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1.
Nature ; 629(8013): 945-950, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38720069

RESUMO

Lipoprotein(a) (Lp(a)), an independent, causal cardiovascular risk factor, is a lipoprotein particle that is formed by the interaction of a low-density lipoprotein (LDL) particle and apolipoprotein(a) (apo(a))1,2. Apo(a) first binds to lysine residues of apolipoprotein B-100 (apoB-100) on LDL through the Kringle IV (KIV) 7 and 8 domains, before a disulfide bond forms between apo(a) and apoB-100 to create Lp(a) (refs. 3-7). Here we show that the first step of Lp(a) formation can be inhibited through small-molecule interactions with apo(a) KIV7-8. We identify compounds that bind to apo(a) KIV7-8, and, through chemical optimization and further application of multivalency, we create compounds with subnanomolar potency that inhibit the formation of Lp(a). Oral doses of prototype compounds and a potent, multivalent disruptor, LY3473329 (muvalaplin), reduced the levels of Lp(a) in transgenic mice and in cynomolgus monkeys. Although multivalent molecules bind to the Kringle domains of rat plasminogen and reduce plasmin activity, species-selective differences in plasminogen sequences suggest that inhibitor molecules will reduce the levels of Lp(a), but not those of plasminogen, in humans. These data support the clinical development of LY3473329-which is already in phase 2 studies-as a potent and specific orally administered agent for reducing the levels of Lp(a).


Assuntos
Descoberta de Drogas , Lipoproteína(a) , Macaca fascicularis , Animais , Feminino , Humanos , Masculino , Camundongos , Administração Oral , Kringles , Lipoproteína(a)/antagonistas & inibidores , Lipoproteína(a)/sangue , Lipoproteína(a)/química , Lipoproteína(a)/metabolismo , Camundongos Transgênicos , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Plasminogênio/química , Plasminogênio/metabolismo , Especificidade da Espécie , Ensaios Clínicos Fase II como Assunto , Apolipoproteínas A/química , Apolipoproteínas A/metabolismo
2.
PLoS Comput Biol ; 20(9): e1012359, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39288161

RESUMO

Considering biological systems as information processing entities and analyzing their organizational structure via information-theoretic measures has become an established approach in life sciences. We transfer this framework to a field of broad general interest, the human gut microbiome. We use BacArena, a software combining agent-based modelling and flux-balance analysis, to simulate a simplified human intestinal microbiome (SIHUMI). In a first step, we derive information theoretic measures from the simulated abundance data, and, in a second step, relate them to the metabolic processes underlying the abundance data. Our study provides further evidence on the role of active information storage as an indicator of unexpected structural change in the observed system. Besides, we show that information transfer reflects coherent behavior in the microbial community, both as a reaction to environmental changes and as a result of direct effective interaction. In this sense, purely abundance-based information theoretic measures can provide meaningful insight on metabolic interactions within bacterial communities. Furthermore, we shed light on the important however little noticed technical aspect of distinguishing immediate and delayed effects in the interpretation of local information theoretical measures.


Assuntos
Simulação por Computador , Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/fisiologia , Biologia Computacional , Modelos Biológicos , Software , Armazenamento e Recuperação da Informação/métodos
3.
Nano Lett ; 24(1): 61-66, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38113396

RESUMO

The decay of excited states via radiative and nonradiative paths is well understood in molecules and bulk semiconductors but less so in nanocrystals. Here, we perform time-resolved photoluminescence (t-PL) experiments on CsPbBr3 metal-halide perovskite nanocrystals, with a time resolution of 3 ps, sufficient to observe the decay of both excitons and biexcitons as a function of temperature. The striking result is that the radiative rate constant of the single exciton increases at low temperatures with an exponential functional form, suggesting quantum coherent effects with dephasing at high temperatures. The opposing directions of the radiative and nonradiative decay rate constants enable enhanced brightening of PL from excitons to biexcitons due to quantum effects, promoting a faster approach to the quantum theoretical limits of light emission. Ab initio quantum dynamics simulations reproduce the experimental observations of radiation controlled by quantum spatial coherence enhanced at low temperatures.

4.
Nano Lett ; 24(12): 3638-3646, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38498912

RESUMO

Tin-based two-dimensional (2D) perovskites are emerging as lead-free alternatives in halide perovskite materials, yet their exciton dynamics and transport remain less understood due to defect scattering. Addressing this, we employed temperature-dependent transient photoluminescence (PL) microscopy to investigate intrinsic exciton transport in three structurally analogous Sn- and Pb-based 2D perovskites. Employing conjugated ligands, we synthesized high-quality crystals with enhanced phase stability at various temperatures. Our results revealed phonon-limited exciton transport in Sn perovskites, with diffusion constants increasing from 0.2 cm2 s-1 at room temperature to 0.6 cm2 s-1 at 40 K, and a narrowing PL line width. Notably, Sn-based perovskites exhibited greater exciton mobility than their Pb-based equivalents, which is attributed to lighter effective masses. Thermally activated optical phonon scattering was observed in Sn-based compounds but was absent in Pb-based materials. These findings, supported by molecular dynamics simulations, demonstrate that the phonon scattering mechanism in Sn-based halide perovskites can be distinct from their Pb counterparts.

5.
J Am Chem Soc ; 146(6): 4260-4269, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38305175

RESUMO

Quantum tunneling, a phenomenon that allows particles to pass through potential barriers, can play a critical role in energy transfer processes. Here, we demonstrate that the proper design of organic-inorganic interfaces in two-dimensional (2D) hybrid perovskites allows for efficient triplet energy transfer (TET), where quantum tunneling of the excitons is the key driving force. By employing temperature-dependent and time-resolved photoluminescence and pump-probe spectroscopy techniques, we establish that triplet excitons can transfer from the inorganic lead-iodide sublattices to the pyrene ligands with rapid and weakly temperature-dependent characteristic times of approximately 50 ps. The energy transfer rates obtained based on the Marcus theory and first-principles calculations show good agreement with the experiments, indicating that the efficient tunneling of triplet excitons within the Marcus-inverted regime is facilitated by high-frequency molecular vibrations. These findings offer valuable insights into how one can effectively manipulate the energy landscape in 2D hybrid perovskites for energy transfer and the creation of diverse excitonic states.

6.
J Am Chem Soc ; 146(37): 25625-25639, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39250739

RESUMO

The functionality of multicomponent self-assembled monolayers (SAMs) can be severely diminished by the segregation of like components into nanoscale domains, a process that maximizes favorable short-range intermolecular interactions. Here, we explore the use of a modular family of sulfur-functionalized metal bis(terpyridine) complexes ([M(tpy-R)2]2+(PF6-)2) to prepare mixed SAMs, considering that the comparable structure, dimensions, and ionic composition of these species should render them interchangeable within the adsorbed surface layer. While surface voltammetry experiments show that these SAMs do exhibit compositions representative of their assembly solutions, they also suggest, in line with previous reports, that adjacent complexes in the monolayer are separated by a gap of ∼ 1 nm. Remarkably, X-ray photoelectron spectroscopy studies reveal no F 1s peak features that would confirm the proliferation of PF6- counterions on the surface. We propose that the loosely packed structure of these SAMs results from the loss or exchange of PF6- counterions, which introduces significant repulsive Coulomb interactions between the adsorbed 2+ charged complexes. The hypothesis is supported by an electrostatic model which indicates that these complexes should form close-packed SAMs if mobile counterions are present. First-principles calculations demonstrate that complex-counterion binding interactions are weakened by charge transfer to the gold substrate, suggesting that this may play an important role in the formation of such low-coverage SAMs. Together, this study raises important questions regarding the assembly, organization, and composition of charged SAMs and highlights new opportunities in the design of multicomponent monolayer assemblies with free volume, for example, to facilitate surface-based reactions or support molecular switches.

7.
J Am Chem Soc ; 146(33): 23437-23448, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39115182

RESUMO

Understanding the sub-band gap luminescence in Ruddlesden-Popper 2D metal halide hybrid perovskites (2D HaPs) is essential for efficient charge injection and collection in optoelectronic devices. Still, its origins are still under debate with respect to the role of self-trapped excitons or radiative recombination via defect states. In this study, we characterized charge separation, recombination, and transport in single crystals, exfoliated layers, and polycrystalline thin films of butylammonium lead iodide (BA2PbI4), one of the most prominent 2D HaPs. We combined complementary defect- and exciton-sensitive methods such as photoluminescence (PL) spectroscopy, modulated and time-resolved surface photovoltage (SPV) spectroscopy, constant final state photoelectron yield spectroscopy (CFSYS), and constant light-induced magneto transport (CLIMAT), to demonstrate striking differences between charge separation induced by dissociation of excitons and by excitation of mobile charge carriers from defect states. Our results suggest that the broad sub-band gap emission in BA2PbI4 and other 2D HaPs is caused by radiative recombination via defect states (shallow as well as midgap states) rather than self-trapped excitons. Density functional theory (DFT) results show that common defects can readily occur and produce an energetic profile that agrees well with the experimental results. The DFT results suggest that the formation of iodine interstitials is the initial process leading to degradation, responsible for the emergence of midgap states, and that defect engineering will play a key role in enhancing the optoelectronic properties of 2D HaPs in the future.

8.
Blood ; 140(2): 140-151, 2022 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-35486842

RESUMO

Antithrombin deficiency, the most severe congenital thrombophilia, might be underestimated, as some pathogenic variants are not detected by routine functional methods. We have identified 2 new SERPINC1 variants, p.Glu227Lys and p.Asn224His, in 4 unrelated thrombophilic patients with early and recurrent thrombosis that had normal antithrombin activity. In one case, the mutation was identified by whole genome sequencing, while in the 3 remaining cases, the mutation was identified by sequencing SERPINC1 based on a single functional positive finding supporting deficiency. The 2 variants shared a common functional defect, an impaired or null N-glycosylation of Asn224 according to a eukaryotic expression model. Carriers had normal anti-FXa or anti-FIIa activities but impaired anti-FVIIa activity and a detectable loss of inhibitory function when incubating the plasma for 1 hour at 41°C. Moreover, the ß glycoform of the variants, lacking 2 N-glycans, had reduced secretion, increased heparin affinity, no inhibitory activity, and a potential dominant-negative effect. These results explain the increased thrombin generation observed in carriers. Mutation experiments reflected the role that Lysine residues close to the N-glycosylation sequon have in impairing the efficacy of N-glycosylation. Our study shows new elements involved in the regulation of N-glycosylation, a key posttranslational modification that, according to our results, affects folding, secretion, and function, providing new evidence of the pathogenic consequence of an incorrect N-glycosylation of antithrombin. This study supports that antithrombin deficiency is underestimated and encourages the development of new functional and genetic tests to diagnose this severe thrombophilia.


Assuntos
Deficiência de Antitrombina III , Antitrombina III , Antitrombina III/genética , Antitrombina III/metabolismo , Deficiência de Antitrombina III/diagnóstico , Deficiência de Antitrombina III/genética , Variação Genética , Glicosilação , Heparina/metabolismo , Humanos
9.
PLoS Comput Biol ; 19(3): e1011010, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36996234

RESUMO

Predicting protein-protein interactions from sequences is an important goal of computational biology. Various sources of information can be used to this end. Starting from the sequences of two interacting protein families, one can use phylogeny or residue coevolution to infer which paralogs are specific interaction partners within each species. We show that these two signals can be combined to improve the performance of the inference of interaction partners among paralogs. For this, we first align the sequence-similarity graphs of the two families through simulated annealing, yielding a robust partial pairing. We next use this partial pairing to seed a coevolution-based iterative pairing algorithm. This combined method improves performance over either separate method. The improvement obtained is striking in the difficult cases where the average number of paralogs per species is large or where the total number of sequences is modest.


Assuntos
Algoritmos , Proteínas , Ligação Proteica , Filogenia , Proteínas/química , Biologia Computacional/métodos
10.
Eur J Appl Physiol ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39259396

RESUMO

Compared to the determination of exercise thresholds based on systemic changes in blood lactate concentrations or gas exchange data, the determination of breakpoints based on muscle oxygen saturation offers a valid alternative to provide specific information on muscle-derived thresholds. Our study explored the profiles and timing of the second muscle oxygenation threshold (MOT2) in different muscles. Twenty-six cyclists and triathletes (15 male: age = 23 ± 7 years, height = 178 ± 5 cm, body mass = 70.2 ± 5.3 kg; 11 female: age = 22 ± 4 years, height = 164 ± 4 cm, body mass = 58.3 ± 8.1 kg) performed a graded exercise test (GXT), on a cycle ergometer. Power output, blood lactate concentration, heart rate, rating of perceived exertion, skinfolds and muscle oxygen saturation were registered in five muscles (vastus lateralis, biceps femoris, gastrocnemius medialis, tibialis anterior and triceps brachii) and percentage at which MOT2 occurred for each muscle was determinated using the Exponential Dmax. The results of Statistical Parametric Mapping and ANOVA showed that, although muscle oxygenation displayed different profiles in each muscle during a GXT, MOT2 occurred at a similar percentage of the GXT in each muscle (77% biceps femoris, 75% tibalis anterior, 76% gastrocnemius medialis and 72% vastus lateralis) and it was similar that systemic threshold (73% of the GXT). In conclusion, this study showed different profiles of muscle oxygen saturation in different muscles, but without notable differences in the timing for MOT2 and concordance with systemic threshold. Finally, we suggest the analysis of the whole signal and not to simplify it to a breakpoint.

11.
Artigo em Inglês | MEDLINE | ID: mdl-39036869

RESUMO

BACKGROUND: Consensus is lacking on adequate deep histological margins in cutaneous squamous cell carcinoma (cSCC). Deep clearance for tumours located on the scalp is limited by anatomic constraints. OBJECTIVE: To determine whether clear but close deep histological margins (<1 mm) confer a higher risk of recurrence in cSCCs of the scalp treated by wide local excision, compared to deep histological margins ≥1 mm. METHODS: Multicentre retrospective observational cohort study and multivariate competing risk analysis to evaluate risk factors for recurrence. RESULTS: In total, 295 patients with 338 cSCCs were included. Close deep histological margins were not associated with an increased cumulative incidence of recurrence (subhazard ratio [SHR] 1.96 [95% CI 0.87-4.41]). However, an increased risk of recurrence was observed for those tumours that presented concurrent invasion of the galea aponeurotica and close deep margins, as opposed to patients without these factors (SHR 3.52 [1.24-10.01]). Tumours with clear but close peripheral margins (<1 mm) also had higher risk of recurrence (SHR 5.01 [1.68-14.97]). LIMITATIONS: Retrospective observational study based on pathology reports. CONCLUSION: Deep histological margins <1 mm do not confer a greater risk of recurrence as long as the tumour is completely excised and the galea aponeurotica is not involved. Surgical excision of cSCC on the scalp should include the galea to ensure proper assessment of deep margins.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38733285

RESUMO

BACKGROUND: Immunosuppressed (IS) patients, particularly solid organ transplant recipients and those on immunosuppressive therapy, face a higher incidence and recurrence of nonmelanoma skin cancers (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Mohs micrographic surgery (MMS) is the preferred treatment for high-risk NMSC due to its high cure rate and margin examination capabilities. However, IS patients may experience more complications, such as surgical site infections, and a greater risk of recurrence, making their outcomes a subject of interest. OBJECTIVES: This study aimed to compare IS and immunocompetent (IC) patients undergoing MMS for NMSC in terms of baseline characteristics, intra- and post-surgical complications, and postoperative recurrence rates. METHODS: The study utilized data from the REGESMOHS registry, a 7-year prospective cohort study in Spain. It included 5226 patients, categorizing them into IC (5069) and IS (157) groups. IS patients included solid organ transplant recipients, those on immunosuppressive treatments, individuals with haematological tumours and HIV-positive patients. Patient data, tumour characteristics, surgical details and outcomes were collected and analysed. RESULTS: IS patients demonstrated a higher proportion of SCC, multiple synchronous tumours and tumours invading deeper structures. Complex closures, unfinished MMS and more surgical sections were observed in the IS group. Although intra-operative morbidity was higher among IS patients, this difference became non-significant when adjusted for other variables such as year of surgery, antiplatelet/anticoagulant treatment or type of closure. Importantly, IS patients had a substantially higher recurrence rate (IRR 2.79) compared to IC patients. CONCLUSIONS: This study suggests that IS patients may be at a higher risk of development of AE such as bleeding or tumour necrosis and are at a higher risk of tumour recurrence. Close follow-up and consideration of the specific characteristics of NMSC in IS patients are crucial. Further research with extended follow-up is needed to better understand the long-term outcomes for this patient group.

13.
Adv Physiol Educ ; 48(3): 512-517, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38721651

RESUMO

Internationalization in higher education is essential, and although active learning methodologies are increasing and allow students to develop transversal skills, most still have a very local scope. In this context, the Collaborative Online International Learning (COIL) methodology is an interesting approach to benefit the students' development. It consists of an online program that involves creating multicultural teams to develop a specific learning project. Although this methodology is expanding, its use in physiology is still scarce. This paper aims to show an example of applying COIL methodology in physiology topics to enhance higher-education students' innovation and business skills. Our example project developed a sports-assessment service concept focused on physiology and biomechanics assessments. The program involved teams from Brazil, Germany, and Spain, comprising undergraduate and master students. Over 7 weeks, these teams, mentored by professors and researchers, engaged in workshops covering COIL methodology, business model design, executive summary planning, economic analyses, and communication techniques. Key outcomes included learning new concepts, developing soft skills, building confidence in innovative solution proposals, and experiencing diverse cultures. Challenges faced were language barriers, scheduling, task complexity, and logistical issues. This experience confirms the effectiveness of incorporating programs using COIL methodology into educational curriculums. Doing so exposes physiology students to innovation, entrepreneurship, and business creation while strengthening their professional connections and opening up postgraduation opportunities.NEW & NOTEWORTHY Although the Collaborative Online International Learning (COIL) methodology is expanding, its use in physiology is still scarce. Our example COIL project of 7 weeks developed a sports-assessment service concept focused on physiology and biomechanics assessments. The program involved teams from Brazil, Germany, and Spain, comprising undergraduate and master's students. Students perceived extracurricular activities in this format as beneficial. Coaches also expressed positive views about such initiatives, noting benefits for students and their development.


Assuntos
Fisiologia , Humanos , Fisiologia/educação , Educação a Distância/métodos , Internacionalidade , Currículo , Comportamento Cooperativo
14.
Sensors (Basel) ; 24(3)2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38339599

RESUMO

Photovoltaic (PV) power prediction plays a critical role amid the accelerating adoption of renewable energy sources. This paper introduces a bidirectional long short-term memory (BiLSTM) deep learning (DL) model designed for forecasting photovoltaic power one hour ahead. The dataset under examination originates from a small PV installation located at the Polytechnic School of the University of Alcala. To improve the quality of historical data and optimize model performance, a robust data preprocessing algorithm is implemented. The BiLSTM model is synergistically combined with a Bayesian optimization algorithm (BOA) to fine-tune its primary hyperparameters, thereby enhancing its predictive efficacy. The performance of the proposed model is evaluated across diverse meteorological and seasonal conditions. In deterministic forecasting, the findings indicate its superiority over alternative models employed in this research domain, specifically a multilayer perceptron (MLP) neural network model and a random forest (RF) ensemble model. Compared with the MLP and RF reference models, the proposed model achieves reductions in the normalized mean absolute error (nMAE) of 75.03% and 77.01%, respectively, demonstrating its effectiveness in this type of prediction. Moreover, interval prediction utilizing the bootstrap resampling method is conducted, with the acquired prediction intervals carefully adjusted to meet the desired confidence levels, thereby enhancing the robustness and flexibility of the predictions.

15.
Sensors (Basel) ; 24(14)2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39065931

RESUMO

The aim of the present study was to evaluate skin temperature (Tsk) asymmetries, using infrared thermography, in professional padel players before (PRE), after (POST) and 10 min after training (POST10), and their relationship with perceptual variables and training characteristics. Thermal images were taken of 10 players before, after and 10 min after a standardized technical training. After training, Tsk of the dominant side was higher than before training in the anterior forearm (30.8 ± 0.4 °C vs. 29.1 ± 1.2 °C, p < 0.01; ES = 1.9), anterior shoulder (31.6 ± 0.6 °C vs. 30.9 ± 0.6 °C, p < 0.05; ES = 1.0) posterior arm (29.5 ± 1.0 °C vs. 28.3 ± 1.2 °C, p < 0.05; ES = 1.0), and posterior forearm (30.8 ± 0.9 °C vs. 29.3 ± 1.6 °C, p < 0.05; ES = 1.1). Likewise, these differences were significant POST10 in the anterior arm, anterior forearm, anterior shoulder, posterior arm and posterior forearm. Comparing the different moments of measurement (PRE, POST and POST10), the temperature was higher POST10 in all the regions analyzed except for the shoulder, abdominals, and lower back. Also, correlations were found between fatigue variation and temperature variation between limbs (Tsk dominance), and no correlation was found except between age and posterior thigh (|r| = 0.69; p < 0.05), and between the racket mass and anterior knee (|r| = 0.81; p < 0.01). In conclusion, infrared thermography allows monitoring of skin asymmetries between limbs in professional padel players, but these asymmetries were not related to overall fatigue variation, overall pain variation, years of experience and training hours.


Assuntos
Temperatura Cutânea , Termografia , Humanos , Temperatura Cutânea/fisiologia , Termografia/métodos , Masculino , Adulto , Raios Infravermelhos , Adulto Jovem , Antebraço/fisiologia , Atletas
16.
J Therm Biol ; 123: 103923, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39067196

RESUMO

Skin temperature responses have been advocated to indicate exercise-induced muscle soreness and recovery status. While the evidence is contradictory, we hypothesize that the presence of muscle damage and the time window of measurement are confounding factors in the skin temperature response. The objective was to determine whether skin temperature is influenced by different workloads and the time course of temperature measurements over the following 24 h. 24 trained male military were assigned to one of three groups: GC group (n = 8) serving as control not performing exercises, GE group (n = 8) performing a simulated military combat protocol in an exercise track with different obstacles but designed not to elicit muscle damage, and the GEMD group (n = 8) performing the simulated military combat protocol plus 5 sets of 20 drop jumps, with 10-sec between repetitions and with 2-min of rest between sets aiming to induce muscle damage. Skin temperature was measured using infrared thermography before exercise (Pre) and 4 (Post4h), 8 (Post8h) and 24h (Post24h) post-exercise. Perception of pain (DOMS) was evaluated Pre, Post24h, and Post48h, and countermovement jump height was evaluated at Pre and Post24h. DOMS did not differ between groups in the Pre and Post24h measures but GEMD presented higher DOMS than the other groups at Post48h (p < 0.001 and large effect size). Jump height did not differ for GEMD and GC, and GE presented higher jump height at Post24h than GC (p = 0.02 and large effect size). Skin temperature responses of GEMD and GG were similar in all measurement moments (p > 0.22), and GE presented higher skin temperature than the GC and the GEMD groups at Post24h (p < 0.01 and large effect sizes). In conclusion, although physical exercise elicits higher skin temperature that lasts up to 24 h following the efforts, muscle soreness depresses this response.


Assuntos
Exercício Físico , Mialgia , Temperatura Cutânea , Humanos , Masculino , Adulto , Mialgia/fisiopatologia , Adulto Jovem , Militares
17.
Int J Mol Sci ; 25(16)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39201709

RESUMO

KMT2A (alias: mixed-lineage leukemia [MLL]) gene mapping on chromosome 11q23 encodes the lysine-specific histone N-methyltransferase 2A and promotes transcription by inducing an open chromatin conformation. Numerous genomic breakpoints within the KMT2A gene have been reported in young children and adults with hematologic disorders and are present in up to 10% of acute leukemias. These rearrangements describe distinct features and worse prognosis depending on the fusion partner, characterized by chemotherapy resistance and high rates of relapse, with a progression-free survival of 30-40% and overall survival below 25%. Less intensive regimens are used in pediatric patients, while new combination therapies and targeted immunotherapeutic agents are being explored in adults. Beneficial therapeutic effects, and even cure, can be reached with hematopoietic stem cell transplantation, mainly in young children with dismal molecular lesions; however, delayed related toxicities represent a concern. Herein, we summarize the translocation partner genes and partial tandem duplications of the KMT2A gene, their molecular impact, clinical aspects, and novel targeted therapies.


Assuntos
Rearranjo Gênico , Histona-Lisina N-Metiltransferase , Leucemia , Proteína de Leucina Linfoide-Mieloide , Humanos , Proteína de Leucina Linfoide-Mieloide/genética , Histona-Lisina N-Metiltransferase/genética , Leucemia/genética , Leucemia/terapia , Transplante de Células-Tronco Hematopoéticas , Translocação Genética
18.
Chembiochem ; 24(13): e202300229, 2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-37171138

RESUMO

Macrocyclization of peptides is typically used to fix specific bioactive conformations and improve their pharmacological properties. Recently, macrobicyclic peptides have received special attention owing to their capacity to mimic protein structures or be key components of peptide-drug conjugates. Here, we describe the development of novel synthetic strategies for two distinctive types of peptide macrobicycles. A multicomponent macrocyclo-dimerization approach is introduced for the production of interconnected ß-turns, allowing two macrocyclic rings to be formed and dimerized in one pot. Also, an on-resin double stapling strategy is described for the assembly of lactam-bridged macrobicycles with stable tertiary folds.


Assuntos
Peptídeos Cíclicos , Peptídeos , Peptídeos Cíclicos/química , Ciclização , Peptídeos/química , Lactamas , Conformação Molecular
19.
Mult Scler ; 29(10): 1304-1315, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37435828

RESUMO

BACKGROUND: Black and Hispanic patients with multiple sclerosis (MS) have been shown to accumulate greater multiple sclerosis-associated disability (MSAD) than White patients. Disparities in social determinants of health (SDOH) among these groups have also been reported. OBJECTIVE: To determine the extent to which associations of race and ethnicity with MSAD may be attributable to differences in SDOH. METHODS: Retrospective chart analysis of patients at an academic MS center grouped by self-identified Black (n = 95), Hispanic (n = 93), and White (n = 98) race/ethnicity. Individual patient addresses were geocoded and matched with neighborhood-level area deprivation index (ADI) and social vulnerability index (SVI). RESULTS: Average Expanded Disability Status Scale (EDSS) scores at last-recorded evaluations of White patients (1.7 ± 2.0) were significantly lower than Black (2.8 ± 2.4, p = 0.001) and Hispanic (2.6 ± 2.6, p = 0.020) patients. Neither Black race nor Hispanic ethnicity was significantly associated with EDSS in multivariable linear regression models that included individual-level SDOH indicators and either ADI or SVI. CONCLUSION: Black race and Hispanic ethnicity are not significantly associated with EDSS in models that include individual and neighborhood-level SDOH indicators. Further research should elucidate mechanisms by which structural inequities affect MS disease course.


Assuntos
Disparidades nos Níveis de Saúde , Esclerose Múltipla , Determinantes Sociais da Saúde , Humanos , Hispânico ou Latino , Estudos Retrospectivos , Negro ou Afro-Americano , Brancos
20.
Inorg Chem ; 62(16): 6197-6201, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37039460

RESUMO

A P162- polyphosphide dianion ink was produced by the reaction of red phosphorus with a binary thiol-amine mixture of ethanethiol (ET) and ethylenediamine (en). The polyphosphide was identified by solution 31P NMR spectroscopy and electrospray ionization mass spectrometry. This solute was compared to the reaction products of white phosphorus (P4) and other elemental pnictides in the same solvent system. The reaction of P4 with ET and en gives the same P162- polyphosphide; however, the easier handling and lower reactivity of red phosphorus highlights the novelty of that reaction. Elemental arsenic and antimony both give mononuclear pnictogen-sulfide-thiolate complexes upon reaction with ET and en under otherwise identical conditions, with this difference likely resulting from the greater covalency and tendency of phosphorus to form P-P bonds.

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