Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 133
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Cell ; 162(3): 465-6, 2015 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-26232214

RESUMEN

Hypertension and obesity are known to be linked, with recent studies in mice proposing that leptin may be mediating this effect. This regulation, however, may not extend to humans, where a yet-to-be-identified factor is likely the underlying cause of hypertension.


Asunto(s)
Hipertensión/metabolismo , Leptina/metabolismo , Obesidad/metabolismo , Animales
2.
Am J Med Genet A ; 194(6): e63533, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38234231

RESUMEN

Morbidity and mortality rates in patients with autosomal recessive, congenital generalized lipodystrophy type 4 (CGL4), an ultra-rare disorder, remain unclear. We report on 30 females and 16 males from 10 countries with biallelic null variants in CAVIN1 gene (mean age, 12 years; range, 2 months to 41 years). Hypertriglyceridemia was seen in 79% (34/43), hepatic steatosis in 82% (27/33) but diabetes mellitus in only 21% (8/44). Myopathy with elevated serum creatine kinase levels (346-3325 IU/L) affected all of them (38/38). 39% had scoliosis (10/26) and 57% had atlantoaxial instability (8/14). Cardiac arrhythmias were detected in 57% (20/35) and 46% had ventricular tachycardia (16/35). Congenital pyloric stenosis was diagnosed in 39% (18/46), 9 had esophageal dysmotility and 19 had intestinal dysmotility. Four patients suffered from intestinal perforations. Seven patients died at mean age of 17 years (range: 2 months to 39 years). The cause of death in four patients was cardiac arrhythmia and sudden death, while others died of prematurity, gastrointestinal perforation, and infected foot ulcers leading to sepsis. Our study highlights high prevalence of myopathy, metabolic abnormalities, cardiac, and gastrointestinal problems in patients with CGL4. CGL4 patients are at high risk of early death mainly caused by cardiac arrhythmias.


Asunto(s)
Lipodistrofia Generalizada Congénita , Proteínas de Unión al ARN , Humanos , Masculino , Femenino , Lipodistrofia Generalizada Congénita/genética , Lipodistrofia Generalizada Congénita/complicaciones , Lipodistrofia Generalizada Congénita/patología , Adolescente , Niño , Lactante , Preescolar , Adulto , Adulto Joven , Arritmias Cardíacas/genética , Arritmias Cardíacas/patología , Hipertrigliceridemia/genética , Hipertrigliceridemia/complicaciones , Hipertrigliceridemia/patología
3.
Crit Rev Toxicol ; 53(5): 326-338, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37526219

RESUMEN

A systematic review was conducted on the sensitivity of fish testing guidelines to detect the anti-androgenic activity of substances. Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) was used to investigate the conservation of the androgen receptor (AR) between humans and fish, and among fish species recommended in test guidelines. The AR is conserved between fish species and humans (i.e. ligand binding domain [LBD] homology ≥70%) and among the recommended fish species (LBD homology >85%). For model anti-androgens, we evaluated literature data on in vitro anti-androgenic activity in fish-specific receptor-based assays and changes in endpoints indicative of endocrine modulation from in vivo studies. Anti-androgenic activity was most consistently and reliably detected in in vitro and in vivo mechanistic studies with co-exposure to an androgen (spiggin in vitro assay, Rapid Androgen Disruption Activity Reporter [RADAR] Assay, and Androgenised Female Stickleback Screen). Regardless of study design (Fish Short-Term Reproduction Assay [FSTRA], Fish Sexual Development Test [FSDT], partial or full life-cycle tests), or endpoint (vitellogenin, secondary sexual characteristics, gonadal histopathology, sex ratio), there was no consistent evidence for detecting anti-androgenic activity in studies without androgen co-exposure, even for the most potent substances (while less potent substances may induce no (clear) response). Therefore, based on studies without androgen co-exposure (35 FSTRAs and 22 other studies), the other studies (including the FSDT) do not outperform the FSTRA for detecting potent anti-androgenic activity, which if suspected, would be best addressed with a RADAR assay. Overall, fish do not appear particularly sensitive to mammalian anti-androgens.


Asunto(s)
Antagonistas de Andrógenos , Smegmamorpha , Animales , Humanos , Femenino , Andrógenos/farmacología , Peces , Smegmamorpha/fisiología , Mamíferos
4.
Liver Int ; 43(12): 2692-2700, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37622286

RESUMEN

BACKGROUND AND AIMS: Fatty liver is common in obesity as well as in partial lipodystrophy (PL) syndromes, characterized by deficient adipose tissue. Insulin resistance is key to fatty liver pathogenesis in both entities. We aimed to compare the contributions of insulin resistance and adipose tissue to hepatic steatosis in PL and non-syndromic, obesity-associated non-alcoholic fatty liver disease (NS-NAFLD). METHODS: In a cross-sectional comparison of people with NS-NAFLD (N = 73) and PL (N = 27), liver fat was measured by FibroScan® controlled attenuation parameter (CAP) and insulin resistance by HOMA-IR, Adipo-IR, and NMR-based LP-IR. RESULTS: Insulin resistance was greater in PL versus NS-NAFLD by HOMA-IR (p = 0.005), Adipo-IR (p = 0.01) and LP-IR (p = 0.05) while liver fat was comparable (304 vs. 324 dB/m, p = 0.12). Liver fat correlated with HOMA-IR in both groups, but CAP values were lower by 32 dB/m in PL compared with NS-NAFLD for any given HOMA-IR. In contrast, Adipo-IR and LP-IR correlated with CAP only in the NS-NAFLD group, suggesting different pathways for fat accumulation. Plasma free fatty acids, reflecting substrate input from the adipose tissue, were comparable between groups. However, the levels of ß-hydroxybutyrate, a marker of ß-oxidation, and large triglyceride-rich lipoprotein particles, a marker of VLDL secretion, were both higher in PL (p < 0.001 for both). CONCLUSION: Liver fat content was comparable in subjects with PL-associated NAFLD and NS-NAFLD, despite worse insulin resistance in partial lipodystrophy. Our data demonstrate higher triglyceride oxidation and export in PL, suggesting a compensatory shift of fat from liver storage into the circulation that does not occur in NS-NAFLD.


Asunto(s)
Resistencia a la Insulina , Lipodistrofia , Enfermedad del Hígado Graso no Alcohólico , Humanos , Enfermedad del Hígado Graso no Alcohólico/patología , Estudios Transversales , Hígado/patología , Obesidad/complicaciones , Obesidad/metabolismo , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Triglicéridos , Lipodistrofia/metabolismo , Lipodistrofia/patología
5.
Regul Toxicol Pharmacol ; 145: 105501, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37820895

RESUMEN

Vitellogenin (VTG) is a biomarker for possible endocrine activity of chemicals acting via the estrogen, androgen, or steroidogenesis pathways. VTG is assessed in standardised fish guideline studies conducted for regulatory safety assessment of chemicals. VTG data can be highly variable leading to concerns for potential equivocal, false positive and/or negative outcomes. Consequently, additional fish testing may be required to address uncertainties in the VTG response, and possibly erroneous/missed identification of endocrine activity. To better understand the technical challenges of VTG assessment and reporting for regulatory purposes, a survey was sent to 27 testing laboratories performing these analyses. The survey results from 16 respondents (6 from the UK, 3 from the USA, and 7 from the EU) were analysed and discussed in a follow-up webinar. High variability in background VTG concentrations was widely acknowledged and thought to be associated with fish batch, husbandry, laboratory practices, and several methodological aspects. These include sample collection and storage, VTG quantification, data handling, and the benchmarks used for data acceptability. Information gathered in the survey provides a basis for improving and harmonizing the measurement of VTG in fish, and an opportunity to reassess the suitability of current acceptability criteria in test guidelines.


Asunto(s)
Vitelogeninas , Contaminantes Químicos del Agua , Animales , Vitelogeninas/metabolismo , Laboratorios , Peces/metabolismo , Estrógenos/metabolismo , Sistema Endocrino , Contaminantes Químicos del Agua/análisis
6.
Ecotoxicol Environ Saf ; 266: 115563, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37827093

RESUMEN

Vitellogenin (VTG), a biomarker for endocrine activity, is a mechanistic component of the regulatory assessment of potential endocrine-disrupting properties of chemicals. This review of VTG data is based on changes reported for 106 substances in standard fish species. High intra-study and inter-laboratory variability in VTG concentrations was confirmed, as well as discrepancies in interpretation of results based on large differences between fish in the dilution water versus solvent control, or due to the presence of outlier measurements. VTG responses in fish were ranked against predictions for estrogen receptor agonist activity and aromatase inhibition from bioactivity model output and ToxCast in vitro assay results, respectively. These endocrine mechanisms explained most of the VTG responses in the absence of systemic toxicity, the magnitude of the VTG response being proportional to the in vitro potency. Interpretation of the VTG data was sometimes confounded by an alternative endocrine mechanism of action. There was evidence for both false positive and negative responses for VTG synthesis, but overall, it was rare for substances without endocrine activity in vitro to cause a concentration-dependent VTG response in fish in the absence of systemic toxicity. To increase confidence in the VTG results, we recommend improvements in the VTG measurement methodologies and greater transparency in reporting of VTG data (including quality control criteria for assay performance). This review supports the application of New Approach Methodologies (NAMs) by demonstrating that endocrine activity in vitro from mammalian cell lines is predictive for in vivo VTG response in fish, suggesting that in vitro mechanistic data could be used more broadly in decision-making to help reduce animal testing.


Asunto(s)
Disruptores Endocrinos , Contaminantes Químicos del Agua , Animales , Vitelogeninas/metabolismo , Peces/metabolismo , Estrógenos/metabolismo , Disruptores Endocrinos/toxicidad , Disruptores Endocrinos/metabolismo , Contaminantes Químicos del Agua/análisis , Mamíferos/metabolismo
8.
Endocr Pract ; 28(6): 610-614, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35301125

RESUMEN

OBJECTIVE: Severe insulin resistance syndromes, such as lipodystrophy, lead to diabetes, which is challenging to control. This study explored the safety and efficacy of sodium-glucose cotransporter 2 inhibitors (SGLT2is) in a series of 12 patients with severe insulin resistance due to partial lipodystrophy. METHODS: A retrospective chart review of the safety (N = 22) and efficacy (N = 12) of SGLT2is in patients with partial lipodystrophy was conducted at our institution. The efficacy outcomes included hemoglobin A1C level, insulin dose, fasting plasma glucose level, C-peptide level, lipid profile, 24-hour urinary glucose excretion, estimated glomerular filtration rate, and blood pressure before and after 12 months of SGLT2i treatment. RESULTS: The hemoglobin A1C level decreased after SGLT2i treatment (at baseline: 9.2% ± 2.0% [77.0 ± 21.9 mmol/mol]; after 12 months: 8.4% ± 1.8% [68.0 ± 19.7 mmol/mol]; P = .028). Significant reductions were also noted in systolic (P = .011) and diastolic blood pressure (P = .013). There was a trend toward a decreased C-peptide level (P = .071). The fasting plasma glucose level, lipid level, and estimated glomerular filtration rate remained unchanged. The adverse effects included extremity pain, hypoglycemia, diabetic ketoacidosis (in a patient who was nonadherent to insulin), pancreatitis (in a patient with prior pancreatitis), and fungal infections. CONCLUSION: SGLT2is reduced the hemoglobin A1C level in patients with partial lipodystrophy, with a similar safety profile compared with that in patients with type 2 diabetes. After individual consideration of the risks and benefits of SGLT2is, these may be considered a part of the treatment armamentarium for these rare forms of diabetes, but larger trials are needed to confirm these findings.


Asunto(s)
Resistencia a la Insulina , Lipodistrofia , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Glucemia , Péptido C/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Transportador de Glucosa de Tipo 2/uso terapéutico , Hemoglobina Glucada/metabolismo , Humanos , Insulina/uso terapéutico , Lipodistrofia/complicaciones , Lipodistrofia/tratamiento farmacológico , Pancreatitis/inducido químicamente , Estudios Retrospectivos , Inhibidores del Cotransportador de Sodio-Glucosa 2/efectos adversos , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico
9.
Comput Inform Nurs ; 40(10): 691-698, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35483103

RESUMEN

Critical care nurses manage complex patient care interventions under dynamic, time-sensitive and constrained conditions, yet clinical decision support systems for nurses are limited compared with advanced practice healthcare providers. In this work, we study and analyze nurses' information-seeking behaviors to inform the development of a clinical decision support system that supports nurses. Nurses from an urban midwestern hospital were recruited to complete an online survey containing eight open-ended questions about resource utilization for various nursing tasks and open space for additional insights. Frequencies and percentages were calculated for resource type, bivariate analyses using Pearson's χ2 test were conducted for differences in resources utilization by years of experience, and content analysis of free text was completed. Forty-five nurses (response rate, 19.6%) identified 38 unique resources, which we organized into a resource taxonomy. Institutional applications were the most common type of resource used (35.6% of all responses) but accounted for only 15.4% of respondents' "go-to resources," suggesting potential areas for improvement. Our findings highlight that knowing where to look for information, the existence of comprehensive information, and fast and easy retrieval of information are key resource seeking attributes that must be considered when designing a clinical decision support system.


Asunto(s)
Cuidados Críticos , Enfermeras y Enfermeros , Actitud del Personal de Salud , Hospitales Urbanos , Humanos , Encuestas y Cuestionarios
10.
Am J Physiol Endocrinol Metab ; 321(6): E795-E801, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34693755

RESUMEN

Gluconeogenesis (GNG), the formation of glucose from noncarbohydrate precursors, requires adenosine triphosphate (ATP). Previous studies have estimated the energetic cost of GNG in humans based on theoretical calculations of rates of GNG, moles of oxygen consumption by GNG, and average oxygen consumption. Few human studies have measured the energy expenditure (EE) due to GNG. We estimated EE attributable to GNG in patients with three insulin resistance conditions and high GNG rates (insulin receptor pathogenic variants, lipodystrophy, and type 2 diabetes) and obesity without diabetes. Fractional GNG was measured by incorporation of deuterium from body water into newly formed glucose, endogenous glucose production (EGP) as glucose appearance following administration of [6,6-2H2]glucose, and total GNG as fractional GNG × EGP. EE was measured by indirect calorimetry and compared with predicted EE from the Mifflin St. Jeor equation. EE attributable to GNG was estimated using linear regression after accounting for age and fat-free mass (FFM). EE in patients with insulin resistance was significantly higher than predicted by the Mifflin St. Jeor equation. GNG correlated with resting EE (REE). EE attributable to GNG in patients with insulin resistance was almost one-third of REE, substantially higher than theorized in healthy subjects. Our findings demonstrate that GNG is a significant contributor to EE in insulin-resistant states. Prediction equations may underestimate caloric needs in patients with insulin resistance. Therefore, targeting caloric needs to account for higher EE due to increased GNG should be considered in energy balance studies in patients with insulin resistance.NEW & NOTEWORTHY Gluconeogenesis is an energy-requiring process that is upregulated in diabetes, contributing to hyperglycemia. Previous studies have estimated that gluconeogenesis accounts for less than 10% of resting energy expenditure. This study estimates the energy expenditure attributable to gluconeogenesis in uncommon and severe forms of insulin resistance and common, milder forms of insulin resistance. In these populations, gluconeogenesis accounts for almost one-third of resting energy expenditure, substantially higher than previously theorized in the literature.


Asunto(s)
Metabolismo Energético/fisiología , Gluconeogénesis/fisiología , Resistencia a la Insulina , Adolescente , Adulto , Calorimetría Indirecta , Niño , Estudios de Cohortes , Estudios Transversales , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Humanos , Lipodistrofia/metabolismo , Masculino , Persona de Mediana Edad , Obesidad/metabolismo , Adulto Joven
11.
Int J Mol Sci ; 22(12)2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-34205507

RESUMEN

Complement overactivation has been reported in most patients with Barraquer-Simons syndrome (BSS), a rare form of acquired partial lipodystrophy. Complement Factor D (FD) is a serine protease with a crucial role in the activation of the alternative pathway of the complement system, which is mainly synthesized by adipose tissue. However, its role in the pathogenesis of BSS has not been addressed. In this study, plasma FD concentration was measured in 13 patients with BSS, 20 patients with acquired generalized lipodystrophy, 22 patients with C3 glomerulopathy (C3G), and 50 healthy controls. Gene expression and immunohistochemistry studies were assayed using atrophied adipose tissue from a patient with BSS. We found significantly elevated FD levels in BSS cases compared with the remaining cohorts (p < 0.001). There were no significant differences in FD levels between sexes but FD was strongly and directly associated with age in BSS (r = 0.7593, p = 0.0036). A positive correlation between FD and C3 was seen in patients with C3G, characterized by decreased FD levels due to chronic C3 consumption, but no correlation was detected for BSS. Following mRNA quantification in the patient's adipose tissue, we observed decreased CFD and C3 but elevated C5 transcript levels. In contrast, the increased FD staining detected in the atrophied areas reflects the effects of persistent tissue damage on the adipose tissue, thus providing information on the ongoing pathogenic process. Our results suggest that FD could be a reliable diagnostic biomarker involved in the pathophysiology of BSS by promoting unrestrained local complement system activation in the adipose tissue environment.


Asunto(s)
Factor D del Complemento/metabolismo , Lipodistrofia/sangre , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Estudios de Casos y Controles , Niño , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
12.
Neurogenetics ; 20(2): 73-82, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30903322

RESUMEN

Celia's encephalopathy (progressive encephalopathy with/without lipodystrophy (PELD)) is a childhood neurodegenerative disorder with a fatal prognosis before the age of 10, due to the variant c.985C>T in the BSCL2 gene that causes a cryptic splicing site leading to skipping of exon 7. For years, different authors have reported cases of congenital generalized lipodystrophy due to the variant c.974dupG in BSCL2 associated with neurological manifestations of variable severity, although some of them clearly superimposable to PELD. To identify the molecular mechanisms responsible for these neurological alterations in two patients with c.974dupG. Clinical characterization, biochemistry, and neuroimaging studies of two girls carrying this variant. In silico analysis, PCR amplification, and BSCL2 cDNA sequencing. BSCL2-201 transcript expression, which lacks exon 7, by qPCR in fibroblasts from the index case, from a healthy child as a control and from two patients with PELD, and in leukocytes from the index case and her parents. One with a severe encephalopathy including a picture of intellectual deficiency, severe language impairment, myoclonic epilepsy, and lipodystrophy as described in PELD, dying at 9 years and 9 months of age. The other 2-year-old patient showed incipient signs of neurological involvement. In silico and cDNA sequencing studies showed that variant c.974dupG gives rise to skipping of exon 7. The expression of BSCL2-201 in fibroblasts was significantly higher in the index case than in the healthy child, although less than in the case with homozygous PELD due to c.985C>T variant. The expression of this transcript was approximately half in the healthy carrier parents of this patient. The c.974dupG variant leads to the skipping of exon 7 of the BSCL2 gene and is responsible for a variant of Celia's encephalopathy, with variable phenotypic expression.


Asunto(s)
Encefalopatías/genética , Subunidades gamma de la Proteína de Unión al GTP/genética , Lipodistrofia Generalizada Congénita/genética , Enfermedades Neurodegenerativas/genética , Empalme Alternativo , Niño , Preescolar , ADN Complementario/genética , Exones , Resultado Fatal , Femenino , Fibroblastos/metabolismo , Variación Genética , Homocigoto , Humanos , Fenotipo , Análisis de Secuencia de ADN
13.
Proc Natl Acad Sci U S A ; 111(24): 8901-6, 2014 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-24889630

RESUMEN

Phosphatidylcholine (PC) is the major glycerophospholipid in eukaryotic cells and is an essential component in all cellular membranes. The biochemistry of de novo PC synthesis by the Kennedy pathway is well established, but less is known about the physiological functions of PC. We identified two unrelated patients with defects in the Kennedy pathway due to biallellic loss-of-function mutations in phosphate cytidylyltransferase 1 alpha (PCYT1A), the rate-limiting enzyme in this pathway. The mutations lead to a marked reduction in PCYT1A expression and PC synthesis. The phenotypic consequences include some features, such as severe fatty liver and low HDL cholesterol levels, that are predicted by the results of previously reported liver-specific deletion of murine Pcyt1a. Both patients also had lipodystrophy, severe insulin resistance, and diabetes, providing evidence for an additional and essential role for PCYT1A-generated PC in the normal function of white adipose tissue and insulin action.


Asunto(s)
Citidililtransferasa de Colina-Fosfato/genética , Hígado Graso/genética , Lipodistrofia/congénito , Lipodistrofia/genética , Fosfatidilcolinas/química , Células 3T3-L1 , Tejido Adiposo/metabolismo , Adolescente , Alelos , Animales , Niño , HDL-Colesterol/química , Citidililtransferasa de Colina-Fosfato/metabolismo , Biología Computacional , Hígado Graso/metabolismo , Femenino , Glicerofosfolípidos/química , Humanos , Insulina/química , Lípidos/química , Lipodistrofia/metabolismo , Ratones , Mutación , Fenotipo , Distribución Tisular
14.
BMC Genomics ; 17(1): 964, 2016 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-27881098

RESUMEN

BACKGROUND: Mycoplasma hominis is an opportunistic human pathogen, associated with clinically diverse disease. Currently, there is no standardised method for typing M. hominis, which would aid in understanding pathogen epidemiology and transmission. Due to availability and costs of whole genome sequencing and the challenges in obtaining adequate M. hominis DNA, the use of whole genome sequence analysis to provide clinical guidance is unpractical for this bacterial species as well as other fastidious organisms. RESULTS: This study identified pan-genome set of 700 genes found to be present in four published reference genomes. A subset of 417 genes was identified to be core genome for 18 isolates and 1 reference. Leave-one-out analysis of the core genes highlighted set of 48 genes that are required to recapture the original phylogenetic relationships observed using whole genome SNP analysis. Three 7-locus MLST schemas with high diversity index (97%) and low dN/dS ratios (0.1, 0.13, and 0.11) were derived that could be used to confer good discrimination between strains and could be of practical use in future studies direct on clinical specimens. CONCLUSIONS: The genes proposed in this study could be utilised to design a cost-effective and rapid PCR-based MLST assay that could be applied directly to clinical isolates, without prior isolation. This study includes additional genomic analysis revealing high levels of genetic heterogeneity among this species. This provides a novel and evidence based approach for the development of MLST schema that accurately represent genomic phylogeny for use in epidemiology and transmission studies.


Asunto(s)
Genoma Bacteriano , Genómica , Mycoplasma hominis/clasificación , Mycoplasma hominis/genética , Alelos , Análisis por Conglomerados , Genes Bacterianos , Genómica/métodos , Genotipo , Humanos , Tipificación de Secuencias Multilocus , Mycoplasma hominis/aislamiento & purificación , Filogenia , Polimorfismo de Nucleótido Simple , Recombinación Genética
15.
Clin Endocrinol (Oxf) ; 85(1): 137-49, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26589105

RESUMEN

OBJECTIVE: Recombinant human leptin (metreleptin) improves glycaemia and hypertriglyceridaemia in patients with generalized lipodystrophy; antibody development with in vitro neutralizing activity has been reported. We aimed to characterize antimetreleptin antibody development, including in vitro neutralizing activity. DESIGN: Two randomized controlled studies in patients with obesity (twice-daily metreleptin ± pramlintide for 20-52 weeks; 2006-2009); two long-term, open-label studies in patients with lipodystrophy (once-daily or twice-daily metreleptin for 2 months to 12·3 years; 2000-2014). PATIENTS: A total of 579 metreleptin-treated patients with obesity and 134 metreleptin-treated patients with lipodystrophy (antibody/neutralizing activity data: n = 105). MEASUREMENTS: Antimetreleptin antibodies, in vitro neutralizing activity. RESULTS: Antimetreleptin antibodies developed in most patients (obese: 96-100%; lipodystrophy: 86-92%). Peak antibody titers (approximately 1:125 to 1:3125) generally occurred within 4-6 months and decreased with continued therapy (lipodystrophy). Antibody development did not adversely impact efficacy or safety (patients with obesity), except for inflammatory injection site reactions, but was associated with elevated leptin concentrations. Three patients with obesity developed in vitro neutralizing activity coincident with weight gain. Weight later returned to baseline in one patient despite persistent neutralizing activity. Four patients with generalized lipodystrophy developed in vitro neutralizing activity concurrent with worsened metabolic control; two with confounding comorbidities had sepsis. One patient with lipodystrophy had resolution of neutralizing activity on metreleptin. CONCLUSIONS: Development of in vitro neutralizing activity could be associated with loss of efficacy but has not been consistently associated with adverse clinical consequences. Whether neutralization of endogenous leptin with clinical consequences occurs remains unclear.


Asunto(s)
Leptina/análogos & derivados , Lipodistrofia/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Adolescente , Adulto , Anticuerpos/sangre , Formación de Anticuerpos , Niño , Femenino , Humanos , Fenómenos Inmunogenéticos , Polipéptido Amiloide de los Islotes Pancreáticos/uso terapéutico , Leptina/efectos adversos , Leptina/sangre , Leptina/inmunología , Leptina/uso terapéutico , Masculino , Persona de Mediana Edad , Adulto Joven
16.
Neuroendocrinology ; 103(3-4): 402-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26336809

RESUMEN

BACKGROUND: Leptin replacement in patients with leptin gene mutations improves hypogonadotropic hypogonadism. The effects of leptin replacement on luteinizing hormone (LH) secretion in patients with lipodystrophy are unknown. AIM: We examined nocturnal LH secretory dynamics on and off exogenous leptin therapy using a 2-period, nonrandomized study that included leptin-naïve and leptin-treated subjects with lipodystrophy. METHODS: In period 1 (5 days) the leptin-treated group (n = 4) continued leptin; leptin was then withdrawn for the next 14 days (period 2). Leptin-naïve subjects (n = 8) were studied without leptin in period 1 and with leptin replacement in period 2. LH secretory dynamics were assessed (23:00-07:00 h, sampling every 10 min, analyzed by multiparameter deconvolution algorithm) at the end of each period. RESULTS: Mean (on vs. off: 5.0 ± 3.1 vs. 3.2 ± 1.3 IU/l, p = 0.04) and integrated LH concentrations (2,403 ± 1,495 vs. 1,534 ± 642 IU × l-1 × min-1, p = 0.04) were higher on leptin therapy. Leptin treatment increased burst mass (9.7± 15.4 vs. 7.0 ± 11.2 IU/l, p = 0.03) and tended to nonsignificantly increase LH burst frequency (0.77 ± 0.26 vs. 0.67 ± 0.24 h-1, p = 0.08). Consequently, leptin therapy increased the pulsatile production rate (64 ± 101 vs. 57 ± 73 IU × l-1 × 8 h-1, p = 0.01). On leptin, testosterone (507 ± 286 vs. 360 ± 174 ng/dl, p = 0.09) and estradiol levels (74 ± 36 vs. 29 ± 24 pg/ml, p = 0.01) were higher in males and females, respectively. CONCLUSIONS: Leptin increases spontaneous nocturnal LH secretion in patients with lipodystrophy. This is consistent with rodent and in vitro studies showing a direct stimulatory effect (hypothalamic, pituitary or both) of leptin on LH secretion. These novel findings may explicate some of the salutary effects of leptin therapy on the hypothalamic-pituitary-gonadal axis in lipodystrophy.


Asunto(s)
Ritmo Circadiano/fisiología , Leptina/análogos & derivados , Lipodistrofia/tratamiento farmacológico , Hormona Luteinizante/metabolismo , Adulto , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Leptina/uso terapéutico , Masculino , Persona de Mediana Edad , Esteroides/metabolismo , Adulto Joven
17.
AIDS Care ; 28(1): 131-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26477602

RESUMEN

Young people who have grown up with perinatally acquired HIV in wealthy nations are increasingly transitioning into adult care settings which expect more independence and self-regulation than paediatric care. Drawing on the first qualitative study on growing up with HIV in Australia, this paper examines "responsibilisation" narratives in semi-structured interviews conducted with young people with HIV and their paediatric and adult care providers. Three dominant narratives were identified: responsibilisation as imperative, practice and contest. This suggests that while young people growing up with HIV in an advanced liberal setting such as Australia may value the independence of adult care, and appreciate the need to take responsibility for their health, the practices involved in becoming a responsible health citizen are shaped by individual histories and circumstances, and in some cases, can lead to serious contestation and conflict with care providers. Placing a stronger emphasis on what young people can gain from taking an active role in managing their health may more successfully foster responsibilisation, rather than focusing on what they will lose. Clinicians could benefit from greater support regarding how to engage young people with the elements of responsibilisation likely to resonate more meaningfully at different points in their lives.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/congénito , Infecciones por VIH/tratamiento farmacológico , Cumplimiento de la Medicación , Transición a la Atención de Adultos , Adolescente , Australia , Femenino , Infecciones por VIH/psicología , Humanos , Entrevistas como Asunto , Masculino , Investigación Cualitativa , Adulto Joven
18.
J Clin Microbiol ; 53(10): 3195-203, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26202118

RESUMEN

Mycoplasma pneumoniae is a major human respiratory pathogen causing both upper and lower respiratory disease in humans of all ages, and it can also result in other serious extrapulmonary sequelae. A multilocus sequence typing (MLST) scheme for M. pneumoniae was developed based on the sequences of eight housekeeping genes (ppa, pgm, gyrB, gmk, glyA, atpA, arcC, and adk) and applied to 55 M. pneumoniae clinical isolates and the two type strains M129 and FH. A total of 12 sequence types (STs) resulted for 57 M. pneumoniae isolates tested, with a discriminatory index of 0.21 STs per isolate. The MLST loci used in this scheme were shown to be stable in 10 strains following 10 sequential subculture passages. Phylogenetic analysis of concatenated sequences of the eight loci indicated two distinct genetic clusters that were directly linked to multilocus variable-number tandem repeat analysis (MLVA) type. Genetic MLST clustering was confirmed by genomic sequence analysis, indicating that the MLST scheme developed in this study is representative of the genome. Furthermore, this MLST scheme was shown to be more discriminatory than both MLVA and P1 typing for the M. pneumoniae isolates examined, providing a method for further and more detailed analysis of observed epidemic peaks of M. pneumoniae infection. This scheme is supported by a public Web-based database (http://pubmlst.org/mpneumoniae).


Asunto(s)
Tipificación de Secuencias Multilocus/métodos , Mycoplasma pneumoniae/clasificación , Mycoplasma pneumoniae/genética , Análisis por Conglomerados , Genes Esenciales , Inestabilidad Genómica , Genotipo , Humanos , Infecciones por Mycoplasma/microbiología , Mycoplasma pneumoniae/aislamiento & purificación , Filogenia
19.
Euro Surveill ; 20(48): 30078, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26675545

RESUMEN

Mycoplasma pneumoniae infection can cause pneumonia, particularly in children. Global increase in macrolide-resistant M. pneumoniae is of concern due to limited therapeutic options. We describe the detection of macrolide resistance-conferring mutations in 9.3% of 43 clinical specimens where M. pneumoniae was detected in England and Wales from September 2014‒September 2015. This study aims to impact by highlighting the presence of macrolide resistance in M. pneumoniae positive patients, promoting increased clinical vigilance.


Asunto(s)
Macrólidos/uso terapéutico , Mycoplasma pneumoniae/efectos de los fármacos , Neumonía por Mycoplasma/tratamiento farmacológico , Adolescente , Adulto , Anciano , Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana/genética , Inglaterra , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Mycoplasma pneumoniae/genética , Neumonía por Mycoplasma/diagnóstico , Reacción en Cadena de la Polimerasa , Gales , Adulto Joven
20.
Pediatr Diabetes ; 15(3): 151-61, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24754463

RESUMEN

Insulin resistance is defined as a state where insulin produces a diminished biological response, primarily in its capacity as a glucose-regulating hormone. Insulin resistance is commonly diagnosed by pediatric clinicians, but is rarely measured directly in children or adolescents. This review provides an overview of the techniques that can be used to assess insulin sensitivity in children, summarizing the methods involved, the assumptions, pitfalls, and appropriate uses of each technique, as well as their validation and reproducibility in pediatric samples.


Asunto(s)
Resistencia a la Insulina , Evaluación Nutricional , Adolescente , Biomarcadores/sangre , Niño , Técnica de Clampeo de la Glucosa , Humanos , Estudios de Validación como Asunto
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA