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1.
Dermatol Surg ; 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39088685

RESUMO

BACKGROUND: The surgical management of leg wounds following skin cancer extirpation is challenging. Pinch grafting (PG) is a technique that has been rarely described in the reconstruction of acute surgical wounds. OBJECTIVE: The purpose of this study was to evaluate whether PG resulted in faster healing times for below the knee wounds following Mohs micrographic surgery (MMS) when compared with second intention healing (SIH). MATERIALS AND METHODS: This was a prospective randomized trial of patients with post-Mohs micrographic surgical wounds of the lower extremity who were randomized either to receive pinch grafts or to heal by second intention. Patients were followed through a combination of in-person and virtual visits until their wounds were completely reepithelialized. RESULTS: Median time to wound healing was 36 days in the PG group versus 56 days for the SIH group, representing a 56% improvement in healing time. There were no differences in complications between the 2 groups with trends toward decreased rates of pain and infection in the PG group. CONCLUSION: PG is an effective simple method to hasten the healing of lower extremity wounds following MMS.

2.
Artigo em Inglês | MEDLINE | ID: mdl-39060552

RESUMO

PURPOSE: To assess the use of bone marrow aspirate (BM) and bone marrow aspirate concentrate (BMAC) in the treatment of long-bone nonunion and to understand mechanism of action. METHODS: A systematic review of PubMed and EBSCOHost was completed to identify studies that investigated the use of BM or BMAC for the diagnosis of delayed union and/or nonunion of long-bone fractures. Studies of isolated bone marrow-mesenchymal stem cells (BM-MSCs) and use in non-long-bone fractures were excluded. Statistical analysis was confounded by heterogeneous fracture fixation methods, treatment history, and scaffold use. RESULTS: Our initial search yielded 430 publications, which was screened down to 25 studies. Successful treatment in aseptic nonunion was reported at 79-100% (BM) and 50-100% (BMAC). Septic nonunion rates were slightly better at 73-100% (BM) and 83.3-100% (BMAC). 18/24 studies report union rates > 80%. One study reports successful treatment of septic nonunion with BMAC and no antibiotics. A separate study reported a significant reduction in autograft reinfection rate when combined with BMAC (P = 0.009). Major adverse events include two deep infections at injection site and one case of heterotopic ossification. Most studies note transient mild donor site discomfort and potential injection site discomfort attributed to needle size. CONCLUSION: The current literature pertaining to use of BM/BMAC for nonunion is extremely heterogeneous in terms of patient population and concomitant treatment modalities. While results are promising for use of BM/BMAC with other gold standard treatment methodologies, the literature requires additional Level I data to clarify the impact of role BM/BMAC in treating nonunion when used alone and in combination with other modalities. LEVEL OF EVIDENCE: Level III.

4.
Phys Med Biol ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39047765

RESUMO

OBJECTIVE: Simulation of Positron Emission Tomography (PET) images is an essential tool in the development and validation of quantitative imaging workflows and advanced image processing pipelines. Existing Monte Carlo or analytical PET simulators often compromise on either efficiency or accuracy. We aim to develop and validate FAST (Fast Analytical Simulator of Tracer)-PET, a novel analytical framework, to simulate PET images accurately and efficiently. Approach: FAST-PET simulates PET images by performing precise forward projection, scatter, and random estimation that match the scanner geometry and statistics. Although the same process should be applicable to other scanner models, we focus on the Siemens Biograph Vision-600 in this work. Calibration and validation of FAST-PET were performed through comparison with an experimental scan of a National Electrical Manufacturers Association (NEMA) Image Quality (IQ) phantom. Further validation was conducted between FAST-PET and Geant4 Application for Tomographic Emission (GATE) quantitatively in clinical image simulations in terms of intensity-based and texture-based features and task-based tumor segmentation. Main results: According to the NEMA IQ phantom simulation, FAST-PET's simulated images exhibited partial volume effects and noise levels comparable to experimental images, with a relative bias of the recovery coefficient within 10% for all spheres and a coefficient of variation for the background region within 6% across various acquisition times. FAST-PET generated clinical PET images exhibit high quantitative accuracy and texture comparable to GATE (correlation coefficients of all features over 0.95) but with ~100-fold lower computation time. The tumor segmentation masks comparison between both methods exhibited significant overlap and shape similarity with high concordance CCC>0.97 across measures. Significance: FAST-PET generated PET images with high quantitative accuracy comparable to GATE, making it ideal for applications requiring extensive PET image simulations such as virtual imaging trials, and the development and validation of image processing pipelines.

5.
Epilepsia ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39056406

RESUMO

OBJECTIVE: Epilepsy is a common neurological disorder affecting 1% of the global population. Loss of consciousness in focal impaired awareness seizures (FIASs) and focal-to-bilateral tonic-clonic seizures (FBTCSs) can be devastating, but the mechanisms are not well understood. Although ictal activity and interictal connectivity changes have been noted, the network states of focal aware seizures (FASs), FIASs, and FBTCSs have not been thoroughly evaluated with network measures ictally. METHODS: We obtained electrographic data from 74 patients with stereoelectroencephalography (SEEG). Sliding window band power, functional connectivity, and segregation were computed on preictal, ictal, and postictal data. Five-minute epochs of wake, rapid eye movement sleep, and deep sleep were also extracted. Connectivity of subcortical arousal structures was analyzed in a cohort of patients with both SEEG and functional magnetic resonance imaging (fMRI). Given that custom neuromodulation of seizures is predicated on detection of seizure type, a convolutional neural network was used to classify seizure types. RESULTS: We found that in the frontoparietal association cortex, an area associated with consciousness, both consciousness-impairing seizures (FIASs and FBTCSs) and deep sleep had increases in slow wave delta (1-4 Hz) band power. However, when network measures were employed, we found that only FIASs and deep sleep exhibited an increase in delta segregation and a decrease in gamma segregation. Furthermore, we found that only patients with FIASs had reduced subcortical-to-neocortical functional connectivity with fMRI versus controls. Finally, our deep learning network demonstrated an area under the curve of .75 for detecting consciousness-impairing seizures. SIGNIFICANCE: This study provides novel insights into ictal network measures in FASs, FIASs, and FBTCSs. Importantly, although both FIASs and FBTCSs result in loss of consciousness, our results suggest that ictal network changes in FIASs uniquely resemble those that occur during deep sleep. Our results may inform novel neuromodulation strategies for preservation of consciousness in epilepsy.

7.
Microbiologyopen ; 13(4): e1425, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38987999

RESUMO

Pigments provide a simple means to rapidly visually ascertain the quantities or presence of specific microbes in a complex community. The selection of pigment-producing colonies that are simple to differentiate from common colony phenotypes provides a high degree of certainty for the identity of pigment-tagged strains. Successful employment of pigment production is dependent on various intrinsic factors related to proper levels of gene expression and pigment production that are not always easy to predict and vary within each microbe. We have constructed a simple transposon system that incorporates the genes for the production of deoxyviolacein, a pigment produced from intracellular reserves of the amino acid tryptophan, to randomly insert these genes throughout the genome. This tool allows the user to select from many thousands of potential sites throughout a bacterial genome for an ideal location to generate the desired amount of pigment. We have applied this system to a small selection of endophytes and other model bacteria to differentiate these strains from complex communities and confirm their presence after several weeks in natural environments. We provide two examples of applications using the pigments to trace strains following introduction into plant tissues or to produce a reporter strain for extracellular nitrogen compound sensing. We recognize that this tool could have far broader utility in other applications and microbes, and describe the methodology for use by the greater scientific community.


Assuntos
Elementos de DNA Transponíveis , Pigmentos Biológicos , Elementos de DNA Transponíveis/genética , Pigmentos Biológicos/metabolismo , Mutagênese Insercional/métodos , Vetores Genéticos/genética , Bactérias/genética , Bactérias/metabolismo , Bactérias/classificação , Triptofano/metabolismo , Endófitos/genética , Endófitos/metabolismo
8.
J Community Psychol ; 52(6): 774-791, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38968375

RESUMO

Does higher perceived neighborhood social cohesion in adolescence lead to better health and well-being 10-12 years later? We evaluated this question using data from a large, prospective, and nationally representative sample of US adolescents (Add Health; N = 10,963), and an outcome-wide approach. Across 38 outcomes, perceived neighborhood social cohesion was associated with some: mental health outcomes (i.e., depressive symptoms, suicidal ideation, perceived stress), psychological well-being outcomes (i.e., happiness, optimism), social outcomes (i.e., loneliness, romantic relationship quality, satisfaction with parenting), and civic/prosocial outcomes (i.e., volunteering). However, it was not associated with health behaviors nor physical health outcomes. These results were maintained after robust control for a wide range of potential confounders.


Assuntos
Características de Residência , Humanos , Adolescente , Masculino , Feminino , Estudos Longitudinais , Adulto Jovem , Estados Unidos/epidemiologia , Estudos Prospectivos , Depressão/psicologia , Depressão/epidemiologia , Solidão/psicologia , Saúde Mental , Satisfação Pessoal , Relações Interpessoais , Ideação Suicida , Nível de Saúde , Felicidade , Estresse Psicológico/psicologia
9.
Methods Mol Biol ; 2842: 23-55, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39012589

RESUMO

The advent of locus-specific protein recruitment technologies has enabled a new class of studies in chromatin biology. Epigenome editors (EEs) enable biochemical modifications of chromatin at almost any specific endogenous locus. Their locus-specificity unlocks unique information including the functional roles of distinct modifications at specific genomic loci. Given the growing interest in using these tools for biological and translational studies, there are many specific design considerations depending on the scientific question or clinical need. Here, we present and discuss important design considerations and challenges regarding the biochemical and locus specificities of epigenome editors. These include how to: account for the complex biochemical diversity of chromatin; control for potential interdependency of epigenome editors and their resultant modifications; avoid sequestration effects; quantify the locus specificity of epigenome editors; and improve locus-specificity by considering concentration, affinity, avidity, and sequestration effects.


Assuntos
Cromatina , Edição de Genes , Humanos , Cromatina/genética , Cromatina/metabolismo , Edição de Genes/métodos , Epigenoma , Epigenômica/métodos , Epigênese Genética , Loci Gênicos , Animais , Sistemas CRISPR-Cas
10.
Cureus ; 16(6): e62693, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39036188

RESUMO

Heyde syndrome is characterized by the association between aortic stenosis and gastrointestinal bleeding. This report examines two cases of Heyde syndrome in elderly females who experience bleeding recurrence within months following aortic valve replacement (AVR). The discussion highlights the controversies surrounding the optimal management of Heyde syndrome, particularly in the context of AVR type (surgical vs. transcatheter) and postoperative complications. The report underscores the need for a multidisciplinary approach to Heyde syndrome management and the importance of individualized treatment strategies considering patient-specific factors such as lesion location and postoperative complications.

11.
J Surg Orthop Adv ; 33(2): 103-107, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38995067

RESUMO

Previous studies have shown a relationship between cigarette use and pain but never in the setting of traumatic spinal cord injury (TSCI). Therefore, the objectives of this study were to (1) determine whether smokers with TSCI experience increased pain compared with nonsmokers with TSCI and (2) determine whether smokers with TSCI experience worse functional outcomes than nonsmokers with TSCI. A retrospective analysis of the National Spinal Cord Injury Statistical Center database was performed. Pain severity, interference, and functional outcomes were compared between 514 nonsmokers and 124 smokers with American Spinal Injury Association (ASIA) C/D TSCI. Smokers reported higher scores for pain severity and interference compared with nonsmokers. These findings were significant on multivariable analysis. Smokers also reported higher rates of job loss compared with nonsmokers, but this finding was not significant on multivariable analysis. Smoking may be an independent risk factor for increased pain severity and interference in the setting of TSCI. (Journal of Surgical Orthopaedic Advances 33(2):103-107, 2024).


Assuntos
Medição da Dor , Fumar , Traumatismos da Medula Espinal , Humanos , Traumatismos da Medula Espinal/complicações , Feminino , Masculino , Estudos Retrospectivos , Adulto , Pessoa de Meia-Idade , Fumar/epidemiologia , Dor/etiologia , Fatores de Risco
12.
F S Sci ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39025326

RESUMO

OBJECTIVE: To study the possible role for HMGA2 overexpression in differentiated myometrial cells and its potential to induce a stem cell-like or dedifferentiating phenotype and drive fibroid development. DESIGN: Myometrial cells were immortalized and transduced with an HMGA2 lentivirus to produce HMGA2hi cells. In vitro stem cell assays were conducted and RNA from HMGA2hi and control cells and fibroid-free myometrial (MyoN) and HMGA2 fibroid (HMGA2F) tissues were submitted for RNA-sequencing. SETTING: University research laboratory SUBJECTS: Women undergoing hysterectomy for symptomatic uterine fibroids or other gynecological conditions. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: In-vitro stem-like properties from myometrium cell lines. RNA-sequencing and collagen production of HMGA2 overexpressing primary leiomyoma tissue and cell lines. RESULTS: HMGA2hi cells have enhanced self-renewal capacity, decreased proliferation, and have a greater ability to differentiate into other mesenchymal cell types. HMGA2hi cells exhibit a stem cell-like signature and share transcriptomic similarities with HMGA2F. Moreover, dysregulated extracellular matrix pathways are observed in both HMGA2hi cells and HMGA2F. CONCLUSION: Our findings suggest that HMGA2 overexpression drives myometrial cells to dedifferentiate into a more plastic phenotype and provides evidence for an alternative mechanism for fibroid etiology, suggesting that fibroids may not only arise from a mutated stem cell but also from a mutated differentiated myometrial cell.

13.
Int J Behav Med ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39026119

RESUMO

BACKGROUND: Previous research has shown that screen-based leisure time is related to physical and mental health, relationships, and prosocial behaviors. However, it remains unclear whether screen-based leisure time causally affects wellbeing, as previous studies have relied on cross-sectional data, focused on one type of media use (e.g., social media, video games, or internet), or assessed a narrow set of outcomes. METHOD: We used three waves (2016, 2017, 2019) of national longitudinal data from the New Zealand Attitudes and Values Study to investigate the effects of screen-based leisure time on 24 parameters of wellbeing (n = 11,085). We operationalized screen-based leisure as the sum of time spent browsing the internet, using social media, watching/reading the news, watching videos, and playing video games. We followed the outcome-wide analytic design for observational data by performing a series of multivariable regression models estimating the effect of screen-based leisure time on 24 wellbeing outcomes and assessed potential unmeasured confounding using sensitivity analyses. RESULTS: In our primary analysis with the total sample, total screen-based leisure time was associated with a very modest decrease in body satisfaction and a very modest increase in body mass index. Possible evidence of associations was found with increases in number of hours spent exercising and volunteering each week, as well as decreases in number of average daily hours of sleep, self-control, and subjective health. CONCLUSION: Screen-based leisure time has the potential to affect health and wellbeing. Results are discussed in light of the high prevalence of screen-based leisure time.

14.
Function (Oxf) ; 5(4)2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38984994

RESUMO

While regular physical activity is a cornerstone of health, wellness, and vitality, the impact of endurance exercise training on molecular signaling within and across tissues remains to be delineated. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) was established to characterize molecular networks underlying the adaptive response to exercise. Here, we describe the endurance exercise training studies undertaken by the Preclinical Animal Sites Studies component of MoTrPAC, in which we sought to develop and implement a standardized endurance exercise protocol in a large cohort of rats. To this end, Adult (6-mo) and Aged (18-mo) female (n = 151) and male (n = 143) Fischer 344 rats were subjected to progressive treadmill training (5 d/wk, ∼70%-75% VO2max) for 1, 2, 4, or 8 wk; sedentary rats were studied as the control group. A total of 18 solid tissues, as well as blood, plasma, and feces, were collected to establish a publicly accessible biorepository and for extensive omics-based analyses by MoTrPAC. Treadmill training was highly effective, with robust improvements in skeletal muscle citrate synthase activity in as little as 1-2 wk and improvements in maximum run speed and maximal oxygen uptake by 4-8 wk. For body mass and composition, notable age- and sex-dependent responses were observed. This work in mature, treadmill-trained rats represents the most comprehensive and publicly accessible tissue biorepository, to date, and provides an unprecedented resource for studying temporal-, sex-, and age-specific responses to endurance exercise training in a preclinical rat model.


Assuntos
Adaptação Fisiológica , Envelhecimento , Condicionamento Físico Animal , Ratos Endogâmicos F344 , Animais , Masculino , Feminino , Condicionamento Físico Animal/fisiologia , Adaptação Fisiológica/fisiologia , Ratos , Envelhecimento/fisiologia , Resistência Física/fisiologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Treino Aeróbico
15.
JAMA Psychiatry ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38959002

RESUMO

Importance: Supporting healthy aging is a US public health priority, and gratitude is a potentially modifiable psychological factor that may enhance health and well-being in older adults. However, the association between gratitude and mortality has not been studied. Objective: To examine the association of gratitude with all-cause and cause-specific mortality in later life. Design, Setting, and Participants: This population-based prospective cohort study used data from self-reported questionnaires and medical records of 49 275 US older female registered nurses who participated in the Nurses' Health Study (2016 questionnaire wave to December 2019). Cox proportional hazards regression models estimated the hazard ratio (HR) of deaths by self-reported levels of gratitude at baseline. These models adjusted for baseline sociodemographic characteristics, social participation, physical health, lifestyle factors, cognitive function, and mental health. Data analysis was conducted from December 2022 to April 2024. Exposure: Gratitude was assessed with the 6-item Gratitude Questionnaire, a validated and widely used measure of one's tendency to experience grateful affect. Main Outcomes and Measures: Deaths were identified from the National Death Index, state statistics records, reports by next of kin, and the postal system. Causes of death were ascertained by physicians through reviewing death certificates and medical records. Results: Among the 49 275 participants (all female; mean [SD] age at baseline, 79 [6.16] years), 4608 incident deaths were identified over 151 496 person-years of follow-up. Greater gratitude at baseline was associated with a lower hazard of mortality in a monotonic fashion. For instance, the highest tertile of gratitude, compared with the lowest tertile, was associated with a lower hazard of all-cause deaths (HR, 0.91; 95% CI, 0.84-0.99) after adjusting for baseline sociodemographic characteristics, social participation, religious involvement, physical health, lifestyle factors, cognitive function, and mental health. When considering cause-specific deaths, death from cardiovascular disease was inversely associated with gratitude (HR, 0.85; 95% CI, 0.73-0.995). Conclusions and Relevance: This study provides the first empirical evidence suggesting that experiencing grateful affect is associated with increased longevity among older adults. The findings will need to be replicated in future studies with more representative samples.

16.
Horm Behav ; 164: 105607, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39059231

RESUMO

The last few decades have seen major advances in neurobiology and uncovered novel genetic and cellular substrates involved in the control of physiological set points. In this Review, I discuss the limitations in the definition of homeostatic set points established by Walter B Canon and highlight evidence that two other physiological systems, namely rheostasis and allostasis provide distinct inputs to independently modify set-point levels. Using data collected over the past decade, the hypothalamic and genetic basis of regulated changes in set-point values by rheostatic mechanisms are described. Then, the role of higher-order brain regions, such as hippocampal circuits, for experience-dependent, allostatic induced changes in set-points are outlined. I propose that these systems provide a hierarchical organization of physiological stability that exists to maintain set-point values. The hierarchical organization of physiology has direct implications for basic and medical research, and clinical practice.

17.
Chem Sci ; 15(26): 10155-10163, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38966368

RESUMO

We describe the preparation and study of novel cavitands, molecular bowls 16+ and 26+, as good binders of the anticancer drug methotrexate (MTX). Molecular bowls are comprised of a curved tribenzotriquinacene (TBTQ) core conjugated to three macrocyclic pyridinium units at the top. The cavitands are easily accessible via two synthetic steps from hexabromo-tribenzotriquinacene in 25% yield. As amphiphilic molecules, bowls 16+ and 26+ self-associate in water by the nucleation-to-aggregation pathway (NMR). The bowls are preorganized, having a semi-rigid framework comprising a fixed bottom with a wobbling pyridinium rim (VT NMR and MD). Further studies, both experimental (NMR) and computational (DFT and MCMM), suggested that a folded MTX occupies the cavity of bowls wherein it forms π-π, C-H-π, and ion pairing intermolecular contacts but also undergoes desolvation to give stable binary complexes (µM) in water. Moreover, a computational protocol is introduced to identify docking pose(s) of MTX inside molecular bowls from NMR shielding data. Both molecular bowls have shown in vitro biocompatibility with liver and kidney cell lines (MTS assay). As bowl 26+ is the strongest binder of MTX reported to date, we envision it as an excellent candidate for further studies on the way toward developing an antidote capable of removing MTX from overdosed cancer patients.

18.
Oncologist ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38979643

RESUMO

BACKGROUND: Atezolizumab plus bevacizumab is the standard of care for advanced hepatocellular carcinoma (HCC) in the first-line setting, although was only evaluated in patients with Child-Pugh (CP) A liver function in the IMbrave150 trial. We sought to determine the outcomes of these patients based on CP score and ALBI grade in the US population. METHODS: This multicenter cohort study included patients with HCC who received atezolizumab with bevacizumab as first-line systemic therapy between March 2018 and November 2023. Overall survival (OS) was determined using the Kaplan-Meier method and multivariate analyses were performed using Cox proportional hazard regression method. RESULTS: Among 322 patients, 226, 86, and 10 patients had CP-A, CP-B, and CP-C liver function, respectively. Median age was 66.5 years, 78.6% were male, and 82.6% were White. Median OS (mOS) was 21.6 months for those with CP-A, 9.1 months for those with CP-B7, and 4.7 months for those with CP-B8-C12 (P < .0001). Among patients with CP-A, those with ALBI grade 1 had an mOS of 34.9 months versus 14.2 months in those with grade 2. In multivariate analyses, CP score, ALBI grade, hepatitis B, performance status, and macrovascular invasion were significantly associated with survival. CONCLUSIONS: CP score is an important prognostic tool for patients with HCC receiving atezolizumab plus bevacizumab, and this regimen remains a viable option for patients with CP-B7 with no additional safety concern, although the benefit is significantly less than those with CP-A. ALBI score has independent predictive value in patients with CP-A liver function.

19.
Cancer Discov ; 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39083809

RESUMO

Conventional immune checkpoint inhibitors (ICI) targeting CTLA-4 elicit durable survival, but primarily in patients with immune-inflamed tumors. Although the mechanisms underlying response to anti-CTLA-4 remain poorly understood, Fc-gamma receptor (FcγR) IIIA co-engagement appears critical for activity, potentially explaining the modest clinical benefits of approved anti-CTLA-4 antibodies. We demonstrate that anti-CTLA-4 engineered for enhanced FcγR affinity leverages FcγR-dependent mechanisms to potentiate T cell responsiveness, reduce intratumoral Tregs, and enhance antigen presenting cell activation. Fc-enhanced anti-CTLA-4 promoted superior efficacy in mouse models and remodeled innate and adaptive immunity versus conventional anti-CTLA-4. These findings extend to patients treated with botensilimab, an Fc-enhanced anti-CTLA-4 antibody, with clinical activity across multiple poorly immunogenic and ICI treatment-refractory cancers. Efficacy was independent of tumor neoantigen burden or FcγRIIIA genotype. However, FcγRIIA and FcγRIIIA expression emerged as potential response biomarkers. These data highlight the therapeutic potential of Fc-enhanced anti-CTLA-4 antibodies in cancers unresponsive to conventional ICI therapy.

20.
Org Lett ; 26(30): 6320-6323, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39046190

RESUMO

Herein, we present a highly efficient method for constructing the intricate 5-5-6 fused ring system commonly found in the polycyclic furanobutenolide-derived cembranoid and norcembranoid natural product family with remarkable diastereoselectivity, utilizing an intramolecular Diels-Alder reaction as the cornerstone. Notably, employing a propargyl ether tether as the dienophile yields significant enhancements in the transformation process compared to its propargyl ester counterpart, as demonstrated in our previous total synthesis of havellockate. This advancement holds promising implications for future investigations, offering a streamlined pathway for rapidly assembling the tricyclic core characteristic of this diverse family of natural products.


Assuntos
Diterpenos , Estrutura Molecular , Diterpenos/química , Diterpenos/síntese química , Estereoisomerismo , Produtos Biológicos/química , Produtos Biológicos/síntese química , Reação de Cicloadição , Furanos/química , Furanos/síntese química , 4-Butirolactona/química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/síntese química
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