ossos/fisiopatologia , Obesidade/cirurgia , Cirurgia Bariátrica , Cirurgia Bariátrica/efeitos adversos , Obesidade/epidemiologia , Obesidade/complicações , Fraturas Ósseas , Suplementos Nutricionais , Terapia Combinada/métodos , Densitometria , Osteoporose/tratamento farmacológico
12.
Endocrinol Diabetes Nutr ; 66(1): 62-68, 2019 Jan.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30266592

RESUMO

The important prevalence and morbidity of obesity has generated an increase in bariatric surgery. It has a positive effect in obesity-related comorbidities. However, it's detrimental to bone health. The underline pathophysiological mechanisms are complex and heterogeneous. The knowledge of these factors may lead us to develop an adequate therapeutic intervention.


Assuntos
Cirurgia Bariátrica/efeitos adversos , Doenças Ósseas/etiologia , Complicações Pós-Operatórias/etiologia , Doenças Ósseas/fisiopatologia , Doenças Ósseas/terapia , Humanos , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/terapia
13.
J Bone Miner Res ; 33(8): 1383-1393, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29947083

RESUMO

In X-linked hypophosphatemia (XLH), inherited loss-of-function mutations in the PHEX gene cause excess circulating levels of fibroblast growth factor 23 (FGF23), leading to lifelong renal phosphate wasting and hypophosphatemia. Adults with XLH present with chronic musculoskeletal pain and stiffness, short stature, lower limb deformities, fractures, and pseudofractures due to osteomalacia, accelerated osteoarthritis, dental abscesses, and enthesopathy. Burosumab, a fully human monoclonal antibody, binds and inhibits FGF23 to correct hypophosphatemia. This report summarizes results from a double-blind, placebo-controlled, phase 3 trial of burosumab in symptomatic adults with XLH. Participants with hypophosphatemia and pain were assigned 1:1 to burosumab 1 mg/kg (n = 68) or placebo (n = 66) subcutaneously every 4 weeks (Q4W) and were comparable at baseline. Across midpoints of dosing intervals, 94.1% of burosumab-treated participants attained mean serum phosphate concentration above the lower limit of normal compared with 7.6% of those receiving placebo (p < 0.001). Burosumab significantly reduced the Western Ontario and the McMaster Universities Osteoarthritis Index (WOMAC) stiffness subscale compared with placebo (least squares [LS] mean ± standard error [SE] difference, -8.1 ± 3.24; p = 0.012). Reductions in WOMAC physical function subscale (-4.9 ± 2.48; p = 0.048) and Brief Pain Inventory worst pain (-0.5 ± 0.28; p = 0.092) did not achieve statistical significance after Hochberg multiplicity adjustment. At week 24, 43.1% (burosumab) and 7.7% (placebo) of baseline active fractures were fully healed; the odds of healed fracture in the burosumab group was 16.8-fold greater than that in the placebo group (p < 0.001). Biochemical markers of bone formation and resorption increased significantly from baseline with burosumab treatment compared with placebo. The safety profile of burosumab was similar to placebo. There were no treatment-related serious adverse events or meaningful changes from baseline in serum or urine calcium, intact parathyroid hormone, or nephrocalcinosis. These data support the conclusion that burosumab is a novel therapeutic addressing an important medical need in adults with XLH.© 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Raquitismo Hipofosfatêmico Familiar/tratamento farmacológico , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Fatores de Crescimento de Fibroblastos/imunologia , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/farmacologia , Biomarcadores/metabolismo , Remodelação Óssea/efeitos dos fármacos , Cálcio/metabolismo , Método Duplo-Cego , Raquitismo Hipofosfatêmico Familiar/fisiopatologia , Feminino , Homeostase , Humanos , Masculino , Placebos , Resultado do Tratamento
14.
N Engl J Med ; 378(21): 1987-1998, 2018 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-29791829

RESUMO

BACKGROUND: X-linked hypophosphatemia is characterized by increased secretion of fibroblast growth factor 23 (FGF-23), which leads to hypophosphatemia and consequently rickets, osteomalacia, and skeletal deformities. We investigated burosumab, a monoclonal antibody that targets FGF-23, in patients with X-linked hypophosphatemia. METHODS: In an open-label, phase 2 trial, we randomly assigned 52 children with X-linked hypophosphatemia, in a 1:1 ratio, to receive subcutaneous burosumab either every 2 weeks or every 4 weeks; the dose was adjusted to achieve a serum phosphorus level at the low end of the normal range. The primary end point was the change from baseline to weeks 40 and 64 in the Thacher rickets severity total score (ranging from 0 to 10, with higher scores indicating greater disease severity). In addition, the Radiographic Global Impression of Change was used to evaluate rachitic changes from baseline to week 40 and to week 64. Additional end points were changes in pharmacodynamic markers, linear growth, physical ability, and patient-reported outcomes and the incidence of adverse events. RESULTS: The mean Thacher rickets severity total score decreased from 1.9 at baseline to 0.8 at week 40 with every-2-week dosing and from 1.7 at baseline to 1.1 at week 40 with every-4-week dosing (P<0.001 for both comparisons); these improvements persisted at week 64. The mean serum phosphorus level increased after the first dose in both groups, and more than half the patients in both groups had levels within the normal range (3.2 to 6.1 mg per deciliter [1.0 to 2.0 mmol per liter]) by week 6. Stable serum phosphorus levels were maintained through week 64 with every-2-week dosing. Renal tubular phosphate reabsorption increased from baseline in both groups, with an overall mean increase of 0.98 mg per deciliter (0.32 mmol per liter). The mean dose of burosumab at week 40 was 0.98 mg per kilogram of body weight with every-2-week dosing and 1.50 mg per kilogram with every-4-week dosing. Across both groups, the mean serum alkaline phosphatase level decreased from 459 U per liter at baseline to 369 U per liter at week 64. The mean standing-height z score increased in both groups, with greater improvement seen at all time points with every-2-week dosing (an increase from baseline of 0.19 at week 64) than with every-4-week dosing (an increase from baseline of 0.12 at week 64). Physical ability improved and pain decreased. Nearly all the adverse events were mild or moderate in severity. CONCLUSIONS: In children with X-linked hypophosphatemia, treatment with burosumab improved renal tubular phosphate reabsorption, serum phosphorus levels, linear growth, and physical function and reduced pain and the severity of rickets. (Funded by Ultragenyx Pharmaceutical and Kyowa Hakko Kirin; ClinicalTrials.gov number, NCT02163577 ; EudraCT number, 2014-000406-35 ).


Assuntos
Anticorpos Monoclonais/uso terapêutico , Raquitismo Hipofosfatêmico Familiar/tratamento farmacológico , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Doenças Genéticas Ligadas ao Cromossomo X/tratamento farmacológico , Fosfatase Alcalina/sangue , Criança , Pré-Escolar , Raquitismo Hipofosfatêmico Familiar/metabolismo , Raquitismo Hipofosfatêmico Familiar/fisiopatologia , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Crescimento/efeitos dos fármacos , Humanos , Túbulos Renais/metabolismo , Articulação do Joelho/diagnóstico por imagem , Masculino , Manejo da Dor , Fósforo/sangue , Radiografia , Índice de Gravidade de Doença
17.
Free Radic Biol Med ; 114: 33-39, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28993272

RESUMO

Down syndrome (DS), also known as trisomy 21, is the most common genetic cause of intellectual disability. It is also a model human disease for exploring consequences of gene dosage imbalance on complex phenotypes. Learning and memory impairments linked to intellectual disabilities in DS could result from synaptic plasticity deficits and excitatory-inhibitory alterations leading to changes in neuronal circuitry in the brain of affected individuals. Increasing number of studies in mouse and cellular models converge towards the assumption that excitatory-inhibitory imbalance occurs in DS, likely early during development. Thus increased inhibition appears to be a common trend that could explain synaptic and circuit disorganization. Interestingly using several potent pharmacological tools, preclinical studies strongly demonstrated that cognitive deficits could be restored in mouse models of DS. Clinical trials have not yet provided robust data for therapeutic application and additional studies are needed. Here we review the literature and our own published work emphasizing the over-inhibition hypothesis in DS and their links with gene dosage imbalance paving the way for future basic and clinical research.


Assuntos
Transtornos Cognitivos/induzido quimicamente , Síndrome de Down/tratamento farmacológico , Antagonistas GABAérgicos/efeitos adversos , Receptores de GABA-A/química , Transdução de Sinais/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Humanos , Receptores de GABA-A/efeitos dos fármacos
18.
J Physiol ; 595(24): 7477-7493, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29072780

RESUMO

KEY POINTS: GABAA receptors have been described in the axonal compartment of neurons; contrary to dendritic GABAA receptors, axonal GABAA receptors usually induce depolarizing responses. In this study we describe the presence of functional axonal GABAA receptors in cerebellar Purkinje cells by using a combination of direct patch-clamp recordings from the axon terminals and laser GABA photolysis. In Purkinje cells, axonal GABAA receptors are depolarizing and induce an increase in neurotransmitter release that results in a change of short-term synaptic plasticity. These results contribute to our understanding of the cellular mechanisms of action of axonal GABAA receptors and highlight the importance of the presynaptic compartment in neuronal computation. ABSTRACT: In neurons of the adult brain, somatodendritic GABAA receptors (GABAA Rs) mediate fast synaptic inhibition and play a crucial role in synaptic integration. GABAA Rs are not only present in the somatodendritic compartment, but also in the axonal compartment where they modulate action potential (AP) propagation and transmitter release. Although presynaptic GABAA Rs have been reported in various brain regions, their mechanisms of action and physiological roles remain obscure, particularly at GABAergic boutons. Here, using a combination of direct whole-bouton or perforated patch-clamp recordings and local GABA photolysis in single axonal varicosities of cerebellar Purkinje cells, we investigate the subcellular localization and functional role of axonal GABAA Rs both in primary cultures and acute slices. Our results indicate that presynaptic terminals of PCs carry GABAA Rs that behave as auto-receptors; their activation leads to a depolarization of the terminal membrane after an AP due to the relatively high cytoplasmic Cl- concentration in the axon, but they do not modulate the AP itself. Paired recordings from different terminals of the same axon show that the GABAA R-mediated local depolarizations propagate substantially to neighbouring varicosities. Finally, the depolarization mediated by presynaptic GABAA R activation augmented Ca2+ influx and transmitter release, resulting in a marked effect on short-term plasticity. Altogether, our results reveal a mechanism by which presynaptic GABAA Rs influence neuronal computation.


Assuntos
Potenciais de Ação , Exocitose , Terminações Pré-Sinápticas/metabolismo , Células de Purkinje/metabolismo , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Células Cultivadas , Feminino , Masculino , Terminações Pré-Sinápticas/fisiologia , Células de Purkinje/fisiologia , Ratos , Ratos Wistar
19.
Endocrinol. nutr. (Ed. impr.) ; 63(9): 495-501, nov. 2016. graf
Artigo em Espanhol | IBECS | ID: ibc-156951

RESUMO

La diabetes mellitus tipo 2 es una patología con una enorme prevalencia y morbilidad, que van en aumento. La fractura osteoporótica se encuentra entre las denominadas complicaciones «no clásicas» de la diabetes y ha sido durante tiempo ignorada, tal vez por su complejo abordaje tanto diagnóstico como terapéutico. Las herramientas habituales para la prevención de la fractura por fragilidad, como el FRAX y la densitometría ósea, no han demostrado la suficiente eficacia en estos pacientes, ya que infraestiman el riesgo. Nuevas técnicas de evaluación ósea, como el trabecular bone score o los marcadores de remodelado óseo, podrían ser de utilidad, aunque requieren una mayor evidencia científica para recomendar su uso en la práctica clínica habitual. Las características especiales de su fisiopatología condicionan la aparición de fracturas sin existir alteraciones densitométricas, en lo que podemos calificar de «paradoja diabética» (AU)


Type 2 diabetes mellitus prevalence and morbidity are increasing. Osteoporotic fractures are among the ‘non-classical’ complications of diabetes and been overlooked for a long time, maybe because of their complex diagnostic and therapeutic approach. The usual tools for preventing fragility fractures (such as the fracture risk assessment tool and bone densitometry) underestimate risk of fractures in type2 diabetic patients. New techniques, such as trabecular bone score or bone turnover markers, could be useful, but greater scientific evidence is required to recommend their use in clinical practice. The special characteristics of their pathophysiology result in decreased bone remodeling with normal or even increased bone mineral density, but with low quality. These changes lead to the occurrence of osteoporotic fractures without evidence of densitometric changes, which could be called ‘the diabetic paradox’ (AU)


Assuntos
Humanos , Diabetes Mellitus Tipo 2/complicações , Osteoporose/epidemiologia , Doenças Ósseas Metabólicas/epidemiologia , Fraturas por Osteoporose/epidemiologia , Fatores de Risco , Qualidade de Vida , Perfil de Impacto da Doença , Hiperglicemia/fisiopatologia
20.
Endocrinol Nutr ; 63(9): 495-501, 2016 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27481443

RESUMO

Type 2 diabetes mellitus prevalence and morbidity are increasing. Osteoporotic fractures are among the 'non-classical' complications of diabetes and been overlooked for a long time, maybe because of their complex diagnostic and therapeutic approach. The usual tools for preventing fragility fractures (such as the fracture risk assessment tool and bone densitometry) underestimate risk of fractures in type2 diabetic patients. New techniques, such as trabecular bone score or bone turnover markers, could be useful, but greater scientific evidence is required to recommend their use in clinical practice. The special characteristics of their pathophysiology result in decreased bone remodeling with normal or even increased bone mineral density, but with low quality. These changes lead to the occurrence of osteoporotic fractures without evidence of densitometric changes, which could be called 'the diabetic paradox'.


Assuntos
Densidade Óssea , Diabetes Mellitus Tipo 2/complicações , Fraturas Espontâneas/etiologia , Osteoporose/etiologia , Acidentes por Quedas , Remodelação Óssea , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Fraturas Espontâneas/prevenção & controle , Humanos , Hiperinsulinismo/fisiopatologia , Hipoglicemiantes/uso terapêutico , Obesidade/complicações , Obesidade/fisiopatologia , Osteoporose/diagnóstico , Osteoporose/metabolismo , Osteoporose/prevenção & controle , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/fisiopatologia
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