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1.
Clin Transl Sci ; 17(8): e13885, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39090829

RESUMO

Prior research highlights that rural populations have been historically underrepresented/excluded from clinical research. The primary objective of this study was to describe the inclusion of rural populations within our research enterprise using Clinical Research Management System demographic information at a large academic medical center in the Southeast. This was a cross-sectional study using participant demographic information for all protocols entered into our Clinical Research Management System between May 2018 and March 2021. Descriptive statistics were used to analyze the representation of rural and non-rural participants and demographic breakdown by age, sex, race, and ethnicity for our entire enterprise and at the state level. We also compared Material Community Deprivation Index levels between urban and rural participants. Results indicated that 19% of the research population was classified as rural and 81% as non-rural for our entire sample, and 17.5% rural and 82.5% urban for our state-level sample. There were significant differences in race, sex, and age between rural and non-rural participants and Material Community Deprivation Indices between rural and non-rural participants. Lessons learned and recommendations for increasing the inclusion of rural populations in research are discussed.


Assuntos
Equidade em Saúde , População Rural , Humanos , População Rural/estatística & dados numéricos , Masculino , Estudos Transversais , Feminino , Pessoa de Meia-Idade , Adulto , Seleção de Pacientes , Idoso , Pesquisa Biomédica/estatística & dados numéricos , Adulto Jovem , População Urbana/estatística & dados numéricos , Centros Médicos Acadêmicos/estatística & dados numéricos , Centros Médicos Acadêmicos/organização & administração
2.
Pediatr Blood Cancer ; 71(7): e31017, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38706206

RESUMO

BACKGROUND: National sickle cell disease (SCD) guidelines recommend oral hydroxyurea (HU) starting at 9 months of age, and annual transcranial Doppler (TCD) screenings to identify stroke risk in children aged 2-16 years. We examined prevalence and proportion of TCD screenings in North Carolina Medicaid enrollees to identify associations with sociodemographic factors and HU adherence over 3 years. STUDY DESIGN: We conducted a longitudinal study with children ages 2-16 years with SCD enrolled in NC Medicaid from years 2016-2019. Prevalence of TCD screening claims was calculated for 3 years, and proportion was calculated for 12, 24, and 36 months of Medicaid enrollment. Enrollee HU adherence was categorized using HU proportion of days covered. Multivariable Poisson regression assessed for TCD screening rates by HU adherence, controlling for age, sex, and rurality. RESULTS: The prevalence of annual TCD screening was between 39.5% and 40.1%. Of those with 12-month enrollment, 77.8% had no TCD claims, compared to 22.2% who had one or higher TCD claims. Inversely, in children with 36 months of enrollment, 36.7% had no TCD claims compared to 63.3% who had one or higher TCD claims. The proportion of children with two or higher TCD claims increased with longer enrollment (10.5% at 12 months, 33.7% at 24 months, and 52.6% at 36 months). Children with good HU adherence were 2.48 (p < .0001) times more likely to have TCD claims than children with poor HU adherence. CONCLUSION: While overall TCD screening prevalence was low, children with better HU adherence and longer Medicaid enrollment had more TCD screenings. Multilevel interventions are needed to engage healthcare providers and families to improve both evidence-based care and annual TCD screenings in children with SCD.


Assuntos
Anemia Falciforme , Antidrepanocíticos , Hidroxiureia , Ultrassonografia Doppler Transcraniana , Humanos , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/epidemiologia , Anemia Falciforme/diagnóstico por imagem , Criança , Hidroxiureia/uso terapêutico , Feminino , Masculino , Adolescente , Pré-Escolar , Estudos Longitudinais , Antidrepanocíticos/uso terapêutico , Medicaid/estatística & dados numéricos , Adesão à Medicação/estatística & dados numéricos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Estados Unidos/epidemiologia , Seguimentos , North Carolina/epidemiologia , Prognóstico
3.
J Clin Transl Sci ; 8(1): e40, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476242

RESUMO

Empowering the Participant Voice (EPV) is an NCATS-funded six-CTSA collaboration to develop, demonstrate, and disseminate a low-cost infrastructure for collecting timely feedback from research participants, fostering trust, and providing data for improving clinical translational research. EPV leverages the validated Research Participant Perception Survey (RPPS) and the popular REDCap electronic data-capture platform. This report describes the development of infrastructure designed to overcome identified institutional barriers to routinely collecting participant feedback using RPPS and demonstration use cases. Sites engaged local stakeholders iteratively, incorporating feedback about anticipated value and potential concerns into project design. The team defined common standards and operations, developed software, and produced a detailed planning and implementation Guide. By May 2023, 2,575 participants diverse in age, race, ethnicity, and sex had responded to approximately 13,850 survey invitations (18.6%); 29% of responses included free-text comments. EPV infrastructure enabled sites to routinely access local and multi-site research participant experience data on an interactive analytics dashboard. The EPV learning collaborative continues to test initiatives to improve survey reach and optimize infrastructure and process. Broad uptake of EPV will expand the evidence base, enable hypothesis generation, and drive research-on-research locally and nationally to enhance the clinical research enterprise.

4.
Biomolecules ; 14(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38397413

RESUMO

Central to the development and survival of all organisms is the regulation of gene expression, which begins with the process of transcription catalyzed by RNA polymerases. During transcription of protein-coding genes, the general transcription factors (GTFs) work alongside RNA polymerase II (Pol II) to assemble the preinitiation complex at the transcription start site, open the promoter DNA, initiate synthesis of the nascent messenger RNA, transition to productive elongation, and ultimately terminate transcription. Through these different stages of transcription, Pol II is dynamically phosphorylated at the C-terminal tail of its largest subunit, serving as a control mechanism for Pol II elongation and a signaling/binding platform for co-transcriptional factors. The large number of core protein factors participating in the fundamental steps of transcription add dense layers of regulation that contribute to the complexity of temporal and spatial control of gene expression within any given cell type. The Pol II transcription system is highly conserved across different levels of eukaryotes; however, most of the information here will focus on the human Pol II system. This review walks through various stages of transcription, from preinitiation complex assembly to termination, highlighting the functions and mechanisms of the core machinery that participates in each stage.


Assuntos
RNA Polimerase II , Transcrição Gênica , Humanos , RNA Polimerase II/química , Fatores de Transcrição/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro
5.
PLoS One ; 18(8): e0286193, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37582100

RESUMO

The transcriptional activator p53 is a tumor suppressor protein that controls cellular pathways important for cell fate decisions, including cell cycle arrest, senescence, and apoptosis. It functions as a tetramer by binding to specific DNA sequences known as response elements (REs) to control transcription via interactions with co-regulatory complexes. Despite its biological importance, the mechanism by which p53 binds REs remains unclear. To address this, we have used an in vitro single molecule fluorescence approach to quantify the dynamic binding of full-length human p53 to five native REs in real time under equilibrium conditions. Our approach enabled us to quantify the oligomeric state of DNA-bound p53. We found little evidence that dimer/DNA complexes form as intermediates en route to binding or dissociation of p53 tetramer/DNA complexes. Interestingly, however, at some REs dimers can rapidly exchange from tetramer/DNA complexes. Real time kinetic measurements enabled us to determine rate constants for association and dissociation at all five REs, which revealed two kinetically distinct populations of tetrameric p53/RE complexes. For the less stable population, the rate constants for dissociation were larger at REs closest to consensus, showing that the more favorable binding sequences form the least kinetically stable complexes. Together our single molecule measurements provide new insight into mechanisms by which tetrameric p53 forms complexes on different native REs.


Assuntos
Proteína Supressora de Tumor p53 , Proteínas Supressoras de Tumor , Humanos , Proteína Supressora de Tumor p53/genética , Ligação Proteica , Proteínas Supressoras de Tumor/genética , Elementos de Resposta , DNA/metabolismo
6.
FEBS Open Bio ; 13(10): 1941-1952, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37572351

RESUMO

Breast cancer is a leading cause of cancer-related deaths in women. Many genetic and behavioral risk factors can contribute to the initiation and progression of breast cancer, one being alcohol consumption. Numerous epidemiological studies have established a positive correlation between alcohol consumption and breast cancer; however, the molecular basis for this link remains ill defined. Elucidating ethanol-induced changes to global transcriptional programming in breast cells is important to ultimately understand how alcohol and breast cancer are connected mechanistically. We investigated induced transcriptional changes in response to a short cellular exposure to moderate levels of alcohol. We treated the nontumorigenic breast cell line MCF10A and the tumorigenic breast cell lines MDA-MB-231 and MCF7, with ethanol for 6 h, and then captured the changes to ongoing transcription using 4-thiouridine metabolic labeling followed by deep sequencing. Only the MCF10A cell line exhibited statistically significant changes in newly transcribed RNA in response to ethanol treatment. Further experiments revealed that some ethanol-upregulated genes are sensitive to the dose of alcohol treatment, while others are not. Gene Ontology and biochemical pathway analyses revealed that ethanol-upregulated genes in MCF10A cells are enriched in biological functions that could contribute to cancer development.


Assuntos
Neoplasias da Mama , Etanol , Feminino , Humanos , Etanol/efeitos adversos , Mama , Neoplasias da Mama/metabolismo , Linhagem Celular
7.
Proc Natl Acad Sci U S A ; 120(26): e2220537120, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37339225

RESUMO

We previously demonstrated that the polycomb repressive complex 2 chromatin-modifying enzyme can directly transfer between RNA and DNA without a free-enzyme intermediate state. Simulations suggested that such a direct transfer mechanism may be generally necessary for RNA to recruit proteins to chromatin, but the prevalence of direct transfer capability is unknown. Herein, we used fluorescence polarization assays and observed direct transfer for several well-characterized nucleic acid-binding proteins: three-prime repair exonuclease 1, heterogeneous nuclear ribonucleoprotein U, Fem-3-binding factor 2, and MS2 bacteriophage coat protein. For TREX1, the direct transfer mechanism was additionally observed in single-molecule assays, and the data suggest that direct transfer occurs through an unstable ternary intermediate with partially associated polynucleotides. Generally, direct transfer could allow many DNA- and RNA-binding proteins to conduct a one-dimensional search for their target sites. Furthermore, proteins that bind both RNA and DNA might be capable of readily translocating between those ligands.


Assuntos
Proteínas de Ligação a DNA , Polinucleotídeos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , RNA/genética , Proteínas de Ligação a RNA/genética , DNA/metabolismo , Cromatina
8.
Microorganisms ; 10(2)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35208810

RESUMO

Legionella pneumophila (Lp) is an opportunistic pathogen that causes respiratory infections primarily through inhalation of contaminated aerosols. Lp can colonize premise plumbing systems due to favorable growth conditions (e.g., lower disinfectant residual, stagnation, warm temperatures). UV-C light-emitting diodes (UV-C LEDs) are an emerging water treatment technology and have been shown to effectively inactivate waterborne pathogens. In this study, the inactivation of four Lp strains (three clinical sg1, 4, and 6; and one sg1 drinking water (DW) isolate) was evaluated using a UV-C LED collimated beam at three wavelengths (255, 265, and 280 nm) and six fluence rates (0.5-34 mJ/cm2). Exposure to 255 nm resulted in higher log reductions at the lower fluences compared to exposures at 265 and 280 nm. Efficacy testing was also performed using a UV-C LED point-of-entry (POE) flow-through device. Based on the log inactivation curves, at 255 nm, the sg4 and sg6 clinical isolates were more susceptible to inactivation compared to the two sg1 isolates. However, at 265 and 280 nm, the sg1 and sg4 clinical isolates were more resistant to inactivation compared to the sg6 clinical and sg1 DW isolates. Differential log reductions were also observed using the POE device. Results indicate that although UV-C LED disinfection is effective, variations in Lp inactivation, wavelengths, and technology applications should be considered, especially when targeting specific isolates within premise plumbing systems.

9.
J Craniomaxillofac Surg ; 50(2): 134-139, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34580005

RESUMO

This study aimed to identify factors that predict complications following cranioplasty, by conducting a retrospective cohort study at a large tertiary care center. Electronic databases were searched to identify all patients who underwent cranioplasty at our institution. Baseline demographics, perioperative variables, and outcomes were extracted. Logistic regression analyses were conducted to identify factors associated with cranioplasty complications. Of the 92 included patients, 15 (16.3%) experienced one or more complications, with 11 (73.3%) experiencing complication within 30 days of cranioplasty. Patients aged ≤60 had decreased odds of all-cause complication (OR 0.058; 95% CI 0.008-0.434) and cranioplasty graft removal (OR 0.035; 95% CI 0.004-0.321) on multivariate analysis. Titanium mesh cranioplasties were associated with increased odds of all-cause complication (OR 19.776; 95% CI 1.021-382.901), and cranioplasty removal (OR 29.780; 95% CI 1.330-666.878). A longer craniectomy-cranioplasty interval was associated with increased odds of cranioplasty removal (OR 1.005; 95% CI 1.000-1.010). An initial craniectomy indication of cerebral infarction was associated with decreased odds of all-cause complication (OR 0.042; 95% CI 0.002-0.876) and cranioplasty removal (OR 0.032; 95% CI 0.001-0.766). Elderly patients may require more aggressive follow-up and antibiotic prophylaxis in the postoperative period following cranioplasty. Additionally, avoiding the use of titanium mesh cranioplasties and prolonged craniectomy-cranioplasty intervals may further reduce complications.


Assuntos
Craniectomia Descompressiva , Implantes Dentários , Procedimentos de Cirurgia Plástica , Idoso , Craniectomia Descompressiva/efeitos adversos , Humanos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Procedimentos de Cirurgia Plástica/efeitos adversos , Estudos Retrospectivos , Crânio/cirurgia
10.
Biomolecules ; 11(10)2021 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-34680084

RESUMO

High Mobility Group Box (HMGB) proteins are small architectural DNA binding proteins that regulate multiple genomic processes such as DNA damage repair, nucleosome sliding, telomere homeostasis, and transcription. In doing so they control both normal cellular functions and impact a myriad of disease states, including cancers and autoimmune diseases. HMGB proteins bind to DNA and nucleosomes to modulate the local chromatin environment, which facilitates the binding of regulatory protein factors to the genome and modulates higher order chromosomal organization. Numerous studies over the years have characterized the structure and function of interactions between HMGB proteins and DNA, both biochemically and inside cells, providing valuable mechanistic insight as well as evidence these interactions influence pathological processes. This review highlights recent studies supporting the roles of HMGB1 and HMGB2 in global organization of the genome, as well as roles in transcriptional regulation and telomere maintenance via interactions with G-quadruplex structures. Moreover, emerging models for how HMGB proteins function as RNA binding proteins are presented. Nuclear HMGB proteins have broad regulatory potential to impact numerous aspects of cellular metabolism in normal and disease states.


Assuntos
Proteínas HMGB/genética , Proteína HMGB1/genética , Proteína HMGB2/genética , Transcrição Gênica , Cromatina/genética , Proteínas de Ligação a DNA/genética , Genoma Humano/genética , Homeostase , Humanos , Nucleossomos/genética
11.
Mol Cell Biol ; 41(10): e0017121, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34251885

RESUMO

Infection by herpes simplex virus 1 (HSV-1) impacts nearly all steps of host cell gene expression. The regulatory mechanisms by which this occurs, and the interplay between host and viral factors, have yet to be fully elucidated. We investigated how the occupancy of RNA polymerase II (Pol II) on the host genome changes during HSV-1 infection and is impacted by the viral immediate early protein ICP4. Pol II ChIP-seq experiments revealed ICP4-dependent decreases and increases in Pol II levels across the bodies of hundreds of genes. Our data suggest ICP4 represses host transcription by inhibiting recruitment of Pol II and activates host genes by promoting release of Pol II from promoter proximal pausing into productive elongation. Consistent with this, ICP4 was required for the decrease in levels of the pausing factor NELF-A on several HSV-1-activated genes after infection. In the absence of infection, exogenous expression of ICP4 activated, but did not repress, transcription of some genes in a chromatin-dependent context. Our data support the model that ICP4 decreases promoter proximal pausing on host genes activated by infection and that ICP4 is necessary, but not sufficient, to repress transcription of host genes during viral infection.


Assuntos
Herpes Simples/genética , Herpesvirus Humano 1/genética , Proteínas Imediatamente Precoces/genética , Células HEK293 , Herpes Simples/metabolismo , Herpes Simples/virologia , Herpesvirus Humano 1/metabolismo , Herpesvirus Humano 1/patogenicidade , Humanos , Proteínas Imediatamente Precoces/metabolismo , Regiões Promotoras Genéticas/genética , RNA Polimerase II/metabolismo , Transcrição Gênica/genética
12.
J Environ Manage ; 280: 111838, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33360257

RESUMO

This paper presents a Stormwater Emergency Response Framework (SERF) for use in the containment and treatment of stormwater runoff following a hazardous material release. The framework consists of four high level process steps and a decision tree. These resources are intended to assist stormwater managers in fulfilling their emergency response responsibilities within the United States' National Incident Management System. Robust hydraulic and watershed modeling may take weeks to months to develop for a contaminated site, whereas decisions made in the initial hours can have a significant impact on limiting contamination spread. Many web resources are publicly available to assist responders in visualizing stormwater runoff flow paths. A case study provided in this paper also demonstrates how simple calculations may be utilized to estimate peak flows and storage volumes necessary to respond to precipitation events immediately. These calculations are useful for decision makers' allocation of containment and treatment resources within the impacted area. This includes where to deploy available resources to minimize contamination risks to downstream communities and where supplemental resources from outside partners are urgently needed.


Assuntos
Chuva , Estados Unidos
13.
Sci Rep ; 10(1): 16176, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32999415

RESUMO

The tumor suppressor protein p53 is critical for cell fate decisions, including apoptosis, senescence, and cell cycle arrest. p53 is a tetrameric transcription factor that binds DNA response elements to regulate transcription of target genes. p53 response elements consist of two decameric half-sites, and data suggest one p53 dimer in the tetramer binds to each half-site. Despite a broad literature describing p53 binding DNA, unanswered questions remain, due partly to the need for more quantitative and structural studies with full length protein. Here we describe a single molecule fluorescence system to visualize full length p53 tetramers binding DNA in real time. The data revealed a dynamic interaction in which tetrameric p53/DNA complexes assembled and disassembled without a dimer/DNA intermediate. On a wild type DNA containing two half sites, p53/DNA complexes existed in two kinetically distinct populations. p53 tetramers bound response elements containing only one half site to form a single population of complexes with reduced kinetic stability. Altering the spacing and helical phasing between two half sites affected both the population distribution of p53/DNA complexes and their kinetic stability. Our real time single molecule measurements of full length p53 tetramers binding DNA reveal the parameters that define the stability of p53/DNA complexes, and provide insight into the pathways by which those complexes assemble.


Assuntos
Elementos de Resposta , Proteína Supressora de Tumor p53/metabolismo , Sítios de Ligação , Humanos , Modelos Moleculares , Conformação de Ácido Nucleico , Ligação Proteica
14.
J Craniofac Surg ; 31(5): 1312-1317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32569055

RESUMO

PURPOSE: Open cranial vault remodeling (CVR) with autologous split calvarial bone grafts redistributes and recontours an abnormal calvarium to create an expanded cranial vault in patients with craniosynostosis. We report a 12-year retrospective review of 162 nonsyndromic patients who underwent operative repair using our previously-described technique which portends excellent surgical outcomes and can be applied to patients of any age group and with any variety of suture fusion. METHODS: Data was gathered on patients who underwent CVR from 2005 to 2016. Surgical records for each patient were analyzed and included operative time, estimated blood loss, and intraoperative transfusion volumes. Intraoperative and postoperative complications, the need for revision surgery, postoperative length of stay, and follow-up records were also reviewed. Syndromic patients were excluded, as well as patients with incomplete data sets. Patients who underwent either anterior or posterior vault remodeling were compared. RESULTS: A total of 162 patients were included in this case series. Patients undergoing anterior CVR were significantly older than those undergoing posterior CVR (13.3 versus 11.0 months, P < 0.015) and also had significantly greater intraoperative red blood transfusion volumes (20.3 versus 15.3cc/kg, P < 0.0207) and longer operative time than posterior CVR patients (274.9 versus 216.7 minutes, P < 0.0001). No patients required reoperation for resorption or recurrence or persistent contour irregularities. There were no visual or neurological complications. Calvarial bone was successfully split in 100% of cases. CONCLUSIONS: This surgical approach to CVR results in good surgical outcomes with a low recurrence rate, while also maximizing operative efficiency, and minimizing total blood loss and transfusion volume. This technique can be applied to any affected suture in a patient with craniosynostosis and in patients of any age group.


Assuntos
Craniossinostoses/cirurgia , Transfusão de Sangue , Humanos , Lactente , Masculino , Duração da Cirurgia , Complicações Pós-Operatórias , Período Pós-Operatório , Procedimentos de Cirurgia Plástica , Reoperação , Estudos Retrospectivos , Crânio/cirurgia , Resultado do Tratamento
15.
J Neuropathol Exp Neurol ; 79(6): 605-617, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32386412

RESUMO

The neuropathology of mild traumatic brain injury in humans resulting from exposure to explosive blast is poorly understood as this condition is rarely fatal. A large animal model may better reflect the injury patterns in humans. We investigated the effect of explosive blasts on the constrained head minimizing the effects of whole head motion. Anesthetized Yucatan minipigs, with body and head restrained, were placed in a 3-walled test structure and exposed to 1, 2, or 3 explosive blast shock waves of the same intensity. Axonal injury was studied 3 weeks to 8 months postblast using ß-amyloid precursor protein immunohistochemistry. Injury was confined to the periventricular white matter as early as 3-5 weeks after exposure to a single blast. The pattern was also present at 8 months postblast. Animals exposed to 2 and 3 blasts had more axonal injury than those exposed to a single blast. Although such increases in axonal injury may relate to the longer postblast survival time, it may also be due to the increased number of blast exposures. It is possible that the injury observed is due to a condition akin to mild traumatic brain injury or subconcussive injury in humans, and that periventricular injury may have neuropsychiatric implications.


Assuntos
Traumatismos por Explosões/patologia , Concussão Encefálica/patologia , Encéfalo/patologia , Substância Branca/patologia , Animais , Axônios/patologia , Modelos Animais de Doenças , Masculino , Suínos , Porco Miniatura
16.
J Mol Biol ; 432(14): 4049-4060, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32417370

RESUMO

RNA polymerase II (Pol II) and its general transcription factors assemble on the promoters of mRNA genes to form large macromolecular complexes that initiate transcription in a regulated manner. During early transcription, these complexes undergo dynamic rearrangement and disassembly as Pol II moves away from the start site of transcription and transitions into elongation. One step in disassembly is the release of the general transcription factor TFIIB, although the mechanism of release and its relationship to the activity of transcribing Pol II is not understood. We developed a single-molecule fluorescence transcription system to investigate TFIIB release in vitro. Leveraging our ability to distinguish active from inactive complexes, we found that nearly all transcriptionally active complexes release TFIIB during early transcription. Release is not dependent on the contacts TFIIB makes with its recognition element in promoter DNA. We identified two different points in early transcription at which release is triggered, reflecting heterogeneity across the population of actively transcribing complexes. TFIIB releases after both trigger points with similar kinetics, suggesting the rate of release is independent of the molecular transformations that prompt release. Together our data support the model that TFIIB release is important for Pol II to successfully escape the promoter as initiating complexes transition into elongation complexes.


Assuntos
DNA/genética , RNA Polimerase II/genética , Fator de Transcrição TFIIB/genética , Transcrição Gênica/genética , Fluorescência , Humanos , Cinética , Regiões Promotoras Genéticas/genética , RNA/biossíntese , RNA/genética , Imagem Individual de Molécula/métodos
17.
RNA Biol ; 17(7): 956-965, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32129700

RESUMO

The muscle specific miRNA, miR-206, is important for the process of myogenesis; however, studying the function of miR-206 in muscle development and differentiation still proves challenging because the complement of mRNA targets it regulates remains undefined. In addition, miR-206 shares close sequence similarity to miR-1, another muscle specific miRNA, making it hard to study the impact of miR-206 alone in cell culture models. Here we used CRISPR/Cas9 technology to knockout miR-206 in C2C12 muscle cells. We show that knocking out miR-206 significantly impairs and delays differentiation and myotube formation, revealing that miR-206 alone is important for myogenesis. In addition, we use an experimental affinity purification technique to identify new mRNA targets of miR-206 in C2C12 cells. We identified over one hundred mRNAs as putative miR-206 targets. Functional experiments on six of these targets indicate that Adam19, Bgn, Cbx5, Smarce1, and Spg20 are direct miR-206 targets in C2C12 cells. Our data show a unique and important role for miR-206 in myogenesis.


Assuntos
Regulação da Expressão Gênica , Técnicas de Inativação de Genes , MicroRNAs/genética , Desenvolvimento Muscular/genética , Interferência de RNA , RNA Mensageiro/genética , Regiões 3' não Traduzidas , Animais , Sistemas CRISPR-Cas , Diferenciação Celular/genética , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , Mioblastos/metabolismo
18.
Childs Nerv Syst ; 36(2): 263-271, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31845030

RESUMO

INTRODUCTION: The endoscopic endonasal approach (EEA) provides visualization of four deep surgical corridors (transcribiform, transtubercular, transsellar, and transclival) with superior illumination and specialized deep-reaching instruments, as compared to microscopic techniques. Several studies have evaluated EEAs in children but do not stratify for the very young of age, whose particularly small nares and developmental anatomy may limit endonasal instrumentation. METHODOLOGY: A comprehensive review of EEAs in infants and children to age 4 was performed to determine the limitations in this age group. RESULTS: Eighteen studies were identified describing this approach for pediatric patients and the surgical caveats and limitations were reviewed. In very small children, CSF leaks, meningioencephaloceles, tumors of the anterior skull base, and lesions at the rostral cervical spine have been successfully treated endonasally. While newer studies advocate using 2.7-mm diameter (18-cm length) lenses, 4-mm diameter rigid lenses have been used without technical difficulty. The youngest patient in whom an EEA was used was a 6-week-old for a dermoid resection. Some have advocated that due to the small nares, approaches via bilateral entry are optimal for multiple instruments, however, others, including authors of a series of 28 repaired CSF leaks demonstrate successful single nare access. DISCUSSION: EEAs are associated with less blood loss, are less likely to hinder normal growth of the skull and midface, and allow for the resection of even malignant lesions. Despite the limitations of the frontal, ethmoid, and sphenoid sinuses before age 3, reports have not documented insurmountable difficulty with EEAs even in infants. 2.7-mm diameter endoscopes are favored unilaterally or bilaterally to treat both benign and malignant lesions and preserve the young patient's facial anatomy better than older methods. Ever improving technology has facilitated the use of this approach in patients it would otherwise be infeasible for in the past, but it still cannot overcome the anatomical constraints of certain young patients in which this approach remains unindicated. Patient selection is therefore of utmost importance and the risks and benefits of more extensive approaches in these cases must be considered.


Assuntos
Endoscopia , Nariz , Seio Esfenoidal , Criança , Pré-Escolar , Humanos , Lactente , Procedimentos Neurocirúrgicos , Nariz/cirurgia , Base do Crânio
19.
J Neurotrauma ; 37(1): 55-65, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31311414

RESUMO

Although whole body cooling is used widely to provide therapeutic hypothermia for the brain, there are undesirable clinical side effects. Selective brain cooling may allow for rapid and controllable neuroprotection while mitigating these undesirable side effects. We evaluated an innovative cerebrospinal fluid (CSF) cooling platform that utilizes chilled saline pumped through surgically implanted intraventricular catheters to induce hypothermia. Magnetic resonance thermal imaging of the healthy sheep brain (n = 4) at 7.0T provided dynamic temperature measurements from the whole brain. Global brain temperature was 38.5 ± 0.8°C at baseline (body temperature of 39.2 ± 0.4°C), and decreased by 3.1 ± 0.3°C over ∼30 min of cooling (p < 0.0001). Significant cooling was achieved in all defined regions across both the ipsilateral and contralateral hemispheres relative to catheter placement. On cooling cessation, global brain temperature increased by 3.1 ± 0.2°C over ∼20 min (p < 0.0001). Rapid and synchronized temperature fall/rise on cooling onset/offset was observed reproducibly with rates ranging from 0.06-0.21°C/min, where rewarming was faster than cooling (p < 0.0001) signifying the importance of thermoregulation in the brain. Although core regions (including the subcortex, midbrain, olfactory tract, temporal lobe, occipital lobe, and parahippocampal cortex) had slightly warmer (∼0.2°C) baseline temperatures, after cooling, temperatures reached the same level as the non-core regions (35.6 ± 0.2°C), indicating the cooling effectiveness of the CSF-based cooling device. In summary, CSF-based intraventricular cooling reliably reduces temperature in all identified brain regions to levels known to be neuroprotective, while maintaining overall systemic normothermia. Dynamic thermal mapping provides high spatiotemporal temperature measurements that can aid in optimizing selective neuroprotective protocols.


Assuntos
Encéfalo , Hipotermia Induzida/métodos , Infusões Intraventriculares , Solução Salina/administração & dosagem , Termografia/métodos , Animais , Espectroscopia de Ressonância Magnética/métodos , Masculino , Modelos Animais , Ovinos
20.
Case Rep Pathol ; 2019: 8034021, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31885995

RESUMO

Sagittal craniosynostosis (CS) is a pathologic condition that results in premature fusion of the sagittal suture, restricting the transverse growth of the skull leading in some cases to elevated intracranial pressure and neurodevelopmental delay. There is still much to be learned about the etiology of CS. Here, we report a case of 56-year-old male cadaver that we describe as sagittal CS with torus palatinus being an additional anomaly. The craniotomy was unsuccessful (cephalic index, CI = 56) and resulted in abnormal vertical outgrowth of the craniotomized bone strip. The histological analysis of the latter revealed atypical, noncompensatory massive bone overproduction. Exome sequencing of DNA extracted from the cadaveric tissue specimen performed on the Next Generation Sequencing (NGS) platform yielded 81 genetic variants identified as pathologic. Nine of those variants could be directly linked to CS with five of them targeting RhoA GTPase signaling, with a potential to make it sustained in nature. The latter could trigger upregulated calvarial osteogenesis leading to premature suture fusion, skull bone thickening, and craniotomized bone strip outgrowth observed in the present case.

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