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1.
Endocr Connect ; 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38838713

RESUMEN

Prader Willi syndrome (PWS) is a rare orphan disease and complex genetic neurodevelopmental disorder, with a birth incidence of approximately 1 in 10,000-30,000. Management of people with PWS requires a multi-disciplinary approach, ideally through a multi-disciplinary team (MDT) clinic with community support. Hypotonia, poor feeding and faltering growth are characteristic features in the neonatal period, followed by hyperphagia and risk of rapid weight gain later in childhood. Children and adolescents (CA) with PWS usually display developmental delay and mild learning disability, and can develop endocrinopathies, scoliosis, respiratory difficulties (both central and obstructive sleep apnoea), challenging behaviours, skin picking, and mental health issues especially into adulthood. This consensus statement is intended to be a reference document for clinicians managing children and adolescents (up to 18 years of age) with PWS. It considers the bio-psycho-social domains of diagnosis, clinical assessment, and management in the paediatric setting as well as during and after transition to adult services. The guidance has been developed from information gathered from peer-reviewed scientific reports and from the expertise of a range of experienced clinicians in the United Kingdom and Ireland involved in the care of patients with PWS.

2.
Int J Equity Health ; 22(1): 188, 2023 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-37697302

RESUMEN

AIMS: With numerous and continuing attempts at adapting diabetes self-management support programmes to better account for underserved populations, its important that the lessons being learned are understood and shared. The work we present here reviews the latest evidence and best practice in designing and embedding culturally and socially sensitive, self-management support programmes. METHODS: We explored the literature with regard to four key design considerations of diabetes self-management support programmes: Composition - the design and content of written materials and digital tools and interfaces; Structure - the combination of individual and group sessions, their frequency, and the overall duration of programmes; Facilitators - the combination of individuals used to deliver the programme; and Context - the influence and mitigation of a range of individual, socio-cultural, and environmental factors. RESULTS: We found useful and recent examples of design innovation within a variety of countries and models of health care delivery including Brazil, Mexico, Netherlands, Spain, United Kingdom, and United States of America. Within Composition we confirmed the importance of retaining best practice in creating readily understood written information and intuitive digital interfaces; Structure the need to offer group, individual, and remote learning options in programmes of flexible duration and frequency; Facilitators where the benefits of using culturally concordant peers and community-based providers were described; and finally in Context the need to integrate self-management support programmes within existing health systems, and tailor their various constituent elements according to the language, resources, and beliefs of individuals and their communities. CONCLUSIONS: A number of design principles across the four design considerations were identified that together offer a promising means of creating the next generation of self-management support programme more readily accessible for underserved communities. Ultimately, we recommend that the precise configuration should be co-produced by all relevant service and patient stakeholders and its delivery embedded in local health systems.


Asunto(s)
Diabetes Mellitus , Automanejo , Humanos , Diabetes Mellitus/terapia , Brasil , Conductas Relacionadas con la Salud , Lenguaje
3.
Pilot Feasibility Stud ; 8(1): 155, 2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35897113

RESUMEN

BACKGROUND: Staff absenteeism and presenteeism incur high costs to the NHS and are associated with adverse health outcomes. The main causes are musculoskeletal complaints and mental ill-health, which are potentially modifiable, and cardiovascular risk factors are also common. We will test the feasibility of an RCT to evaluate the clinical and cost-effectiveness of an employee health screening clinic on reducing sickness absenteeism and presenteeism. METHODS: This is an individually randomised controlled pilot trial aiming to recruit 480 participants. All previously unscreened employees from four hospitals within three UK NHS hospital Trusts will be eligible. Those randomised to the intervention arm will be invited to attend an employee health screening clinic consisting of a screening assessment for musculoskeletal (STarT MSK and STarT Back), mental (PHQ-9 and GAD-7) and cardiovascular (NHS Health Check if aged ≥ 40, lifestyle check if < 40 years) health. Screen positives will be given advice and/or referral to recommended services. Those randomised to the control arm will receive usual care. Participants will complete a questionnaire at baseline and 26 weeks; anonymised absenteeism and staff demographics will also be collected from personnel records. The co-primary outcomes are as follows: recruitment, referrals and uptake of recommended services in the intervention arm. Secondary outcomes include the following: results of screening assessments, uptake of individual referrals, reported changes in health behaviours, acceptability and feasibility of intervention, indication of contamination and costs. Outcomes related to the definitive trial include self-reported and employee records of absenteeism with reasons. Process evaluation to inform a future trial includes interviews with participants, intervention delivery staff and service providers receiving referrals. Analyses will include presentation of descriptive statistics, framework analysis for qualitative data and costs and consequences presented for health economics. DISCUSSION: The study will provide data to inform the design of a definitive RCT which aims to find an effective and cost-effective method of reducing absenteeism and presenteeism amongst NHS staff. The feasibility study will test trial procedures, and process outcomes, including the success of strategies for including underserved groups, and provide information and data to help inform the design and sample size for a definitive trial. TRIAL REGISTRATION: ISRCTN reference number 10237475 .

4.
Artículo en Inglés | MEDLINE | ID: mdl-35450871

RESUMEN

OBJECTIVE: Type 1 diabetes (T1D) is the most common form of diabetes in children, accounting for 96% of cases, with 29 000 children affected in the UK. Studies have recently identified immunotherapies that safely delay the development of T1D for at least 3 years, and further therapies are in development. General population screening programs in other countries can now accurately identify children with presymptomatic T1D who can be entered into prevention studies. The UK does not have such a system in place. We aim to explore whether parents and children in the UK would want to be part of such a program of testing for T1D in the general population, how they would want to be informed and participate in such a program, and how any barriers to recruitment and participation can be addressed. Additionally, the views of stakeholders who would be involved in the testing program will be collected and analyzed. RESEARCH DESIGN AND METHODS: We will interview parents/guardians and children aged 3-13 years about their views on screening for T1D. We will recruit purposefully to ensure representation across ethnicities and socioeconomic groups. Interviews will be transcribed, analyzed and used to inform iterative co-design work with additional families to address any issues raised. Similar qualitative work will be undertaken with professional stakeholders who would be involved in implementing any future screening program. Where possible, all aspects of this study will be performed remotely by phone or online to minimize infection risk. CONCLUSIONS: This qualitative study will provide the first insights into acceptability of testing and monitoring for T1D in the general population from the perspective of families and stakeholders in the UK. Co-design work will help establish the barriers and identify strategies to mitigate and overcome these issues, as an important step towards consideration of national testing for T1D.


Asunto(s)
Diabetes Mellitus Tipo 1 , Niño , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/terapia , Humanos , Investigación Cualitativa , Reino Unido/epidemiología
5.
J Med Chem ; 65(8): 6338-6351, 2022 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-35440138

RESUMEN

Autotaxin (ATX) facilitates the hydrolysis of lysophosphatidylcholine to lysophosphatidic acid (LPA), a bioactive phospholipid, which facilitates a diverse range of cellular effects in multiple tissue types. Abnormal LPA expression can lead to the progression of diseases such as cancer and fibrosis. Previously, we identified a potent ATX steroid-derived hybrid (partially orthosteric and allosteric) inhibitor which did not form interactions with the catalytic site. Herein, we describe the design, synthesis, and biological evaluation of a focused library of novel steroid-derived analogues targeting the bimetallic catalytic site, representing an entirely unique class of ATX inhibitors of type V designation, which demonstrate significant pathway-relevant biochemical and phenotypic biological effects. The current compounds modulated LPA-mediated ATX allostery and achieved indirect blockage of LPA1 internalization, in line with the observed reduction in downstream signaling cascades and chemotaxis induction. These novel type V ATX inhibitors represent a promising tool to inactivate the ATX-LPA signaling axis.


Asunto(s)
Neoplasias , Hidrolasas Diéster Fosfóricas , Quimiotaxis , Humanos , Hidrólisis , Lisofosfatidilcolinas/metabolismo , Lisofosfolípidos/metabolismo , Hidrolasas Diéster Fosfóricas/metabolismo , Transducción de Señal
6.
Eur J Pharmacol ; 913: 174618, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34762934

RESUMEN

Fibrosis is the formation of scar tissue due to injury or long-term inflammation and is a leading cause of morbidity and mortality. Activation of the pro-fibrotic cytokine transforming growth factor-ß (TGFß) via the alpha-V beta-6 (αvß6) integrin has been identified as playing a key role in the development of fibrosis. Therefore, a drug discovery programme to identify an orally bioavailable small molecule αvß6 arginyl-glycinyl-aspartic acid (RGD)-mimetic was initiated. As part of a medicinal chemistry programme GSK3335103 was identified and profiled in a range of pre-clinical in vitro and in vivo systems. GSK3335103 was shown to bind to the αvß6 with high affinity and demonstrated fast binding kinetics. In primary human lung epithelial cells, GSK3335103-induced concentration- and time-dependent internalisation of αvß6 with a rapid return of integrin to the cell surface observed after washout. Following sustained engagement of the αvß6 integrin in vitro, lysosomal degradation was induced by GSK3335103. GSK3335103 was shown to engage with the αvß6 integrin and inhibit the activation of TGFß in both ex vivo IPF tissue and in a murine model of bleomycin-induced lung fibrosis, as measured by αvß6 engagement, TGFß signalling and collagen deposition, with a prolonged duration of action observed in vivo. In summary, GSK3335103 is a potent αvß6 inhibitor that attenuates TGFß signalling in vitro and in vivo with a well-defined pharmacokinetic/pharmacodynamic relationship. This translates to a significant reduction of collagen deposition in vivo and therefore GSK3335103 represents a potential novel oral therapy for fibrotic disorders.


Asunto(s)
Antifibróticos/farmacología , Integrinas/antagonistas & inhibidores , Fibrosis Pulmonar/tratamiento farmacológico , Administración Oral , Animales , Antifibróticos/química , Antifibróticos/uso terapéutico , Antígenos de Neoplasias/química , Antígenos de Neoplasias/metabolismo , Disponibilidad Biológica , Bleomicina/administración & dosificación , Bleomicina/toxicidad , Células Cultivadas , Modelos Animales de Enfermedad , Células Epiteliales/efectos de los fármacos , Células Epiteliales/patología , Humanos , Integrinas/química , Integrinas/metabolismo , Pulmón/efectos de los fármacos , Pulmón/patología , Lisosomas/metabolismo , Masculino , Ratones , Oligopéptidos/química , Cultivo Primario de Células , Proteolisis/efectos de los fármacos , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/patología , Factor de Crecimiento Transformador beta/metabolismo
7.
J Org Chem ; 86(4): 3583-3604, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33513016

RESUMEN

Substituted arylethylamines represent a key structural motif in natural, pharmaceutical, and agrochemical compounds. Access to such scaffolds has been the subject of long-standing synthetic interest. Herein, we report the synthesis of such scaffolds via a palladium-catalyzed C(sp3)-C(sp3) coupling between (chloromethyl)aryls and air-/moisture-stable N,N-dialkylaminomethyltrifluoroborate salts. Rapid hit identification was achieved using microscale high-throughput experimentation and was followed by millimolar-scale reaction parameter optimization. A range of structurally and electronically varied arylethylamine products were obtained in moderate to excellent yields (27-96%, >60 examples). The reaction mechanism is proposed to proceed via formation of a trialkylbenzylammonium species prior to oxidative addition.


Asunto(s)
Paladio , Sales (Química) , Catálisis
8.
Eur J Med Chem ; 208: 112719, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32865176

RESUMEN

Integrins αvß5 and αvß3 are closely related, proangiogenic members of the wider RGD-binding integrin family. Due to their high sequence homology, the development of αvß5-selective compounds has remained elusive to synthetic and medicinal chemists. Herein, we describe a survey of SAR around a series of amide-containing 3-aryl-succinamic acid-based RGD mimetics. This resulted in the discovery of α,α,α-trifluorotolyl 12 which exhibits 800 × selectivity for αvß5versus αvß3 with a pyrrolidine amide linker that confers selectivity for αvß5 by positioning a key aryl ring in the SDL of αvß5 with good complementarity; binding in this mode is disfavoured in αvß3 due to clashes with key residues in the ß3-subunit. Compound 12 exhibits selective inhibition by a cell adhesion assay, high passive permeability and solubility which enables potential use of this inhibitor as an αvß5-selective in vitro tool compound.


Asunto(s)
Amidas/farmacología , Pirrolidinas/farmacología , Receptores de Vitronectina/antagonistas & inhibidores , Amidas/síntesis química , Amidas/metabolismo , Adhesión Celular/efectos de los fármacos , Humanos , Células K562 , Simulación del Acoplamiento Molecular , Estructura Molecular , Naftiridinas/síntesis química , Naftiridinas/metabolismo , Naftiridinas/farmacología , Unión Proteica , Pirrolidinas/síntesis química , Pirrolidinas/metabolismo , Receptores de Vitronectina/metabolismo , Estereoisomerismo , Relación Estructura-Actividad
9.
Beilstein J Org Chem ; 16: 1617-1626, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32704328

RESUMEN

Integrin inhibitors based on the tripeptide sequence Arg-Gly-Asp (RGD) are potential therapeutics for the treatment of idiopathic pulmonary fibrosis (IPF). Herein, we describe an expeditious three-step synthetic sequence of Horner-Wadsworth-Emmons olefination, diimide reduction, and global deprotection to synthesise cores for these compounds in high yields (63-83% over 3 steps) with no need for chromatography. Key to this transformation is the phosphoramidate protecting group, which is stable to metalation steps.

10.
J Med Chem ; 62(16): 7543-7556, 2019 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-31381331

RESUMEN

A quaternary ammonium betaine 7 is described which shows exceptional potency and selectivity (1.4 to >3 logs) for the αvß6 integrin receptor over the other αv integrins as determined in cell adhesion assays. 7 is prepared by remarkably stereoselective methylation, the origins of which are discussed. The chemical, biological, physicochemical, and pharmacokinetic properties of 7 and its docking into αvß6 are described along with related analogues.


Asunto(s)
Betaína/farmacología , Integrinas/antagonistas & inhibidores , Pirrolidinas/química , Compuestos de Amonio Cuaternario/farmacología , Animales , Antígenos de Neoplasias/química , Antígenos de Neoplasias/metabolismo , Betaína/química , Betaína/farmacocinética , Células Cultivadas , Cristalografía por Rayos X , Hepatocitos/citología , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Integrinas/química , Integrinas/metabolismo , Metilación , Modelos Químicos , Simulación del Acoplamiento Molecular , Estructura Molecular , Unión Proteica , Conformación Proteica , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/farmacocinética , Ratas , Estereoisomerismo
11.
ChemMedChem ; 14(14): 1315-1320, 2019 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-31207080

RESUMEN

Up to 45 % of deaths in developed nations can be attributed to chronic fibroproliferative diseases, highlighting the need for effective therapies. The RGD (Arg-Gly-Asp) integrin αvß1 was recently investigated for its role in fibrotic disease, and thus warrants therapeutic targeting. Herein we describe the identification of non-RGD hit small-molecule αvß1 inhibitors. We show that αvß1 activity is embedded in a range of published α4ß1 (VLA-4) ligands; we also demonstrate how a non-RGD integrin inhibitor (of α4ß1 in this case) was converted into a potent non-zwitterionic RGD integrin inhibitor (of αvß1 in this case). We designed urea ligands with excellent selectivity over α4ß1 and the other αv integrins (αvß3, αvß5, αvß6, αvß8). In silico docking models and density functional theory (DFT) calculations aided the discovery of the lead urea series.


Asunto(s)
Fenilalanina/análogos & derivados , Receptores de Vitronectina/antagonistas & inhibidores , Urea/análogos & derivados , Animales , Sitios de Unión , Diseño de Fármacos , Estabilidad de Medicamentos , Humanos , Ligandos , Hígado/metabolismo , Masculino , Fenilalanina/síntesis química , Fenilalanina/metabolismo , Ratas Sprague-Dawley , Receptores de Vitronectina/química , Receptores de Vitronectina/metabolismo , Urea/síntesis química , Urea/metabolismo
12.
J Med Chem ; 61(18): 8417-8443, 2018 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-30215258

RESUMEN

A series of 3-aryl(pyrrolidin-1-yl)butanoic acids were synthesized using a diastereoselective route, via a rhodium catalyzed asymmetric 1,4-addition of arylboronic acids in the presence of ( R)-BINAP to a crotonate ester to provide the ( S) absolute configuration for the major product. A variety of aryl substituents including morpholine, pyrazole, triazole, imidazole, and cyclic ether were screened in cell adhesion assays for affinity against αvß1, αvß3, αvß5, αvß6, and αvß8 integrins. Numerous analogs with high affinity and selectivity for the αvß6 integrin were identified. The analog ( S)-3-(3-(3,5-dimethyl-1 H-pyrazol-1-yl)phenyl)-4-(( R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)pyrrolidin-1-yl)butanoic acid hydrochloride salt was found to have very high affinity for αvß6 integrin in a radioligand binding assay (p Ki = 11), a long dissociation half-life (7 h), very high solubility in saline at pH 7 (>71 mg/mL), and pharmacokinetic properties commensurate with inhaled dosing by nebulization. It was selected for further clinical investigation as a potential therapeutic agent for the treatment of idiopathic pulmonary fibrosis.


Asunto(s)
Descubrimiento de Drogas , Fibrosis Pulmonar Idiopática/tratamiento farmacológico , Integrinas/antagonistas & inhibidores , Pulmón/efectos de los fármacos , Pirazoles/química , Animales , Antígenos de Neoplasias , Adhesión Celular , Perros , Humanos , Pulmón/metabolismo , Masculino , Ratones , Modelos Moleculares , Estructura Molecular , Conformación Proteica , Ratas , Ratas Wistar , Relación Estructura-Actividad , Distribución Tisular
13.
BMJ ; 360: k211, 2018 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-29437667

RESUMEN

OBJECTIVE: To assess the effectiveness of a school and family based healthy lifestyle programme (WAVES intervention) compared with usual practice, in preventing childhood obesity. DESIGN: Cluster randomised controlled trial. SETTING: UK primary schools from the West Midlands. PARTICIPANTS: 200 schools were randomly selected from all state run primary schools within 35 miles of the study centre (n=980), oversampling those with high minority ethnic populations. These schools were randomly ordered and sequentially invited to participate. 144 eligible schools were approached to achieve the target recruitment of 54 schools. After baseline measurements 1467 year 1 pupils aged 5 and 6 years (control: 28 schools, 778 pupils) were randomised, using a blocked balancing algorithm. 53 schools remained in the trial and data on 1287 (87.7%) and 1169 (79.7%) pupils were available at first follow-up (15 month) and second follow-up (30 month), respectively. INTERVENTIONS: The 12 month intervention encouraged healthy eating and physical activity, including a daily additional 30 minute school time physical activity opportunity, a six week interactive skill based programme in conjunction with Aston Villa football club, signposting of local family physical activity opportunities through mail-outs every six months, and termly school led family workshops on healthy cooking skills. MAIN OUTCOME MEASURES: The protocol defined primary outcomes, assessed blind to allocation, were between arm difference in body mass index (BMI) z score at 15 and 30 months. Secondary outcomes were further anthropometric, dietary, physical activity, and psychological measurements, and difference in BMI z score at 39 months in a subset. RESULTS: Data for primary outcome analyses were: baseline, 54 schools: 1392 pupils (732 controls); first follow-up (15 months post-baseline), 53 schools: 1249 pupils (675 controls); second follow-up (30 months post-baseline), 53 schools: 1145 pupils (621 controls). The mean BMI z score was non-significantly lower in the intervention arm compared with the control arm at 15 months (mean difference -0.075 (95% confidence interval -0.183 to 0.033, P=0.18) in the baseline adjusted models. At 30 months the mean difference was -0.027 (-0.137 to 0.083, P=0.63). There was no statistically significant difference between groups for other anthropometric, dietary, physical activity, or psychological measurements (including assessment of harm). CONCLUSIONS: The primary analyses suggest that this experiential focused intervention had no statistically significant effect on BMI z score or on preventing childhood obesity. Schools are unlikely to impact on the childhood obesity epidemic by incorporating such interventions without wider support across multiple sectors and environments. TRIAL REGISTRATION: Current Controlled Trials ISRCTN97000586.


Asunto(s)
Evaluación de Procesos y Resultados en Atención de Salud , Obesidad Infantil/prevención & control , Servicios de Salud Escolar/organización & administración , Índice de Masa Corporal , Niño , Inglaterra , Femenino , Humanos , Masculino
14.
J Clin Endocrinol Metab ; 103(4): 1330-1341, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-29165577

RESUMEN

Context: Brain white matter hyperintensities are seen on routine clinical imaging in 46% of adults with congenital adrenal hyperplasia (CAH). The extent and functional relevance of these abnormalities have not been studied with quantitative magnetic resonance imaging (MRI) analysis. Objective: To examine white matter microstructure, neural volumes, and central nervous system (CNS) metabolites in CAH due to 21-hydroxylase deficiency (21OHD) and to determine whether identified abnormalities are associated with cognition, glucocorticoid, and androgen exposure. Design, Setting, and Participants: A cross-sectional study at a tertiary hospital including 19 women (18 to 50 years) with 21OHD and 19 age-matched healthy women. Main Outcome Measure: Recruits underwent cognitive assessment and brain imaging, including diffusion weighted imaging of white matter, T1-weighted volumetry, and magnetic resonance spectroscopy for neural metabolites. We evaluated white matter microstructure by using tract-based spatial statistics. We compared cognitive scores, neural volumes, and metabolites between groups and relationships between glucocorticoid exposure, MRI, and neurologic outcomes. Results: Patients with 21OHD had widespread reductions in white matter structural integrity, reduced volumes of right hippocampus, bilateral thalami, cerebellum, and brainstem, and reduced mesial temporal lobe total choline content. Working memory, processing speed, and digit span and matrix reasoning scores were reduced in patients with 21OHD, despite similar education and intelligence to controls. Patients with 21OHD exposed to higher glucocorticoid doses had greater abnormalities in white matter microstructure and cognitive performance. Conclusion: We demonstrate that 21OHD and current glucocorticoid replacement regimens have a profound impact on brain morphology and function. If reversible, these CNS markers are a potential target for treatment.


Asunto(s)
Hiperplasia Suprarrenal Congénita/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Cognición , Glucocorticoides/farmacología , Adolescente , Hiperplasia Suprarrenal Congénita/tratamiento farmacológico , Hiperplasia Suprarrenal Congénita/metabolismo , Hiperplasia Suprarrenal Congénita/psicología , Adulto , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Colina/metabolismo , Cognición/efectos de los fármacos , Estudios Transversales , Relación Dosis-Respuesta a Droga , Femenino , Glucocorticoides/administración & dosificación , Glucocorticoides/uso terapéutico , Humanos , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Persona de Mediana Edad , Pruebas Neuropsicológicas , Psicometría , Calidad de Vida , Adulto Joven
15.
Acc Chem Res ; 48(3): 628-42, 2015 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-25689674

RESUMEN

Resorcylates are a large group of bioactive natural products that are biosynthesized from acetate and malonate units via the intermediacy of polyketides. These polyketides undergo cyclization reactions to introduce the aromatic core. The bioactivities of the resorcylates including resorcylate macrocyclic lactones include anticancer, antimalarial, mycotoxicity, antifungal, and antibiotic properties, and several compounds in the series are already in use in medicine. Examples are prodrugs derived from mycophenolic acid as immunosuppressants and the Hsp-90 inhibitor, AT13387, which is in phase-II clinical trials for the treatment of small cell lung cancer and melanoma. In consequence of these biological activities, methods for the concise synthesis of diverse resorcylates are of considerable importance. In natural product chemistry, biomimetic total synthesis can have significant advantages including functional group tolerance in key steps, the minimization of the use of protection and deprotection reactions and the shortening of the total number of synthetic steps. This Account provides a description of our adaption of the dioxinone chemistry of Hyatt, Clemens, and Feldman for the synthesis and retro-Diels-Alder reactions of diketo-dioxinones. Such dioxinones, which were synthesized by a range of C-acylation reactions, were found to undergo retro-Diels-Alder reactions on heating to provide the corresponding triketo-ketenes with the loss of acetone. The ketene reactive intermediates were rapidly trapped both inter- and intramolecularly with alcohols to provide the corresponding ß,δ,ζ-triketo-esters. These compounds, which consist of keto-enol mixtures, readily undergo cycloaromatization to produce resorcylate esters and macrocyclic lactones. We have established the use of diketo-dioxinones as key general intermediates for the synthesis of diverse resorcylate natural products and for the synthesis of new classes of compounds for the generation of medicinal chemistry lead structures. Many of the methods used were found to be tolerant of multiple sensitive functional groups. These include enolate C-acylations with acyl chlorides, 1-acyl-benzotriazoles, acyl imidazolides, or Weinreb amides to prepare diketo-dioxinones and their subsequent use to prepare ß,δ,ζ-triketo-esters and lactones and hence resorcylates. In addition, in most cases, phenol protection was avoided. As an alternative to the synthesis of ß,δ,ζ-triketo-esters, diketo-dioxinones were also found to undergo cycloaromatization with retention of the ketal entity via a nonketene pathway. Finally, diketo-dioxinones with an allyl, prenyl, geranyl, or other 2-alkenyl carboxylate esters at the γ-carbon underwent decarboxylative rearrangement with tetrakis(triphenylphosphine)palladium catalysis to produce α-substituted diketo-dioxinones and resorcylates with 3-allyl, prenyl, geranyl, or other 2-alkenyl groups. Such diketo-dioxinone chemistry was used in the total synthesis of natural products including aigialomycin, cruentaren A, and the oligomeric resorcylate antibiotics ent-W1278 A, B, and C. Additionally, tandem use of the decarboxylative rearrangement process and cycloaromatization was used in the total synthesis of natural products including the methyl ester of cristatic acid, mycophenolic acid, and hongoquercin B. The methodology was also applied to the synthesis of 9,10-anthraquinones, o-aminoalkyl resorcylates, dihydroxyisoindolinones, oligomers, and resorcinamides. The development of this methodology is described in this Account, showcasing its applicability and versatility for the synthesis of complex resorcylate products.


Asunto(s)
Productos Biológicos/síntesis química , Biomimética , Dioxanos/síntesis química , Lactonas/síntesis química , Productos Biológicos/química , Ciclización , Dioxanos/química , Lactonas/química , Estructura Molecular
16.
J Am Chem Soc ; 136(49): 17013-5, 2014 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-25423048

RESUMEN

The total synthesis of hongoquercin B was carried out in 9 steps from trans,trans-farnesyl acetate using a palladium catalyzed decarboxylative π-farnesyl rearrangement of a diketo-dioxinone ester, aromatization and cationic diene-epoxide cyclization as key steps. This cascade tetracyclization simplifies the synthesis of terpenoid resorcylate natural products.


Asunto(s)
Polienos/química , Policétidos/química , Ciclización , Conformación Molecular , Sesquiterpenos/síntesis química , Sesquiterpenos/química , Estereoisomerismo
17.
J Pediatr Endocrinol Metab ; 26(11-12): 1041-6, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23751384

RESUMEN

AIM: Cranial diabetes insipidus (CDI) is rare in infants with no guidelines on its management. We describe the first case series, characterizing the clinical features and treatment challenges. METHOD: Retrospective case note review of infants diagnosed with CDI between April 1992 and February 2011. RESULTS: Nineteen infants (52% male) were identified. Eight were born preterm. Median (range) age at diagnosis was 24 days (5-300); preterm babies were younger at diagnosis (21 vs. 46 days). In 58% (11/19) of infants, hypernatraemia was discovered incidentally. In 37% of cases there was associated midline anomalies, however, only four patients (21%) had absent posterior pituitary signal on a magnetic resonance imaging brain scan. The most frequent (5/19) underlying diagnosis was septo-optic dysplasia. Eight patients had isolated CDI and 11 had multiple pituitary hormone deficiencies. Isolated CDI tended to be more common in preterm, compared to term babies (p=0.11). Des-amino arginine vasopressin (DDAVP) was administered intranasally in eight and orally in 11 infants. Plasma sodium nadir following DDAVP administration was lower following intranasal compared to an oral route of administration (median: 128 vs. 133 mmol/L, p=0.022). No cases resolved on follow-up. CONCLUSIONS: CDI in infants is often diagnosed incidentally. Aetiology, clinical, and imaging features are very variable, with some differences between preterm and term infants. Oral DDAVP appears to be superior to intranasal with less pronounced serum sodium fluctuations.


Asunto(s)
Diabetes Insípida/terapia , Cráneo/patología , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Imagen por Resonancia Magnética , Estudios Retrospectivos
18.
Pediatr Diabetes ; 14(6): 422-8, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22957743

RESUMEN

OBJECTIVE: To investigate whether center differences in glycemic control are present in prepubertal children <11 yr with type 1 diabetes mellitus. RESEARCH DESIGN AND METHODS: This cross-sectional study involved 18 pediatric centers worldwide. All children, <11 y with a diabetes duration ≥12 months were invited to participate. Case Record Forms included information on clinical characteristics, insulin regimens, diabetic ketoacidosis (DKA), severe hypoglycemia, language difficulties, and comorbidities. Hemoglobin A1c (HbA1c) was measured centrally by liquid chromatography (DCCT aligned, range: 4.4-6.3%; IFFC: 25-45 mmol/mol). RESULTS: A total of 1133 children participated (mean age: 8.0 ± 2.1 y; females: 47.5%, mean diabetes duration: 3.8 ± 2.1 y). HbA1c (overall mean: 8.0 ± 1.0%; range: 7.3-8.9%) and severe hypoglycemia frequency (mean 21.7 events per 100 patient-years), but not DKA, differed significantly between centers (p < 0.001 resp. p = 0.179). Language difficulties showed a negative relationship with HbA1c (8.3 ± 1.2% vs. 8.0 ± 1.0%; p = 0.036). Frequency of blood glucose monitoring demonstrated a significant but weak association with HbA1c (r = -0.17; p < 0.0001). Although significant different HbA1c levels were obtained with diverse insulin regimens (range: 7.3-8.5%; p < 0.001), center differences remained after adjusting for insulin regimen (p < 0.001). Differences between insulin regimens were no longer significant after adjusting for center effect (p = 0.199). CONCLUSIONS: Center differences in metabolic outcomes are present in children <11 yr, irrespective of diabetes duration, age, or gender. The incidence of severe hypoglycemia is lower than in adolescents despite achieving better glycemic control. Insulin regimens show a significant relationship with HbA1c but do not explain center differences. Each center's effectiveness in using specific treatment strategies remains the key factor for outcome.


Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Cetoacidosis Diabética/prevención & control , Hiperglucemia/prevención & control , Hipoglucemia/prevención & control , Hipoglucemiantes/uso terapéutico , Insulina/uso terapéutico , Niño , Estudios de Cohortes , Estudios Transversales , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/fisiopatología , Cetoacidosis Diabética/inducido químicamente , Cetoacidosis Diabética/epidemiología , Cetoacidosis Diabética/fisiopatología , Femenino , Hemoglobina Glucada/análisis , Humanos , Hiperglucemia/epidemiología , Hipoglucemia/epidemiología , Hipoglucemiantes/efectos adversos , Incidencia , Insulina/efectos adversos , Masculino , Índice de Severidad de la Enfermedad , Factores de Tiempo
19.
J Nat Prod ; 74(9): 1980-4, 2011 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-21875052

RESUMEN

(±)-Polysiphenol (1), an atropisomerically stable 4,5-dibrominated 9,10-dihydrophenanthrene from Polysiphonia ferulacea, was prepared by a biomimetically inspired highly regioselective intramolecular oxidative coupling of a dibrominated dihydrostilbene. The installation of the two bromine atoms prior to oxidative coupling prevents further oxidation to a planar aromatized phenanthrene. By this strategy, the synthesis of (±)-polysiphenol was achieved in four steps in 70% overall yield. Synthesis of the naturally occurring 5,5'-(ethane-1,2-diyl)bis(3-bromobenzene-1,2-diol) (2) (the likely biogenetic precursor of polysiphenol) and 5,5'-(ethane-1,2-diyl)bis(3,4,6-tribromobenzene-1,2-diol) (9) are also reported. The origins of the regioselectivity in the oxidative coupling are explored.


Asunto(s)
Hidrocarburos Bromados/síntesis química , Fenantrenos/síntesis química , Bromo , Hidrocarburos Bromados/química , Hidrocarburos Bromados/aislamiento & purificación , Biología Marina , Estructura Molecular , Acoplamiento Oxidativo , Fenantrenos/química , Fenantrenos/aislamiento & purificación , Rhodophyta/química , Estereoisomerismo
20.
Mamm Genome ; 21(9-10): 442-9, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20963592

RESUMEN

Using genome-wide mutagenesis with N-ethyl-N-nitrosourea (ENU), a mouse mutant with cryptorchidism was identified. Genome mapping and exon sequencing identified a novel missense mutation (D294G) in Relaxin/insulin-like family peptide receptor 2 (Rxfp2). The mutation impaired testicular descent and resulted in decreased testis weight in Rxfp2 ( DG/DG ) mice compared to Rxfp2 (+/DG ) and Rxfp2 (+/+) mice. Testicular histology of the Rxfp2 ( DG/DG ) mice revealed spermatogenic defects ranging from germ cell loss to tubules with Sertoli-cell-only features. Genetic complementation analysis using a loss-of-function allele (Rxfp2 (-)) confirmed causality of the D294G mutation. Specifically, mice with one of each mutant allele (Rxfp2 ( DG/-)) exhibited decreased testis weight and failure of the testes to descend compared to their Rxfp2 (+/-) littermates. Total and cell-surface expression of mouse RXFP2 protein and intracellular cAMP accumulation were measured. Total expression of the D294G protein was minimally reduced compared to wild-type, but cell-surface expression was markedly decreased. When analyzed for cAMP accumulation, the EC50 was similar for cells transfected with wild-type and mutant RXFP2 receptor. However, the maximum cAMP response that the mutant receptor reached was greatly reduced compared to the wild-type receptor. In silico modeling of leucine rich repeats (LRRs) 7-9 indicated that aspartic acid 294 is located within the ß-pleated sheet of LRR8. We thus postulate that mutation of D294 results in protein misfolding and aberrant trafficking. The ENU-induced D294G mutation underscores the role of the INSL3/RXFP2-mediated pathway in testicular descent and expands the repertoire of mutations known to affect receptor trafficking and function.


Asunto(s)
Criptorquidismo/genética , Mutación Missense , Receptores Acoplados a Proteínas G/genética , Animales , Mapeo Cromosómico , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Etilnitrosourea , Técnicas de Inactivación de Genes , Prueba de Complementación Genética , Masculino , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis , Reacción en Cadena de la Polimerasa , Conformación Proteica , Pliegue de Proteína , Receptores Acoplados a Proteínas G/química , Transducción de Señal , Testículo/anomalías , Testículo/fisiopatología
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