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1.
Mol Cell ; 84(13): 2455-2471.e8, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38908370

RESUMO

Protein folding is assisted by molecular chaperones that bind nascent polypeptides during mRNA translation. Several structurally distinct classes of chaperones promote de novo folding, suggesting that their activities are coordinated at the ribosome. We used biochemical reconstitution and structural proteomics to explore the molecular basis for cotranslational chaperone action in bacteria. We found that chaperone binding is disfavored close to the ribosome, allowing folding to precede chaperone recruitment. Trigger factor recognizes compact folding intermediates that expose an extensive unfolded surface, and dictates DnaJ access to nascent chains. DnaJ uses a large surface to bind structurally diverse intermediates and recruits DnaK to sequence-diverse solvent-accessible sites. Neither Trigger factor, DnaJ, nor DnaK destabilize cotranslational folding intermediates. Instead, the chaperones collaborate to protect incipient structure in the nascent polypeptide well beyond the ribosome exit tunnel. Our findings show how the chaperone network selects and modulates cotranslational folding intermediates.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Proteínas de Choque Térmico HSP40 , Proteínas de Choque Térmico HSP70 , Biossíntese de Proteínas , Dobramento de Proteína , Ribossomos , Ribossomos/metabolismo , Ribossomos/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/química , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP40/genética , Escherichia coli/metabolismo , Escherichia coli/genética , Ligação Proteica , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Modelos Moleculares , Conformação Proteica , Peptidilprolil Isomerase
2.
Mol Cell ; 84(19): 3826-3842.e8, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39303722

RESUMO

RNA interactome studies have revealed that hundreds of zinc-finger proteins (ZFPs) are candidate RNA-binding proteins (RBPs), yet their RNA substrates and functional significance remain largely uncharacterized. Here, we present a systematic multi-omics analysis of the DNA- and RNA-binding targets and regulatory roles of more than 100 ZFPs representing 37 zinc-finger families. We show that multiple ZFPs are previously unknown regulators of RNA splicing, alternative polyadenylation, stability, or translation. The examined ZFPs show widespread sequence-specific RNA binding and preferentially bind proximal to transcription start sites. Additionally, several ZFPs associate with their targets at both the DNA and RNA levels. We highlight ZNF277, a C2H2 ZFP that binds thousands of RNA targets and acts as a multi-functional RBP. We also show that ZNF473 is a DNA/RNA-associated protein that regulates the expression and splicing of cell cycle genes. Our results reveal diverse roles for ZFPs in transcriptional and post-transcriptional gene regulation.


Assuntos
Splicing de RNA , Proteínas de Ligação a RNA , Dedos de Zinco , Humanos , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Regulação da Expressão Gênica , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , RNA/metabolismo , RNA/genética , Ligação Proteica , Células HEK293 , Células HeLa , Processamento Alternativo , Sítios de Ligação , Multiômica
3.
Nature ; 625(7995): 535-539, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38200315

RESUMO

The largest ever primate and one of the largest of the southeast Asian megafauna, Gigantopithecus blacki1, persisted in China from about 2.0 million years until the late middle Pleistocene when it became extinct2-4. Its demise is enigmatic considering that it was one of the few Asian great apes to go extinct in the last 2.6 million years, whereas others, including orangutan, survived until the present5. The cause of the disappearance of G. blacki remains unresolved but could shed light on primate resilience and the fate of megafauna in this region6. Here we applied three multidisciplinary analyses-timing, past environments and behaviour-to 22 caves in southern China. We used 157 radiometric ages from six dating techniques to establish a timeline for the demise of G. blacki. We show that from 2.3 million years ago the environment was a mosaic of forests and grasses, providing ideal conditions for thriving G. blacki populations. However, just before and during the extinction window between 295,000 and 215,000 years ago there was enhanced environmental variability from increased seasonality, which caused changes in plant communities and an increase in open forest environments. Although its close relative Pongo weidenreichi managed to adapt its dietary preferences and behaviour to this variability, G. blacki showed signs of chronic stress and dwindling populations. Ultimately its struggle to adapt led to the extinction of the greatest primate to ever inhabit the Earth.


Assuntos
Extinção Biológica , Fósseis , Hominidae , Animais , Cavernas , China , Dieta/veterinária , Florestas , Hominidae/classificação , Plantas , Pongo , Datação Radiométrica , Estações do Ano , Fatores de Tempo
4.
Proc Natl Acad Sci U S A ; 121(11): e2321595121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38437551

RESUMO

Polynyas, areas of open water embedded within sea ice, are a key component of ocean-atmosphere interactions that act as hotspots of sea-ice production, bottom-water formation, and primary productivity. The specific drivers of polynya dynamics remain, however, elusive and coupled climate models struggle to replicate Antarctic polynya activity. Here, we leverage a 44-y time series of Antarctic sea ice to elucidate long-term trends. We identify Antarctic-wide linear increases and a hitherto undescribed cyclical pattern of polynya activity across the Ross Sea region that potentially arises from interactions between the Amundsen Sea Low and Southern Annular Mode. While their specific drivers remain unknown, identifying these emerging patterns augments our capacity to understand the processes that influence sea ice. As we enter a potentially new age of Antarctic sea ice, this advance in understanding will, in turn, lead to more accurate predictions of environmental change, and its implications for Antarctic ecosystems.

5.
Plant Physiol ; 196(2): 1674-1690, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38713768

RESUMO

Synechococcus sp. PCC 11901 (PCC 11901) is a fast-growing marine cyanobacterial strain that has a capacity for sustained biomass accumulation to very high cell densities, comparable to that achieved by commercially relevant heterotrophic organisms. However, genetic tools to engineer PCC 11901 for biotechnology applications are limited. Here we describe a suite of tools based on the CyanoGate MoClo system to unlock the engineering potential of PCC 11901. First, we characterized neutral sites suitable for stable genomic integration that do not affect growth even at high cell densities. Second, we tested a suite of constitutive promoters, terminators, and inducible promoters including a 2,4-diacetylphloroglucinol (DAPG)-inducible PhlF repressor system, which has not previously been demonstrated in cyanobacteria and showed tight regulation and a 228-fold dynamic range of induction. Lastly, we developed a DAPG-inducible dCas9-based CRISPR interference (CRISPRi) system and a modular method to generate markerless mutants using CRISPR-Cas12a. Based on our findings, PCC 11901 is highly responsive to CRISPRi-based repression and showed high efficiencies for single insertion (31% to 81%) and multiplex double insertion (25%) genome editing with Cas12a. We envision that these tools will lay the foundations for the adoption of PCC 11901 as a robust model strain for engineering biology and green biotechnology.


Assuntos
Synechococcus , Synechococcus/genética , Synechococcus/crescimento & desenvolvimento , Regiões Promotoras Genéticas/genética , Sistemas CRISPR-Cas , Engenharia Genética/métodos , Edição de Genes/métodos
6.
Neuroimage ; 286: 120517, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38211705

RESUMO

Recently, Clarke et al. published a study using spinal cord susceptibility weighted imaging in multiple sclerosis patients at 7T. They discovered dilated intradural extramedullary veins surrounding the cord. The purpose of this commentary is to point out some recent research by our group, which suggests this dilatation also occurs in the bridging cortical veins surrounding the brain. The dilatation indicates a focal elevation in the venous pressure secondary to impedance mismatching. Due to the shared outflow geometry, dilatation of the outflow veins will obstruct the glymphatic pathway of the spinal cord altering the immune response.


Assuntos
Sistema Glinfático , Esclerose Múltipla , Humanos , Veias , Encéfalo/irrigação sanguínea , Medula Espinal , Imageamento por Ressonância Magnética/métodos
7.
J Am Chem Soc ; 146(23): 15681-15687, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38813987

RESUMO

Alcohols are among the most abundant chemical feedstocks, yet they remain vastly underutilized as coupling partners in transition metal catalysis. Herein, we describe a copper metallaphotoredox manifold for the open shell deoxygenative coupling of alcohols with N-nucleophiles to forge C(sp3)-N bonds, a linkage of high value in pharmaceutical agents that is challenging to access via conventional cross-coupling techniques. N-heterocyclic carbene (NHC)-mediated conversion of alcohols into the corresponding alkyl radicals followed by copper-catalyzed C-N coupling renders this platform successful for a broad range of structurally unbiased alcohols and 18 classes of N-nucleophiles.

8.
EMBO J ; 39(21): e105111, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32945574

RESUMO

Elevated ribosome biogenesis in oncogene-driven cancers is commonly targeted by DNA-damaging cytotoxic drugs. Our previous first-in-human trial of CX-5461, a novel, less genotoxic agent that specifically inhibits ribosome biogenesis via suppression of RNA polymerase I (Pol I) transcription, revealed single-agent efficacy in refractory blood cancers. Despite this clinical response, patients were not cured. In parallel, we demonstrated a marked improvement in the in vivo efficacy of CX-5461 in combination with PI3K/AKT/mTORC1 pathway inhibitors. Here, we reveal the molecular basis for this improved efficacy observed in vivo, which is associated with specific suppression of translation of mRNAs encoding regulators of cellular metabolism. Importantly, acquired resistance to this cotreatment is driven by translational rewiring that results in dysregulated cellular metabolism and induction of a cAMP-dependent pathway critical for the survival of blood cancers including lymphoma and acute myeloid leukemia. Our studies thus identify key molecular mechanisms underpinning the response of blood cancers to selective inhibition of ribosome biogenesis and define metabolic vulnerabilities that will facilitate the rational design of more effective regimens for Pol I-directed therapies.


Assuntos
Neoplasias/metabolismo , Biossíntese de Proteínas/genética , Biossíntese de Proteínas/fisiologia , Ribossomos/metabolismo , Transcrição Gênica/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Benzotiazóis/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Naftiridinas/farmacologia , Neoplasias/genética , Fosfatidilinositol 3-Quinases/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores de Proteínas Quinases , RNA Polimerase I/metabolismo , RNA Mensageiro/metabolismo , RNA Ribossômico , Ribossomos/efeitos dos fármacos , Transcriptoma
9.
J Synchrotron Radiat ; 31(Pt 3): 485-492, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38630438

RESUMO

Synchrotron light sources can provide the required spatial coherence, stability and control to support the development of advanced lithography at the extreme ultraviolet and soft X-ray wavelengths that are relevant to current and future fabricating technologies. Here an evaluation of the optical performance of the soft X-ray (SXR) beamline of the Australian Synchrotron (AS) and its suitability for developing interference lithography using radiation in the 91.8 eV (13.5 nm) to 300 eV (4.13 nm) range are presented. A comprehensive physical optics model of the APPLE-II undulator source and SXR beamline was constructed to simulate the properties of the illumination at the proposed location of a photomask, as a function of photon energy, collimation and monochromator parameters. The model is validated using a combination of experimental measurements of the photon intensity distribution of the undulator harmonics. It is shown that the undulator harmonics intensity ratio can be accurately measured using an imaging detector and controlled using beamline optics. Finally, the photomask geometric constraints and achievable performance for the limiting case of fully spatially coherent illumination are evaluated.

10.
Mol Genet Metab ; 142(1): 108345, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38387306

RESUMO

Mutations in MMACHC cause cobalamin C disease (cblC, OMIM 277400), the commonest inborn error of vitamin B12 metabolism. In cblC, deficient activation of cobalamin results in methylcobalamin and adenosylcobalamin deficiency, elevating methylmalonic acid (MMA) and total plasma homocysteine (tHcy). We retrospectively reviewed the medical files of seven cblC patients: three compound heterozygotes for the MMACHC (NM_015506.3) missense variant c.158T>C p.(Leu53Pro) in trans with the common pathogenic mutation c.271dupA (p.(Arg91Lysfs*14), "compounds"), and four c.271dupA homozygotes ("homozygotes"). Compounds receiving hydroxocobalamin intramuscular injection monotherapy had age-appropriate psychomotor performance and normal ophthalmological examinations. In contrast, c.271dupA homozygotes showed marked psychomotor retardation, retinopathy and feeding problems despite penta-therapy (hydroxocobalamin, betaine, folinic acid, l-carnitine and acetylsalicylic acid). Pretreatment levels of plasma and urine MMA and tHcy were higher in c.271dupA homozygotes than in compounds. Under treatment, levels of the compounds approached or entered the reference range but not those of c.271dupA homozygotes (tHcy: compounds 9.8-32.9 µM, homozygotes 41.6-106.8 (normal (N) < 14); plasma MMA: compounds 0.14-0.81 µM, homozygotes, 10.4-61 (N < 0.4); urine MMA: compounds 1.75-48 mmol/mol creatinine, homozygotes 143-493 (N < 10)). Patient skin fibroblasts all had low cobalamin uptake, but this was milder in compound cells. Also, the distribution pattern of cobalamin species was qualitatively different between cells from compounds and from homozygotes. Compared to the classic cblC phenotype presented by c.271dupA homozygous patients, c.[158T>C];[271dupA] compounds had mild clinical and biochemical phenotypes and responded strikingly to hydroxocobalamin monotherapy.


Assuntos
Proteínas de Transporte , Hidroxocobalamina , Fenótipo , Deficiência de Vitamina B 12 , Vitamina B 12 , Humanos , Hidroxocobalamina/administração & dosagem , Hidroxocobalamina/uso terapêutico , Masculino , Feminino , Deficiência de Vitamina B 12/genética , Deficiência de Vitamina B 12/tratamento farmacológico , Deficiência de Vitamina B 12/sangue , Vitamina B 12/sangue , Pré-Escolar , Proteínas de Transporte/genética , Estudos Retrospectivos , Oxirredutases/genética , Criança , Ácido Metilmalônico/sangue , Homocistinúria/tratamento farmacológico , Homocistinúria/genética , Lactente , Mutação de Sentido Incorreto , Homozigoto , Heterozigoto , Homocisteína/sangue , Adolescente , Erros Inatos do Metabolismo dos Aminoácidos/genética , Erros Inatos do Metabolismo dos Aminoácidos/tratamento farmacológico , Erros Inatos do Metabolismo dos Aminoácidos/sangue , Adulto
11.
Ophthalmology ; 131(5): 534-544, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38008289

RESUMO

PURPOSE: To quantify the burden of ocular injuries on deployed US service members by calculating disability-adjusted life years (DALYs). DESIGN: Retrospective, observational cohort study. PARTICIPANTS: US service members with ocular injuries sustained in combat zones from January 1, 2001 to May 19, 2020. METHODS: Health states and duration of injuries were identified using data from the Defense and Veterans Eye Injury and Vision Registry. These health states were mapped to disability weights from the Global Burden of Disease (GBD) study. Average duration of injury or illness was calculated until remission or death. For the latter, life expectancy at age of sustaining injury, as identified from US Life Tables from the National Vital Statistics Reports 2020, was used. Using Defense Manpower Data Center reports capturing number of service members deployed per year, incidence rates were calculated for ocular injury and DALYs. MAIN OUTCOME MEASURES: Disability-adjusted life years of ocular injury. RESULTS: Seventeen thousand five hundred fifty-five patients sustained ocular injury that incurred DALYs. In total, these injuries resulted in 11 214 DALYs (average, 0.64 DALYs per included patient and 20.6 DALYs per 10 000 US service members per year). Severe impairment of distance vision (77.9%) and blindness (10.6%) were the primary contributors of DALYs. Although only 9.3% of patients sustained a permanent ocular injury, permanent disability accounted for 99.5% of total DALYs. The average yearly incidence rate of ocular injury was 32.0 cases per 10 000 US service members. Foreign body was the most frequent injury type (2754 occurrences), followed by abrasion (2419 occurrences) and multiple injury types (1429 occurrences). The most DALYs occurred in patients with multiple injury types (2485 DALYs), followed by abrasion (accounting for 725 DALYs) and foreign body (accounting for 461 DALYs). DISCUSSION: We report higher average DALYs per case ratio among US service members compared with the general population studied by the GBD study, highlighting the differences in probabilities of permanent injury between the two studies. Our study provides understanding of the impact of ocular injuries on active-duty service members and lays the groundwork for further research and interventions to mitigate their burden. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

12.
Ophthalmology ; 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39218161

RESUMO

TOPIC: The timing of primary repair of open-globe injury is variable in major trauma centers worldwide, and consensus on optimal timing is lacking. CLINICAL RELEVANCE: Surgery is the mainstay of open-globe injury management, and appropriate timing of surgical repair may minimize the risk of potentially blinding complications such as endophthalmitis, thereby optimizing visual outcomes. METHODS: A systematic literature review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (International Prospective Register of Systematic Reviews identifier, CRD42023442972). The Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and ISRCTN registries and ClinicalTrials.gov were searched from inception through October 29, 2023. Prospective and retrospective nonrandomized studies of patients with open-globe injury with a minimum of 1 month of follow-up after primary repair were included. Primary outcomes included visual acuity at last follow-up and the proportion of patients with endophthalmitis. Certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. RESULTS: Fifteen studies met inclusion criteria, reporting a total of 8497 eyes. The most common injury types were penetrating and intraocular foreign body (IOFB). Meta-analysis found that primary repair less than 24 hours after open-globe injury was associated with 0.30 odds of endophthalmitis compared with primary repair conducted more than 24 hours after trauma (odds ratio, 0.39; 95% confidence interval [CI], 0.19-0.79; I2 = 95%; P = 0.01). No significant difference was found in reported visual outcomes between patients whose open-globe injuries were repaired more than, compared with less than, 24 hours after trauma (odds ratio, 0.89; 95% CI, 0.61-1.29; I2 = 70%; P = 0.52). All included studies were retrospective and nonrandomized, demonstrating an overall low certainty of evidence on GRADE assessment. DISCUSSION: Only retrospective data exist around the effect of timing of open-globe repair, resulting in low certainty of the available evidence. However, this review of current evidence, predominantly including penetrating and IOFB injuries, suggests that primary repair performed less than 24 hours after open-globe injury is associated with a reduced endophthalmitis rate compared with longer delays, consistent with delay to primary repair increasing endophthalmitis risk. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

13.
Ophthalmology ; 131(5): 557-567, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38086434

RESUMO

TOPIC: Sympathetic ophthalmia (SO) is a sight-threatening granulomatous panuveitis caused by a sensitizing event. Primary enucleation or primary evisceration, versus primary repair, as a risk management strategy after open-globe injury (OGI) remains controversial. CLINICAL RELEVANCE: This systematic review was conducted to report the incidence of SO after primary repair compared with that of after primary enucleation or primary evisceration. This enabled the reporting of an estimated number needed to treat. METHODS: Five journal databases were searched. This review was registered with International Prospective Register of Systematic Reviews (identifier, CRD42021262616). Searches were carried out on June 29, 2021, and were updated on December 10, 2022. Prospective or retrospective studies that reported outcomes (including SO or lack of SO) in a patient population who underwent either primary repair and primary enucleation or primary evisceration were included. A systematic review and meta-analysis were carried out in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Random effects modelling was used to estimate pooled SO rates and absolute risk reduction (ARR). RESULTS: Eight studies reporting SO as an outcome were included in total. The included studies contained 7500 patients and 7635 OGIs. In total, 7620 OGIs met the criteria for inclusion in this analysis; SO developed in 21 patients with OGI. When all included studies were pooled, the estimated SO rate was 0.12% (95% confidence interval [CI], 0.00%-0.25%) after OGI. Of 779 patients who underwent primary enucleation or primary evisceration, no SO cases were reported, resulting in a pooled SO estimate of 0.05% (95% CI, 0.00%-0.21%). For primary repair, the pooled estimate of SO rate was 0.15% (95% CI, 0.00%-0.33%). The ARR using a random effects model was -0.0010 (in favour of eye removal; 95% CI, -0.0031 [in favor of eye removal] to 0.0011 [in favor of primary repair]). Grading of Recommendations, Assessment, Development, and Evaluations analysis highlighted a low certainty of evidence because the included studies were observational, and a risk of bias resulted from missing data. DISCUSSION: Based on the available data, no evidence exists that primary enucleation or primary evisceration reduce the risk of secondary SO. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

14.
Br J Dermatol ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39166481

RESUMO

BACKGROUND: A portion of approximately 2-20% of cutaneous melanoma (CM) are diagnosed as amelanotic/hypopigmented melanoma (AHM) and represent a challenge for early diagnosis. OBJECTIVES: Since the degree to which somatic mutations and copy number aberrations (CNA) in genes associated with skin-lightening or albinism may contribute to the loss of tumour pigmentation in AHM samples has not yet been addressed, we have investigated loss of function mutations of key pigmentation genes in matched germline and AHM as well as pigmented melanoma (PM) tumour DNA samples. METHODS: An analysis of clinical and histopathological characteristics together with whole exome sequencing data of 34 fresh frozen primary CM, graded according to the amount of pigmentation present was performed. Together with germline and somatic variant analysis, 30 samples were previously analysed for CNA changes. This study focussed on germline and somatic variants in the coding region of 16 genes known to be associated with albinism/hypopigmentation or variation in human pigmentation in all samples. Chromosomal regions encompassing these 16 genes were examined for DNA copy loss or gain. RESULTS: The finding that red hair related MC1R and TYR R402Q loss of activity gene variant alleles and genotypes are associated with AHM was validated in this study. Germline AHM-related gene variants were enriched in 70% (n=7 of 10) of AHM patients vs 8.3% (n=2 of 24) of PM patients. This surprisingly high frequency of rare germline variants in AHM patients constitutes the "first hit" and confirms that AHM patients are more likely to be albinism allele carriers than patients with PM. Next, in CNA analysis of each tumour sample, 50% (n=4 of 8) AHM samples with a pigmentation gene variant had LOH in the region containing the corresponding gene, and 25% (=2 of 8) had loss-of-heterozygosity (LOH) in chromosomal regions of two AHM-related genes. CONCLUSIONS: This study proposes that the likely molecular mechanism for development of amelanogenesis in AHM is carriage of an albinism/hypopigmentation allele followed by LOH of the corresponding gene in the tumour.

15.
Br J Dermatol ; 190(4): 549-558, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38006317

RESUMO

BACKGROUND: Combined expression of the autophagy-regulatory protein AMBRA1 (activating molecule in Beclin1-regulated autophagy) and the terminal differentiation marker loricrin in the peritumoral epidermis of stage I melanomas can identify tumour subsets at low risk of -metastasis. OBJECTIVES: To validate the combined expression of peritumoral AMBRA1 and loricrin (AMBLor) as a prognostic biomarker able to identify both stage I and II melanomas at low risk of tumour recurrence. METHODS: Automated immunohistochemistry was used to analyse peritumoral AMBRA1 and loricrin expression in geographically distinct discovery (n = 540) and validation (n = 300) cohorts of nonulcerated American Joint Committee on Cancer (AJCC) stage I and II melanomas. AMBLor status was correlated with clinical outcomes in the discovery and validation cohorts separately and combined. RESULTS: Analysis of AMBLor in the discovery cohort revealed a recurrence-free survival (RFS) rate of 95.5% in the AMBLor low-risk group vs. 81.7% in the AMBLor at-risk group (multivariate log-rank, P < 0.001) and a negative predictive value (NPV) of 96.0%. In the validation cohort, AMBLor analysis revealed a RFS rate of 97.6% in the AMBLor low-risk group vs. 78.3% in the at-risk group (multivariate log-rank, P < 0.001) and a NPV of 97.6%. In a multivariate model considering AMBLor, Breslow thickness, age and sex, analysis of the combined discovery and validation cohorts showed that the estimated effect of AMBLor was statistically significant, with a hazard ratio of 3.469 (95% confidence interval 1.403-8.580, P = 0.007) and an overall NPV of 96.5%. CONCLUSIONS: These data provide further evidence validating AMBLor as a prognostic biomarker to identify nonulcerated AJCC stage I and II melanoma tumours at low risk of disease recurrence.


Assuntos
Melanoma , Proteínas de Membrana , Neoplasias Cutâneas , Humanos , Estados Unidos , Melanoma/patologia , Prognóstico , Recidiva Local de Neoplasia/patologia , Epiderme/metabolismo , Biomarcadores , Estadiamento de Neoplasias , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
16.
Ann Bot ; 133(1): 169-182, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-37804485

RESUMO

BACKGROUND AND AIMS: Contrasting patterns of host and microbiome biogeography can provide insight into the drivers of microbial community assembly. Distance-decay relationships are a classic biogeographical pattern shaped by interactions between selective and non-selective processes. Joint biogeography of microbiomes and their hosts is of increasing interest owing to the potential for microbiome-facilitated adaptation. METHODS: In this study, we examine the coupled biogeography of the model macroalga Durvillaea and its microbiome using a combination of genotyping by sequencing (host) and 16S rRNA amplicon sequencing (microbiome). Alongside these approaches, we use environmental data to characterize the relationship between the microbiome, the host, and the environment. KEY RESULTS: We show that although the host and microbiome exhibit shared biogeographical structure, these arise from different processes, with host biogeography showing classic signs of geographical distance decay, but with the microbiome showing environmental distance decay. Examination of microbial subcommunities, defined by abundance, revealed that the abundance of microbes is linked to environmental selection. As microbes become less common, the dominant ecological processes shift away from selective processes and towards neutral processes. Contrary to expectations, we found that ecological drift does not promote structuring of the microbiome. CONCLUSIONS: Our results suggest that although host macroalgae exhibit a relatively 'typical' biogeographical pattern of declining similarity with increasing geographical distance, the microbiome is more variable and is shaped primarily by environmental conditions. Our findings suggest that the Baas Becking hypothesis of 'everything is everywhere, the environment selects' might be a useful hypothesis to understand the biogeography of macroalgal microbiomes. As environmental conditions change in response to anthropogenic influences, the processes structuring the microbiome of macroalgae might shift, whereas those governing the host biogeography are less likely to change. As a result, increasingly decoupled host-microbe biogeography might be observed in response to such human influences.


Assuntos
Microbiota , Humanos , RNA Ribossômico 16S/genética , Geografia
17.
CA Cancer J Clin ; 67(6): 472-492, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29028110

RESUMO

Answer questions and earn CME/CNE To update the melanoma staging system of the American Joint Committee on Cancer (AJCC) a large database was assembled comprising >46,000 patients from 10 centers worldwide with stages I, II, and III melanoma diagnosed since 1998. Based on analyses of this new database, the existing seventh edition AJCC stage IV database, and contemporary clinical trial data, the AJCC Melanoma Expert Panel introduced several important changes to the Tumor, Nodes, Metastasis (TNM) classification and stage grouping criteria. Key changes in the eighth edition AJCC Cancer Staging Manual include: 1) tumor thickness measurements to be recorded to the nearest 0.1 mm, not 0.01 mm; 2) definitions of T1a and T1b are revised (T1a, <0.8 mm without ulceration; T1b, 0.8-1.0 mm with or without ulceration or <0.8 mm with ulceration), with mitotic rate no longer a T category criterion; 3) pathological (but not clinical) stage IA is revised to include T1b N0 M0 (formerly pathologic stage IB); 4) the N category descriptors "microscopic" and "macroscopic" for regional node metastasis are redefined as "clinically occult" and "clinically apparent"; 5) prognostic stage III groupings are based on N category criteria and T category criteria (ie, primary tumor thickness and ulceration) and increased from 3 to 4 subgroups (stages IIIA-IIID); 6) definitions of N subcategories are revised, with the presence of microsatellites, satellites, or in-transit metastases now categorized as N1c, N2c, or N3c based on the number of tumor-involved regional lymph nodes, if any; 7) descriptors are added to each M1 subcategory designation for lactate dehydrogenase (LDH) level (LDH elevation no longer upstages to M1c); and 8) a new M1d designation is added for central nervous system metastases. This evidence-based revision of the AJCC melanoma staging system will guide patient treatment, provide better prognostic estimates, and refine stratification of patients entering clinical trials. CA Cancer J Clin 2017;67:472-492. © 2017 American Cancer Society.


Assuntos
Melanoma/patologia , Estadiamento de Neoplasias/normas , Neoplasias Cutâneas/patologia , Humanos , Metástase Linfática , Melanoma/epidemiologia , Guias de Prática Clínica como Assunto , Sistema de Registros , Neoplasias Cutâneas/epidemiologia , Sociedades Médicas , Estados Unidos/epidemiologia
18.
Bioorg Med Chem Lett ; 98: 129596, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142914

RESUMO

To identify new compounds that can effectively inhibit Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), we screened, synthesized, and evaluated a series of novel aryl fluorosulfate derivatives for their in vitro inhibitory activity against Mtb. Compound 21b exhibited an in vitro minimum inhibitory concentration (MIC) of 0.06 µM against Mtb, no cytotoxicity against both HEK293T and HepG2 mammalian cell lines, and had good in vivo mouse plasma exposure and lung concentration with a 20 mg/kg oral dose, which supports advanced development as a new chemical entity for TB treatment.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Animais , Humanos , Camundongos , Antituberculosos , Células HEK293 , Mamíferos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Tuberculose/tratamento farmacológico , Ésteres do Ácido Sulfúrico/química , Ésteres do Ácido Sulfúrico/farmacologia
19.
Chem Rev ; 122(2): 1485-1542, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-34793128

RESUMO

The merger of photoredox catalysis with transition metal catalysis, termed metallaphotoredox catalysis, has become a mainstay in synthetic methodology over the past decade. Metallaphotoredox catalysis has combined the unparalleled capacity of transition metal catalysis for bond formation with the broad utility of photoinduced electron- and energy-transfer processes. Photocatalytic substrate activation has allowed the engagement of simple starting materials in metal-mediated bond-forming processes. Moreover, electron or energy transfer directly with key organometallic intermediates has provided novel activation modes entirely complementary to traditional catalytic platforms. This Review details and contextualizes the advancements in molecule construction brought forth by metallaphotocatalysis.


Assuntos
Elétrons , Elementos de Transição , Catálise , Níquel/química , Oxirredução
20.
J Pediatr Gastroenterol Nutr ; 78(3): 644-652, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38334232

RESUMO

OBJECTIVES: The safety, efficacy, and cost savings associated with biosimilar medications are well established. However, a lack of pediatric data exists surrounding clinical outcomes when switching from an originator to a biosimilar. Our primary aim is to evaluate clinical outcomes following a nonmedical switch from the infliximab originator to a biosimilar in children and young adults with inflammatory bowel disease (IBD). Our secondary aim is to estimate cost savings associated with this switch. METHODS: A quality improvement project was implemented to establish safe switching protocols, then those patients who underwent a nonmedical switch from the infliximab originator to the biosimilar were retrospectively reviewed. Demographic data, physician global assessments (PGAs), and laboratory values were recorded 1 year pre- and post-switch. Continuation rates on the biosimilar were reported at 6 and 12 months. Cost savings were estimated using two different pricing models. RESULTS: Fifty-three patients underwent a nonmedical switch. Laboratory values including inflammatory markers, infliximab levels, and PGA scores remained similar when assessed pre- and post-switch. No infusion reactions or antidrug antibody development occurred. Two patients reported psoriasis-like rashes. Five patients switched back to the originator during the study period. There were 379 biosimilar infusions completed with an estimated total cost savings of $11,260 (average sales price) and $566,223 (wholesale acquisition cost). CONCLUSIONS: Clinical remission rates, inflammatory laboratory markers, serious adverse events, infliximab levels, and antidrug antibodies remained similar after a one-time nonmedical switch to an infliximab biosimilar. Nonmedical switching to biosimilars resulted in significant cost savings.


Assuntos
Medicamentos Biossimilares , Doenças Inflamatórias Intestinais , Humanos , Adulto Jovem , Criança , Infliximab/uso terapêutico , Medicamentos Biossimilares/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Estudos Retrospectivos , Redução de Custos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Resultado do Tratamento , Fármacos Gastrointestinais/uso terapêutico
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