Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 225
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Gastroenterology ; 165(1): 252-266, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36948424

RESUMO

BACKGROUND & AIMS: Colorectal cancer (CRC) screening guidelines include screening colonoscopy and sequential high-sensitivity fecal occult blood testing (HSgFOBT), with expectation of similar effectiveness based on the assumption of similar high adherence. However, adherence to screening colonoscopy compared with sequential HSgFOBT has not been reported. In this randomized clinical trial, we assessed adherence and pathology findings for a single screening colonoscopy vs sequential and nonsequential HSgFOBTs. METHODS: Participants aged 40-69 years were enrolled at 3 centers representing different clinical settings. Participants were randomized into a single screening colonoscopy arm vs sequential HSgFOBT arm composed of 4-7 rounds. Initial adherence to screening colonoscopy and sequential adherence to HSgFOBT, follow-up colonoscopy for positive HSgFOBT tests, crossover to colonoscopy, and detection of advanced neoplasia or large serrated lesions (ADN-SERs) were measured. RESULTS: There were 3523 participants included in the trial; 1761 and 1762 participants were randomized to the screening colonoscopy and HSgFOBT arms, respectively. Adherence was 1473 (83.6%) for the screening colonoscopy arm vs 1288 (73.1%) for the HSgFOBT arm after 1 round (relative risk [RR], 1.14; 95% CI, 1.10-1.19; P ≤ .001), but only 674 (38.3%) over 4 sequential HSgFOBT rounds (RR, 2.19; 95% CI, 2.05-2.33). Overall adherence to any screening increased to 1558 (88.5%) in the screening colonoscopy arm during the entire study period and 1493 (84.7%) in the HSgFOBT arm (RR, 1.04; 95% CI, 1.02-1.07). Four hundred thirty-six participants (24.7%) crossed over to screening colonoscopy during the first 4 rounds. ADN-SERs were detected in 121 of the 1473 participants (8.2%) in the colonoscopy arm who were adherent to protocol in the first 12 months of the study, whereas detection of ADN-SERs among those who were not sequentially adherent (n = 709) to HSgFOBT was subpar (0.6%) (RR, 14.72; 95% CI, 5.46-39.67) compared with those who were sequentially adherent (3.3%) (n = 647) (RR, 2.52; 95% CI, 1.61-3.98) to HSgFOBT in the first 4 rounds. When including colonoscopies from HSgFOBT patients who were never positive yet crossed over (n = 1483), 5.5% of ADN-SERs were detected (RR, 1.50; 95% CI, 1.15-1.96) in the first 4 rounds. CONCLUSIONS: Observed adherence to sequential rounds of HSgFOBT was suboptimal compared with a single screening colonoscopy. Detection of ADN-SERs was inferior when nonsequential HSgFOBT adherence was compared with sequential adherence. However, the greatest number of ADN-SERs was detected among those who crossed over to colonoscopy and opted to receive a colonoscopy. The effectiveness of an HSgFOBT screening program may be enhanced if crossover to screening colonoscopy is permitted. CLINICALTRIALS: gov, Number: NCT00102011.


Assuntos
Neoplasias Colorretais , Sangue Oculto , Humanos , Colonoscopia , Programas de Rastreamento/métodos , Testes Hematológicos , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer/métodos
2.
Am J Gastroenterol ; 119(7): 1392-1401, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38318949

RESUMO

INTRODUCTION: Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data. METHODS: The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial. RESULTS: Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon. DISCUSSION: Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.


Assuntos
Colonoscopia , Neoplasias Colorretais , Detecção Precoce de Câncer , Sangue Oculto , Cooperação do Paciente , Humanos , Colonoscopia/estatística & dados numéricos , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/mortalidade , Detecção Precoce de Câncer/métodos , Incidência , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Cooperação do Paciente/estatística & dados numéricos , Programas de Rastreamento/métodos , Guaiaco
3.
J Exp Bot ; 75(8): 2545-2557, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38271585

RESUMO

Non-structural carbohydrates (NSCs) are building blocks for biomass and fuel metabolic processes. However, it remains unclear how tropical forests mobilize, export, and transport NSCs to cope with extreme droughts. We combined drought manipulation and ecosystem 13CO2 pulse-labeling in an enclosed rainforest at Biosphere 2, assessed changes in NSCs, and traced newly assimilated carbohydrates in plant species with diverse hydraulic traits and canopy positions. We show that drought caused a depletion of leaf starch reserves and slowed export and transport of newly assimilated carbohydrates below ground. Drought effects were more pronounced in conservative canopy trees with limited supply of new photosynthates and relatively constant water status than in those with continual photosynthetic supply and deteriorated water status. We provide experimental evidence that local utilization, export, and transport of newly assimilated carbon are closely coupled with plant water use in canopy trees. We highlight that these processes are critical for understanding and predicting tree resistance and ecosystem fluxes in tropical forest under drought.


Assuntos
Carbono , Floresta Úmida , Carbono/metabolismo , Ecossistema , Secas , Água/metabolismo , Árvores/metabolismo , Carboidratos , Folhas de Planta/metabolismo
4.
Glob Chang Biol ; 30(3): e17209, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38469989

RESUMO

Active restoration through silvicultural treatments (enrichment planting, cutting climbers and liberation thinning) is considered an important intervention in logged forests. However, its ability to enhance regeneration is key for long-term recovery of logged forests, which remains poorly understood, particularly for the production and survival of seedlings in subsequent generations. To understand the long-term impacts of logging and restoration we tracked the diversity, survival and traits of seedlings that germinated immediately after a mast fruiting in North Borneo in unlogged and logged forests 30-35 years after logging. We monitored 5119 seedlings from germination for ~1.5 years across a mixed landscape of unlogged forests (ULs), naturally regenerating logged forests (NR) and actively restored logged forests via rehabilitative silvicultural treatments (AR), 15-27 years after restoration. We measured 14 leaf, root and biomass allocation traits on 399 seedlings from 15 species. Soon after fruiting, UL and AR forests had higher seedling densities than NR forest, but survival was the lowest in AR forests in the first 6 months. Community composition differed among forest types; AR and NR forests had lower species richness and lower evenness than UL forests by 5-6 months post-mast but did not differ between them. Differences in community composition altered community-weighted mean trait values across forest types, with higher root biomass allocation in NR relative to UL forest. Traits influenced mortality ~3 months post-mast, with more acquisitive traits and relative aboveground investment favoured in AR forests relative to UL forests. Our findings of reduced seedling survival and diversity suggest long time lags in post-logging recruitment, particularly for some taxa. Active restoration of logged forests recovers initial seedling production, but elevated mortality in AR forests lowers the efficacy of active restoration to enhance recruitment or diversity of seedling communities. This suggests current active restoration practices may fail to overcome barriers to regeneration in logged forests, which may drive long-term changes in future forest plant communities.


A restauração ativa por meio de tratamentos silviculturais (plantio de enriquecimento, corte de trepadeiras e desbaste) é considerada uma intervenção importante em florestas com exploração de madeira. No entanto, sua capacidade de melhorar a regeneração, essencial para a recuperação de longo prazo das florestas exploradas, permanece pouco compreendida, especialmente no que diz respeito à produção e sobrevivência de mudas em gerações subsequentes. Para compreender os impactos de longo prazo da exploração madeireira e da restauração, acompanhamos a diversidade, sobrevivência e características de plântulas que germinaram imediatamente após uma frutificação em massa no norte de Bornéu, em florestas com e sem exploração de madeira, 30-35 anos após o fim da extração. Monitoramos 5119 mudas desde a germinação por aproximadamente 1,5 anos em uma paisagem mista de florestas não exploradas (UL), florestas exploradas em regeneração natural (NR) e florestas exploradas restauradas ativamente por meio de tratamentos silviculturais de reabilitação (AR), 15-27 anos após a restauração. Medimos 14 traços funcionais de folhas, raízes e alocação de biomassa em 399 mudas de 15 espécies. Logo após a frutificação, as florestas UL e AR apresentaram densidades de mudas mais altas do que as florestas NR, mas a sobrevivência foi mais baixa nas florestas AR nos primeiros seis meses. A composição da comunidade diferiu entre os tipos de floresta; as florestas AR e NR teviram menor riqueza de espécies e menor equidade do que as florestas UL 5-6 meses após a frutificação, mas não diferiram entre si. As diferenças na composição da comunidade alteraram os valores de média ponderada pela comunidade das características entre os tipos de floresta com maior alocação de biomassa radicular nas florestas NR em relação às florestas UL. As características influenciaram a mortalidade aproximadamente 3 meses após a frutificação, com traços mais aquisitivos maior investimento em biomassa relativa acima do solo nas florestas AR em relação às florestas UL. Nossas descobertas de redução na sobrevivência e diversidade de plântulas sugerem que há longos retardos no recrutamento após o fim da exploração de madeira, particularmente para alguns táxons. A restauração ativa de florestas exploradas recupera a produção inicial de plântulas, mas a mortalidade elevada nas florestas AR diminui a eficácia da restauração ativa no melhorio do recrutamento e da diversidade das comunidades de mudas. Isso sugere que as práticas atuais de restauração ativa podem não superar as barreiras à regeneração em florestas exploradas, o que pode levar a mudanças de longo prazo nas comunidades florestais no futuro.


Assuntos
Agricultura Florestal , Árvores , Florestas , Plântula , Germinação , Clima Tropical
5.
Evol Anthropol ; 33(1): e22009, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37961949

RESUMO

The theory of punctuated equilibrium (PE) was developed a little over 50 years ago to explain long-term, large-scale appearance and disappearance of species in the fossil record. A theory designed specifically for that purpose cannot be expected, out of the box, to be directly applicable to biocultural evolution, but in revised form, PE offers a promising approach to incorporating not only a wealth of recent empirical research on genetic, linguistic, and technological evolution but also large databases that document human biological and cultural diversity across time and space. Here we isolate the fundamental components of PE and propose which pieces, when reassembled or renamed, can be highly useful in evolutionary anthropology, especially as humanity faces abrupt ecological challenges on an increasingly larger scale.


Assuntos
Evolução Biológica , Fósseis , Humanos , Diversidade Cultural , Bases de Dados Factuais
6.
Methods ; 217: 18-26, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37356780

RESUMO

Global Run-On sequencing is a reliable and widely used approach for monitoring nascent transcription on a genomewide scale. The assay has been successfully used for studying global transcription in humans, plants, worms, flies, and fission yeast. Here we describe a GRO-seq protocol for studying transcription in budding yeast, Saccharomyces cerevisiae. Briefly, the technique involves permeabilization of actively growing yeast cells, allowing transcription to proceed in permeabilized cells in the presence of brominated UTP, affinity purification of bromo-UMP incorporated nascent transcripts followed by cDNA library construction, deep sequencing, and mapping against the reference genome. The approach maps the position of transcriptionally active RNA polymerase on a genomewide basis. In addition to identifying the complete set of transcriptionally active genes in a cell under a given set of conditions, the method can be used to determine elongation rate, termination defect and promoter directionality at the genomewide level. The approach is especially useful in identifying short-lived unstable transcripts that are rapidly degraded even before they leave the nucleus.


Assuntos
Saccharomyces cerevisiae , Transcrição Gênica , Humanos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Análise de Sequência de RNA/métodos , Núcleo Celular/metabolismo , RNA Polimerase II/metabolismo
7.
Ophthalmic Physiol Opt ; 44(6): 1091-1099, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38853693

RESUMO

INTRODUCTION: Visual function deficits have been reported in adolescents following concussion. We compared vergence and accommodation deficits in paediatric and adolescent patients at a tertiary medical centre in the sub-acute (15 days to 12 weeks) and chronic (12 weeks to 1 year) phases of concussion recovery. METHODS: The study included patients aged 7 to <18 years seen between 2014 and 2021, who had a binocular vision (BV) examination conducted within 15 days and 1 year of their concussion injury. Included patients had to have 0.10 logMAR monocular best-corrected vision or better in both eyes and be wearing a habitual refractive correction. BV examinations at near included measurements of near point of convergence, convergence and divergence amplitudes, vergence facility, monocular accommodative amplitude and monocular accommodative facility. Vergence and accommodation deficits were diagnosed using established clinical criteria. Group differences were assessed using nonparametric statistics and ANCOVA modelling. RESULTS: A total of 259 patients were included with 111 in the sub-acute phase and 148 in the chronic phase of concussion recovery. There was no significant difference in the rates of vergence deficits between the two phases of concussion recovery (sub-acute = 48.6%; chronic = 49.3%). There was also no significant difference in the rates of accommodation deficits between the two phases of concussion recovery (sub-acute = 82.0%; chronic = 77.0%). CONCLUSION: Patients in both the sub-acute and chronic phases of concussion recovery exhibited a high frequency of vergence and accommodation deficits, with no significant differences between groups. Results indicate that patients exhibiting vision deficits in the sub-acute phase may not resolve without intervention, though a prospective, longitudinal study is required to test the hypothesis.


Assuntos
Acomodação Ocular , Concussão Encefálica , Convergência Ocular , Recuperação de Função Fisiológica , Visão Binocular , Humanos , Adolescente , Criança , Masculino , Feminino , Acomodação Ocular/fisiologia , Convergência Ocular/fisiologia , Visão Binocular/fisiologia , Concussão Encefálica/fisiopatologia , Concussão Encefálica/complicações , Acuidade Visual/fisiologia , Estudos Retrospectivos , Doença Crônica , Seguimentos , Transtornos da Visão/fisiopatologia , Transtornos da Visão/etiologia
8.
Arthroscopy ; 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38593928

RESUMO

PURPOSE: To perform a systematic review evaluating clinical outcomes in patients undergoing medial ulnar collateral ligament reconstruction (MUCLR) with soft-tissue allograft. METHODS: A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcomes evaluated were patient-reported outcome scores, return to play (RTP) rates, incidence of postoperative complications, and rates of graft rupture or mechanical failure. RESULTS: The literature search identified 395 articles, and 5 studies met final inclusion criteria after full-text review. A total of 274 patients were analyzed in the included studies and follow-up ranged from 3.0 to 7.6 years. Two studies (number of patients = 141) reported outcomes exclusively of MUCLR with allograft, whereas 3 studies (number of patients = 133) reported outcomes in patients undergoing MUCLR with either allograft or autograft. Allograft sources included gracilis, semitendinosus, plantaris, peroneus longus, and palmaris longus. Level of patient athletic competition ranged from recreational athletes to the professional level; however, nonathletes in the setting of trauma were also included. The RTP rate after MUCLR with soft-tissue allograft was 95.3%, and 89.3% of patients returned to a similar or greater level of play postoperatively. The Timmerman-Andrews score was reported in 2 studies, and the means postoperatively ranged from 94.55 to 97. Postoperative complication rates were low (range, 0% to 20%), and there were no reported incidences of allograft rupture or mechanical failure. CONCLUSIONS: Based on the available data, soft-tissue allograft for MUCLR in athletic patient populations provides excellent clinical outcomes, high rates of RTP, and low rates of postoperative complications and graft failure at short-term follow-up. There remains a lack of high-quality evidence directly comparing autograft versus allograft outcomes in elite overhead-throwing athletes to support allograft as an acceptable alternative for MUCLR in this patient population. LEVEL OF EVIDENCE: Level IV, systematic review of Level III-IV studies.

9.
J Shoulder Elbow Surg ; 33(2): 457-465, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37844833

RESUMO

There has been an epidemic increase in injuries to the elbow in our youth sports over the past 15 years. Initially, career-ending elbow injuries occurred almost exclusively in the professional population. The landmark procedure developed by Dr. Frank Jobe, colloquially termed "Tommy John surgery" after the initial player in whom he performed the surgical procedure, allowed roughly two-thirds of professional athletes to return to play at or near the same level. As the surgical procedure became more widespread, modifications of the technique by Jobe and many other contributors raised the return-to-play level to 85%-94% of players regaining the ability to return to sport at the preinjury level. Almost simultaneously, the emphasis on velocity in the professional ranks led to an unintentional increase in stress on the throwing elbow. This was magnified in our athletes by the advent of year-round sports, as well as the formation of "showcase" events to demonstrate skills and measure velocity. This, unfortunately, has resulted in an increase in both repetitive stress injuries and acute traumatic injuries in our young athletes. The purpose of this article is to discuss age-related injuries from both a preventative standpoint and a treatment standpoint.


Assuntos
Traumatismos do Braço , Traumatismos em Atletas , Beisebol , Ligamentos Colaterais , Lesões no Cotovelo , Articulação do Cotovelo , Masculino , Adolescente , Humanos , Cotovelo , Beisebol/lesões , Articulação do Cotovelo/cirurgia , Atletas , Traumatismos em Atletas/diagnóstico , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/cirurgia , Ligamentos Colaterais/cirurgia
10.
Int J Mol Sci ; 25(16)2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39201330

RESUMO

Apart from its well-established role in the initiation of transcription, the general transcription factor TFIIB has been implicated in the termination step as well. The ubiquity of TFIIB involvement in termination as well as mechanistic details of its termination function, however, remain largely unexplored. Using GRO-seq analyses, we compared the terminator readthrough phenotype in the sua7-1 mutant (TFIIBsua7-1) and the isogenic wild type (TFIIBWT) strains. Approximately 74% of genes analyzed exhibited a 2-3-fold increase in readthrough of the poly(A)-termination signal in the TFIIBsua7-1 mutant compared to TFIIBWT cells. To understand the mechanistic basis of TFIIB's role in termination, we performed the mass spectrometry of TFIIB-affinity purified from chromatin and soluble cellular fractions-from TFIIBsua7-1 and TFIIBWT cells. TFIIB purified from the chromatin fraction of TFIIBWT cells exhibited significant enrichment of CF1A and Rat1 termination complexes. There was, however, a drastic decrease in TFIIB interaction with CF1A and Rat1 complexes in the TFIIBsua7-1 mutant. ChIP assays revealed about a 90% decline in the recruitment of termination factors in the TFIIBsua7-1 mutant compared to wild type cells. The overall conclusion of these results is that TFIIB affects the termination of transcription on a genome-wide scale, and the TFIIB-termination factor interaction plays a crucial role in the process.


Assuntos
Fator de Transcrição TFIIB , Fator de Transcrição TFIIB/metabolismo , Fator de Transcrição TFIIB/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Terminação da Transcrição Genética , Mutação , Ligação Proteica , Transcrição Gênica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA