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1.
Ann Surg ; 275(1): 73-79, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33856386

RESUMEN

OBJECTIVE: To extend the IDEAL framework for device innovation, IDEAL-D, to include the preclinical stage of development (stage 0). BACKGROUND: In previous work, the IDEAL collaboration has proposed frameworks for new surgical techniques and complex therapeutic technologies, the central tenet being that development and evaluation can and should proceed together in an ordered and logical manner that balances innovation and safety. METHODS: Following agreement at the IDEAL Collaboration Council, a multidisciplinary working group was formed comprising 12 representatives from healthcare, academia, industry, and a patient advocate. The group conducted a series of discussions following the principles used in the development of the original IDEAL framework. Importantly, IDEAL aims for maximal transparency, optimal validity in the evaluation of primary effects, and minimization of potential risk to patients or others. The proposals were subjected to further review and editing by members of the IDEAL Council before a final consensus version was adopted. RESULTS: In considering which studies are required before a first-in-human study, we have: (1) classified devices according to what they do and the risks they carry, (2) classified studies according to what they show about the device, and (3) made recommendations based on the principle that the more invasive and high risk a device is, the greater proof required of their safety and effectiveness before progression to clinical studies (stage 1). CONCLUSIONS: The proposed recommendations for preclinical evaluation of medical devices represent a proportionate and pragmatic approach that balances the de-risking of first-in-human translational studies against the benefits of rapid translation of new devices into clinical practice.


Asunto(s)
Equipos y Suministros , Investigación Biomédica Traslacional , Diseño de Equipo , Seguridad de Equipos , Equipos y Suministros/clasificación , Humanos , Medición de Riesgo
2.
Br J Surg ; 110(1): 92-97, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36336577

RESUMEN

BACKGROUND: At the onset of the COVID-19 pandemic, elective surgical provision was severely affected by the need for hospital reorganization to care for critically ill patients. In response, National Health Service (NHS) England issued national guidance proposing acceptable time intervals for postponing different types of surgical procedure. This study reports healthcare professionals' private accounts of the strategies adopted to manage the imbalance of demand and resource, using colorectal cancer surgery as a case study. METHODS: Twenty-seven semistructured interviews were conducted with healthcare professionals between June and November 2020. A key informant sampling approach was used, followed by snowballing to achieve maximum regional variation across the UK. Data were analysed thematically using the constant comparison approach. RESULTS: In the context of considerable resource constraint, surgical teams overcame challenges to continue elective cancer provision. They achieved this by pursuing a combination of strategies: relocating surgical services; prioritizing patients within and across surgical specialties; adapting patient treatment plans; and introducing changes to surgical team working practices. Despite national guidance, prioritization decisions were framed as complex, and the most challenging of the strategies to implement, both practically and emotionally. CONCLUSION: There is a need to better support surgeons tasked with prioritizing patients when capacity exceeds demand.


Asunto(s)
COVID-19 , Neoplasias Colorrectales , Humanos , COVID-19/epidemiología , Pandemias , Medicina Estatal , Procedimientos Quirúrgicos Electivos , Neoplasias Colorrectales/cirugía
3.
Bioorg Med Chem ; 69: 116812, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35772287

RESUMEN

A therapeutic approach that holds the potential to treat all Duchenne muscular dystrophy (DMD) patient populations is utrophin modulation. Ezutromid, a first generation utrophin modulator which was later found to act via antagonism of the arylhydrocarbon receptor, progressed to Phase 2 clinical trials. Although interim data showed target engagement and functional improvements, ezutromid ultimately failed to meet its clinical endpoints. We recently described the identification of a new class of hydrazide utrophin modulators which has a different mechanism of action to ezutromid. In this study we report our early optimisation studies on this hydrazide series. The new analogues had significantly improved potency in cell-based assays, increased sp3 character and reduced lipophilicity, which also improved their physicochemical properties. A representative new analogue combining these attributes increased utrophin protein in dystrophic mouse cells showing it can be used as a chemical tool to reveal new insights regarding utrophin upregulation as a strategy for DMD therapeutic intervention.


Asunto(s)
Distrofia Muscular de Duchenne , Animales , Hidrazinas/farmacología , Hidrazinas/uso terapéutico , Ratones , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/metabolismo , Relación Estructura-Actividad , Regulación hacia Arriba , Utrofina/genética , Utrofina/metabolismo , Utrofina/uso terapéutico
4.
Hum Mol Genet ; 28(13): 2189-2200, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-30990876

RESUMEN

Duchenne muscular dystrophy (DMD) is a lethal neuromuscular disorder caused by loss of dystrophin. Several therapeutic modalities are currently in clinical trials but none will achieve maximum functional rescue and full disease correction. Therefore, we explored the potential of combining the benefits of dystrophin with increases of utrophin, an autosomal paralogue of dystrophin. Utrophin and dystrophin can be co-expressed and co-localized at the same muscle membrane. Wild-type (wt) levels of dystrophin are not significantly affected by a moderate increase of utrophin whereas higher levels of utrophin reduce wt dystrophin, suggesting a finite number of actin binding sites at the sarcolemma. Thus, utrophin upregulation strategies may be applied to the more mildly affected Becker patients with lower dystrophin levels. Whereas increased dystrophin in wt animals does not offer functional improvement, overexpression of utrophin in wt mice results in a significant supra-functional benefit over wt. These findings highlight an additive benefit of the combined therapy and potential new unique roles of utrophin. Finally, we show a 30% restoration of wt dystrophin levels, using exon-skipping, together with increased utrophin levels restores dystrophic muscle function to wt levels offering greater therapeutic benefit than either single approach alone. Thus, this combination therapy results in additive functional benefit and paves the way for potential future combinations of dystrophin- and utrophin-based strategies.


Asunto(s)
Distrofina/genética , Distrofia Muscular de Duchenne/terapia , Utrofina/genética , Animales , Distrofina/metabolismo , Exones , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Morfolinos/síntesis química , Morfolinos/uso terapéutico , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/genética , Miofibrillas/metabolismo , Sarcolema/metabolismo , Regulación hacia Arriba , Utrofina/metabolismo
5.
Hum Mol Genet ; 28(2): 307-319, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30304405

RESUMEN

Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. Constitutive utrophin expression, a structural and functional paralogue of dystrophin, can successfully prevent the dystrophic pathology in the dystrophin-deficient mdx mouse model. In dystrophic muscles, utrophin is increased as part of the repair process and localized at the sarcolemma of regenerating myofibers. The presence of developmental myosin such as embryonic myosin (MyHC-emb) and neonatal represents a useful marker of muscle regeneration and a meaningful indicator of muscle damage, which correlates with the clinical severity of milder Becker muscular dystrophy and DMD patients. In the present study, we demonstrate that MyHC-emb is a robust marker of regeneration at different ages and in different skeletal muscles. We also evaluate the correlation between utrophin, dystrophin and MyHC-emb in wild-type (wt) and regenerating dystrophic muscles. Restoration of dystrophin significantly reduced MyHC-emb levels. Similarly, overexpression of utrophin in the transgenic mdx-Fiona mice reduced the number of MyHC-emb positive fibers to wt level, prevented the regenerative process and rescued the muscle function. In contrast, the absence of utrophin in the dystrophin-deficient double-knockout mice resulted in a higher MyHC-emb content and in a more severe dystrophic pathophysiology than in mdx mice. These data illustrate the importance of monitoring utrophin and MyHC-emb levels in the preclinical evaluation of therapies and provide translational support for the use of developmental myosin as a disease biomarker in DMD clinical trials.


Asunto(s)
Distrofina/metabolismo , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Miosinas/metabolismo , Regeneración , Utrofina/metabolismo , Animales , Biomarcadores/metabolismo , Ensayos Clínicos como Asunto , Modelos Animales de Enfermedad , Embrión de Mamíferos/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Ratones Transgénicos , Músculo Esquelético/embriología , Músculo Esquelético/fisiología , Distrofia Muscular Animal , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/embriología , Distrofia Muscular de Duchenne/patología , Sarcolema/metabolismo
6.
Colorectal Dis ; 23(6): 1524-1551, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33615666

RESUMEN

AIM: Discussions regarding sex after colorectal and pelvic floor surgery are often overlooked by clinicians. This is the first patient designed and delivered study to explore sexual function and practices after colorectal surgery. The aim was to explore the questions about sex that matter to patients and their partners following colorectal or pelvic floor surgery through a patient and public involvement survey. The results of this work will underpin the creation of a sex patient reported outcome measure. METHODS: An anonymous online survey tool (Survey Monkey™) was disseminated via social media (Twitter, Facebook). Thematic analysis was applied to 130 free text comments posted by participants to identify key themes. RESULTS: Some 632 individuals completed the survey. Most respondents were women (80% n = 507), 49.5% (n = 312) were married and 14% (n = 87) identified as LGBT+ (lesbian, gay, bisexual and transgender +). Indications for surgery varied: 34% were treated for ulcerative colitis (n = 214); 31% Crohn's (n = 196); 17% (n = 109) cancer; and 17% (n = 110) for perianal fistula. For patients who had a stoma formed (85%, n = 540), over half (51%, n = 324) lived with their stoma for 1-5 years. Respondents reported substantial alterations to their preferences for sexual positions, sexual activity and body confidence following surgery. Most respondents indicated that they were not offered advice about sex by a healthcare professional. CONCLUSIONS: The survey showed a substantial impact on the mechanics of sex following colorectal surgery. Few patients were offered preoperative information regarding sex, which has implications for informed consent. This study demonstrates a clear unmet need, voiced by patients, that open dialogue is necessary preoperatively to discuss sexual (dys)function.


Asunto(s)
Neoplasias Colorrectales , Trastornos del Suelo Pélvico , Neoplasias Colorrectales/cirugía , Femenino , Humanos , Diafragma Pélvico/cirugía , Conducta Sexual , Encuestas y Cuestionarios
7.
Biochem Soc Trans ; 48(3): 813-821, 2020 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-32597486

RESUMEN

Genetic approaches for the diagnosis and treatment of inherited muscle diseases have advanced rapidly in recent years. Many of the advances have occurred in the treatment of Duchenne muscular dystrophy (DMD), a muscle wasting disease where affected boys are typically wheelchair bound by age 12 years and generally die in their twenties from respiratory failure or cardiomyopathy. Dystrophin is a 421 kD protein which links F-actin to the extracellular matrix via the dystrophin-associated protein complex (DAPC) at the muscle membrane. In the absence of dystrophin, the DAPC is lost, making the muscle membrane more susceptible to contraction-induced injury. The identification of the gene causing DMD in 1986 resulted in improved diagnosis of the disease and the identification of hotspots for mutation. There is currently no effective treatment. However, there are several promising genetic therapeutic approaches at the preclinical stage or in clinical trials including read-through of stop codons, exon skipping, delivery of dystrophin minigenes and the modulation of expression of the dystrophin related protein, utrophin. In spite of significant progress, the problem of targeting all muscles, including diaphragm and heart at sufficiently high levels, remains a challenge. Any therapy also needs to consider the immune response and some treatments are mutation specific and therefore limited to a subgroup of patients. This short review provides a summary of the current status of DMD therapy with a particular focus on those genetic strategies that have been taken to the clinic.


Asunto(s)
Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/terapia , Sistemas CRISPR-Cas , Codón de Terminación , Distrofina/genética , Exones , Terapia Genética/métodos , Humanos , Masculino , Distrofia Muscular de Duchenne/genética
8.
Tetrahedron ; 76(2): 130819, 2020 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-32713969

RESUMEN

Following on from ezutromid, the first-in-class benzoxazole utrophin modulator that progressed to Phase 2 clinical trials for the treatment of Duchenne muscular dystrophy, a new chemotype was designed to optimise its physicochemical and ADME profile. Herein we report the synthesis of SMT022357, a second generation utrophin modulator preclinical candidate, and an asymmetric synthesis of its constituent enantiomers. The pharmacological properties of both enantiomers were evaluated in vitro and in vivo. No significant difference in the activity or efficacy was observed between the two enantiomers; activity was found to be comparable to the racemic mixture.

9.
Angew Chem Int Ed Engl ; 59(6): 2420-2428, 2020 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-31755636

RESUMEN

Duchenne muscular dystrophy (DMD) is a fatal muscle-wasting disease arising from mutations in the dystrophin gene. Upregulation of utrophin to compensate for the missing dystrophin offers a potential therapy independent of patient genotype. The first-in-class utrophin modulator ezutromid/SMT C1100 was developed from a phenotypic screen through to a Phase 2 clinical trial. Promising efficacy and evidence of target engagement was observed in DMD patients after 24 weeks of treatment, however trial endpoints were not met after 48 weeks. The objective of this study was to understand the mechanism of action of ezutromid which could explain the lack of sustained efficacy and help development of new generations of utrophin modulators. Using chemical proteomics and phenotypic profiling we show that the aryl hydrocarbon receptor (AhR) is a target of ezutromid. Several lines of evidence demonstrate that ezutromid binds AhR with an apparent KD of 50 nm and behaves as an AhR antagonist. Furthermore, other reported AhR antagonists also upregulate utrophin, showing that this pathway, which is currently being explored in other clinical applications including oncology and rheumatoid arthritis, could also be exploited in future DMD therapies.


Asunto(s)
Benzoxazoles/química , Naftalenos/química , Proteómica/métodos , Receptores de Hidrocarburo de Aril/metabolismo , Utrofina/metabolismo , Animales , Benzoxazoles/metabolismo , Benzoxazoles/farmacología , Benzoxazoles/uso terapéutico , Reacción de Cicloadición , Diseño de Fármacos , Humanos , Cinética , Ratones , Sondas Moleculares/química , Distrofia Muscular de Duchenne/tratamiento farmacológico , Mioblastos/citología , Mioblastos/metabolismo , Naftalenos/metabolismo , Naftalenos/farmacología , Naftalenos/uso terapéutico , Unión Proteica , Receptores de Hidrocarburo de Aril/antagonistas & inhibidores , Receptores de Hidrocarburo de Aril/genética , Regulación hacia Arriba/efectos de los fármacos , Utrofina/agonistas , Utrofina/genética
10.
Hum Mol Genet ; 24(15): 4212-24, 2015 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-25935002

RESUMEN

Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. There is currently no cure for DMD although various promising approaches are progressing through human clinical trials. By pharmacologically modulating the expression of the dystrophin-related protein utrophin, we have previously demonstrated in dystrophin-deficient mdx studies, daily SMT C1100 treatment significantly reduced muscle degeneration leading to improved muscle function. This manuscript describes the significant disease modifying benefits associated with daily dosing of SMT022357, a second-generation compound in this drug series with improved physicochemical properties and a more robust metabolism profile. These studies in the mdx mouse demonstrate that oral administration of SMT022357 leads to increased utrophin expression in skeletal, respiratory and cardiac muscles. Significantly, utrophin expression is localized along the length of the muscle fibre, not just at the synapse, and is fibre-type independent, suggesting that drug treatment is modulating utrophin transcription in extra-synaptic myonuclei. This results in improved sarcolemmal stability and prevents dystrophic pathology through a significant reduction of regeneration, necrosis and fibrosis. All these improvements combine to protect the mdx muscle from contraction induced damage and enhance physiological function. This detailed evaluation of the SMT C1100 drug series strongly endorses the therapeutic potential of utrophin modulation as a disease modifying therapeutic strategy for all DMD patients irrespective of their dystrophin mutation.


Asunto(s)
Distrofina/biosíntesis , Fibras Musculares Esqueléticas/efectos de los fármacos , Distrofia Muscular de Duchenne/tratamiento farmacológico , Utrofina/biosíntesis , Animales , Distrofina/genética , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Ratones Endogámicos mdx , Contracción Muscular/efectos de los fármacos , Contracción Muscular/genética , Fibras Musculares Esqueléticas/patología , Músculos/efectos de los fármacos , Músculos/patología , Distrofia Muscular Animal/genética , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patología , Sarcolema/efectos de los fármacos , Sarcolema/genética , Utrofina/genética
11.
Stereotact Funct Neurosurg ; 90(3): 145-50, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22508112

RESUMEN

BACKGROUND: Intracranial neoplasms can cause pain similar to trigeminal neuralgia. Literature regarding radiosurgery for this is limited. We present a retrospective review of patients with tumor-related facial pain from benign lesions treated with gamma knife radiosurgery (GKRS) at Wake Forest University. OBJECTIVES: The primary objectives were to determine long-term pain relief and predictive factors for pain alleviation. METHODS: We reviewed 515 patients treated with GKRS for benign meningioma, vestibular schwannoma or trigeminal schwannoma between August 1999 and August 2010. Twenty-one eligible patients had tumor-related facial pain prior to GKRS. The median marginal tumor dose was 12 Gy. Long-term pain relief data were obtained by chart review and telephone interview. RESULTS: The median follow-up for symptom evaluation was 3.8 years. Seventeen of 21 patients (81%) experienced a Barrow Neurological Institute (BNI) score of I-III at 6 months following GKRS. Kaplan-Meier estimates of freedom from BNI IV-V relapse were 66% at 1 year and 53% at 2 years. No pain relapses occurred after 2 years. CONCLUSION: GKRS of benign lesions is a noninvasive option for patients with tumor-related facial pain. Pain relief is modest, with the majority of pain relapses occurring within 2 years and approximately one half of patients maintaining relief beyond 2 years.


Asunto(s)
Neoplasias Encefálicas/cirugía , Dolor Facial/cirugía , Meningioma/cirugía , Neurilemoma/cirugía , Radiocirugia/instrumentación , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/complicaciones , Dolor Facial/etiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Meningioma/complicaciones , Persona de Mediana Edad , Neurilemoma/complicaciones , Dimensión del Dolor , Estudios Retrospectivos , Resultado del Tratamiento
12.
Eur J Med Chem ; 220: 113431, 2021 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-33915371

RESUMEN

Duchenne muscular dystrophy is a fatal disease with no cure, caused by lack of the cytoskeletal protein dystrophin. Upregulation of utrophin, a dystrophin paralogue, offers a potential therapy independent of mutation type. The failure of first-in-class utrophin modulator ezutromid/SMT C1100 in Phase II clinical trials necessitates development of compounds with better efficacy, physicochemical and ADME properties and/or complementary mechanisms. We have discovered and performed a preliminary optimisation of a novel class of utrophin modulators using an improved phenotypic screen, where reporter expression is derived from the full genomic context of the utrophin promoter. We further demonstrate through target deconvolution studies, including expression analysis and chemical proteomics, that this compound series operates via a novel mechanism of action, distinct from that of ezutromid.


Asunto(s)
Descubrimiento de Drogas , Hidrazinas/farmacología , Distrofia Muscular de Duchenne/tratamiento farmacológico , Pirimidinas/farmacología , Utrofina/metabolismo , Relación Dosis-Respuesta a Droga , Humanos , Hidrazinas/síntesis química , Hidrazinas/química , Estructura Molecular , Distrofia Muscular de Duchenne/metabolismo , Pirimidinas/síntesis química , Pirimidinas/química , ARN Mensajero/metabolismo , Relación Estructura-Actividad
13.
ACS Med Chem Lett ; 11(12): 2421-2427, 2020 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-33335663

RESUMEN

Utrophin modulation is a disease-modifying therapeutic strategy for Duchenne muscular dystrophy that would be applicable to all patient populations. To improve the suboptimal profile of ezutromid, the first-in-class clinical candidate, a second generation of utrophin modulators bearing a phosphinate ester moiety was developed. This modification significantly improved the physicochemical and ADME properties, but one of the main lead molecules was found to have dose-limiting hepatotoxicity. In this work we describe how less lipophilic analogues retained utrophin modulatory activity in a reporter gene assay, upregulated utrophin protein in dystrophic mouse muscle cells, but also had improved physicochemical and ADME properties. Notably, ClogP was found to directly correlate with pIC50 in HepG2 cells, hence leading to a potentially safer toxicological profiles in this series. Compound 21 showed a balanced profile (H2K EC50: 4.17 µM, solubility: 477 µM, mouse hepatocyte T 1/2 > 240 min) and increased utrophin protein 1.6-fold in a Western blot assay.

14.
J Med Chem ; 63(14): 7880-7891, 2020 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-32551645

RESUMEN

Utrophin modulation is a promising therapeutic strategy for Duchenne muscular dystrophy (DMD), which should be applicable to all patient populations. Following on from ezutromid, the first-generation utrophin modulator, we describe the development of a second generation of utrophin modulators, based on the bioisosteric replacement of the sulfone group with a phosphinate ester and substitution of the metabolically labile naphthalene with a haloaryl substituent. The improved physicochemical and absorption, distribution, metabolism, and excretion (ADME) properties, further reflected in the enhanced pharmacokinetic profile of the most advanced compounds, 30 and 27, led to significantly better in vivo exposure compared to ezutromid and alleviation of the dystrophic phenotype in mdx mice. While 30 was found to have dose-limiting hepatotoxicity, 27 and its enantiomers exhibited limited off-target effects, resulting in a safe profile and highlighting their potential utility as next-generation utrophin modulators suitable for progression toward a future DMD therapy.


Asunto(s)
Benzoxazoles/uso terapéutico , Distrofia Muscular de Duchenne/tratamiento farmacológico , Utrofina/metabolismo , Animales , Benzoxazoles/síntesis química , Benzoxazoles/farmacocinética , Benzoxazoles/toxicidad , Escherichia coli/efectos de los fármacos , Ratones Endogámicos mdx , Estructura Molecular , Distrofia Muscular de Duchenne/metabolismo , Pruebas de Mutagenicidad , Ratas , Salmonella typhimurium/efectos de los fármacos , Estereoisomerismo , Relación Estructura-Actividad , Regulación hacia Arriba/efectos de los fármacos
15.
Sci Rep ; 7: 43697, 2017 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-28252048

RESUMEN

Despite promising therapeutic avenues, there is currently no effective treatment for Duchenne muscular dystrophy (DMD), a lethal monogenic disorder caused by the loss of the large cytoskeletal protein, dystrophin. A highly promising approach to therapy, applicable to all DMD patients irrespective to their genetic defect, is to modulate utrophin, a functional paralogue of dystrophin, able to compensate for the primary defects of DMD restoring sarcolemmal stability. One of the major difficulties in assessing the effectiveness of therapeutic strategies is to define appropriate outcome measures. In the present study, we utilised an aptamer based proteomics approach to profile 1,310 proteins in plasma of wild-type, mdx and Fiona (mdx overexpressing utrophin) mice. Comparison of the C57 and mdx sera revealed 83 proteins with statistically significant >2 fold changes in dystrophic serum abundance. A large majority of previously described biomarkers (ANP32B, THBS4, CAMK2A/B/D, CYCS, CAPNI) were normalised towards wild-type levels in Fiona animals. This work also identified potential mdx markers specific to increased utrophin (DUS3, TPI1) and highlights novel mdx biomarkers (GITR, MYBPC1, HSP60, SIRT2, SMAD3, CNTN1). We define a panel of putative protein mdx biomarkers to evaluate utrophin based strategies which may help to accelerate their translation to the clinic.


Asunto(s)
Biomarcadores , Proteínas Sanguíneas , Utrofina/sangre , Animales , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Humanos , Ratones , Ratones Transgénicos , Distrofia Muscular Animal , Distrofia Muscular de Duchenne/sangre , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/terapia , Proteoma , Proteómica/métodos , Investigación Biomédica Traslacional , Utrofina/uso terapéutico
16.
PLoS One ; 6(12): e28699, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22174871

RESUMEN

Mutations in the skeletal muscle α-actin gene (ACTA1) cause congenital myopathies including nemaline myopathy, actin aggregate myopathy and rod-core disease. The majority of patients with ACTA1 mutations have severe hypotonia and do not survive beyond the age of one. A transgenic mouse model was generated expressing an autosomal dominant mutant (D286G) of ACTA1 (identified in a severe nemaline myopathy patient) fused with EGFP. Nemaline bodies were observed in multiple skeletal muscles, with serial sections showing these correlated to aggregates of the mutant skeletal muscle α-actin-EGFP. Isolated extensor digitorum longus and soleus muscles were significantly weaker than wild-type (WT) muscle at 4 weeks of age, coinciding with the peak in structural lesions. These 4 week-old mice were ~30% less active on voluntary running wheels than WT mice. The α-actin-EGFP protein clearly demonstrated that the transgene was expressed equally in all myosin heavy chain (MHC) fibre types during the early postnatal period, but subsequently became largely confined to MHCIIB fibres. Ringbinden fibres, internal nuclei and myofibrillar myopathy pathologies, not typical features in nemaline myopathy or patients with ACTA1 mutations, were frequently observed. Ringbinden were found in fast fibre predominant muscles of adult mice and were exclusively MHCIIB-positive fibres. Thus, this mouse model presents a reliable model for the investigation of the pathobiology of nemaline body formation and muscle weakness and for evaluation of potential therapeutic interventions. The occurrence of core-like regions, internal nuclei and ringbinden will allow analysis of the mechanisms underlying these lesions. The occurrence of ringbinden and features of myofibrillar myopathy in this mouse model of ACTA1 disease suggests that patients with these pathologies and no genetic explanation should be screened for ACTA1 mutations.


Asunto(s)
Actinas/metabolismo , Expresión Génica , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Miopatías Nemalínicas/patología , Transgenes/genética , Animales , Conducta Animal , Modelos Animales de Enfermedad , Proteínas Fluorescentes Verdes/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Contracción Muscular/fisiología , Fibras Musculares Esqueléticas/patología , Fibras Musculares Esqueléticas/ultraestructura , Músculo Esquelético/fisiopatología , Músculo Esquelético/ultraestructura , Miopatías Nemalínicas/fisiopatología , Cadenas Pesadas de Miosina/metabolismo , Fenotipo , Proteínas Recombinantes de Fusión/metabolismo
17.
PLoS One ; 6(5): e19189, 2011 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-21573153

RESUMEN

BACKGROUND: Duchenne muscular dystrophy (DMD) is a lethal, progressive muscle wasting disease caused by a loss of sarcolemmal bound dystrophin, which results in the death of the muscle fibers leading to the gradual depletion of skeletal muscle. There is significant evidence demonstrating that increasing levels of the dystrophin-related protein, utrophin, in mouse models results in sarcolemmal bound utrophin and prevents the muscular dystrophy pathology. The aim of this work was to develop a small molecule which increases the levels of utrophin in muscle and thus has therapeutic potential. METHODOLOGY AND PRINCIPAL FINDINGS: We describe the in vivo activity of SMT C1100; the first orally bioavailable small molecule utrophin upregulator. Once-a-day daily-dosing with SMT C1100 reduces a number of the pathological effects of dystrophin deficiency. Treatment results in reduced pathology, better muscle physiology leading to an increase in overall strength, and an ability to resist fatigue after forced exercise; a surrogate for the six minute walk test currently recommended as the pivotal outcome measure in human trials for DMD. CONCLUSIONS AND SIGNIFICANCE: This study demonstrates proof-of-principle for the use of in vitro screening methods in allowing identification of pharmacological agents for utrophin transcriptional upregulation. The best compound identified, SMT C1100, demonstrated significant disease modifying effects in DMD models. Our data warrant the full evaluation of this compound in clinical trials in DMD patients.


Asunto(s)
Distrofia Muscular Animal/tratamiento farmacológico , Distrofia Muscular Animal/metabolismo , Utrofina/metabolismo , Animales , Células Cultivadas , Electrofisiología , Humanos , Masculino , Ratones , Ratones Endogámicos mdx , Distrofia Muscular Animal/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Utrofina/genética
18.
Int J Radiat Oncol Biol Phys ; 78(4): 1142-6, 2010 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-20832185

RESUMEN

PURPOSE: To investigate the efficacy of 3.0-T magnetic resonance imaging (MRI) for detecting brain metastases for stereotactic radiosurgery (SRS) planning. METHODS AND MATERIALS: All adult patients scheduled for SRS treatment for brain metastases at our institution between October 2005 and January 2008 were eligible for analysis. All patients underwent radiosurgery treatment planning 3.0-T MRI on the day of scheduled radiosurgery and a diagnostic 1.5-T MRI in the days or weeks prior to radiosurgery for comparison. Both scans were interpreted by neuroradiologists who reported their findings in the radiology reports. We performed a retrospective review of the radiology reports to determine the number of brain metastases identified using each MRI system. RESULTS: Of 254 patients scheduled for treatment from October 2005 to January 2008, 138 patients had radiology reports that explicitly described the number of metastases identified on both scans. With a median interval of 17 days (range, 1-82) between scans, the number of metastases detected using 1.5-T MRI system ranged from 1 to 5 and from 1 to 8 using the 3.0 T-MRI system. Twenty-two percent of patients were found to have a greater number of metastases with the 3.0 T-MRI system. The difference in number of metastases detected between the two scans for the entire cohort ranged from 0 to 6. Neither histology (p = 0.52 by chi-sq test) nor time between scans (p = 0.62 by linear regression) were significantly associated with the difference in number of metastases between scans. CONCLUSIONS: The 3.0-T MRI system appears to be superior to a 1.5-T MRI system for detecting brain metastases, which may have significant implications in determining the appropriate treatment modality. Our findings suggest the need for a prospectively designed study to further evaluate the use of a 3.0 T-MRI system for stereotactic radiosurgery planning in the treatment of brain metastases.


Asunto(s)
Neoplasias Encefálicas/secundario , Neoplasias Encefálicas/cirugía , Imagen por Resonancia Magnética/métodos , Radiocirugia , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Distribución de Chi-Cuadrado , Humanos , Imagen por Resonancia Magnética/estadística & datos numéricos , Registros Médicos/estadística & datos numéricos , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Adulto Joven
19.
J Cell Biol ; 185(5): 903-15, 2009 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-19468071

RESUMEN

Skeletal muscle alpha-actin (ACTA1) is the major actin in postnatal skeletal muscle. Mutations of ACTA1 cause mostly fatal congenital myopathies. Cardiac alpha-actin (ACTC) is the major striated actin in adult heart and fetal skeletal muscle. It is unknown why ACTC and ACTA1 expression switch during development. We investigated whether ACTC can replace ACTA1 in postnatal skeletal muscle. Two ACTC transgenic mouse lines were crossed with Acta1 knockout mice (which all die by 9 d after birth). Offspring resulting from the cross with the high expressing line survive to old age, and their skeletal muscles show no gross pathological features. The mice are not impaired on grip strength, rotarod, or locomotor activity. These findings indicate that ACTC is sufficiently similar to ACTA1 to produce adequate function in postnatal skeletal muscle. This raises the prospect that ACTC reactivation might provide a therapy for ACTA1 diseases. In addition, the mouse model will allow analysis of the precise functional differences between ACTA1 and ACTC.


Asunto(s)
Actinas/fisiología , Músculo Esquelético/metabolismo , Miocardio/metabolismo , Actinas/genética , Animales , Perfilación de la Expresión Génica , Corazón/embriología , Ratones , Ratones Noqueados , Músculo Esquelético/ultraestructura , Miocardio/ultraestructura , Isoformas de Proteínas/fisiología
20.
J Neurooncol ; 81(1): 97-111, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16855864

RESUMEN

To date, approximately 200 cases of atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system have been described in the literature. This CNS tumor tends to present at an age of less than 3 years, and most patients succumb to their disease within 1 year of diagnosis. Prior to the rise in utilization of immunohistochemical (IHC) testing in the late 1990s, this tumor was likely mistaken as medulloblastoma and treated as such. However, lessons learned from regimens based upon medulloblastoma have revealed that AT/RT requires more aggressive treatment. A significant portion of patients die of local recurrence in spite of aggressive surgery and chemotherapy. As most patients with AT/RT present as infants or young children, radiation therapy has been a less than standard treatment option. However, recent evidence suggests that long-term survival can occur with use of more aggressive treatment approaches including dose-intense chemotherapy as well as adjuvant radiation therapy. A standardized and effective approach to treating this usually fatal tumor remains elusive, and the role of radiation therapy presents a particular dilemma as young patients with this disease may experience devastating late effects of therapy if they achieve a long-term survival. Review of the literature reveals an association between initial radiation therapy and the ability to achieve a prolonged survival. Our review underscores the importance or enrolling patients in multi-institutional prospective studies to further investigate the value of radiation to treat this pediatric neoplasm.


Asunto(s)
Neoplasias del Sistema Nervioso Central/radioterapia , Radioterapia/métodos , Tumor Rabdoide/radioterapia , Teratoma/radioterapia , Antineoplásicos/uso terapéutico , Neoplasias del Sistema Nervioso Central/tratamiento farmacológico , Preescolar , Terapia Combinada , Supervivencia sin Enfermedad , Humanos , Tumor Rabdoide/tratamiento farmacológico , Teratoma/tratamiento farmacológico
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