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1.
Chemistry ; 28(53): e202201830, 2022 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-35793203

RESUMEN

Vinyl triflimides are a new compound class with unknown reactivity. A computational analysis identified homolytic cleavage of the N-Tf bond induced by triplet-triplet energy transfer (EnT) as a highly interesting reaction type that might be accessible. A combination of experimental and mechanistic work verified this hypothesis and proved the generated radicals to be amenable to radical-radical coupling. Thereby, vinyl triflimides were transformed into a range of α-quaternary, ß-trifluoromethylated amines in a 1,2-difunctionalization reaction with no need for external CF3 reagents.


Asunto(s)
Aminas , Ciclohexanonas , Transferencia de Energía , Fotoquímica
2.
Clin Genet ; 100(1): 14-28, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33619735

RESUMEN

Up to 40% of neurodevelopmental disorders (NDDs) such as intellectual disability, developmental delay, autism spectrum disorder, and developmental motor abnormalities have a documented underlying monogenic defect, primarily due to de novo variants. Still, the overall burden of de novo variants as well as novel disease genes in NDDs await discovery. We performed parent-offspring trio exome sequencing in 231 individuals with NDDs. Phenotypes were compiled using human phenotype ontology terms. The overall diagnostic yield was 49.8% (n = 115/231) with de novo variants contributing to more than 80% (n = 93/115) of all solved cases. De novo variants affected 72 different-mostly constrained-genes. In addition, we identified putative pathogenic variants in 16 genes not linked to NDDs to date. Reanalysis performed in 80 initially unsolved cases revealed a definitive diagnosis in two additional cases. Our study consolidates the contribution and genetic heterogeneity of de novo variants in NDDs highlighting trio exome sequencing as effective diagnostic tool for NDDs. Besides, we illustrate the potential of a trio-approach for candidate gene discovery and the power of systematic reanalysis of unsolved cases.


Asunto(s)
Variación Genética/genética , Trastornos del Neurodesarrollo/genética , Adolescente , Adulto , Niño , Preescolar , Exoma/genética , Femenino , Predisposición Genética a la Enfermedad/genética , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Fenotipo , Estudios Retrospectivos , Centros de Atención Terciaria , Secuenciación del Exoma/métodos , Adulto Joven
4.
Angew Chem Int Ed Engl ; 58(15): 5119-5123, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30694004

RESUMEN

A new concept for selectivity control in carbocation-driven reactions has been identified which allows for the chemo-, regio-, and stereoselective addition of nucleophiles to alkynes-assisted vinyl cation formation-enabled by a Li+ -based supramolecular framework. Mechanistic analysis of a model complex (Li2 NTf2 + ⋅3 H2 O) confirms that solely the formation of a complex between the incoming nucleophile and the transition state of the alkyne protonation is responsible for the resulting selective N addition to the vinyl cation. Into the bargain, a general, operationally simple synthetic procedure to previously inaccessible vinyl triflimides is provided.

5.
J Headache Pain ; 20(1): 8, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30658563

RESUMEN

BACKGROUND: Research in migraine points towards central-peripheral complexity with a widespread pattern of structures involved. Migraine-associated neck and shoulder muscle pain has clinically been conceptualized as myofascial trigger points (mTrPs). However, concepts remain controversial, and the identification of mTrPs is mostly restricted to manual palpation in clinical routine. This study investigates a more objective, quantitative assessment of mTrPs by means of magnetic resonance imaging (MRI) with T2 mapping. METHODS: Ten subjects (nine females, 25.6 ± 5.2 years) with a diagnosis of migraine according to ICHD-3 underwent bilateral manual palpation of the upper trapezius muscles to localize mTrPs. Capsules were attached to the skin adjacent to the palpated mTrPs for marking. MRI of the neck and shoulder region was performed at 3 T, including a T2-prepared, three-dimensional (3D) turbo spin echo (TSE) sequence. The T2-prepared 3D TSE sequence was used to generate T2 maps, followed by manual placement of regions of interest (ROIs) covering the trapezius muscles of both sides and signal alterations attributable to mTrPs. RESULTS: The trapezius muscles showed an average T2 value of 27.7 ± 1.4 ms for the right and an average T2 value of 28.7 ± 1.0 ms for the left side (p = 0.1055). Concerning signal alterations in T2 maps attributed to mTrPs, nine values were obtained for the right (32.3 ± 2.5 ms) and left side (33.0 ± 1.5 ms), respectively (p = 0.0781). When comparing the T2 values of the trapezius muscles to the T2 values extracted from the signal alterations attributed to the mTrPs of the ipsilateral side, we observed a statistically significant difference (p = 0.0039). T2 hyperintensities according to visual image inspection were only reported in four subjects for the right and in two subjects for the left side. CONCLUSIONS: Our approach enables the identification of mTrPs and their quantification in terms of T2 mapping even in the absence of qualitative signal alterations. Thus, it (1) might potentially challenge the current gold-standard method of physical examination of mTrPs, (2) could allow for more targeted and objectively verifiable interventions, and (3) could add valuable models to understand better central-peripheral mechanisms in migraine.


Asunto(s)
Trastornos Migrañosos/diagnóstico por imagen , Músculos Superficiales de la Espalda/diagnóstico por imagen , Puntos Disparadores/diagnóstico por imagen , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Palpación , Adulto Joven
6.
Front Pediatr ; 6: 182, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29988546

RESUMEN

Objective: Acute childhood stroke is an emergency requiring a high level of awareness among first-line healthcare providers. This survey serves as an indicator of the awareness of, the interest in, and knowledge of childhood stroke of German pediatricians. Methods: Thousand six hundred and ninety-seven physicians of pediatric in- and outpatient facilities in Bavaria, Germany, were invited via email to an online-survey about childhood stroke. Results: The overall participation rate was 14%. Forty-six percent of participants considered a diagnosis of childhood stroke at least once during the past year, and 47% provide care for patients who have suffered childhood stroke. The acronym FAST (Face-Arm-Speech-Time-Test) was correctly cited in 27% of the questionnaires. Most commonly quoted symptoms of childhood stroke were hemiparesis (90%), speech disorder (58%), seizure (44%), headache (40%), and impaired consciousness (33%). Migraine (63%), seizure (39%), and infections of the brain (31%) were most frequently named as stroke mimics. Main diagnostic measures indicated were magnetic resonance imaging (MRI) (96%) and computer tomography (CT) (55%). Main therapeutic strategies were thrombolysis (80%), anticoagulation (41%), neuroprotective measures, and thrombectomies (15% each). Thirty-nine percent of participants had taken part in training sessions, 61% studied literature, 37% discussed with colleagues, and 25% performed internet research on childhood stroke. Ninety-three percent of participants approve skill enhancement, favoring training sessions (80%), publications (43%), and web based offers (35%). Consent for offering a flyer on the topic to caregivers in facilities was given in 49%. Conclusion: Childhood stroke constitutes a topic of clinical importance to pediatricians. Participants demonstrate a considerable level of comprehension concerning the subject, but room for improvement remains. A multi-modal approach encompassing an elaborate training program, regular educational publications in professional journals, and web based offers could reach a broad range of health care providers. Paired with a public adult and childhood stroke awareness campaign, these efforts could contribute to optimize the care for children suffering from stroke.

7.
J Neuroeng Rehabil ; 15(1): 30, 2018 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-29625628

RESUMEN

BACKGROUND: The application of rehabilitation robots has grown during the last decade. While meta-analyses have shown beneficial effects of robotic interventions for some patient groups, the evidence is less in others. We established the Advanced Robotic Therapy Integrated Centers (ARTIC) network with the goal of advancing the science and clinical practice of rehabilitation robotics. The investigators hope to exploit variations in practice to learn about current clinical application and outcomes. The aim of this paper is to introduce the ARTIC network to the clinical and research community, present the initial data set and its characteristics and compare the outcome data collected so far with data from prior studies. METHODS: ARTIC is a pragmatic observational study of clinical care. The database includes patients with various neurological and gait deficits who used the driven gait orthosis Lokomat® as part of their treatment. Patient characteristics, diagnosis-specific information, and indicators of impairment severity are collected. Core clinical assessments include the 10-Meter Walk Test and the Goal Attainment Scaling. Data from each Lokomat® training session are automatically collected. RESULTS: At time of analysis, the database contained data collected from 595 patients (cerebral palsy: n = 208; stroke: n = 129; spinal cord injury: n = 93; traumatic brain injury: n = 39; and various other diagnoses: n = 126). At onset, average walking speeds were slow. The training intensity increased from the first to the final therapy session and most patients achieved their goals. CONCLUSIONS: The characteristics of the patients matched epidemiological data for the target populations. When patient characteristics differed from epidemiological data, this was mainly due to the selection criteria used to assess eligibility for Lokomat® training. While patients included in randomized controlled interventional trials have to fulfill many inclusion and exclusion criteria, the only selection criteria applying to patients in the ARTIC database are those required for use of the Lokomat®. We suggest that the ARTIC network offers an opportunity to investigate the clinical application and effectiveness of rehabilitation technologies for various diagnoses. Due to the standardization of assessments and the use of a common technology, this network could serve as a basis for researchers interested in specific interventional studies expanding beyond the Lokomat®.


Asunto(s)
Bases de Datos como Asunto/organización & administración , Dispositivo Exoesqueleto , Trastornos Neurológicos de la Marcha/rehabilitación , Femenino , Humanos , Masculino
9.
Eur J Paediatr Neurol ; 19(6): 640-6, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26455815

RESUMEN

BACKGROUND/PURPOSE: The six minute walk test is a widely accepted primary outcome parameter in most studies in Duchenne muscular dystrophy (DMD). To compare information obtained by the six minute walk distance (6MWD) test and the two minute walk distance (2MWD) in patients with DMD, a cohort of 13 voluntary DMD boys did a repeated six minute walking test. METHODS: Patients had to be ambulatory with a physical disability according to Levels 1-3 on the Vignos-Scale for lower extremity. Measurements were taken at one minute intervals. Reliability was measured by intraclass correlation. RESULTS: Test-retest reliability for 6MWD and 2MWD in two different age classes was very good for both subgroups. Test-retest-reliability was lower in patients with more advanced disability in both tests. Walking speed remained completely stable from time points 1-6 minutes in the whole study patient collective, which indicates that physical exhaustion is not reached after six minutes even in more disabled patients. CONCLUSION: Thus the 6MWD in DMD patients does not give additional information as compared to a 2MWD.


Asunto(s)
Prueba de Esfuerzo/métodos , Distrofia Muscular de Duchenne/diagnóstico , Niño , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Reproducibilidad de los Resultados , Factores de Tiempo , Caminata
10.
Chemistry ; 21(45): 15929-33, 2015 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-26403228

RESUMEN

The first transition metal-free cycloisomerization of easily accessible diynols is presented as a novel approach to bicyclic 2H-pyrans. As a one-step protocol, the reaction proceeds in a single reaction cascade by intertwining mechanistic fragments borrowed from transition metal-catalyzed Claisen rearrangment of vinyl ethers with our own work on allenyl/propargyl cation rearrangements and a 6π-oxo-electrocylization. It is enabled by a new cooperative catalytic system that combines a simple Ca(2+) catalyst with camphorsulfonic acid.

11.
Dev Neurorehabil ; 17(6): 420-5, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25057804

RESUMEN

OBJECTIVE: To evaluate the association of hip lateralisation with health-related quality of life (HRQL) in children with cerebral palsy (CP) using the Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD(®)) questionnaire. METHODS: We assessed n = 34 patients (mean age: 10.2 years, SD: 4.7 years; female: n = 16) with bilateral CP and Gross Motor Function Classification System (GMFCS) Level III-V using the CPCHILD(®) questionnaire. Hip lateralisation was measured by Reimer`s migration percentage (MP). RESULTS: There was an association between both, MP and GMFCS with CPCHILD(®) total score. Stratified analyses did not suggest interaction of the association between MP and CPCHILD(®) total score by GMFCS level. After adjustment for GMFCS level, we found a significant linear decrease of CPCHILD(®) total score of -0.188 points by 1% increment in MP. CONCLUSIONS: There was an association between MP and HRQL, which could not be explained by the GMFCS level.


Asunto(s)
Parálisis Cerebral/fisiopatología , Luxación de la Cadera , Calidad de Vida , Adolescente , Cuidadores , Parálisis Cerebral/psicología , Niño , Preescolar , Niños con Discapacidad , Femenino , Cadera/fisiopatología , Humanos , Masculino , Encuestas y Cuestionarios , Resultado del Tratamiento , Adulto Joven
12.
Cell Cycle ; 12(3): 452-62, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23255218

RESUMEN

The therapeutic potential of pharmacologic inhibition of bromodomain and extraterminal (BET) proteins has recently emerged in hematological malignancies and chronic inflammation. We find that BET inhibitor compounds (JQ1, I-Bet, I-Bet151 and MS417) reactivate HIV from latency. This is evident in polyclonal Jurkat cell populations containing latent infectious HIV, as well as in a primary T-cell model of HIV latency. Importantly, we show that this activation is dependent on the positive transcription elongation factor p-TEFb but independent from the viral Tat protein, arguing against the possibility that removal of the BET protein BRD4, which functions as a cellular competitor for Tat, serves as a primary mechanism for BET inhibitor action. Instead, we find that the related BET protein, BRD2, enforces HIV latency in the absence of Tat, pointing to a new target for BET inhibitor treatment in HIV infection. In shRNA-mediated knockdown experiments, knockdown of BRD2 activates HIV transcription to the same extent as JQ1 treatment, while a lesser effect is observed with BRD4. In single-cell time-lapse fluorescence microscopy, quantitative analyses across ~2,000 viral integration sites confirm the Tat-independent effect of JQ1 and point to positive effects of JQ1 on transcription elongation, while delaying re-initiation of the polymerase complex at the viral promoter. Collectively, our results identify BRD2 as a new Tat-independent suppressor of HIV transcription in latently infected cells and underscore the therapeutic potential of BET inhibitors in the reversal of HIV latency.


Asunto(s)
Infecciones por VIH/virología , VIH-1/fisiología , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Factores de Transcripción/metabolismo , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo , Azepinas/farmacología , Benzodiazepinas/farmacología , Linfocitos T CD4-Positivos/virología , Proteínas de Ciclo Celular , Células Cultivadas , Células HEK293 , VIH-1/efectos de los fármacos , VIH-1/genética , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Humanos , Células Jurkat , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/genética , Factor B de Elongación Transcripcional Positiva/genética , Factor B de Elongación Transcripcional Positiva/metabolismo , Regiones Promotoras Genéticas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Interferencia de ARN , ARN Interferente Pequeño , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Transcripción Genética/efectos de los fármacos , Triazoles/farmacología , Latencia del Virus , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética
13.
Dev Med Child Neurol ; 53(2): 179-86, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21121906

RESUMEN

AIM: In children with bilateral spastic cerebral palsy (CP), periventricular leukomalacia (PVL) is commonly identified on magnetic resonance imaging. We characterized this white matter condition by examining callosal microstructure, interhemispheric inhibitory competence (IIC), and mirror movements. METHOD: We examined seven children (age range 11y 9mo-17y 9mo, median age 15y 10mo, four females, three males) with bilateral spastic CP/PVL (Gross Motor Function Classification System level I or II, Manual Ability Classification System level I) and 12 age-matched controls (age range 11y 7mo-17y 1mo, median age 15y 6mo, seven females, five males). Fractional anisotropy of the transcallosal motor fibres (TCMF) and the corticospinal tract (CST) of both sides were calculated. The parameters of IIC (transcranial magnetic stimulation) and mirror movements were measured using a standardized clinical examination and a computer-based hand motor test. RESULTS: Fractional anisotropy was lower in children with bilateral spastic CP/PVL regarding the TCMF, but not the left or right CST. Resting motor threshold was elevated in children with bilateral spastic CP/PVL whereas measures of IIC tended to be lower. Mirror movements were markedly elevated in bilateral spastic CP/PVL. INTERPRETATION: This study provides new information on different aspects of motor function in children with bilateral spastic CP/PVL. Decreased fractional anisotropy of TCMF is consistent with impairment of hand motor function in children with bilateral spastic CP/PVL. The previously overlooked microstructure of the TCMF may serve as a potential indicator for hand motor function in patients with bilateral spastic CP/PVL.


Asunto(s)
Anisotropía , Parálisis Cerebral/diagnóstico , Parálisis Cerebral/fisiopatología , Cuerpo Calloso/patología , Cuerpo Calloso/fisiopatología , Imagen de Difusión por Resonancia Magnética , Dominancia Cerebral/fisiología , Procesamiento de Imagen Asistido por Computador , Leucomalacia Periventricular/diagnóstico , Leucomalacia Periventricular/fisiopatología , Neuronas Motoras/patología , Neuronas Motoras/fisiología , Fibras Nerviosas/fisiología , Tractos Piramidales/fisiopatología , Adolescente , Mapeo Encefálico , Niño , Imagen de Difusión Tensora , Potenciales Evocados Motores/fisiología , Femenino , Lateralidad Funcional/fisiología , Humanos , Recién Nacido , Leucomalacia Periventricular/patología , Masculino , Fibras Nerviosas/patología , Inhibición Neural/fisiología , Trastornos Psicomotores/diagnóstico , Trastornos Psicomotores/patología , Trastornos Psicomotores/fisiopatología , Tractos Piramidales/patología , Umbral Sensorial/fisiología , Estimulación Magnética Transcraneal
14.
Neuron ; 67(6): 953-66, 2010 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-20869593

RESUMEN

Neurodegenerative tauopathies characterized by hyperphosphorylated tau include frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17) and Alzheimer's disease (AD). Reducing tau levels improves cognitive function in mouse models of AD and FTDP-17, but the mechanisms regulating the turnover of pathogenic tau are unknown. We found that tau is acetylated and that tau acetylation prevents degradation of phosphorylated tau (p-tau). We generated two antibodies specific for acetylated tau and showed that tau acetylation is elevated in patients at early and moderate Braak stages of tauopathy. Histone acetyltransferase p300 was involved in tau acetylation and the class III protein deacetylase SIRT1 in deacetylation. Deleting SIRT1 enhanced levels of acetylated-tau and pathogenic forms of p-tau, probably by blocking proteasome-mediated degradation. Inhibiting p300 with a small molecule promoted tau deacetylation and eliminated p-tau associated with tauopathy. Modulating tau acetylation could be a new therapeutic strategy to reduce tau-mediated neurodegeneration.


Asunto(s)
Tauopatías/etiología , Tauopatías/metabolismo , Proteínas tau/metabolismo , Acetilación/efectos de los fármacos , Análisis de Varianza , Animales , Animales Recién Nacidos , Carbazoles/farmacología , Células Cultivadas , Corteza Cerebral/citología , Cicloheximida/farmacología , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Inmunoprecipitación/métodos , Ratones , Ratones Transgénicos , Modelos Biológicos , Mutación/genética , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fosforilación/efectos de los fármacos , Fosforilación/fisiología , Inhibidores de la Síntesis de la Proteína/farmacología , Ratas , Ratas Sprague-Dawley , Sirtuina 1/genética , Sirtuina 1/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Tauopatías/genética , Factores de Tiempo , Transfección/métodos , Ubiquitinación/efectos de los fármacos , Factores de Transcripción p300-CBP/fisiología , Proteínas tau/genética
15.
Cell Cycle ; 9(9): 1697-705, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20436276

RESUMEN

The cyclin T/CDK9 complex, also called positive transcription elongation factor b (P-TEFb) phosphorylates the C-terminal domain of the large fragment of the RNA polymerase II. This action is a hallmark of the transition from transcription initiation to elongation. P-TEFb is itself modified by phosphorylation and ubiquitination. Recently, the core components of P-TEFb, cyclin T1 and CDK9, were identified as novel substrates of histone acetyltransferases. Here, we review how posttranslational modifications regulate the activity of the P-TEFb complex and discuss how acetylation of the complex optimizes transcription elongation in the context of other posttranslational modifications.


Asunto(s)
Factor B de Elongación Transcripcional Positiva/metabolismo , Procesamiento Proteico-Postraduccional , Ciclina T/metabolismo , Quinasa 9 Dependiente de la Ciclina/metabolismo , Histona Acetiltransferasas/metabolismo , ARN Polimerasa II/metabolismo , Factores de Transcripción/metabolismo , Transcripción Genética
16.
Dev Neurorehabil ; 13(2): 114-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20222772

RESUMEN

OBJECTIVE: The aim of the present study was to report on adverse events encountered with robotic-assisted treadmill therapy in children and adolescents with gait disorders. METHODS: Eighty-nine patients who underwent a trial of robotic assisted treadmill therapy in the two participating centres were analysed. Demographic data and safety data of the patients were analysed using descriptive statistics. RESULTS: In 38 (42.7%) out of 89 patients, adverse events were documented. Most commonly, mild skin erythema at the sites of the cuffs of the device and muscle pain were encountered. In five patients (5.6%), open skin lesions (n = 2), joint pain (n = 2) or tendinopathy (n = 1) limited the continuation of the therapy with the Lokomat. No severe side-effects emerged. CONCLUSIONS: Robotic assisted treadmill therapy is a safe method to enable longer periods of gait therapy in children and adolescents with gait disorders.


Asunto(s)
Eritema/etiología , Terapia por Ejercicio/efectos adversos , Trastornos Neurológicos de la Marcha/rehabilitación , Dolor/etiología , Robótica , Tendinopatía/etiología , Adolescente , Niño , Eritema/fisiopatología , Terapia por Ejercicio/métodos , Femenino , Trastornos Neurológicos de la Marcha/fisiopatología , Humanos , Articulaciones/fisiopatología , Masculino , Músculo Esquelético/fisiopatología , Dolor/fisiopatología , Robótica/instrumentación , Piel/fisiopatología , Tendinopatía/fisiopatología , Resultado del Tratamiento
17.
Cell Host Microbe ; 7(3): 234-44, 2010 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-20227666

RESUMEN

The Tat protein of HIV-1 plays an essential role in HIV gene expression by promoting efficient elongation of viral transcripts. Posttranslational modifications of Tat fine-tune interactions of Tat with cellular cofactors and TAR RNA, a stem-loop structure at the 5' ends of viral transcripts. Here, we identify the lysine methyltransferase Set7/9 (KMT7) as a coactivator of HIV transcription. Set7/9-KMT7 associates with the HIV promoter in vivo and monomethylates lysine 51, a highly conserved residue located in the RNA-binding domain of Tat. Knockdown of Set7/9-KMT7 suppresses Tat transactivation of the HIV promoter, but does not affect the transcriptional activity of methylation-deficient Tat (K51A). Set7/9-KMT7 binds TAR RNA by itself and in complex with Tat and the positive transcription elongation factor P-TEFb. Our findings uncover a positive role for Set7/9-KMT7 and Tat methylation during early steps of the Tat transactivation cycle.


Asunto(s)
Duplicado del Terminal Largo de VIH , VIH-1/fisiología , N-Metiltransferasa de Histona-Lisina/metabolismo , Interacciones Huésped-Patógeno , ARN Viral/metabolismo , Transcripción Genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo , Técnicas de Silenciamiento del Gen , Células HeLa , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Metilación , Factor B de Elongación Transcripcional Positiva/metabolismo , Unión Proteica , Procesamiento Proteico-Postraduccional
18.
Cancer ; 116(7): 1767-75, 2010 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-20143434

RESUMEN

BACKGROUND: : Ipilimumab is a monoclonal antibody that antagonizes cytotoxic T lymphocyte antigen-4, a negative regulator of the immune system. The authors report on advanced refractory melanoma patients treated in a compassionate use trial of ipilimumab at the Memorial Sloan-Kettering Cancer Center. METHODS: : Patients with advanced refractory melanoma were treated in a compassionate use trial with ipilimumab 10 mg/kg every 3 weeks for 4 doses. Those with evidence of clinical benefit at Week 24 (complete response [CR], partial response [PR], or stable disease [SD]) then received ipilimumab every 12 weeks. RESULTS: : A total of 53 patients were enrolled, with 51 evaluable. Grade 3/4 immune-related adverse events were noted in 29% of patients, with the most common immune-related adverse events being pruritus (43%), rash (37%), and diarrhea (33%). On the basis of immune-related response criteria, the response rate (CR + PR) was 12% (95% confidence interval [CI], 5%-25%), whereas 29% had SD (95% CI, 18%-44%). The median progression-free survival was 2.6 months (95% CI, 2.3-5.2 months), whereas the median overall survival (OS) was 7.2 months (95% CI, 4.0-13.3 months). Patients with an absolute lymphocyte count (ALC) > micro =1000/microL after 2 ipilimumab treatments (Week 7) had a significantly improved clinical benefit rate (51% vs 0%; P = .01) and median OS (11.9 vs 1.4 months; P < .001) compared with those with an ALC <1000/microL. CONCLUSIONS: : The results confirm that ipilimumab is clinically active in patients with advanced refractory melanoma. The ALC after 2 ipilimumab treatments appears to correlate with clinical benefit and OS, and should be prospectively validated. Cancer 2010. (c) 2010 American Cancer Society.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/efectos adversos , Biomarcadores de Tumor , Ensayos de Uso Compasivo , Femenino , Humanos , Ipilimumab , Recuento de Linfocitos , Masculino , Melanoma/mortalidad , Melanoma/patología , Persona de Mediana Edad , Retratamiento , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/patología
19.
EMBO J ; 28(10): 1407-17, 2009 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-19387490

RESUMEN

The elongation competence of the RNA polymerase II complex is critically dependent on the positive transcription elongation factor b (P-TEFb). P-TEFb exists in two forms in cells, an active form composed of cyclin T1 and CDK9 and an inactive form, in which cyclin T1/CDK9 is sequestered by Hexim1 and 7SK snRNA. Here, we report that partitioning of active and inactive P-TEFb is regulated by acetylation of cyclin T1. Cyclin T1 acetylation triggers dissociation of Hexim1 and 7SK snRNA from cyclin T1/CDK9 and activates the transcriptional activity of P-TEFb. This activation is lost in P-TEFb complexes containing cyclin T1 that can no longer be acetylated. An acetylation-deficient cyclin T1 mutant dominantly suppresses NF-kappaB-mediated activation of the interleukin-8 promoter but continues to synergize normally with the HIV Tat protein to transactivate the HIV long terminal repeat. These findings support the model that acetylation of cyclin T1 serves as a physiological switch that liberates P-TEFb from its endogenous inhibitors Hexim1 and 7SK snRNA, but is not required for the cooperative action with HIV Tat.


Asunto(s)
Ciclinas/metabolismo , Factor B de Elongación Transcripcional Positiva/metabolismo , Acetilación , Secuencia de Aminoácidos , Línea Celular , Ciclina T , Quinasa 9 Dependiente de la Ciclina/metabolismo , Ciclinas/genética , Humanos , Modelos Biológicos , Datos de Secuencia Molecular , Mutación , Unión Proteica , ARN Nuclear Pequeño/metabolismo , Proteínas de Unión al ARN/metabolismo , Factores de Transcripción , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo
20.
Exp Cell Res ; 306(1): 192-202, 2005 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-15878344

RESUMEN

Diaphanous-related formins (DRFs) are actin nucleators that mediate rearrangements of the actin cytoskeleton downstream of specific Rho GTPases. The DRF Formin Homology 2 Domain containing 1 (FHOD1) interacts with the Rac1 GTPase and induces the formation of and associates with bundled actin stress fibers. Here we report that active FHOD1 also coordinates microtubules with these actin stress fibers. Expression of a constitutive active FHOD1 variant in HeLa cells not only resulted in pronounced formation of FHOD1-actin fibers but also caused marked cell elongation and parallel alignment of microtubules without affecting cytokinesis of these cells. The analysis of deletions in the FH1 and FH2 functional regions revealed that the integrity of both domains was strictly required for FHOD1's effects on the cytoskeleton. Dominant-negative approaches demonstrated that filament coordination and cell elongation depended on the activity of the Rho-ROCK cascade, but did not involve Rac or Cdc42 activity. Experimental depolymerization of actin filaments or microtubules revealed that the formation of FHOD1-actin fibers was a prerequisite for the polarization of microtubules. However, only simultaneous disruption of both filament systems reversed the cell elongation induced by activated FHOD1. Thus, sustained cell elongation was a consequence of FHOD1-mediated actin-microtubule coordination. These results suggest filament coordination as a conserved function of mammalian DRFs.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Proteínas Fetales/fisiología , Microtúbulos/metabolismo , Proteínas Nucleares/fisiología , Citoesqueleto de Actina/efectos de los fármacos , Animales , Forma de la Célula/efectos de los fármacos , Citocalasina D/farmacología , Citocinesis/efectos de los fármacos , Proteínas Fetales/genética , Forminas , Células HeLa , Humanos , Ratones , Microtúbulos/efectos de los fármacos , Mutación , Células 3T3 NIH , Nocodazol/farmacología , Proteínas Nucleares/genética , Transducción de Señal/fisiología , Fibras de Estrés/efectos de los fármacos , Fibras de Estrés/metabolismo , Transfección , Proteínas de Unión al GTP rho/genética , Proteínas de Unión al GTP rho/fisiología
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