Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Exp Neurol ; 380: 114912, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39097075

RESUMO

Traumatic brain injury impairs brain function through various mechanisms. Recent studies have shown that alterations in pericytes in various diseases affect neurovascular function, but the effects of TBI on hippocampal pericytes remain unclear. Here, we investigated the effects of RAGE activation on pericytes after TBI using male C57BL/6 J mice. Hippocampal samples were collected at different time points within 7 days after TBI, the expression of PDGFR-ß, NG2 and the HMGB1-S100B/RAGE signaling pathway was assessed by Western blotting, and the integrity of the hippocampal BBB at different time points was measured by immunofluorescence. RAGE-associated BBB damage in hippocampal pericytes occurred early after cortical impact. By culturing primary mouse brain microvascular pericytes, we determined the different effects of HMGB1-S100B on pericyte RAGE. To investigate whether RAGE blockade could protect neurological function after TBI, we reproduced the process of CCI by administering FPS-ZM1 to RAGE-/- mice. TEM images and BBB damage-related assays showed that inhibition of RAGE resulted in a significant improvement in the number of hippocampal vascular basement membranes and tight junctions and a reduction in perivascular oedema compared with those in the untreated group. In contrast, mouse behavioural testing and doublecortin staining indicated that targeting the HMGB1-S100B/RAGE axis after CCI could protect neurological function by reducing pericyte-associated BBB damage. In conclusion, the present study provides experimental evidence for the strong correlation between the pericyte HMGB1-S100B/RAGE axis and NVU damage in the hippocampus at the early stage of TBI and further demonstrates that pericyte RAGE serves as an important target for the protection of neurological function after TBI.

2.
Nat Commun ; 15(1): 6348, 2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39068178

RESUMO

The spliceosome executes pre-mRNA splicing through four sequential stages: assembly, activation, catalysis, and disassembly. Activation of the spliceosome, namely remodeling of the pre-catalytic spliceosome (B complex) into the activated spliceosome (Bact complex) and the catalytically activated spliceosome (B* complex), involves major flux of protein components and structural rearrangements. Relying on a splicing inhibitor, we have captured six intermediate states between the B and B* complexes: pre-Bact, Bact-I, Bact-II, Bact-III, Bact-IV, and post-Bact. Their cryo-EM structures, together with an improved structure of the catalytic step I spliceosome (C complex), reveal how the catalytic center matures around the internal stem loop of U6 snRNA, how the branch site approaches 5'-splice site, how the RNA helicase PRP2 rearranges to bind pre-mRNA, and how U2 snRNP undergoes remarkable movement to facilitate activation. We identify a previously unrecognized key role of PRP2 in spliceosome activation. Our study recapitulates a molecular choreography of the human spliceosome during its catalytic activation.


Assuntos
Microscopia Crioeletrônica , Precursores de RNA , Splicing de RNA , RNA Nuclear Pequeno , Spliceossomos , Spliceossomos/metabolismo , Humanos , Precursores de RNA/metabolismo , Precursores de RNA/genética , RNA Nuclear Pequeno/metabolismo , Ribonucleoproteína Nuclear Pequena U2/metabolismo , Ribonucleoproteína Nuclear Pequena U2/genética , Modelos Moleculares , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , Domínio Catalítico
3.
Orthop Surg ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39056482

RESUMO

BACKGROUND: Periprosthetic bone loss is a well-known phenomenon following total hip arthroplasty (THA). However, the choice of drugs for prevention remains controversial. Therefore, the aim of this study was to determine the best drug to treat periprosthetic bone loss by comparing changes in bone mineral density (BMD) at different times after THA. METHODS: A comprehensive search of five databases and two clinical trial registration platforms was undertaken from their inception through to August 31, 2023 to identify eligible randomized controlled trials. A Bayesian network meta-analysis (NMA) was carried out for calculating the standardized mean difference (SMD) and the surface under cumulative ranking curve (SUCRA) of the BMD in calcar (Gruen zone 7) at 6 months, 12 months, and 24 months and over. RESULTS: Twenty-nine trials involving 1427 patients and 10 different interventions were included. The results demonstrated that at 6 months, denosumab had the highest ranking (SUCRA = 0.90), followed by alendronate (SUCRA = 0.76), and zoledronate (SUCRA = 0.73). At 12 months, clodronate ranked highest (SUCRA = 0.96), followed by denosumab (SUCRA = 0.84) and teriparatide (SUCRA = 0.82). For interventions with a duration of 24 months and over, denosumab had the highest SUCRA value (SUCRA = 0.96), followed by raloxifene (SUCRA = 0.90) and zoledronate (SUCRA = 0.75). CONCLUSION: Investigating the existing body of evidence revealed that denosumab demonstrates potential as an intervention of superior efficacy at the three specifically examined time points. However, it remains crucial to conduct further research to confirm these findings and determine the most effective treatment strategy.

4.
Phys Rev Lett ; 132(23): 233802, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38905673

RESUMO

Non-line-of-sight (NLOS) imaging has the ability to reconstruct hidden objects, allowing a wide range of applications. Existing NLOS systems rely on pulsed lasers and time-resolved single-photon detectors to capture the information encoded in the time of flight of scattered photons. Despite remarkable advances, the pulsed time-of-flight LIDAR approach has limited temporal resolution and struggles to detect the frequency-associated information directly. Here, we propose and demonstrate the coherent scheme-frequency-modulated continuous wave calibrated by optical frequency comb-for high-resolution NLOS imaging, velocimetry, and vibrometry. Our comb-calibrated coherent sensor presents a system temporal resolution at subpicosecond and its superior signal-to-noise ratio permits NLOS imaging of complex scenes under strong ambient light. We show the capability of NLOS localization and 3D imaging at submillimeter scale and demonstrate NLOS vibrometry sensing at an accuracy of dozen Hertz. Our approach unlocks the coherent LIDAR techniques for widespread use in imaging science and optical sensing.

5.
JAMA Netw Open ; 7(5): e249286, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38700864

RESUMO

Importance: Response Evaluation Criteria in Solid Tumors (RECIST) are commonly used to assess therapeutic response in clinical trials but not in routine care; thus, RECIST-based end points are difficult to include in observational studies. Clinician-anchored approaches for measuring clinical response have been validated but not widely compared with clinical trial data, limiting their use as evidence for clinical decision-making. Objective: To compare response- and progression-based end points in clinical trial and observational cohorts of patients with non-small cell lung cancer (NSCLC). Design, Setting, and Participants: This retrospective cohort study used patient-level data from the IMpower132 trial (conducted April 7, 2016, to May 31, 2017) and a nationwide electronic health record (EHR)-derived deidentified database (data collected January 1, 2011, to March 31, 2022). Patients in the observational cohort were selected according to the inclusion and exclusion criteria of the IMpower132 trial. All patients in the observational cohort had stage IV NSCLC. Exposure: All patients were randomized to or received first-line carboplatin or cisplatin plus pemetrexed. Main Outcomes and Measures: End points included response rates, duration of response, and progression-free survival, compared between the trial and observational cohorts before and after weighting. Response rates for the observational cohort were derived from the EHR. Results: A total of 769 patients met inclusion criteria, 494 in the observational cohort (median [IQR] age, 67 [60-74] years; 228 [46.2%] female; 45 [9.1%] Black or African American; 352 [71.3%] White; 53 [10.7%] American Indian or Alaska Native, Asian, Hawaiian or Pacific Islander, or multiracial) and 275 in the trial cohort (median [IQR] age, 63 [56-68] years; 90 [32.7%] female; 4 [1.5%] Black or African American; 194 [70.5%] White; 65 [23.6%] American Indian or Alaska Native, Asian, Hawaiian or Pacific Islander, or multiracial). All 3 end points were comparable between the study cohorts. Trial patients had a higher number of response assessments compared with patients in the weighted observational cohort. The EHR-derived response rate was numerically higher than the objective response rate after weighting (100.3 of 249.3 [40.2%] vs 105 of 275 [38.2%]) due to higher rates of observed partial response than RECIST-based partial response. Among patients with at least 1 response assessment, the EHR-derived response rate remained higher than the objective response rate (100.3 of 193.4 [51.9%] vs 105 of 256 [41.0%]) due to a higher proportion of patients in the observational cohort with no response assessment. Conclusions and Relevance: In this study, response- and progression-based end points were similar between clinical trial and weighted observational cohorts, which increases confidence in the reliability of observational end points and can inform their interpretation in relation to trial end points. Additionally, the difference observed in response rates (including vs excluding patients with no response assessment) highlights the importance of future research adopting this 2-way approach when evaluating the relationship of EHR-derived and objective response rates.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Feminino , Masculino , Neoplasias Pulmonares/tratamento farmacológico , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Carboplatina/uso terapêutico , Progressão da Doença , Cisplatino/uso terapêutico , Pemetrexede/uso terapêutico , Estudos de Coortes , Critérios de Avaliação de Resposta em Tumores Sólidos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Intervalo Livre de Progressão
6.
NEJM Evid ; 3(4): EVIDoa2300236, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38771994

RESUMO

BACKGROUND: Certain populations have been historically underrepresented in clinical trials. Broadening eligibility criteria is one approach to inclusive clinical research and achieving enrollment goals. How broadened trial eligibility criteria affect the diversity of eligible participants is unknown. METHODS: Using a nationwide electronic health record-derived deidentified database, we identified a retrospective cohort of patients diagnosed with 22 cancer types between April 1, 2013 and December 31, 2022 who received systemic therapy (N=235,234) for cancer. We evaluated strict versus broadened eligibility criteria using performance status and liver, kidney, and hematologic function around first line of therapy. We performed logistic regression to estimate odds ratios for exclusion by strict criteria and their association with measures of patient diversity, including sex, age, race or ethnicity, and area-level socioeconomic status (SES); estimated the impact of broadening criteria on the number and distribution of eligible patients; and performed Cox regression to estimate hazard ratios for real-world overall survival (rwOS) comparing patients meeting strict versus broadened criteria. RESULTS: When applying common strict cutoffs for eligibility criteria to patients with complete data and weighting each cancer type equally, 48% of patients were eligible for clinical trials. Female (odds ratio, 1.30; 95% confidence interval [CI], 1.25 to 1.35), older (age 75+ vs. 18 to 49 years old: odds ratio, 3.04; 95% CI, 2.85 to 3.24), Latinx (odds ratio, 1.46; 95% CI, 1.39 to 1.54), non-Latinx Black (odds ratio, 1.11; 95% CI, 1.06 to 1.16), and lower-SES patients were more likely to be excluded using strict eligibility criteria. Broadening criteria increased the number of eligible patients by 78%, with the strongest impact for older, female, non-Latinx Black, and lower-SES patients. Patients who met only broadened criteria had worse rwOS versus those with strict criteria (hazard ratio, 1.31; 95% CI, 1.27 to 1.34). CONCLUSIONS: Data-driven evaluation of clinical trial eligibility criteria may optimize the eligibility of certain historically underrepresented groups and promote access to more inclusive trials. (Sponsored by Flatiron Health.).


Assuntos
Ensaios Clínicos como Assunto , Definição da Elegibilidade , Neoplasias , Seleção de Pacientes , Humanos , Feminino , Neoplasias/terapia , Neoplasias/etnologia , Neoplasias/mortalidade , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Adulto , Adolescente , Adulto Jovem
7.
Orthop Surg ; 16(3): 718-723, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38180272

RESUMO

INTRODUCTION: Patients with hemophilia (PWH) constantly suffer hemarthrosis, which leads to deformity of the hip joint. Therefore, PWH who are going to receive total hip arthroplasty (THA) should be exclusively treated before the surgery with careful measurement of their proximal femur. Hence, we conducted a retrospective study to explore the anatomical parameters of and differences in the proximal femur in hemophilic patients who underwent THA. METHODS: The retrospective study comprised data of adult patients who received total hip arthroplasty from 2020 to 2022 in the research center. Patients having a diagnosis of hemophilic arthritis and received THA were included in experimental group, and patients with hip arthritis or femoral head necrosis were taken as control group. Parameters including femoral offset, neck-shaft angle (NSA), medullary cavity of 20 mm above mid-lesser trochanter level (T+20), mid-lesser trochanter level (T), and 20 mm blow it (T-20), and canal flare index (CFI), femoral cortical index (FCI) were measured on X-ray and CT images with PACS by two independent doctors. Data was analyzed by SPSS 20. Kolmogorov-Smirnov test was used to test data normality. Student's t-test was performed between PWH and control group. p < 0.05 was considered statistically significant. RESULTS: Among the 94 hips, 39 (41.5%) were included in group hemophilia and 55(58.5%) in control group. The mean age of the patients was 49.36 ± 12.92 years. All cases were male patients. Data demonstrated significantly smaller femoral cortical index (FCI), femoral offset, medullary cavity of 20 mm above mid-lesser trochanter level, mid-lesser trochanter level, and 20 mm below it, and neck-shaft angle (NSA) was obviously larger in PWH than control group (p < 0.05). No significant difference was found in canal flare index (CFI). CONCLUSION: Hemophilic patients undergoing THA were prone to longer and thinner proximal femur. Preoperative morphological analysis of femur is recommended.


Assuntos
Artrite , Artroplastia de Quadril , Hemofilia A , Prótese de Quadril , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Artroplastia de Quadril/métodos , Estudos Retrospectivos , Hemofilia A/complicações , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Fêmur/anatomia & histologia , Artrite/cirurgia
8.
Nat Struct Mol Biol ; 31(5): 835-845, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38196034

RESUMO

Selection of the pre-mRNA branch site (BS) by the U2 small nuclear ribonucleoprotein (snRNP) is crucial to prespliceosome (A complex) assembly. The RNA helicase PRP5 proofreads BS selection but the underlying mechanism remains unclear. Here we report the atomic structures of two sequential complexes leading to prespliceosome assembly: human 17S U2 snRNP and a cross-exon pre-A complex. PRP5 is anchored on 17S U2 snRNP mainly through occupation of the RNA path of SF3B1 by an acidic loop of PRP5; the helicase domain of PRP5 associates with U2 snRNA; the BS-interacting stem-loop (BSL) of U2 snRNA is shielded by TAT-SF1, unable to engage the BS. In the pre-A complex, an initial U2-BS duplex is formed; the translocated helicase domain of PRP5 stays with U2 snRNA and the acidic loop still occupies the RNA path. The pre-A conformation is specifically stabilized by the splicing factors SF1, DNAJC8 and SF3A2. Cancer-derived mutations in SF3B1 damage its association with PRP5, compromising BS proofreading. Together, these findings reveal key insights into prespliceosome assembly and BS selection or proofreading by PRP5.


Assuntos
Modelos Moleculares , Fatores de Processamento de RNA , Spliceossomos , Humanos , Spliceossomos/metabolismo , Spliceossomos/química , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de RNA/química , Ribonucleoproteína Nuclear Pequena U2/metabolismo , Ribonucleoproteína Nuclear Pequena U2/química , Ribonucleoproteína Nuclear Pequena U2/genética , Microscopia Crioeletrônica , Splicing de RNA , Precursores de RNA/metabolismo , Conformação de Ácido Nucleico , RNA Nuclear Pequeno/metabolismo , RNA Nuclear Pequeno/química , Fosfoproteínas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...