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1.
Am J Respir Crit Care Med ; 209(2): 153-163, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37931077

RESUMO

Rationale: Multiciliated cell (MCC) loss and/or dysfunction is common in the small airways of patients with chronic obstructive pulmonary disease (COPD), but it is unclear if this contributes to COPD lung pathology. Objectives: To determine if loss of p73 causes a COPD-like phenotype in mice and explore whether smoking or COPD impact p73 expression. Methods: p73floxE7-E9 mice were crossed with Shh-Cre mice to generate mice lacking MCCs in the airway epithelium. The resulting p73Δairway mice were analyzed using electron microscopy, flow cytometry, morphometry, forced oscillation technique, and single-cell RNA sequencing. Furthermore, the effects of cigarette smoke on p73 transcript and protein expression were examined using in vitro and in vivo models and in studies including airway epithelium from smokers and patients with COPD. Measurements and Main Results: Loss of functional p73 in the respiratory epithelium resulted in a near-complete absence of MCCs in p73Δairway mice. In adulthood, these mice spontaneously developed neutrophilic inflammation and emphysema-like lung remodeling and had progressive loss of secretory cells. Exposure of normal airway epithelium cells to cigarette smoke rapidly and durably suppressed p73 expression in vitro and in vivo. Furthermore, tumor protein 73 mRNA expression was reduced in the airways of current smokers (n = 82) compared with former smokers (n = 69), and p73-expressing MCCs were reduced in the small airways of patients with COPD (n = 11) compared with control subjects without COPD (n = 12). Conclusions: Loss of functional p73 in murine airway epithelium results in the absence of MCCs and promotes COPD-like lung pathology. In smokers and patients with COPD, loss of p73 may contribute to MCC loss or dysfunction.


Assuntos
Enfisema , Doença Pulmonar Obstrutiva Crônica , Enfisema Pulmonar , Animais , Humanos , Camundongos , Epitélio/metabolismo , Pulmão , Doença Pulmonar Obstrutiva Crônica/patologia
2.
Int Urogynecol J ; 35(3): 483-489, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38329493

RESUMO

INTRODUCTION AND HYPOTHESIS: Antibiotic resistance is an unavoidable consequence of antibiotic use and growing rates of resistance are an urgent issue. Methenamine is a non-antibiotic alternative used for urinary tract infection (UTI) prophylaxis. The objective of this review is to evaluate recently published literature regarding the efficacy and safety of methenamine for UTI prophylaxis. METHODS: PubMed, Embase, and CENTRAL databases were queried in March 2023 using the following search terms: urinary tract infection, cystitis, bacteriuria, or dysuria, and methenamine. Studies prior to 2012 were excluded from this review to focus on appraisal of the most recent evidence. Prospective and controlled retrospective trials were included for review. RESULTS: A total of seven studies (three prospective and four retrospective) met the inclusion criteria for review. Two of the 3 prospective studies demonstrated no or non-inferior differences in clinical efficacy to prevent recurrent UTIs between methenamine and antibiotic prophylaxis and the third showed decreased rates of UTI with methenamine use in patients with short-term indwelling catheters compared with cranberry alone. The retrospective studies consistently supported the efficacy and safety of methenamine for UTI prophylaxis in a variety of populations and clinical settings. Adverse effects reported with methenamine were similar to comparators and included nausea, abdominal pain, and headache. CONCLUSIONS: The use of methenamine for UTI prophylaxis was shown to be effective in a variety of settings without an increased risk of adverse effects compared with prophylactic antibiotics. Larger blinded clinical trials are needed to further define the role of methenamine in UTI prophylaxis.

3.
Nucleic Acids Res ; 48(18): 10034-10044, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32453412

RESUMO

S-adenosyl-l-methionine dependent methyltransferases catalyze methyl transfers onto a wide variety of target molecules, including DNA and RNA. We discuss a family of methyltransferases, those that act on the amino groups of adenine or cytosine in DNA, have conserved motifs in a particular order in their amino acid sequence, and are referred to as class beta MTases. Members of this class include M.EcoGII and M.EcoP15I from Escherichia coli, Caulobacter crescentus cell cycle-regulated DNA methyltransferase (CcrM), the MTA1-MTA9 complex from the ciliate Oxytricha, and the mammalian MettL3-MettL14 complex. These methyltransferases all generate N6-methyladenine in DNA, with some members having activity on single-stranded DNA as well as RNA. The beta class of methyltransferases has a unique multimeric feature, forming either homo- or hetero-dimers, allowing the enzyme to use division of labor between two subunits in terms of substrate recognition and methylation. We suggest that M.EcoGII may represent an ancestral form of these enzymes, as its activity is independent of the nucleic acid type (RNA or DNA), its strandedness (single or double), and its sequence (aside from the target adenine).


Assuntos
Evolução Molecular , Metiltransferases/química , Sequência de Aminoácidos , Animais , Caenorhabditis elegans/enzimologia , Caulobacter crescentus/enzimologia , Escherichia coli/enzimologia , Humanos , Metiltransferases/classificação , Camundongos , Oxytricha/enzimologia , Conformação Proteica , Especificidade por Substrato
4.
Nucleic Acids Res ; 48(18): 10329-10341, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32663306

RESUMO

The recently characterized mammalian writer (methyltransferase) and eraser (demethylase) of the DNA N6-methyladenine (N6mA) methyl mark act on single-stranded (ss) and transiently-unpaired DNA. As YTH domain-containing proteins bind N6mA-containing RNA in mammalian cells, we investigated whether mammalian YTH domains are also methyl mark readers of N6mA DNA. Here, we show that the YTH domain of YTHDC1 (known to localize in the nucleus) binds ssDNA containing N6mA, with a 10 nM dissociation constant. This binding is stronger by a factor of 5 than in an RNA context, tested under the same conditions. However, the YTH domains of YTHDF2 and YTHDF1 (predominantly cytoplasmic) exhibited the opposite effect with ∼1.5-2נstronger binding to ssRNA containing N6mA than to the corresponding DNA. We determined two structures of the YTH domain of YTHDC1 in complex with N6mA-containing ssDNA, which illustrated that YTHDC1 binds the methylated adenine in a single-stranded region flanked by duplexed DNA. We discuss the hypothesis that the writer-reader-eraser of N6mA-containining ssDNA is associated with maintaining genome stability. Structural comparison of YTH and SRA domains (the latter a DNA 5-methylcytosine reader) revealed them to be diverse members of a larger family of DNA/RNA modification readers, apparently having originated from bacterial modification-dependent restriction enzymes.


Assuntos
Adenina/química , Complexos Multiproteicos/química , Proteínas do Tecido Nervoso/química , Conformação Proteica , Fatores de Processamento de RNA/química , DNA/química , DNA/genética , DNA/ultraestrutura , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Histona Desmetilases/genética , Humanos , Metilação , Metiltransferases/genética , Complexos Multiproteicos/genética , Complexos Multiproteicos/ultraestrutura , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/ultraestrutura , Domínios Proteicos/genética , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/ultraestrutura , Proteínas de Ligação a RNA/genética
5.
J Biol Chem ; 295(32): 10901-10910, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32503840

RESUMO

Most characterized protein methylation events encompass arginine and lysine N-methylation, and only a few cases of protein methionine thiomethylation have been reported. Newly discovered oncohistone mutations include lysine-to-methionine substitutions at positions 27 and 36 of histone H3.3. In these instances, the methionine substitution localizes to the active-site pocket of the corresponding histone lysine methyltransferase, thereby inhibiting the respective transmethylation activity. SET domain-containing 3 (SETD3) is a protein (i.e. actin) histidine methyltransferase. Here, we generated an actin variant in which the histidine target of SETD3 was substituted with methionine. As for previously characterized histone SET domain proteins, the methionine substitution substantially (76-fold) increased binding affinity for SETD3 and inhibited SETD3 activity on histidine. Unexpectedly, SETD3 was active on the substituted methionine, generating S-methylmethionine in the context of actin peptide. The ternary structure of SETD3 in complex with the methionine-containing actin peptide at 1.9 Å resolution revealed that the hydrophobic thioether side chain is packed by the aromatic rings of Tyr312 and Trp273, as well as the hydrocarbon side chain of Ile310 Our results suggest that placing methionine properly in the active site-within close proximity to and in line with the incoming methyl group of SAM-would allow some SET domain proteins to selectively methylate methionine in proteins.


Assuntos
Histona Metiltransferases/metabolismo , Metionina/metabolismo , Histona Metiltransferases/química , Humanos , Metilação , Ligação Proteica , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína
6.
Pediatr Blood Cancer ; 68 Suppl 2: e28299, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32743983

RESUMO

This report provides a summary of the global burden of childhood cancer morbidity and mortality, which disproportionately affects low- and middle-income countries as well as low- and middle-income communities within high-income countries. We review past successes and current challenges to improving clinical pediatric radiotherapy, education, and research in these regions. The Pediatric Radiation Oncology Society Taskforce in Low- and Middle-Income Countries recently outlined specific aims: (a) to increase access and quality of radiotherapy for children and adolescents afflicted with cancer; (b) to enumerate, engage, and educate a global community of providers of childhood and adolescent radiotherapy; and (c) to create evidence establishing the outcomes of setting-specific treatment standards of care when first-world standards are not achievable. This report will improve awareness of these disparities and promote attempts to correct them.


Assuntos
Países em Desenvolvimento/economia , Necessidades e Demandas de Serviços de Saúde , Neoplasias/radioterapia , Radioterapia/métodos , Criança , Saúde Global , Humanos , Neoplasias/economia , Neoplasias/patologia , Prognóstico , Taxa de Sobrevida
7.
Nanotechnology ; 32(19): 195710, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33477125

RESUMO

Electrical scanning probe microscopies (SPM) use ultrasharp metallic tips to obtain nanometer spatial resolution and are a key tool for characterizing nanoscale semiconducting materials and systems. However, these tips are not passive probes; their high work functions can induce local band bending whose effects depend sensitively on the local geometry and material properties and thus are inherently difficult to quantify. We use sequential finite element simulations to first explore the magnitude and spatial distribution of charge reorganization due to tip-induced band bending (TIBB) for planar and nanostructured geometries. We demonstrate that tip-induced depletion and accumulation of carriers can be significantly modified in confined geometries such as nanowires compared to a bulk planar response. This charge reorganization is due to finite size effects that arise as the nanostructure size approaches the Debye length, with significant implications for a range of SPM techniques. We then use the reorganized charge distribution from our model to describe experimentally measured quantities, using in operando scanning microwave impedance microscopy measurements on axial p-i-n silicon nanowire devices as a specific example. By incorporating TIBB, we reveal that our experimentally observed enhancement (absence) of contrast at the p-i (i-n) junction is explained by the tip-induced accumulation (depletion) of carriers at the interface. Our results demonstrate that the inclusion of TIBB is critical for an accurate interpretation of electrical SPM measurements, and is especially important for weakly screening or low-doped materials, as well as the complex doping patterns and confined geometries commonly encountered in nanoscale systems.

8.
Cancer ; 126(23): 5109-5113, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32986274

RESUMO

BACKGROUND: Individuals of advanced age with comorbidities face a higher risk of death from coronavirus disease 2019 (COVID-19), especially once they are ventilator-dependent. Respiratory decline in patients with COVID-19 is precipitated by a lung-mediated aberrant immune cytokine storm. Low-dose lung radiation was used to treat pneumonia in the pre-antibiotic era. Radiation immunomodulatory effects may improve outcomes for select patients with COVID-19. METHODS: A single-institution trial evaluating the safety and efficacy of single-fraction, low-dose whole-lung radiation for patients with COVID-19 pneumonia is being performed for the first time. This report describes outcomes of a planned day 7 interim analysis. Eligible patients were hospitalized, had radiographic consolidation, required supplemental oxygen, and were clinically deteriorating. RESULTS: Of 9 patients screened, 5 were treated with whole-lung radiation on April 24 until April 28 2020, and they were followed for a minimum of 7 days. The median age was 90 years (range, 64-94 years), and 4 were nursing home residents with multiple comorbidities. Within 24 hours of radiation, 3 patients (60%) were weaned from supplemental oxygen to ambient air, 4 (80%) exhibited radiographic improvement, and the median Glasgow Coma Scale score improved from 10 to 14. A fourth patient (80% overall recovery) was weaned from oxygen at hour 96. The mean time to clinical recovery was 35 hours. There were no acute toxicities. CONCLUSIONS: In a pilot trial of 5 oxygen-dependent elderly patients with COVID-19 pneumonia, low-dose whole-lung radiation led to rapid improvements in clinical status, encephalopathy, and radiographic consolidation without acute toxicity. Low-dose whole-lung radiation appears to be safe, shows early promise of efficacy, and warrants further study. LAY SUMMARY: Researchers at Emory University report preliminary safety outcomes for patients treated with low-dose lung irradiation for coronavirus disease 2019 (COVID-19) pneumonia. Five residents of nursing or group homes were hospitalized after testing positive for COVID-19. Each had pneumonia visible on a chest x-ray, required supplemental oxygen, and experienced a clinical decline in mental status or in work of breathing or a prolonged or escalating supplemental oxygen requirement. A single treatment of low-dose (1.5-Gy) radiation to both lungs was delivered over the course of 10 to 15 minutes. There was no acute toxicity attributable to radiation therapy. Within 24 hours, 4 patients had rapidly improved breathing, and they recovered to room air at an average of 1.5 days (range, 3-96 hours). Three were discharged at a mean time of 12 days, and 1 was preparing for discharge. Blood tests and repeat imaging confirm that low-dose whole-lung radiation treatment appears safe for COVID-19 pneumonia. Further trials are warranted.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/complicações , Pneumonia Viral/complicações , Idoso , Idoso de 80 Anos ou mais , COVID-19 , Ensaios Clínicos como Assunto , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Relação Dose-Resposta à Radiação , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Prognóstico , Fatores de Risco , SARS-CoV-2 , Taxa de Sobrevida , Estados Unidos/epidemiologia
9.
Chemphyschem ; 21(3): 188-193, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31912640

RESUMO

Tip-enhanced Raman spectroscopy (TERS) is a promising technique for structural studies of biological systems and biomolecules, owing to its ability to provide a chemical fingerprint with sub-diffraction-limit spatial resolution. This application of TERS has thus far been limited, due to difficulties in generating high field enhancements while maintaining biocompatibility. The high sensitivity achievable through TERS arises from the excitation of a localized surface plasmon resonance in a noble metal atomic force microscope (AFM) tip, which in combination with a metallic surface can produce huge enhancements in the local optical field. However, metals have poor biocompatibility, potentially introducing difficulties in characterizing native structure and conformation in biomolecules, whereas biocompatible surfaces have weak optical field enhancements. Herein, a novel, biocompatible, highly enhancing surface is designed and fabricated based on few-monolayer mica flakes, mechanically exfoliated on a metal surface. These surfaces allow the formation of coupled plasmon enhancements for TERS imaging, while maintaining the biocompatibility and atomic flatness of the mica surface for high resolution AFM. The capability of these substrates for TERS is confirmed numerically and experimentally. We demonstrate up to five orders of magnitude improvement in TERS signals over conventional mica surfaces, expanding the sensitivity of TERS to a wide range of non-resonant biomolecules with weak Raman cross-sections. The increase in sensitivity obtained through this approach also enables the collection of nanoscale spectra with short integration times, improving hyperspectral mapping for these applications. These mica/metal surfaces therefore have the potential to revolutionize spectromicroscopy of complex, heterogeneous biological systems such as DNA and protein complexes.


Assuntos
Silicatos de Alumínio/química , Materiais Biocompatíveis/química , Ouro/química , Microscopia de Força Atômica/instrumentação , DNA/análise , Microscopia de Força Atômica/métodos , Análise Espectral Raman/métodos , Ressonância de Plasmônio de Superfície/métodos
10.
Pediatr Blood Cancer ; 67(10): e28629, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32776500

RESUMO

This report by the Radiation Oncology Discipline of Children's Oncology Group (COG) describes the practice patterns of pediatric image-guided radiotherapy (IGRT) based on a member survey and provides practice recommendations accordingly. The survey comprised of 11 vignettes asking clinicians about their recommended treatment modalities, IGRT preferences, and frequency of in-room verification. Technical questions asked physicists about imaging protocols, dose reduction, setup correction, and adaptive therapy. In this report, the COG Radiation Oncology Discipline provides an IGRT modality/frequency decision tree and the expert guidelines for the practice of ionizing image guidance in pediatric radiotherapy patients.


Assuntos
Neoplasias/radioterapia , Guias de Prática Clínica como Assunto/normas , Padrões de Prática Médica/normas , Radioterapia (Especialidade)/normas , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Criança , Humanos , Neoplasias/patologia , Dosagem Radioterapêutica
11.
J Biol Chem ; 293(49): 19038-19046, 2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30323065

RESUMO

Two DNA methyltransferases, Dam and ß-class cell cycle-regulated DNA methyltransferase (CcrM), are key mediators of bacterial epigenetics. CcrM from the bacterium Caulobacter crescentus (CcrM C. crescentus, methylates adenine at 5'-GANTC-3') displays 105-107-fold sequence discrimination against noncognate sequences. However, the underlying recognition mechanism is unclear. Here, CcrM C. crescentus activity was either improved or mildly attenuated with substrates having one to three mismatched bp within or adjacent to the recognition site, but only if the strand undergoing methylation is left unchanged. By comparison, single-mismatched substrates resulted in up to 106-fold losses of activity with α (Dam) and γ-class (M.HhaI) DNA methyltransferases. We found that CcrM C. crescentus has a greatly expanded DNA-interaction surface, covering six nucleotides on the 5' side and eight nucleotides on the 3' side of its recognition site. Such a large interface may contribute to the enzyme's high sequence fidelity. CcrM C. crescentus displayed the same sequence discrimination with single-stranded substrates, and a surprisingly large (>107-fold) discrimination against ssRNA was largely due to the presence of two or more riboses within the cognate (DNA) site but not outside the site. Results from C-terminal truncations and point mutants supported our hypothesis that the recently identified C-terminal, 80-residue segment is essential for dsDNA recognition but is not required for single-stranded substrates. CcrM orthologs from Agrobacterium tumefaciens and Brucella abortus share some of these newly discovered features of the C. crescentus enzyme, suggesting that the recognition mechanism is conserved. In summary, CcrM C. crescentus uses a previously unknown DNA recognition mechanism.


Assuntos
Proteínas de Bactérias/metabolismo , Caulobacter crescentus/enzimologia , DNA Bacteriano/metabolismo , DNA Metiltransferases Sítio Específica (Adenina-Específica)/metabolismo , Agrobacterium tumefaciens/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Pareamento Incorreto de Bases , Brucella abortus/enzimologia , Domínio Catalítico , Metilação de DNA , DNA Bacteriano/genética , Domínios Proteicos , DNA Metiltransferases Sítio Específica (Adenina-Específica)/química
12.
J Pediatr Orthop ; 39(2): e102-e107, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29068805

RESUMO

BACKGROUND: Few studies exist to inform the extrapolated practice of irradiating children for heterotopic ossification (HO) prevention. We report the incidence of HO formation following prophylactic preoperative compared with postoperative radiation therapy (RT) in children with neuromuscular hip dysplasia (NHD) following proximal femoral resection (PFR). METHODS: A retrospective, 2-institution chart review was performed. Eligibility was limited to patients with at least 1 year of follow-up. Evaluation included radiographic HO grading by a combined severity scale, assessment of synchronous symptoms of pain or decreased range of motion, and stratification by preoperative versus postoperative reception of RT. A control cohort included 4 nonirradiated hips with NHD after PFR. RESULTS: Twenty-five hips in 20 children met eligibility criteria. Eleven hips were irradiated preoperatively and 14 postoperatively. Radiographic evidence of post-RT development of radiographic evidence of heterotopic ossification (rHO) was found in all 25 hips and earlier in patients irradiated preoperatively (median time to rHO was 4.0 vs. 15.7 mo, P=0.03, 95% confidence interval, 0.24-21.5). There was no statistically significant difference in the development of symptomatic HO (P=0.62) between the preoperative (45.5%) and postoperative (35.7%) groups, nor in HO grade (P=0.34). Seven (28%) of the 25 hips (5 preoperative and 2 postoperative) had documentation of rHO-free intervals after surgery, with an average duration of 5.6 months, while the remaining presented with rHO at first follow-up visit. All eligible control hips (100%) developed rHO and symptomatic heterotopic ossification. CONCLUSIONS: Perioperative RT did not prevent the formation of HO in any child with NHD after PFR. Extrapolation of evidence of the efficacy of RT for HO prevention in ambulatory adults after traumatic hip injury to a population of children with central nervous system injury and NHD may be premature. Additional studies are needed to clarify optimal prevention of HO in this population. LEVEL OF EVIDENCE: Level III-therapeutic retrospective comparative study.


Assuntos
Luxação do Quadril/radioterapia , Luxação do Quadril/cirurgia , Articulação do Quadril/efeitos da radiação , Ossificação Heterotópica/prevenção & controle , Ossificação Heterotópica/radioterapia , Adolescente , Criança , Terapia Combinada , Feminino , Luxação do Quadril/complicações , Luxação Congênita de Quadril/complicações , Humanos , Incidência , Masculino , Ossificação Heterotópica/epidemiologia , Ossificação Heterotópica/etiologia , Período Pós-Operatório , Período Pré-Operatório , Estudos Retrospectivos , Fatores de Risco
13.
Cancer ; 124(16): 3390-3400, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29905942

RESUMO

BACKGROUND: To the authors' knowledge, health-related quality of life (HRQOL) outcomes are not well described in patients with medulloblastoma. The use of proton radiotherapy (RT) may translate into an improved HRQOL. In the current study, the authors report long-term HRQOL in patients with proton-treated pediatric medulloblastoma. METHODS: The current study was a prospective cohort HRQOL study of patients with medulloblastoma who were treated with proton RT and enrolled between August 5, 2002, and October 8, 2015. Both child report and parent-proxy report Pediatric Quality of Life Inventory (PedsQL) surveys were collected at baseline during RT and annually thereafter (score range on surveys of 0-100, with higher scores indicating better HRQOL). Patients were dichotomized by clinical/treatment variables and subgroups were compared. Mixed-model analysis was performed to determine the longitudinal trajectory of PedsQL scores. The Student t test was used to compare long-term HRQOL measures with published means from a healthy child population. RESULTS: Survey data were evaluable for 116 patients with a median follow-up of 5 years (range, 1-10.6 years); the median age at the time of diagnosis was 7.6 years (range, 2.1-18.1 years). At baseline, children reported a total core score (TCS) of 65.9, which increased by 1.8 points annually (P<.001); parents reported a TCS of 59.1, which increased by 2.0 points annually. Posterior fossa syndrome adversely affected baseline scores, but these scores significantly improved with time. At the time of last follow-up, children reported a TCS of 76.3, which was 3.3 points lower than that of healthy children (P = .09); parents reported a TCS of 69, which was 11.9 points lower than that of parents of healthy children (P<.001). Increased follow-up time from diagnosis correlated with improved HRQOL scores. CONCLUSIONS: HRQOL scores appear to increase over time after treatment in children treated with proton RT for medulloblastoma but remain lower compared with those of parent-proxy reports as well as published means from a healthy normative sample of children. Additional follow-up may translate into continued improvements in HRQOL. Cancer 2018. © 2018 American Cancer Society.


Assuntos
Meduloblastoma/epidemiologia , Meduloblastoma/radioterapia , Pediatria , Terapia com Prótons/efeitos adversos , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Meduloblastoma/patologia , Pais , Qualidade de Vida , Inquéritos e Questionários , Adulto Jovem
14.
Cancer ; 124(10): 2238-2245, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29499085

RESUMO

BACKGROUND: Radiotherapy (RT) in the pediatric brain tumor population causes late neurocognitive effects. In the current study, the authors investigated associations between clinical and dosimetric risk factors and memory outcomes in a cohort of patients treated with proton radiotherapy (PRT). METHODS: A total of 70 patients (median age at PRT, 12.1 years [range, 5.0-22.5 years]) who were treated with PRT were identified with baseline and follow-up evaluations of visual and verbal memory (Children's Memory Scale and the third edition of the Wechsler Memory Scale). Whole-brain as well as bilateral hippocampal and temporal lobe contours were delineated for the calculation of dosimetric indices. Multivariate analyses were performed to assess associations of score changes over time with clinical factors and dosimetric indices. RESULTS: The median neurocognitive follow-up was 3.0 years (range, 1.1-11.4 years). For the entire cohort, delayed and immediate verbal memory scaled scores demonstrated small declines. The mean decline for delayed verbal memory scores was 0.6 (P = .01), and that for immediate verbal memory scores was 0.5 (P = .06). Immediate and delayed visual memory scores were not found to change significantly (+0.1 and -0.3, respectively; P>.30). A higher left hippocampal V20GyE (percentage of the volume of a particular anatomical region receiving at least a 20 gray equivalent) was correlated with a score decline in all 4 measures. Female sex was found to be predictive of lower delayed verbal memory follow-up scores (P = .035). CONCLUSIONS: Only delayed verbal memory scores were found to have declined statistically significantly at follow-up after PRT, reflecting some weakness in verbal memory retrieval. Given a correlation of left hippocampal dosimetry and memory outcomes after PRT, left hippocampal-sparing PRT plans may assist patients with pediatric brain tumors in preserving memory-retrieval abilities. Cancer 2018;124:2238-45. © 2018 American Cancer Society.


Assuntos
Neoplasias Encefálicas/radioterapia , Sobreviventes de Câncer/estatística & dados numéricos , Hipocampo/efeitos da radiação , Transtornos da Memória/diagnóstico , Terapia com Prótons/efeitos adversos , Adolescente , Adulto , Criança , Pré-Escolar , Cognição/fisiologia , Cognição/efeitos da radiação , Feminino , Seguimentos , Hipocampo/fisiopatologia , Humanos , Masculino , Memória/fisiologia , Memória/efeitos da radiação , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Testes Neuropsicológicos , Tratamentos com Preservação do Órgão/efeitos adversos , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/fisiopatologia , Órgãos em Risco/efeitos da radiação , Terapia com Prótons/métodos , Radiometria , Planejamento da Radioterapia Assistida por Computador/métodos , Resultado do Tratamento , Adulto Jovem
15.
Biochemistry ; 56(30): 3913-3922, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28661661

RESUMO

Caulobacter crescentus relies on DNA methylation by the cell cycle-regulated methyltransferase (CcrM) in addition to key transcription factors to control the cell cycle and direct cellular differentiation. CcrM is shown here to efficiently methylate its cognate recognition site 5'-GANTC-3' in single-stranded and hemimethylated double-stranded DNA. We report the Km, kcat, kmethylation, and Kd for single-stranded and hemimethylated substrates, revealing discrimination of 107-fold for noncognate sequences. The enzyme also shows a similar discrimination against single-stranded RNA. Two independent assays clearly show that CcrM is highly processive with single-stranded and hemimethylated DNA. Collectively, the data provide evidence that CcrM and other DNA-modifying enzymes may use a new mechanism to recognize DNA in a key epigenetic process.


Assuntos
Caulobacter crescentus/enzimologia , Metilação de DNA , DNA de Cadeia Simples/metabolismo , DNA/metabolismo , DNA Metiltransferases Sítio Específica (Adenina-Específica)/metabolismo , Caulobacter crescentus/citologia , Ciclo Celular , Coenzimas/metabolismo , DNA/química , DNA de Cadeia Simples/química , Ensaio de Desvio de Mobilidade Eletroforética , Fluoresceínas/análise , Corantes Fluorescentes/análise , Cinética , Motivos de Nucleotídeos , RNA/química , RNA/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/metabolismo , S-Adenosilmetionina/metabolismo , DNA Metiltransferases Sítio Específica (Adenina-Específica)/genética , Especificidade por Substrato , Termodinâmica , Trítio
16.
Chembiochem ; 17(21): 2018-2021, 2016 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-27595234

RESUMO

The human DNA methyltransferase 3A (DNMT 3A) is responsible for de novo epigenetic regulation, which is essential for mammalian viability and implicated in diverse diseases. All DNA cytosine C5 methyltransferases follow a broadly conserved catalytic mechanism. We investigated whether C5 ß-elimination contributes to the rate-limiting step in catalysis by DNMT3A and the bacterial M.HhaI by using deuterium substitutions of C5 and C6 hydrogens. This substitution caused a 1.59-1.83 fold change in the rate of catalysis, thus suggesting that ß-elimination is partly rate-limiting for both enzymes. We used a multisite substrate to explore the consequences of slowing ß-elimination during multiple cycles of catalysis. Processive catalysis was slower for both enzymes, and deuterium substitution resulted in DNMT 3A dissociating from its substrate. The decrease in DNA methylation rate by DNMT 3A provides the basis of our ongoing efforts to alter cellular DNA methylation levels without the toxicity of currently used methods.


Assuntos
Citosina/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , DNA/metabolismo , Deutério/metabolismo , Biocatálise , Citosina/química , DNA/genética , DNA (Citosina-5-)-Metiltransferases/química , DNA Metiltransferase 3A , Deutério/química , Humanos
17.
Clin Radiol ; 71(2): 151-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26703115

RESUMO

AIM: To assess the diagnostic accuracy of computed tomography coronary angiography (CTCA) using a combination of high-definition CT (HD-CTCA) and high level of reader experience, with invasive coronary angiography (ICA) as the reference standard, in high-risk patients for the investigation of coronary artery disease (CAD). MATERIALS AND METHODS: Three hundred high-risk patients underwent HD-CTCA and ICA. Independent experts evaluated the images for the presence of significant CAD, defined primarily as the presence of moderate (≥ 50%) stenosis and secondarily as the presence of severe (≥ 70%) stenosis in at least one coronary segment, in a blinded fashion. HD-CTCA was compared to ICA as the reference standard. RESULTS: No patients were excluded. Two hundred and six patients (69%) had moderate and 178 (59%) had severe stenosis in at least one vessel at ICA. The sensitivity, specificity, positive predictive value, and negative predictive value were 97.1%, 97.9%, 99% and 93.9% for moderate stenosis, and 98.9%, 93.4%, 95.7% and 98.3%, for severe stenosis, on a per-patient basis. CONCLUSION: The combination of HD-CTCA and experienced readers applied to a high-risk population, results in high diagnostic accuracy comparable to ICA. Modern generation CT systems in experienced hands might be considered for an expanded role.


Assuntos
Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Risco , Sensibilidade e Especificidade
18.
Clin Radiol ; 71(8): 722-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27207375

RESUMO

Computed tomography coronary angiography is increasingly used in imaging departments in the investigation of patients with chest pain and suspected coronary artery disease. Due to the routine use of heart rate controlling medication and the potential for very high radiation doses during these scans, there is a need for guidance on best practice for departments performing this examination, so the patient can be assured of a good quality scan and outcome in a safe environment. This article is a summary of the document on 'Standards of practice of computed tomography coronary angiography (CTCA) in adult patients' published by the Royal College of Radiologists (RCR) in December 2014.


Assuntos
Angiografia por Tomografia Computadorizada/normas , Angiografia Coronária/normas , Segurança do Paciente/normas , Guias de Prática Clínica como Assunto , Proteção Radiológica/normas , Radiologia/normas , Cardiologia/normas , Humanos , Exposição à Radiação/prevenção & controle , Exposição à Radiação/normas , Reino Unido
19.
Psychooncology ; 23(8): 841-54, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24846702

RESUMO

BACKGROUND: This paper aimed to systematically review the (1) prevalence, (2) risk factors, (3) interventions, and (4) measurement instruments associated with psychosocial function decline in radiation therapy (RT) patients. METHODS: A MEDLINE systematic literature review was performed to identify studies monitoring psychosocial function among RT patients as a primary endpoint. RESULTS: Fifty-seven and 22 risk factors for RT-related psychosocial function decline were identified and refuted, respectively, in 93 eligible studies representing 12,808 patients. Median prevalences of psychosocial function decline prior to, during, and following RT were 20%, 36%, and 25%. Prior to RT, anxiety was more prevalent than depression (20% vs 15%), but dropped following completion of RT, whereas median depression levels remained elevated (17% vs. 27%). Of the 79 identified risk factors, 17 were reported as predictive of psychosocial decline by two or more more studies, and five had robust support: (1) physical symptoms, (2) time point during RT, (3) chemotherapy reception, (4) female gender, and (5) younger age. Three interventions were consensually reported to improve psychosocial function: psychotherapy, nursing consultation/patient education, and self-management training. Eighty-six different assessment tools were used to monitor RT-related psychosocial function decline with the Hospital Anxiety and Depression Scale (25.8%) and the psychiatric interview (22.6%) being the most utilized. The distress thermometer has been used in 5 studies (5.4%) to date. CONCLUSION: Psychosocial function declines in approximately one-third of RT patients. Anxiety can dissipate after initiation of RT, whereas depression can persist throughout and after RT. Severe physical symptoms and time-related factors most robustly predict psychosocial function decline, which can be improved by psychotherapy and interventions aimed to improve patient education.


Assuntos
Ansiedade/psicologia , Depressão/psicologia , Neoplasias/psicologia , Instituições de Assistência Ambulatorial , Humanos , Neoplasias/radioterapia , Radioterapia (Especialidade) , Radioterapia/psicologia
20.
Otolaryngol Head Neck Surg ; 170(1): 265-271, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37622584

RESUMO

OBJECTIVE: Create an aerosol containment mask (ACM) for common otolaryngologic endoscopic procedures which also provides nanoparticle-level protection to patients. STUDY DESIGN: Prospective feasibility study. SETTING: In-person testing with a novel ACM. METHODS: The mask was designed in Solidworks and 3-dimensional printed. Measurements were made on 100 consecutive clinic patients who underwent medically necessarily endoscopy, 50 rigid nasal and 50 flexible, by 9 surgeons. RESULTS: Of the 50 patients who underwent rigid nasal endoscopy with the ACM, 0 of 25 patients with the suction off and 0 of 25 patients with the suction on had evidence of leakage of 0.3 µm particles. Of the 50 patients who underwent flexible endoscopy with the ACM, 0 of 25 patients with the suction off and 0 of 25 patients with the suction on had evidence of leakage of 0.3 µm particles. In terms of comfort, 73% of patients found the ACM somewhat or very comfortable without suction, compared to 86% with the suction on. Surgeons were able to visualize all necessary anatomic areas in 98% of procedures. In 97% of procedures, the masks were able to be placed easily. CONCLUSION: ACM can accommodate rigid nasal and flexible endoscopes and may prevent leakage of patient-generated aerosols, thus avoiding contamination of the room and protecting health care workers from airborne contagions. LEVEL OF EVIDENCE: The level of evidence is 2.


Assuntos
COVID-19 , Humanos , COVID-19/prevenção & controle , Estudos Prospectivos , Aerossóis e Gotículas Respiratórios , Endoscopia , Nariz
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