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1.
Development ; 149(4)2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35103284

RESUMEN

The contractile phenotype of smooth muscle cells (SMCs) is transcriptionally controlled by a complex of the DNA-binding protein SRF and the transcriptional co-activator MYOCD. The pathways that activate expression of Myocd and of SMC structural genes in mesenchymal progenitors are diverse, reflecting different intrinsic and extrinsic signaling inputs. Taking the ureter as a model, we analyzed whether Notch signaling, a pathway previously implicated in vascular SMC development, also affects visceral SMC differentiation. We show that mice with a conditional deletion of the unique Notch mediator RBPJ in the undifferentiated ureteric mesenchyme exhibit altered ureter peristalsis with a delayed onset, and decreased contraction frequency and intensity at fetal stages. They also develop hydroureter 2 weeks after birth. Notch signaling is required for precise temporal activation of Myocd expression and, independently, for expression of a group of late SMC structural genes. Based on additional expression analyses, we suggest that a mesenchymal JAG1-NOTCH2/NOTCH3 module regulates visceral SMC differentiation in the ureter in a biphasic and bimodal manner, and that its molecular function differs from that in the vascular system.


Asunto(s)
Diferenciación Celular , Miocitos del Músculo Liso/metabolismo , Transducción de Señal , Uréter/metabolismo , Actinas/genética , Actinas/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Diaminas/farmacología , Femenino , Regulación del Desarrollo de la Expresión Génica , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/deficiencia , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/genética , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/metabolismo , Proteína Jagged-1/genética , Proteína Jagged-1/metabolismo , Masculino , Ratones , Ratones Noqueados , Miocitos del Músculo Liso/citología , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Receptores Notch/metabolismo , Transducción de Señal/efectos de los fármacos , Tiazoles/farmacología , Transactivadores/genética , Transactivadores/metabolismo , Uréter/citología , Uréter/crecimiento & desarrollo , Vísceras/citología , Vísceras/metabolismo
2.
Anal Chem ; 96(16): 6255-6263, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38588398

RESUMEN

Molecular Rotational Resonance (MRR) spectroscopy is a uniquely precise tool for the determination of molecular structures of volatile compounds in mixtures, as the characteristic rotational transition frequencies of a molecule are extremely sensitive to its 3D structure through the moments of inertia in a three-dimensional coordinate system. This enables identification of the compounds based on just a few parameters that can be calculated, as opposed to, for example, mass spectrometric data, which often require expert analysis of 10-20 different signals and the use of many standards/model compounds. This paper introduces a new sampling technique for MRR, laser-induced acoustic desorption (LIAD), to allow the vaporization of nonvolatile and thermally labile analytes without the need for excessive heating or derivatization. In this proof-of-concept study, LIAD was successfully coupled to an MRR instrument to conduct measurements on seven compounds with differing polarities, molecular weights, and melting and boiling points. Identification of three isomers in a mixture was also successfully performed using LIAD/MRR. Based on these results, LIAD/MRR is demonstrated to provide a powerful approach for the identification of nonvolatile and/or thermally labile analytes with molecular weights up to 600 Da in simple mixtures, which does not require the use of reference compounds. In the future, applications to more complex mixtures, such as those relevant to pharmaceutical research, and quantitative aspects of LIAD/MRR will be reported.

3.
Hum Genomics ; 17(1): 69, 2023 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-37491351

RESUMEN

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Genome-wide association studies (GWAS) have identified many single nucleotide polymorphisms (SNPs) appearing in non-coding genomic regions in CVDs. The SNPs may alter gene expression by modifying transcription factor (TF) binding sites and lead to functional consequences in cardiovascular traits or diseases. To understand the underlying molecular mechanisms, it is crucial to identify which variations are involved and how they affect TF binding. METHODS: The SNEEP (SNP exploration and analysis using epigenomics data) pipeline was used to identify regulatory SNPs, which alter the binding behavior of TFs and link GWAS SNPs to their potential target genes for six CVDs. The human-induced pluripotent stem cells derived cardiomyocytes (hiPSC-CMs), monoculture cardiac organoids (MCOs) and self-organized cardiac organoids (SCOs) were used in the study. Gene expression, cardiomyocyte size and cardiac contractility were assessed. RESULTS: By using our integrative computational pipeline, we identified 1905 regulatory SNPs in CVD GWAS data. These were associated with hundreds of genes, half of them non-coding RNAs (ncRNAs), suggesting novel CVD genes. We experimentally tested 40 CVD-associated non-coding RNAs, among them RP11-98F14.11, RPL23AP92, IGBP1P1, and CTD-2383I20.1, which were upregulated in hiPSC-CMs, MCOs and SCOs under hypoxic conditions. Further experiments showed that IGBP1P1 depletion rescued expression of hypertrophic marker genes, reduced hypoxia-induced cardiomyocyte size and improved hypoxia-reduced cardiac contractility in hiPSC-CMs and MCOs. CONCLUSIONS: IGBP1P1 is a novel ncRNA with key regulatory functions in modulating cardiomyocyte size and cardiac function in our disease models. Our data suggest ncRNA IGBP1P1 as a potential therapeutic target to improve cardiac function in CVDs.


Asunto(s)
Enfermedades Cardiovasculares , Polimorfismo de Nucleótido Simple , Humanos , Polimorfismo de Nucleótido Simple/genética , Estudio de Asociación del Genoma Completo , Enfermedades Cardiovasculares/genética , Genómica , Genoma
4.
Analyst ; 149(9): 2573-2585, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38469706

RESUMEN

Gaseous fragment ions generated in mass spectrometers may be employed as "building blocks" for the synthesis of novel molecules on surfaces using ion soft-landing. A fundamental understanding of the reactivity of the fragment ions is required to control bond formation of deposited fragments in surface layers. The fragment ion [B12X11]- (X = halogen) is formed by collision-induced dissociation (CID) from the precursor [B12X12]2- dianion. [B12X11]- is highly reactive and ion soft-landing experiments have shown that this ion binds to the alkyl chains of organic molecules on surfaces. In this work we investigate whether specific modifications of the precursor ion affect the chemical properties of the fragment ions to such an extent that attachment to functional groups of organic molecules on surfaces occurs and binding of alkyl chains is prevented. Therefore, a halogen substituent was replaced by a thiocyanate substituent. CID of the precursor [B12I11(SCN)]2- ion preferentially yields the fragment ion [B12I8S(CN)]-, which shows significantly altered reactivity compared to the fragment ions of [B12I12]2-. [B12I8S(CN)]- has a previously unknown structural element, wherein a sulfur atom bridges three boron atoms. Gas-phase reactions with different neutral reactants (cyclohexane, dimethyl sulfide, and dimethyl amine) accompanied by theoretical studies indicate that [B12I8S(CN)]- binds with higher selectivity to functional groups of organic molecules than fragment ions of [B12I12]2- (e.g., [B12I11]- and [B12I9]-). These findings were further confirmed by ion soft-landing experiments, which showed that [B12I8S(CN)]- ions attacked ester groups of adipates and phthalates, whereas [B12I11]- ions only bound to alkyl chains of the same reagents.

5.
J Org Chem ; 88(13): 8865-8873, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37350755

RESUMEN

Aziridines are commonly used as reagents for the synthesis of drug substances although they are potentially mutagenic and genotoxic. Therefore, their unambiguous detection is critically important. Unfortunately, tandem mass spectrometry (MS2) based on collision-activated dissociation (CAD), a powerful method used for the identification of many unknown compounds in complex mixtures, does not provide diagnostic fragmentation patterns for ionized aziridines. Therefore, a different mass spectrometry approach based on MS3 experiments is presented here for the identification of the aziridine functionalities. This approach is based on selective gas-phase ion-molecule reactions of protonated analytes with tris(dimethylamino)borane (TDMAB) followed by diagnostic CAD reactions in a modified linear quadrupole ion trap (LQIT) mass spectrometer. TDMAB reacts with protonated aziridines by forming adduct ions that have lost a dimethylamine (DMA) molecule ([M + H + TDMAB - HN(CH3)2]+). CAD on these product ions generated diagnostic fragment ions with m/z-values 25- and 43-units lower than those of the ion-molecule reaction product ions. None of the ion-molecule reaction product ions formed from other, structurally related, protonated analytes produced related fragment ions. Quantum chemical calculations were employed to explore the mechanisms of the observed reactions.

6.
Pharm Res ; 39(11): 2817-2829, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36195824

RESUMEN

PURPOSE: The aim of current study is to formulate, optimize and characterize the developed formulation of Mesalamine-Curcumin Nanostructured Lipid Carriers (Mes-Cur NLCs). METHODS: It was formulated using high pressure homogenization followed by probe sonication and formulation variables were optimized using Central Composite Design. The particle size (PS), zeta potential (ZP), entrapment efficiency (EE), drug release, cytotoxicity on NIH 3T3 fibroblasts cells and HaCaT keratinocytes cells and efficacy on RAW264.7 cells for optimized formulation was determined. RESULTS: The PS, ZP and EE were found to be 85.26 nm, -23.7 ± 7.45 mV, 99.2 ± 2.62 % (Mes) and 84 ± 1.51 % (Cur), respectively. The good correlation between predicted and obtained value indicated suitability and reproducibility of experimental design. NLCs showed spherical shape as confirmed by TEM. In vitro drug release profile of prepared formulation showed that Mes exhibited 100 % release at 48 h, whereas Cur exhibited 82.23 ± 2.97% release at 120 h. Both the drugs exhibited sustained release upon incorporation into the NLCs. The absence of any significant cell death during MTT assay performed on NIH 3T3 fibroblasts cells and HaCaT keratinocytes cells indicated that NLCs' were safe for use. Furthermore, significant reduction in nitric oxide level during anti-inflammatory evaluation of formulation on RAW264.7 cells showed excellent potential for the formulation to treat inflammation. The formulation was found stable as no significant difference between the PS, ZP and EE of the fresh and aged NLCs was observed. CONCLUSION: The outcomes of study deciphered successful formulation of Mes-Cur NLCs.


Asunto(s)
Curcumina , Nanoestructuras , Curcumina/farmacología , Portadores de Fármacos , Mesalamina , Lípidos , Reproducibilidad de los Resultados , Tamaño de la Partícula
7.
CMAJ ; 193(47): E1798-E1806, 2021 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-34844937

RESUMEN

BACKGROUND: The COVID-19 pandemic has had a major impact on access to health care resources. Our objective was to estimate the impact of the COVID-19 pandemic on the incidence of childhood cancer in Canada. We also aimed to compare the proportion of patients who enrolled in clinical trials at diagnosis, presented with metastatic disease or had an early death during the first 9 months of the COVID-19 pandemic compared with previous years. METHODS: We conducted an observational study that included children younger than 15 years with a new diagnosis of cancer between March 2016 and November 2020 at 1 of 17 Canadian pediatric oncology centres. Our primary outcome was the monthly age-standardized incidence rates (ASIRs) of cancers. We evaluated level and trend changes using interventional autoregressive integrated moving average models. Secondary outcomes were the proportion of patients who were enrolled in a clinical trial, who had metastatic or advanced disease and who died within 30 days. We compared the baseline and pandemic periods using rate ratios (RRs) and 95% confidence intervals (CIs). RESULTS: Age-standardized incidence rates during COVID-19 quarters were 157.7, 164.6, and 148.0 per million, respectively, whereas quarterly baseline ASIRs ranged between 150.3 and 175.1 per million (incidence RR 0.93 [95% CI 0.78 to 1.12] to incidence RR 1.04 [95% CI 0.87 to 1.24]). We found no statistically significant level or slope changes between the projected and observed ASIRs for all new cancers (parameter estimate [ß], level 4.98, 95% CI -15.1 to 25.04, p = 0.25), or when stratified by cancer type or by geographic area. Clinical trial enrolment rate was stable or increased during the pandemic compared with baseline (RR 1.22 [95% CI 0.70 to 2.13] to RR 1.71 [95% CI 1.01 to 2.89]). There was no difference in the proportion of patients with metastatic disease (RR 0.84 [95% CI 0.55 to 1.29] to RR 1.22 [0.84 to 1.79]), or who died within 30 days (RR 0.16 [95% CI 0.01 to 3.04] to RR 1.73 [95% CI 0.38 to 15.2]). INTERPRETATION: We did not observe a statistically significant change in the incidence of childhood cancer, or in the proportion of children enrolling in a clinical trial, presenting with metastatic disease or who died early during the first 9 months of the COVID-19 pandemic, which suggests that access to health care in pediatric oncology was not reduced substantially in Canada.


Asunto(s)
COVID-19/epidemiología , Neoplasias/epidemiología , Pandemias , Adolescente , Canadá/epidemiología , Niño , Preescolar , Ensayos Clínicos como Asunto/estadística & datos numéricos , Femenino , Humanos , Incidencia , Lactante , Masculino , Neoplasias/mortalidad , Estudios Retrospectivos , SARS-CoV-2 , Factores de Tiempo
8.
Am J Emerg Med ; 50: 553-560, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34547697

RESUMEN

OBJECTIVES: Suicide rates in the United States rose 35.2% from 1999-2018. As emergency department (ED) providers often have limited training in management of suicidal patients and minimal access to mental health experts, clinical practice guidelines (CPGs) may improve care for these patients. However, clinical practice guidelines that do not adhere to quality standards for development may be harmful both to patients, if they promote practices based on flawed evidence, and to ED providers, if used in malpractice claims. In 2011, the Institute of Medicine created standards to determine the trustworthiness of CPGs. This review assessed the adherence of suicide prevention CPGs, intended for the ED, to these standards. Secondary objectives were to assess the association of adherence both with first author/organization specialty (ED vs non-ED) and with inclusion of recommendations on substance use, a potent risk factor for suicide. METHODS: This is a systematic review of available suicide-prevention CPGs for the ED in both peer-reviewed and gray literature. This review followed the PRISMA standards for reporting systematic reviews. RESULTS: Of 22 included CPGs, the 7 ED-sponsored CPGs had higher adherence to quality standards (3.1 vs 2.4) and included the highest-rated CPG (ICAR2E) identified by this review. Regardless of specialty, nearly all CPGs included some mention of identifying or managing substance use. CONCLUSIONS: Most suicide prevention CPGs intended for the ED are written by non-ED first authors or organizations and have low adherence to quality standards. Future CPGs should be developed with more scientific rigor, include a multidisciplinary writing group, and be created by authors working in the practice environment to which the CPG applies.


Asunto(s)
Servicio de Urgencia en Hospital , Adhesión a Directriz , Prevención del Suicidio , Humanos , Guías de Práctica Clínica como Asunto
9.
Bioorg Chem ; 100: 103867, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32353564

RESUMEN

Diabetes is a ubiquitously a metabolic disorder and life-threatening disease. Peroxisome proliferator-activated receptors (PPARs) belong to the class of nuclear receptors which acts as transcription factors to regulate lipid and glucose metabolism. PPAR alpha/gamma dual agonists tend to corroborate the functions of both thiazolidinediones and fibrates and they hold substantial promise for ameliorating the type 2 diabetic treatments and providing potential therapeutic diabetic interventions. New 1,2,4-oxadiazole based trans- acrylic acid derivatives compounds possessing aryl/methylene linker in between pharmacophore head and lipophilic tail for dual PPAR-alpha/gamma agonists are studied. AutoDock Vina used for potential PPAR alpha/gamma dual agonists and 6 compounds 9a, 9g, 9 m, 9n, 9o, and 9r were identified comparable to PPAR gamma agonist Pioglitazone on the basis of their affinity scores and further their in-silico toxicity and in-silico ADME properties. The selected compounds showed better-calculated lipophilicity (iLogP) was found to be 0.92 to 3.19. Compound 9n and 9a were found to be most potent on both PPAR alpha and gamma receptors with EC50 of 0.07 ± 0.0006 µM, 0.06 ± 0.0005 µM and 0.781 ± 0.008 µM, 3.29 µM ± 0.03 respectively as better to pioglitazone having EC50 of 32.38 ± 0.2 and 38.03 ± 0.13 for both receptors. The in-vivo evaluation found to reduce the plasma glucose level and total cholesterol level significantly in diabetic rats compared to pioglitazone at 5 mg/kg/day dose for 7 days of treatment. Thus, trans- acrylic acid derivatives can be further developed as oral therapeutic agents for diabetic interventions as PPAR alpha/gamma dual agonists.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Oxadiazoles/química , Oxadiazoles/farmacología , PPAR alfa/agonistas , PPAR gamma/agonistas , Animales , Glucemia/análisis , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/metabolismo , Diseño de Fármacos , Femenino , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Simulación del Acoplamiento Molecular , Oxadiazoles/uso terapéutico , PPAR alfa/metabolismo , PPAR gamma/metabolismo , Ratas Sprague-Dawley
10.
AAPS PharmSciTech ; 21(3): 95, 2020 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-32096106

RESUMEN

Taking the articular and periarticular structures as a litmus test for gold-based nanoformulations, the potential of gold nanoparticles in protecting the normal physiological functions of these structures particularly in geriatric patients is one of the research areas of current interest. Aside from its use to make the traditional and fashionable ornaments for human usage, the gold metal is also known for its rich therapeutic activity. This is especially true when the gold is converted from its bulk form into nanosized form before its administering into the human body. Since it is the age of nanocomponents in medical and pharmaceutical research areas, this review is therefore mainly focused on nanoparticulate systems consisting of aurum. Accumulating research reports nevertheless show concrete evidence indicating the potential of gold-based nanoformulations to manage joint syndromes such as osteoarthritis and rheumatoid arthritis. This review embarks from preparation techniques and characterization methods to therapeutical application potentials of gold-based nanoformulations.


Asunto(s)
Cartílago Articular/efectos de los fármacos , Oro/administración & dosificación , Oro/química , Cápsula Articular/efectos de los fármacos , Nanopartículas del Metal/administración & dosificación , Nanopartículas del Metal/química , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Antiinflamatorios/farmacocinética , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Cartílago Articular/metabolismo , Composición de Medicamentos/métodos , Oro/farmacocinética , Humanos , Cápsula Articular/metabolismo
12.
Nucleic Acids Res ; 40(12): e88, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22422844

RESUMEN

We present a flexible, real-time-coupled transcription-translation assay that involves the continuous monitoring of fluorescent Emerald GFP formation. Along with numerical simulation of a reaction kinetics model, the assay permits quantitative estimation of the effects on full-length protein synthesis of various additions, subtractions or substitutions to the protein synthesis machinery. Since the assay uses continuous fluorescence monitoring, it is much simpler and more rapid than other assays of protein synthesis and is compatible with high-throughput formats. Straightforward alterations of the assay permit determination of (i) the fraction of ribosomes in a cell-free protein synthesis kit that is active in full-length protein synthesis and (ii) the relative activities in supporting protein synthesis of modified (e.g. mutated, fluorescent-labeled) exogenous components (ribosomes, amino acid-specific tRNAs) that replace the corresponding endogenous components. Ribosomes containing fluorescent-labeled L11 and tRNAs labeled with fluorophores in the D-loop retain substantial activity. In the latter case, the extent of activity loss correlates with a combination of steric bulk and hydrophobicity of the fluorophore.


Asunto(s)
Fluorometría/métodos , Biosíntesis de Proteínas , Sistema Libre de Células , Proteínas Fluorescentes Verdes/biosíntesis , Sustancias Luminiscentes/análisis , Fenilalanina/metabolismo , Aminoacil-ARN de Transferencia/metabolismo , ARN de Transferencia de Fenilalanina/metabolismo , Ribosomas/metabolismo , Transcripción Genética
13.
Proc Natl Acad Sci U S A ; 108(41): 16980-5, 2011 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-21969541

RESUMEN

During protein synthesis, deacylated transfer RNAs leave the ribosome via an exit (E) site after mRNA translocation. How the ribosome regulates tRNA dissociation and whether functional linkages between the aminoacyl (A) and E sites modulate the dynamics of protein synthesis have long been debated. Using single molecule fluorescence resonance energy transfer experiments, we find that, during early cycles of protein elongation, tRNAs are often held in the E site until being allosterically released when the next aminoacyl tRNA binds to the A site. This process is regulated by the length and sequence of the nascent peptide and by the conformational state, detected by tRNA proximity, prior to translocation. In later cycles, E-site tRNA dissociates spontaneously. Our results suggest that the distribution of pretranslocation tRNA states and posttranslocation pathways are correlated within each elongation cycle via communication between distant subdomains in the ribosome, but that this correlation between elongation cycle intermediates does not persist into succeeding cycles.


Asunto(s)
Biosíntesis de Proteínas/fisiología , ARN de Transferencia/metabolismo , Sitio Alostérico , Secuencia de Aminoácidos , Secuencia de Bases , Transporte Biológico Activo , Fenómenos Biofísicos , Transferencia Resonante de Energía de Fluorescencia , Cinética , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Extensión de la Cadena Peptídica de Translación/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN de Transferencia/química , Ribosomas/metabolismo
14.
Proc Natl Acad Sci U S A ; 108(39): 16223-8, 2011 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-21930951

RESUMEN

EF4 (LepA), a strongly conserved protein, is important for bacterial growth and functional protein biosynthesis under certain conditions and is quite similar structurally to the translocase EF-G. The elongation cycle in protein synthesis is characterized by ribosome oscillation between pretranslocation (PRE) and posttranslocation (POST) complexes. Here, using ensemble single turnover and equilibrium experiments, as well as single molecule FRET measurements, we demonstrate that EF4 can compete with EF-G for binding to the PRE complex. Such EF4 binding results in formation of a complex, denoted X(3), that effectively sequesters a catalytically active ribosome, leading to a transient inhibition of elongation that provides a mechanism for optimization of functional protein synthesis. Earlier [Liu H, et al. (2010) J Mol Biol 396:1043-1052] we demonstrated that EF4 also reacts with POST complex, leading to the formation of a complex, I(3), that appears to be identical with X(3). Our present results strongly suggest that PRE complex is the principal target of EF4 action on translation, rather than POST complex as had been previously supposed.


Asunto(s)
Proteínas de Escherichia coli/fisiología , Biosíntesis de Proteínas/fisiología , Factores de Elongación Transcripcional/fisiología , Proteínas de Escherichia coli/biosíntesis , Proteínas de Escherichia coli/metabolismo , Fluorescencia , Cinética , Magnesio/metabolismo , Factor G de Elongación Peptídica/metabolismo , Factores de Iniciación de Péptidos , Factores de Elongación Transcripcional/metabolismo
15.
Front Oncol ; 14: 1376652, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38606094

RESUMEN

Introduction: From the advancement of treatment of pediatric cancer diagnosis, the five-year survival rate has increased significantly. However, the adverse consequence of improved survival rate is the second malignant neoplasm. Although previous studies provided information on the incidence and risk of SMN in long term survivors of childhood cancer, there is still scarce information known for short term (< 5 years) prognosis. This study aims to assess the incidence, characteristics, management, and outcome of children who develop SMN malignancies within 5 years of diagnosis of their initial cancer. Method: This is a retrospective cohort study of early Second Malignant Neoplasms (SMN) in pediatric oncology patients. The Cancer in Young People - Canada (CYP-C) national pediatric cancer registry was used and reviewed pediatric patients diagnosed with their first cancer from 2000-2015. Results: A total of 20,272 pediatric patients with a diagnosis of a first malignancy were analyzed. Of them, 0.7% were diagnosed with a SMN within the first 5 years following their first cancer diagnosis. Development of a SMN impacted survival, shown by an inferior survival rate in the SMN cohort (79.1%) after three years compared to that of the non-SMN cohort (89.7%). Several possible risk factors have been identified in the study including the use of epipodophyllotoxins, exposure to radiation, and hematopoietic stem cell 169 transplant. Discussion: This is the first national study assessing the incidence, 170 characteristics, risk factors and outcome of early SMN in Canadian children 171 from age 0-15 from 2000-2015.

17.
J Am Chem Soc ; 135(30): 11322-9, 2013 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-23822614

RESUMEN

Pauses regulate the rhythm of ribosomal protein synthesis. Mutations disrupting even minor pauses can give rise to improperly formed proteins and human disease. Such minor pauses are difficult to characterize by ensemble methods, but can be readily examined by single-molecule (sm) approaches. Here we use smFRET to carry out real-time monitoring of the expression of a full-length protein, the green fluorescent protein variant Emerald GFP. We demonstrate significant correlations between measured elongation rates and codon and isoacceptor tRNA usage, and provide a quantitative estimate of the effect on elongation rate of replacing a codon recognizing an abundant tRNA with a synonymous codon cognate to a rarer tRNA. Our results suggest that tRNA selection plays an important general role in modulating the rates and rhythms of protein synthesis, potentially influencing simultaneous co-translational processes such as folding and chemical modification.


Asunto(s)
Transferencia Resonante de Energía de Fluorescencia , Extensión de la Cadena Peptídica de Translación , Secuencia de Aminoácidos , Codón/genética , Proteínas Fluorescentes Verdes/química , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Fragmentos de Péptidos/biosíntesis , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Conformación Proteica , ARN de Transferencia/genética , Ribosomas/genética , Ribosomas/metabolismo
18.
RNA ; 17(7): 1393-400, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21628433

RESUMEN

Dihydrouridine (DHU) positions within tRNAs have long been used as sites to covalently attach fluorophores, by virtue of their unique chemical reactivity toward reduction by NaBH(4), their abundance within prokaryotic and eukaryotic tRNAs, and the biochemical functionality of the labeled tRNAs so produced. Interpretation of experiments employing labeled tRNAs can depend on knowing the distribution of dye among the DHU positions present in a labeled tRNA. Here we combine matrix-assisted laser desorption/ionization mass spectroscopy (MALDI-MS) analysis of oligonucleotide fragments and thin layer chromatography to resolve and quantify sites of DHU labeling by the fluorophores Cy3, Cy5, and proflavin in Escherichia coli tRNA(Phe) and E. coli tRNA(Arg). The MALDI-MS results led us to re-examine the precise chemistry of the reactions that result in fluorophore introduction into tRNA. We demonstrate that, in contrast to an earlier suggestion that has long been unchallenged in the literature, such introduction proceeds via a substitution reaction on tetrahydrouridine, the product of NaBH(4) reduction of DHU, resulting in formation of substituted tetrahydrocytidines within tRNA.


Asunto(s)
Colorantes Fluorescentes/farmacocinética , ARN de Transferencia/química , ARN de Transferencia/metabolismo , Coloración y Etiquetado/métodos , Uridina/metabolismo , Citidina/química , Citidina/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Colorantes Fluorescentes/química , Colorantes Fluorescentes/farmacología , Modelos Biológicos , Organismos Modificados Genéticamente , Ribonucleasas/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Distribución Tisular , Uridina/análogos & derivados , Uridina/química
19.
Nucleic Acids Res ; 39(19): e129, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21795382

RESUMEN

We have developed a novel technique of using fluorescent tRNA for translation monitoring (FtTM). FtTM enables the identification and monitoring of active protein synthesis sites within live cells at submicron resolution through quantitative microscopy of transfected bulk uncharged tRNA, fluorescently labeled in the D-loop (fl-tRNA). The localization of fl-tRNA to active translation sites was confirmed through its co-localization with cellular factors and its dynamic alterations upon inhibition of protein synthesis. Moreover, fluorescence resonance energy transfer (FRET) signals, generated when fl-tRNAs, separately labeled as a FRET pair occupy adjacent sites on the ribosome, quantitatively reflect levels of protein synthesis in defined cellular regions. In addition, FRET signals enable detection of intra-populational variability in protein synthesis activity. We demonstrate that FtTM allows quantitative comparison of protein synthesis between different cell types, monitoring effects of antibiotics and stress agents, and characterization of changes in spatial compartmentalization of protein synthesis upon viral infection.


Asunto(s)
Colorantes Fluorescentes , Microscopía Fluorescente , Biosíntesis de Proteínas , ARN de Transferencia , Análisis de la Célula Individual , Animales , Astrocitos/metabolismo , Células CHO , Cricetinae , Cricetulus , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes/análisis , Ratones , Ratones Endogámicos C57BL , ARN de Transferencia/análisis , Proteínas Virales/biosíntesis
20.
Curr Radiopharm ; 2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38031270

RESUMEN

BACKGROUND: Ovarian disease constitutes various types of endocrine disorders, such as polycystic ovarian syndrome (PCOS), ovarian cancer, premature ovarian failure, ovarian endometriosis, and ovarian cysts. The prevalence of ovarian-related diseases is highly vulnerable in the world. The utility of various drug delivery systems for ovarian diseases has resulted in varied success. Moreover, most of them lead to severe adverse effects and are incapable of ameliorating the signs and symptoms of the condition. HYPOTHESIS: Intrauterine devices (IUDs) have positioned themselves as a mechanism to deliver the drug for various ovarian-related diseases. Thereby avoiding various stability-related issues arising due to various physiological barriers of the female reproductive tract. However, the use of intrauterine devices for drug delivery to the ovaries has not been fully explored. This is attributed to the fact that they cause cysts in the ovaries and skepticism among patients and physicians. Photo-sensitive devices are an appealing approach for managing disorders affecting the ovaries. Photo-sensitive in situ forming intrauterine implants (IUIs) have several advantages, including simplicity in application, reduced invasiveness, as well as improved site-specific drug release control. Polymeric nanoparticles (PNPs) loaded with a drug may be a suitable choice to provide sustained release, alter the pharmacokinetics, and reduce the dose and dosing frequency. CONCLUSION: The current manuscript hypothesizes the utility of a PNP-loaded biodegradable photo-responsive intrauterine implantable device as an alternate novel strategy for ameliorating ovarian-related diseases.

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