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1.
Brain Commun ; 6(5): fcae293, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39291168

RESUMO

Magnetic resonance-guided, focused ultrasound thalamotomy is a neurosurgical treatment for refractory essential tremor. This study examined cognitive outcomes following unilateral magnetic resonance-guided, focused ultrasound thalamotomy, targeting the ventral intermediate nucleus of the thalamus for essential tremor. The research was conducted at two sites: Sunnybrook Research Institute in Toronto, Canada, and West Virginia University School of Medicine Rockefeller Neuroscience Institute in West Virginia, USA. The study focused on cognitive changes at both the group and individual levels. Patients with refractory essential tremor completed cognitive testing before and after magnetic resonance-guided, focused ultrasound thalamotomy at both sites. The cognitive testing assessed domains of attention, processing speed, working memory, executive function, language and learning/memory. Postoperative changes in cognition were examined using paired t-tests and Wilcoxon signed-rank tests, as appropriate. Reliable change indices were calculated to assess clinically significant changes at the individual level. A total of 33 patients from Toronto and 22 patients from West Virginia were included. Following magnetic resonance-guided, focused ultrasound thalamotomy, there was a significant reduction in tremor severity in both cohorts. At the group level, there were no significant declines in postoperative cognitive performance in either cohort. The reliable change analyses revealed some variability at the individual level, with most patients maintaining stable performance or showing improvement. Taken together, the results from these two independent cohorts demonstrate that unilateral magnetic resonance-guided, focused ultrasound thalamotomy significantly reduces tremor severity without negatively impacting cognition at both the group and individual levels, highlighting the cognitive safety of magnetic resonance-guided focused ultrasound thalamotomy for essential tremor.

2.
Headache ; 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39176658

RESUMO

OBJECTIVE: To develop machine learning models using patient and migraine features that can predict treatment responses to commonly used migraine preventive medications. BACKGROUND: Currently, there is no accurate way to predict response to migraine preventive medications, and the standard trial-and-error approach is inefficient. METHODS: In this cohort study, we analyzed data from the Mayo Clinic Headache database prospectively collected from 2001 to December 2023. Adult patients with migraine completed questionnaires during their initial headache consultation to record detailed clinical features and then at each follow-up to track preventive medication changes and monthly headache days. We included patients treated with at least one of the following migraine preventive medications: topiramate, beta-blockers (propranolol, metoprolol, atenolol, nadolol, timolol), tricyclic antidepressants (amitriptyline, nortriptyline), verapamil, gabapentin, onabotulinumtoxinA, and calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) (erenumab, fremanezumab, galcanezumab, eptinezumab). We pre-trained a deep neural network, "TabNet," using 145 variables, then employed TabNet-embedded data to construct prediction models for each medication to predict binary outcomes (responder vs. non-responder). A treatment responder was defined as having at least a 30% reduction in monthly headache days from baseline. All model performances were evaluated, and metrics were reported in the held-out test set (train 85%, test 15%). SHapley Additive exPlanations (SHAP) were conducted to determine variable importance. RESULTS: Our final analysis included 4260 patients. The responder rate for each medication ranged from 28.7% to 34.9%, and the mean time to treatment outcome for each medication ranged from 151.3 to 209.5 days. The CGRP mAb prediction model achieved a high area under the receiver operating characteristics curve (AUC) of 0.825 (95% confidence interval [CI] 0.726, 0.920) and an accuracy of 0.80 (95% CI 0.70, 0.88). The AUCs of prediction models for beta-blockers, tricyclic antidepressants, topiramate, verapamil, gabapentin, and onabotulinumtoxinA were: 0.664 (95% CI 0.579, 0.745), 0.611 (95% CI 0.562, 0.682), 0.605 (95% CI 0.520, 0.688), 0.673 (95% CI 0.569, 0.724), 0.628 (0.533, 0.661), and 0.581 (95% CI 0.550, 0.632), respectively. Baseline monthly headache days, age, body mass index (BMI), duration of migraine attacks, responses to previous medication trials, cranial autonomic symptoms, family history of headache, and migraine attack triggers were among the most important variables across all models. A variable could have different contributions; for example, lower BMI predicts responsiveness to CGRP mAbs and beta-blockers, while higher BMI predicts responsiveness to onabotulinumtoxinA, topiramate, and gabapentin. CONCLUSION: We developed an accurate prediction model for CGRP mAbs treatment response, leveraging detailed migraine features gathered from a headache questionnaire before starting treatment. Employing the same methods, the model performances for other medications were less impressive, though similar to the machine learning models reported in the literature for other diseases. This may be due to CGRP mAbs being migraine-specific. Incorporating medical comorbidities, genomic, and imaging factors might enhance the model performance. We demonstrated that migraine characteristics are important in predicting treatment responses and identified the most crucial predictors for each of the seven types of preventive medications. Our results suggest that precision migraine treatment is feasible.

3.
JAMA Neurol ; 81(9): 939-946, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39073822

RESUMO

Importance: Unilateral magnetic resonance-guided focused ultrasound ablation of ventralis intermedius nucleus of the thalamus for essential tremor reduces tremor on 1 side, but untreated contralateral or midline symptoms remain limiting for some patients. Historically, bilateral lesioning produced unacceptable risks and was supplanted by deep brain stimulation; increasing acceptance of unilateral focused ultrasound lesioning has led to interest in a bilateral option. Objective: To evaluate the safety and efficacy of staged, bilateral focused ultrasound thalamotomy. Design, Setting, and Participants: This prospective, open-label, multicenter trial treated patients with essential tremor from July 2020 to October 2021, with a 12-month follow-up, at 7 US academic medical centers. Of 62 enrolled patients who had undergone unilateral focused ultrasound thalamotomy at least 9 months prior to enrollment, 11 were excluded and 51 were treated. Eligibility criteria included patient age (22 years and older), medication refractory, tremor severity (Clinical Rating Scale for Tremor [CRST] part A score ≥2 for postural or kinetic tremor), and functional disability (CRST part C score ≥2 in any category). Intervention: A focused ultrasound system interfaced with magnetic resonance imaging allowed real-time alignment of thermography maps with anatomy. Subthreshold sonications allowed target interrogation for efficacy and off-target effects before creating an ablation. Main Outcomes and Measures: Tremor/motor score (CRST parts A and B) at 3 months for the treated side after treatment was the primary outcome measure, and secondary assessments for efficacy and safety continued to 12 months. Results: The mean (SD) population age was 73 (13.9) years, and 44 participants (86.3%) were male. The mean (SD) tremor/motor score improved from 17.4 (5.4; 95% CI, 15.9-18.9) to 6.4 (5.3; 95% CI, 4.9 to 7.9) at 3 months (66% improvement in CRST parts A and B scores; 95% CI, 59.8-72.2; P < .001). There was significant improvement in mean (SD) postural tremor (from 2.5 [0.8]; 95% CI, 2.3 to 2.7 to 0.6 [0.9]; 95% CI, 0.3 to 0.8; P < .001) and mean (SD) disability score (from 10.3 [4.7]; 95% CI, 9.0-11.6 to 2.2 [2.8]; 95% CI, 1.4-2.9; P < .001). Twelve participants developed mild (study-defined) ataxia, which persisted in 6 participants at 12 months. Adverse events (159 of 188 [85%] mild, 25 of 188 [13%] moderate, and 1 severe urinary tract infection) reported most commonly included numbness/tingling (n = 17 total; n = 8 at 12 months), dysarthria (n = 15 total; n = 7 at 12 months), ataxia (n = 12 total; n = 6 at 12 months), unsteadiness/imbalance (n = 10 total; n = 0 at 12 months), and taste disturbance (n = 7 total; n = 3 at 12 months). Speech difficulty, including phonation, articulation, and dysphagia, were generally mild (rated as not clinically significant, no participants with worsening in all 3 measures) and transient. Conclusions and Relevance: Staged, bilateral focused ultrasound thalamotomy significantly reduced tremor severity and functional disability scores. Adverse events for speech, swallowing, and ataxia were mostly mild and transient. Trial Registration: ClinicalTrials.gov Identifier NCT04112381.


Assuntos
Tremor Essencial , Tálamo , Humanos , Tremor Essencial/cirurgia , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Resultado do Tratamento , Tálamo/cirurgia , Tálamo/diagnóstico por imagem , Estudos Prospectivos , Núcleos Ventrais do Tálamo/cirurgia , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/efeitos adversos
4.
Genetics ; 226(2)2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-37950911

RESUMO

Chromosome segregation is crucial for the faithful inheritance of DNA to the daughter cells after DNA replication. For this, the kinetochore, a megadalton protein complex, assembles on centromeric chromatin containing the histone H3 variant CENP-A, and provides a physical connection to the microtubules. Here, we report an unanticipated role for enzymes required for ß-1,6- and ß-1,3-glucan biosynthesis in regulating kinetochore function in Saccharomyces cerevisiae. These carbohydrates are the major constituents of the yeast cell wall. We found that the deletion of KRE6, which encodes a glycosylhydrolase/ transglycosidase required for ß-1,6-glucan synthesis, suppressed the centromeric defect of mutations in components of the kinetochore, foremost the NDC80 components Spc24, Spc25, the MIND component Nsl1, and Okp1, a constitutive centromere-associated network protein. Similarly, the absence of Fks1, a ß-1,3-glucan synthase, and Kre11/Trs65, a TRAPPII component, suppressed a mutation in SPC25. Genetic analysis indicates that the reduction of intracellular ß-1,6- and ß-1,3-glucans, rather than the cell wall glucan content, regulates kinetochore function. Furthermore, we found a physical interaction between Kre6 and CENP-A/Cse4 in yeast, suggesting a potential function for Kre6 in glycosylating CENP-A/Cse4 or another kinetochore protein. This work shows a moonlighting function for selected cell wall synthesis proteins in regulating kinetochore assembly, which may provide a mechanism to connect the nutritional status of the cell to cell-cycle progression and chromosome segregation.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , beta-Glucanas , Saccharomyces cerevisiae/genética , Cinetocoros/metabolismo , Proteína Centromérica A/genética , Glucanos/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/genética , Centrômero/metabolismo , Proteínas Nucleares/genética , Proteínas de Ciclo Celular/genética
6.
J Clin Sleep Med ; 19(12): 2145-2146, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-38041535
7.
ACS Chem Biol ; 18(12): 2441-2449, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37962075

RESUMO

The chemical biology of native nucleic acid modifications has seen an intense upswing, first concerning DNA modifications in the field of epigenetics and then concerning RNA modifications in a field that was correspondingly rebaptized epitranscriptomics by analogy. The German Research Foundation (DFG) has funded several consortia with a scientific focus in these fields, strengthening the traditionally well-developed nucleic acid chemistry community and inciting it to team up with colleagues from the life sciences and data science to tackle interdisciplinary challenges. This Perspective focuses on the genesis, scientific outcome, and downstream impact of the DFG priority program SPP1784 and offers insight into how it fecundated further consortia in the field. Pertinent research was funded from mid-2015 to 2022, including an extension related to the coronavirus pandemic. Despite being a detriment to research activity in general, the pandemic has resulted in tremendously boosted interest in the field of RNA and RNA modifications as a consequence of their widespread and successful use in vaccination campaigns against SARS-CoV-2. Funded principal investigators published over 250 pertinent papers with a very substantial impact on the field. The program also helped to redirect numerous laboratories toward this dynamic field. Finally, SPP1784 spawned initiatives for several funded consortia that continue to drive the fields of nucleic acid modification.


Assuntos
Ácidos Nucleicos , RNA , Epigênese Genética , Biologia
8.
Nucleic Acids Res ; 51(20): 11197-11212, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37811872

RESUMO

Queuosine (Q) is a complex tRNA modification found in bacteria and eukaryotes at position 34 of four tRNAs with a GUN anticodon, and it regulates the translational efficiency and fidelity of the respective codons that differ at the Wobble position. In bacteria, the biosynthesis of Q involves two precursors, preQ0 and preQ1, whereas eukaryotes directly obtain Q from bacterial sources. The study of queuosine has been challenging due to the limited availability of high-throughput methods for its detection and analysis. Here, we have employed direct RNA sequencing using nanopore technology to detect the modification of tRNAs with Q and Q precursors. These modifications were detected with high accuracy on synthetic tRNAs as well as on tRNAs extracted from Schizosaccharomyces pombe and Escherichia coli by comparing unmodified to modified tRNAs using the tool JACUSA2. Furthermore, we present an improved protocol for the alignment of raw sequence reads that gives high specificity and recall for tRNAs ex cellulo that, by nature, carry multiple modifications. Altogether, our results show that 7-deazaguanine-derivatives such as queuosine are readily detectable using direct RNA sequencing. This advancement opens up new possibilities for investigating these modifications in native tRNAs, furthering our understanding of their biological function.


Assuntos
Nucleosídeo Q , RNA de Transferência , Anticódon/genética , Escherichia coli/genética , Eucariotos/genética , Nucleosídeo Q/análise , RNA , RNA de Transferência/química , Schizosaccharomyces/química , Schizosaccharomyces/genética , Análise de Sequência de RNA
9.
Nucleic Acids Res ; 51(8): 3971-3987, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36971106

RESUMO

More than 170 posttranscriptional RNA modifications are so far known on both coding and noncoding RNA species. Within this group, pseudouridine (Ψ) and queuosine (Q) represent conserved RNA modifications with fundamental functional roles in regulating translation. Current detection methods of these modifications, which both are reverse transcription (RT)-silent, are mostly based on the chemical treatment of RNA prior to analysis. To overcome the drawbacks associated with indirect detection strategies, we have engineered an RT-active DNA polymerase variant called RT-KTq I614Y that produces error RT signatures specific for Ψ or Q without prior chemical treatment of the RNA samples. Combining this polymerase with next-generation sequencing techniques allows the direct identification of Ψ and Q sites of untreated RNA samples using a single enzymatic tool.


Assuntos
Nucleosídeo Q , Pseudouridina , RNA Mensageiro/metabolismo , Pseudouridina/metabolismo , RNA , RNA não Traduzido , Processamento Pós-Transcricional do RNA
10.
Genetics ; 223(4)2023 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-36810679

RESUMO

Post-translational modifications on histones are well known to regulate chromatin structure and function, but much less information is available on modifications of the centromeric histone H3 variant and their effect at the kinetochore. Here, we report two modifications on the centromeric histone H3 variant CENP-A/Cse4 in the yeast Saccharomyces cerevisiae, methylation at arginine 143 (R143me) and lysine 131 (K131me), that affect centromere stability and kinetochore function. Both R143me and K131me lie in the core region of the centromeric nucleosome, near the entry/exit sites of the DNA from the nucleosome. Unexpectedly, mutation of Cse4-R143 (cse4-R143A) exacerbated the kinetochore defect of mutations in components of the NDC80 complex of the outer kinetochore (spc25-1) and the MIND complex (dsn1-7). The analysis of suppressor mutations of the spc25-1 cse4-R143A growth defect highlighted residues in Spc24, Ndc80, and Spc25 that localize to the tetramerization domain of the NDC80 complex and the Spc24-Spc25 stalk, suggesting that the mutations enhance interactions among NDC80 complex components and thus stabilize the complex. Furthermore, the Set2 histone methyltransferase inhibited kinetochore function in spc25-1 cse4-R143A cells, possibly by methylating Cse4-K131. Taken together, our data suggest that Cse4-R143 methylation and Cse4-K131 methylation affect the stability of the centromeric nucleosome, which is detrimental in the context of defective NDC80 tetramerization and can be compensated for by strengthening interactions among NDC80 complex components.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Cinetocoros/metabolismo , Proteína Centromérica A/genética , Proteína Centromérica A/metabolismo , Lisina/genética , Histonas/metabolismo , Metilação , Nucleossomos/genética , Arginina/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Nucleares/genética
11.
Cardiol Young ; 33(2): 242-247, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35411845

RESUMO

Vaccination coverage for infants with CHD is unknown, yet these patients are at high risk for morbidity and mortality associated with vaccine-preventable illnesses. We determined vaccination rates for this population and identified predictors of undervaccination. We prospectively enrolled infants with CHD born between 1 January, 2012 and 31 December, 2015, seen in a single-centre cardiology clinic between 15 February, 2016 and 28 February, 2017. We assessed vaccination during the first year of life. Subjects who by age 1 year received all routine immunisations recommended during the first 6 months of life were considered fully vaccinated. We also evaluated influenza vaccination during subjects' first eligible influenza season. We obtained immunisation histories from primary care providers and collected demographic and clinical data via a parent survey and chart review. We used multivariable logistic regression to identify predictors of undervaccination. Among 260 subjects, only 60% were fully vaccinated. Vaccination rates were lowest for influenza (64.6%), rotavirus (71.1%), and Haemophilus influenzae type b (79.3%). Cardiac surgery with cardiopulmonary bypass during the first year of life was associated with undervaccination (51.5% versus 76.4% fully vaccinated, adjusted odds ratio 2.1 [95% confidence interval 1.1-3.9]). Other predictors of undervaccination were out-of-state primary care (adjusted odds ratio 2.7 [1.5-4.9]), multiple comorbidities (≥2 versus 0-1, adjusted odds ratio 2.0 [1.1-3.6]), and hospitalisation for >25% of the first year of life (>25% versus ≤25%, adjusted odds ratio 2.1 [1.1-3.9]). Targeted quality improvement initiatives focused on improving vaccination coverage for these infants, especially surrounding cardiac surgery, are needed.


Assuntos
Vacinas contra Influenza , Influenza Humana , Lactente , Humanos , Influenza Humana/prevenção & controle , Vacinação , Imunização , Modelos Logísticos
12.
Nucleic Acids Res ; 50(18): 10785-10800, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36169220

RESUMO

Substitution of the queuine nucleobase precursor preQ1 by an azide-containing derivative (azido-propyl-preQ1) led to incorporation of this clickable chemical entity into tRNA via transglycosylation in vitro as well as in vivo in Escherichia coli, Schizosaccharomyces pombe and human cells. The resulting semi-synthetic RNA modification, here termed Q-L1, was present in tRNAs on actively translating ribosomes, indicating functional integration into aminoacylation and recruitment to the ribosome. The azide moiety of Q-L1 facilitates analytics via click conjugation of a fluorescent dye, or of biotin for affinity purification. Combining the latter with RNAseq showed that TGT maintained its native tRNA substrate specificity in S. pombe cells. The semi-synthetic tRNA modification Q-L1 was also functional in tRNA maturation, in effectively replacing the natural queuosine in its stimulation of further modification of tRNAAsp with 5-methylcytosine at position 38 by the tRNA methyltransferase Dnmt2 in S. pombe. This is the first demonstrated in vivo integration of a synthetic moiety into an RNA modification circuit, where one RNA modification stimulates another. In summary, the scarcity of queuosinylation sites in cellular RNA, makes our synthetic q/Q system a 'minimally invasive' system for placement of a non-natural, clickable nucleobase within the total cellular RNA.


Assuntos
Nucleosídeo Q , Schizosaccharomyces , 5-Metilcitosina/metabolismo , Azidas , Biotina/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Corantes Fluorescentes/metabolismo , Humanos , Nucleosídeo Q/química , RNA de Transferência/metabolismo , RNA de Transferência de Ácido Aspártico/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , tRNA Metiltransferases/metabolismo
13.
Curr Pain Headache Rep ; 26(10): 783-794, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36063264

RESUMO

PURPOSE OF REVIEW: To summarize available calcitonin gene-related peptide (CGRP)-targeting therapies for migraine and discuss their use in real-world populations. BACKGROUND: CGRP has long been a topic of interest in migraine pathophysiology, with new therapies targeting CGRP since 2018 for both the preventive and acute treatment of migraine. METHODS: We searched PubMed using keywords including "migraine," "CGRP," "real-world," "erenumab," "galcanezumab," "fremanezumab," "eptinezumab," "ubrogepant," "rimegepant," and "atogepant." We reviewed all pertinent studies and summarized main findings. We also compiled detailed patient characteristics (e.g., migraine diagnoses, medication overuse, prior treatment failures) and treatment outcome measures, such as 50% responder rates, reduction in migraine days, and adverse event rates in several tables. Overall, studies reporting real-world patient experiences of CGRP-targeting therapies suggested meaningful effectiveness for migraine treatment with response rates comparable to the numbers reported in clinical trials. Furthermore, studies suggested benefit in patients with multiple prior unsuccessful treatment trials, medication overuse, and complex medical comorbidities. In some studies, adverse event rates have been notably higher than reported in clinical trials. Additional long-term data is needed to further evaluate sustained efficacy, predictors of treatment response, and adverse events.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Transtornos de Enxaqueca , Humanos , Peptídeo Relacionado com Gene de Calcitonina/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/prevenção & controle , Receptores de Peptídeo Relacionado com o Gene de Calcitonina/uso terapêutico , Avaliação de Resultados da Assistência ao Paciente
14.
Biochem Biophys Res Commun ; 624: 146-150, 2022 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-35940128

RESUMO

Queuosine (Q) is a hypermodified 7-deaza-guanosine nucleoside that is found at position 34, also known as the wobble position, of tRNAs with a GUN anticodon, and Q ensures faithful translation of the respective C- and U-ending codons. While Q is present in tRNAs in most eukaryotes, only bacteria can synthesize it denovo. In contrast, eukaryotes rely on external sources like their food and the gut microbiome in order to Q-modify their tRNAs, and Q therefore can be regarded as a micronutrient. The eukaryotic tRNA guanine transglycosylase (eTGT) uses the base queuine (q) as a substrate to replace G34 by Q in the tRNAs. Eukaryotic cells can uptake both q and Q, raising the question how the Q nucleoside is converted to q for incorporation into the tRNAs. Here, we identified Qng1 (also termed Duf2419) as a queuosine nucleoside glycosylase in Schizosaccharomyces pombe. S. pombe cells with a deletion of qng1+ contained Q-modified tRNAs only when cultured in the presence of the nucleobase q, but not with the nucleoside Q, indicating that the cells are proficient at q incorporation, but not in Q hydrolysis. Furthermore, purified recombinant Qng1 hydrolyzed Q to q in vitro. Qng1 displays homology to DNA glycosylases and has orthologs across eukaryotes, including flies, mice and humans. Qng1 therefore plays an essential role in allowing eukaryotic cells to salvage Q from bacterial sources and to recycle Q from endogenous tRNAs.


Assuntos
Nucleosídeo Q , Schizosaccharomyces , Animais , Bactérias/metabolismo , Guanina/análogos & derivados , Humanos , Hidrólise , Camundongos , Nucleosídeo Q/metabolismo , Nucleosídeos/metabolismo , RNA de Transferência/genética , RNA de Transferência/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo
15.
Med Sci Educ ; 31(5): 1567-1573, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34603831

RESUMO

First-year medical student groups rotated through classrooms, each containing a Neurology patient and physician, as a "Neuro Day" event to make direct clinical connections with the basic sciences. Inspired by post-graduate Clerkships, this event provided timely first-hand experiences focusing on pathological neurologic exam findings. Qualitative and quantitative data were collected from end-of-course surveys. The results show how the event served to reinvigorate enthusiasm for learning Clinical Neurobiology outside the traditional lecture environment and could empower patients as educators within a teaching community.

16.
Biochem Biophys Res Commun ; 573: 112-116, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34403807

RESUMO

Heritable DNA methylation variation is frequently observed in natural populations of plants, but is thought mostly to be functionally inconsequential. An exception to this is the "Peloria" mutant of Linaria vulgaris, which was originally described by Carl von Linné in 1744. A study in 1999 found that the Peloria phenotype is caused by an epiallele of the L. vulgaris cycloidea homolog Lcyc that showed increased levels of DNA methylation compared to wild-type. The DNA methylation results in silencing of Lcyc, which causes radial flower symmetry in the peloric mutant, whereas wild-type plants have flowers with bilateral symmetry. However, a detailed view of DNA methylation at Lcyc at the single-nucleotide level has not been available. In this study, we investigated DNA methylation at Lcyc and, as a control, at the LvHIRZ gene in wild-type and peloric plants of L. vulgaris using DNA bisulfite treatment coupled to next-generation sequencing. We found strong increases in CHG and CHH methylation at Lcyc, but not LvHIRZ, in Peloria. CG methylation was also increased, but wild-type Lcyc also showed moderate levels of CG methylation. Our results suggest that DNA methylation in all three sequence contexts has been maintained, and potentially transgenerationally inherited, in the peloric L. vulgaris population over decades or even centuries.


Assuntos
DNA de Plantas/genética , Linaria/genética , Metilação de DNA , Regulação da Expressão Gênica de Plantas/genética , Mutação
17.
PLoS One ; 16(5): e0251660, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34014972

RESUMO

The acetylation of H4 lysine 16 (H4 K16Ac) in Saccharomyces cerevisiae counteracts the binding of the heterochromatin complex SIR to chromatin and inhibits gene silencing. Contrary to other histone acetylation marks, the H4 K16Ac level is high on genes with low transcription, whereas highly transcribed genes show low H4 K16Ac. Approximately 60% of cellular H4 K16Ac in S. cerevisiae is provided by the SAS-I complex, which consists of the MYST-family acetyltransferase Sas2, Sas4 and Sas5. The absence of SAS-I causes inappropriate spreading of the SIR complex and gene silencing in subtelomeric regions. Here, we investigated the genome-wide dynamics of SAS-I dependent H4 K16Ac during DNA replication. Replication is highly disruptive to chromatin and histone marks, since histones are removed to allow progression of the replication fork, and chromatin is reformed with old and new histones after fork passage. We found that H4 K16Ac appears in chromatin immediately upon replication. Importantly, this increase depends on the presence of functional SAS-I complex. Moreover, the appearance of H4 K16Ac is delayed in genes that are strongly transcribed. This indicates that transcription counteracts SAS-I-mediated H4 K16 acetylation, thus "sculpting" histone modification marks at the time of replication. We furthermore investigated which acetyltransferase acts redundantly with SAS-I to acetylate H4 K16Ac. esa1Δ sds3Δ cells, which were also sas2Δ sir3Δ in order to maintain viability, contained no detectable H4 K16Ac, showing that Esa1 and Sas2 are redundant for cellular H4 K16 acetylation. Furthermore, esa1Δ sds3Δ sas2Δ sir3Δ showed a more pronounced growth defect compared to the already defective esa1Δ sds3Δ sir3Δ. This indicates that SAS-I has cellular functions beyond preventing the spreading of heterochromatin.


Assuntos
Replicação do DNA , DNA Fúngico/metabolismo , Histonas/metabolismo , Complexos Multiproteicos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Acetilação , DNA Fúngico/genética , Histonas/genética , Complexos Multiproteicos/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
18.
Neurology ; 96(10): e1482-e1486, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33686009

RESUMO

OBJECTIVE: To determine whether increased patient interaction, exposure to the neurologic examination, and access to positive neurology mentors increase interest in neurology for first-year medical students. METHODS: Neuro Day was a 2-part experience for first-year medical students. The first part consisted of a flipped classroom to teach the standard neurologic examination. The second part involved patient encounters modeled off of the traditional patient rounds. Students rotated from room to room, listening to patients' experiences with different neurologic diseases and eliciting pathologic neurologic examinations. Students were surveyed before and after Neuro Day. RESULTS: The result of the binomial test indicated that the proportion of medical students interested in neurology significantly increased from 78% to 85% (95% confidence interval [CI] 0.79-0.92; p = 0.034) after participating in Neuro Day. The proportion of students' knowledge of clinical neurology increased from 45% to 63.1% (95% CI 0.54-0.72; p < 0.0001), comfort with performing a neurologic examination increased from 30% to 78.4% (95% CI 0.70-0.86; p < 0.0001), and fear of studying neurology decreased from 46% to 26% (95% CI 0.17-0.34; p < 0.0001) following Neuro Day. One hundred percent of students indicated that they would recommend Neuro Day to their peers. CONCLUSION: Neuro Day is a feasible and effective model to incorporate into medical education. There was increased interest in and decreased fear of neurology. We anticipate that this paradigm can be used in the future to encourage students to consider a career in neurology.


Assuntos
Currículo , Internato e Residência , Neurologia/educação , Estudantes de Medicina , Escolha da Profissão , Estágio Clínico , Educação de Graduação em Medicina , Humanos , Mentores , Pacientes , Estudos Prospectivos , Inquéritos e Questionários
19.
Proc Natl Acad Sci U S A ; 117(10): 5386-5393, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32079723

RESUMO

The AAA+ ATPase and bromodomain factor ATAD2/ANCCA is overexpressed in many types of cancer, but how it contributes to tumorigenesis is not understood. Here, we report that the Saccharomyces cerevisiae homolog Yta7ATAD2 is a deposition factor for the centromeric histone H3 variant Cse4CENP-A at the centromere in yeast. Yta7ATAD2 regulates the levels of centromeric Cse4CENP-A in that yta7∆ causes reduced Cse4CENP-A deposition, whereas YTA7 overexpression causes increased Cse4CENP-A deposition. Yta7ATAD2 coimmunoprecipitates with Cse4CENP-A and is associated with the centromere, arguing for a direct role of Yta7ATAD2 in Cse4CENP-A deposition. Furthermore, increasing centromeric Cse4CENP-A levels by YTA7 overexpression requires the activity of Scm3HJURP, the centromeric nucleosome assembly factor. Importantly, Yta7ATAD2 interacts in vivo with Scm3HJURP, indicating that Yta7ATAD2 is a cochaperone for Scm3HJURP The absence of Yta7 causes defects in growth and chromosome segregation with mutations in components of the inner kinetochore (CTF19/CCAN, Mif2CENP-C, Cbf1). Since Yta7ATAD2 is an AAA+ ATPase and potential hexameric unfoldase, our results suggest that it may unfold the Cse4CENP-A histone and hand it over to Scm3HJURP for subsequent deposition in the centromeric nucleosome. Furthermore, our findings suggest that ATAD2 overexpression may enhance malignant transformation in humans by misregulating centromeric CENP-A levels, thus leading to defects in kinetochore assembly and chromosome segregation.


Assuntos
Centrômero/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , ATPases Associadas a Diversas Atividades Celulares/genética , Proteína Centromérica A/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Imunoprecipitação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética
20.
Telemed J E Health ; 26(7): 865-871, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31596679

RESUMO

Background: The state of West Virginia (WV) is often seen as a health care desert with a scarcity of hospitals and resources. The prevalence of cerebrovascular disease and associated comorbidities are also some of the highest in the nation. Introduction: Ischemic stroke is a time-sensitive diagnosis. Prompt treatment in WV is difficult due to limited and isolated stroke-ready hospitals. Adoption of telestroke has helped to bypass these obstacles and improve access to care. Materials and Methods: Retrospective analyses; using data from the American Heart Association's Get With The Guidelines Stroke Data Registry, and other statewide agencies, we looked for trends in the volume of patients treated with intravenous-tissue plasminogen activator (tPA) in WV. We also reviewed data from West Virginia University's (WVU) telestroke database to assess trends in consult volumes and quality metrics. Results: Since the establishment of WVU telestroke, the total number of stroke patients receiving tPA across the state increased by 173% from 2015 (259 patients) to 2018 (448 patients) (p < 0.0001). Telestroke consults made up 24% (107/448) of total statewide tPA administrations for 2018. Between 2016 and 2018, the total symptomatic hemorrhage rate for tPA treated patients through telestroke was 1% (3/292). Telestroke also facilitated local care by avoiding patient transfer on average 65% of the time.Conclusion: Not only has telestroke increased the quantity of treated acute ischemic strokes, but it has also done so safely and effectively even in resource-poor areas. These findings demonstrate that telestroke is a useful tool for treating strokes, particularly those that happen far from stroke centers.


Assuntos
Acidente Vascular Cerebral , Telemedicina , Fibrinolíticos/uso terapêutico , Humanos , Estudos Retrospectivos , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Ativador de Plasminogênio Tecidual/uso terapêutico
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