Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 295
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Mol Carcinog ; 63(4): 688-700, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38224261

RESUMEN

Gastric cancer (GC) is a prevalent malignancy of the digestive system. Distant metastasis and chemotherapy resistance are the crucial obstacles to prognosis in GC. Recent research has discovered that the glucose-6-phosphatase catalytic subunit (G6PC) plays an important role in tumor malignant development. However, little evidence has highlighted its role in GC. Herein, through a comprehensive analysis including profiling of tissue samples and functional validation in vivo and in vitro, we identify G6PC as a crucial factor in GC tumorigenesis. Importantly, we found that the FOXO1/G6PC axis could accelerate GC cell proliferation, metastasis, and 5-Fluorouracil (5-FU) resistance by targeting the PI3K/AKT/mTOR signaling pathway, implicating that as a prospective therapeutic approach in GC.


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fluorouracilo/farmacología , Fluorouracilo/uso terapéutico , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Línea Celular Tumoral , Proliferación Celular , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo
2.
J Pathol ; 261(2): 198-209, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37584165

RESUMEN

Non-invasive biomarkers for immunotherapy response remain a compelling unmet medical need. POLARIS-03 is a multicenter phase II trial to evaluate the safety and efficacy of toripalimab (anti-programmed cell death 1) in refractory metastatic urothelial carcinoma (mUC). We assessed the predictive utility of longitudinal circulating tumor DNA (ctDNA) analysis from a single-institution biomarker cohort. Twenty-seven mUC patients receiving toripalimab (3 mg/kg Q2W) at Ren Ji Hospital were enrolled. Serial plasma specimens were obtained at baseline and then every two cycles during treatment. The 600-gene panel (PredicineATLAS™) liquid biopsy assay was applied to probe somatic variants and cancer cell fraction (CCF). Low-pass whole genome sequencing was used to determine the copy number abnormality (CNA) score. Across the entire cohort, we observed different degrees of concordance between somatic aberrations detected by ctDNA and those inferred by matched tumor samples. Although the baseline CCF or CNA had limited predictive value, early ctDNA response at week 8 was associated with toripalimab efficacy and prolonged patient survival. Integrating CCF and CNA decrease achieved a superior accuracy of 90.5% in classifying responders and non-responders and predicted long-term benefit from toripalimab. Dynamic changes in the CCF and CNA in blood exquisitely reflected radiographic assessment of malignant lesions, including those with FGFR3-TACC3 gene fusion or microsatellite instability. This study demonstrates the feasibility and effectiveness of integrated longitudinal ctDNA profiling as a potential biomarker in mUC patients undergoing immunotherapy and supports further clinical evaluation of minimally invasive liquid biopsy assays for treatment stratification and therapy monitoring. © 2023 The Pathological Society of Great Britain and Ireland.


Asunto(s)
Carcinoma de Células Transicionales , ADN Tumoral Circulante , Neoplasias de la Vejiga Urinaria , Humanos , ADN Tumoral Circulante/genética , Carcinoma de Células Transicionales/tratamiento farmacológico , Carcinoma de Células Transicionales/genética , Biomarcadores de Tumor/genética , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/genética , Inmunoterapia , Mutación , Proteínas Asociadas a Microtúbulos/genética
3.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-33558418

RESUMEN

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.


Asunto(s)
Arqueología , Cuevas/química , ADN Antiguo/análisis , Fósiles , Sedimentos Geológicos/análisis , Migración Humana/historia , Datación Radiométrica/métodos , China , Historia Antigua , Humanos
4.
Angew Chem Int Ed Engl ; 63(28): e202401163, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38702974

RESUMEN

Aqueous zinc-metal batteries are prospective energy storge devices due to their intrinsically high safety and cost effectiveness. Yet, uneven deposition of zinc ions in electrochemical reduction and side reactions at the anode interface significantly hinder their development and application. Here, we propose a solvation-interface attenuation strategy enabled by a frustrated tertiary amine amphiphilic dipolymer electrolyte additive. The configuration of superhydrophilic segments with covalently bonded lipophilic spacers enables coupled steric hindrance/coordination, which establishes a balanced push-pull dynamic of dipolymer-H2O-Zn2+. Such interplay reconstructs the solvation structure of Zn2+ and allows the formation of a stable dipolymer-inorganic hybrid solid electrolyte interface (SEI) layer. This SEI layer effectively shields the zinc-metal anode from water and anions, significantly reducing side reactions. In addition, the dipolymer adsorbed at the zinc-metal anode interface regulates the interfacial electrochemical reduction kinetics and ensures uniform zinc deposition. As a result, the Zn-Zn symmetric cells with dipolymer-containing electrolyte exhibit remarkable cycling stability exceeding 5800 h (242 days). The Zn-NVO batteries and Zn-AC hybrid ion supercapacitors also deliver stable cycling for up to 1440 h (60 days) with high-capacity retention over 80 %. This research demonstrates the potential to facilitate the development and commercialization of zinc-based energy storage devices.

5.
Int Wound J ; 20(5): 1544-1551, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36480562

RESUMEN

To assess the impact of oxidised regenerated cellulose/collagen dressing on the management of chronic skin wounds, we conducted a meta-analysis. A thorough review of the literature up to September 2022 revealed that 1521 participants had chronic skin wounds at the start of the investigations; 763 of them used oxidised regenerated cellulose/collagen dressing, while 758 received control. Using dichotomous or contentious methods and a random or fixed-effect model, odds ratios (OR) and mean difference (MD) with 95% confidence intervals (CIs) were estimated to evaluate the impact of oxidised regenerated cellulose/collagen dressing on the management of chronic skin wounds. The oxidised regenerated cellulose/collagen dressing had significantly higher complete wound healing (OR, 1.74; 95% CI, 1.06-2.85; P = .03), higher wound relative reduction percent (MD, 13.50; 95% CI, 2.39-24.61; P = .02), and lower adverse events in wound healing (OR, 0.63; 95% CI, 0.41-0.98; P = .04) compared with control in chronic skin wounds. The oxidised regenerated cellulose/collagen dressing had significantly higher complete wound healing, higher wound relative reduction percent and lower adverse events in wound healing compared with control in chronic skin wounds. The low sample size of 8 out of 10 researches in the meta-analysis and the small number of studies in several comparisons calls for care when analysing the results.


Asunto(s)
Celulosa Oxidada , Traumatismos de los Tejidos Blandos , Humanos , Colágeno , Cicatrización de Heridas , Celulosa , Vendajes
6.
Curr Issues Mol Biol ; 44(12): 5995-6005, 2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36547069

RESUMEN

The Nocardia rubra cell wall skeleton (Nr-CWS) is an immunomodulator used clinically for its ability to modulate the body's immune function. Macrophages are an important hub of the immune response during wound healing. In this study, we hypothesized that a Nr-CWS could modulate macrophage physiological activities, polarize macrophages toward M2, and promote wound healing. Through in vivo experiments, we made two full-thickness excisional wounds on the backs of mice; one was treated with a Nr-CWS, and the other was treated with saline. We photographed and recorded the wound change every other day. We observed the histopathological examination and collagen deposition using H&E and Masson staining, then analyzed the macrophage surface markers using immunofluorescence. Through in vitro experiments, we studied the effect of the Nr-CWS on RAW264.7 cells through CCK8, transwell, flow cytometry, western blot, immunofluorescence, and ELISA. We found that the Nr-CWS can enhance the proliferation, migration, and phagocytosis of macrophages. In addition, it can promote the recruitment of macrophages on the wound surface, polarize macrophages to M2, and increase the expression of pro-healing cytokines. Ultimately, the Nr-CWS accelerated wound healing.

7.
PLoS Med ; 19(5): e1003953, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35617368

RESUMEN

BACKGROUND: Heterologous boost vaccination has been proposed as an option to elicit stronger and broader, or longer-lasting immunity. We assessed the safety and immunogenicity of heterologous immunization with a recombinant adenovirus type-5-vectored Coronavirus Disease 2019 (COVID-19) vaccine (Convidecia, hereafter referred to as CV) and a protein-subunit-based COVID-19 vaccine (ZF2001, hereafter referred to as ZF). METHODS AND FINDINGS: We conducted a randomized, observer-blinded, placebo-controlled trial, in which healthy adults aged 18 years or older, who have received 1 dose of Convidecia, with no history of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, were recruited in Jiangsu, China. Sixty participants were randomly assigned (2:1) to receive either 1 dose of ZF2001 or placebo control (trivalent inactivated influenza vaccine (TIV)) administered at 28 days after priming, and received the third injection with ZF2001 at 5 months, referred to as CV/ZF/ZF (D0-D28-M5) and CV/ZF (D0-M5) regimen, respectively. Sixty participants were randomly assigned (2:1) to receive either 1 dose of ZF2001 or TIV administered at 56 days after priming, and received the third injection with ZF2001 at 6 months, referred to as CV/ZF/ZF (D0-D56-M6) and CV/ZF (D0-M6) regimen, respectively. Participants and investigators were masked to the vaccine received but not to the boosting interval. Primary endpoints were the geometric mean titer (GMT) of neutralizing antibodies against wild-type SARS-CoV-2 and 7-day solicited adverse reactions. The primary analysis was done in the intention-to-treat population. Between April 7, 2021 and May 6, 2021, 120 eligible participants were randomly assigned to receive ZF2001/ZF2001 (n = 40) or TIV/ZF2001 (n = 20) 28 days and 5 months post priming, and receive ZF2001/ZF2001 (n = 40) or TIV/ZF2001 (n = 20) 56 days and 6 months post priming. Of them, 7 participants did not receive the third injection with ZF2001. A total of 26 participants (21.7%) reported solicited adverse reactions within 7 days post boost vaccinations, and all the reported adverse reactions were mild, with 13 (32.5%) in CV/ZF/ZF (D0-D28-M5) regimen, 7 (35.0%) in CV/ZF (D0- M5) regimen, 4 (10.0%) in CV/ZF/ZF (D0-D56-M6) regimen, and 2 (10.0%) in CV/ZF (D0-M6) regimen, respectively. At 14 days post first boost, GMTs of neutralizing antibodies in recipients receiving ZF2001 at 28 days and 56 days post priming were 18.7 (95% CI 13.7 to 25.5) and 25.9 (17.0 to 39.3), respectively, with geometric mean ratios of 2.0 (1.2 to 3.5) and 3.4 (1.8 to 6.4) compared to TIV. GMTs at 14 days after second boost of neutralizing antibodies increased to 107.2 (73.7 to 155.8) in CV/ZF/ZF (D0-D28-M5) regimen and 141.2 (83.4 to 238.8) in CV/ZF/ZF (D0-D56-M6) regimen. Two-dose schedules of CV/ZF (D0-M5) and CV/ZF (D0-M6) induced antibody levels comparable with that elicited by 3-dose schedules, with GMTs of 90.5 (45.6, 179.8) and 94.1 (44.0, 200.9), respectively. Study limitations include the absence of vaccine effectiveness in a real-world setting and current lack of immune persistence data. CONCLUSIONS: Heterologous boosting with ZF2001 following primary vaccination with Convidecia is more immunogenic than a single dose of Convidecia and is not associated with safety concerns. These results support flexibility in cooperating viral vectored and recombinant protein vaccines. TRIAL REGISTRATION: Study on Heterologous Prime-boost of Recombinant COVID-19 Vaccine (Ad5 Vector) and RBD-based Protein Subunit Vaccine; ClinicalTrial.gov NCT04833101.


Asunto(s)
COVID-19 , Vacunas contra la Influenza , Adenoviridae/genética , Adulto , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19/efectos adversos , Método Doble Ciego , Humanos , Inmunogenicidad Vacunal , SARS-CoV-2 , Vacunación , Vacunas Sintéticas/efectos adversos
8.
BMC Med ; 20(1): 112, 2022 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-35331214

RESUMEN

BACKGROUND: Both changes in circulating lipids represented by a validated poor prognostic 3-lipid signature (3LS) and somatic tumour genetic aberrations are individually associated with worse clinical outcomes in men with metastatic castration-resistant prostate cancer (mCRPC). A key question is how the lipid environment and the cancer genome are interrelated in order to exploit this therapeutically. We assessed the association between the poor prognostic 3-lipid signature (3LS), somatic genetic aberrations and clinical outcomes in mCRPC. METHODS: We performed plasma lipidomic analysis and cell-free DNA (cfDNA) sequencing on 106 men with mCRPC commencing docetaxel, cabazitaxel, abiraterone or enzalutamide (discovery cohort) and 94 men with mCRPC commencing docetaxel (validation cohort). Differences in lipid levels between men ± somatic genetic aberrations were assessed with t-tests. Associations between the 3LS and genetic aberrations with overall survival (OS) were examined using Kaplan-Meier methods and Cox proportional hazard models. RESULTS: The 3LS was associated with shorter OS in the discovery (hazard ratio [HR] 2.15, 95% confidence interval [CI] 1.4-3.3, p < 0.001) and validation cohorts (HR 2.32, 95% CI 1.59-3.38, p < 0.001). Elevated plasma sphingolipids were associated with AR, TP53, RB1 and PI3K aberrations (p < 0.05). Men with both the 3LS and aberrations in AR, TP53, RB1 or PI3K had shorter OS than men with neither in both cohorts (p ≤ 0.001). The presence of 3LS and/or genetic aberration was independently associated with shorter OS for men with AR, TP53, RB1 and PI3K aberrations (p < 0.02). Furthermore, aggressive-variant prostate cancer (AVPC), defined as 2 or more aberrations in TP53, RB1 and/or PTEN, was associated with elevated sphingolipids. The combination of AVPC and 3LS predicted for a median survival of ~12 months. The relatively small sample size of the cohorts limits clinical applicability and warrants future studies. CONCLUSIONS: Elevated circulating sphingolipids were associated with AR, TP53, RB1, PI3K and AVPC aberrations in mCRPC, and the combination of lipid and genetic abnormalities conferred a worse prognosis. These findings suggest that certain genotypes in mCRPC may benefit from metabolic therapies.


Asunto(s)
Neoplasias de la Próstata Resistentes a la Castración , Biomarcadores de Tumor/genética , Docetaxel/uso terapéutico , Femenino , Humanos , Lipidómica , Lípidos , Masculino , Fosfatidilinositol 3-Quinasas/uso terapéutico , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Neoplasias de la Próstata Resistentes a la Castración/genética , Neoplasias de la Próstata Resistentes a la Castración/metabolismo , Receptores Androgénicos/metabolismo , Esfingolípidos/uso terapéutico
9.
J Transl Med ; 20(1): 211, 2022 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-35562750

RESUMEN

BACKGROUND: The correlations between circulating tumour DNA (ctDNA)-derived genomic markers and treatment response and survival outcome in Chinese patients with advanced breast cancer (ABC) have not been extensively characterized. METHODS: Blood samples from 141 ABC patients who underwent first-line standard treatment in Peking University Cancer Hospital were collected. A next-generation sequencing based liquid biopsy assay (PredicineCARE) was used to detect somatic mutations and copy number variations (CNVs) in ctDNA. A subset of matched blood samples and tumour tissue biopsies were compared to evaluate the concordance. RESULTS: Overall, TP53 (44.0%) and PIK3CA (28.4%) were the top two altered genes. Frequent CNVs included amplifications of ERBB2 (24.8%) and FGFR1 (8.5%) and deletions of CDKN2A (3.5%). PIK3CA/TP53 and FGFR1/2/3 variants were associated with drug resistance in hormone receptor-positive (HR +) and human epidermal growth factor receptor 2-positive (HER2 +) patients. The comparison of genomic variants across matched tumour tissue and ctDNA samples revealed a moderate to high concordance that was gene dependent. Triple-negative breast cancer (TNBC) patients harbouring TP53 or PIK3CA alterations had a shorter overall survival than those without corresponding mutations (P = 0.03 and 0.008). A high ctDNA fraction was correlated with a shorter progression-free survival (PFS) (P = 0.005) in TNBC patients. High blood-based tumor mutation burden (bTMB) was associated with a shorter PFS for HER2 + and TNBC patients (P = 0.009 and 0.05). Moreover, disease monitoring revealed several acquired genomic variants such as ESR1 mutations, CDKN2A deletions, and FGFR1 amplifications. CONCLUSIONS: This study revealed the molecular profiles of Chinese patients with ABC and the clinical validity of ctDNA-derived markers, including the ctDNA fraction and bTMB, for predicting treatment response, prognosis, and disease progression. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03792529. Registered January 3rd 2019, https://clinicaltrials.gov/ct2/show/NCT03792529 .


Asunto(s)
Neoplasias de la Mama , ADN Tumoral Circulante , Neoplasias de la Mama Triple Negativas , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , ADN Tumoral Circulante/genética , Fosfatidilinositol 3-Quinasa Clase I/genética , Variaciones en el Número de Copia de ADN , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación/genética , Pronóstico
10.
J Hum Genet ; 67(3): 175-180, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34531527

RESUMEN

The Kyrgyz are a trans-border ethnic group, mainly living in Kyrgyzstan. Previous genetic investigations of Central Asian populations have repeatedly investigated the Central Asian Kyrgyz. However, from the standpoint of human evolution and genetic diversity, Northwest Chinese Kyrgyz is one of the more poorly studied populations. In this study, we analyzed the non-recombining portion of the Y-chromosome from 298 male Kyrgyz samples from Xinjiang Uygur Autonomous Region in northwestern China, using a high-resolution analysis of 108 biallelic markers and 17 or 24 STRs. First, via a Y-SNP-based PCA plot, Northwest Chinese Kyrgyz tended to cluster with other Kyrgyz population and are located in the West Asian and Central Asian group. Second, we found that the Northwest Chinese Kyrgyz display a high proportion of Y-lineage R1a1a1b2a2a-Z2125, related to Bronze Age Siberian, and followed by Y-lineage C2b1a3a1-F3796, related to Medieval Niru'un Mongols, such as Uissun tribe from Kazakhs. In these two dominant lineages, two unique recent descent clusters have been detected via NETWORK analysis, respectively, but they have nearly the same TMRCA ages (about 13th-14th centuries). This finding once again shows that the expansions of Mongol Empire had a striking effect on the Central Asian gene pool.


Asunto(s)
Cromosomas Humanos Y , Genética de Población , Pueblo Asiatico/genética , China , Cromosomas Humanos Y/genética , Etnicidad , Haplotipos , Humanos , Masculino
11.
Reprod Biol Endocrinol ; 20(1): 50, 2022 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-35277194

RESUMEN

BACKGROUND: The glucose-6-phosphatase catalytic subunit (G6PC) is a key enzyme that is involved in gluconeogenesis and glycogen decomposition during glycometabolism. Studies have shown that G6PC is abnormally expressed in various cancers and participates in the proliferation and metastasis of tumors. However, the role of G6PC in cervical cancer remains poorly established. METHODS: To analyze the expression of G6PC in cervical cancer tissues in patients by immunohistochemistry. Effects of G6PC deregulation on cervical cancer phenotype were determined using MTT, colony formation, transwell, and wound-healing assays. And constructed a nude mouse xenograft tumor model and CAM assay in vivo. The effect of G6PC on glycolysis in cervical cancer was also evaluated. Effect of G6PC on PI3K/AKT/mTOR pathway was detected by Western blot assay. RESULTS: In this study, G6PC expression was found to be upregulated in cervical cancer tissues, and this upregulated expression was associated with LN metastasis, clinical stage, recurrence, and disease-free survival and overall survival rates, indicating that G6PC could serve as a novel marker of early diagnosis in cervical cancer. G6PC promoted proliferation, invasion, epithelial mesenchymal transition (EMT) progression, and angiogenesis of cervical cancer cells. Mechanistically, G6PC activated PI3K/AKT/mTOR pathways. The PI3K/AKT pathway inhibitor, LY294002 could partially attenuate the effect. CONCLUSIONS: G6PC plays a key role in the progression of cervical cancer, and overexpressed G6PC is closely related to patient LN metastasis, clinical stage, recurrence and shortened survival. G6PC promoted cervical cancer proliferation, invasion, migration, EMT progression, and angiogenesis, partially through activating the PI3K/AKT pathway. G6PC, as a metabolic gene, not only plays a role in metabolism, but also participates in the development of cervical cancer. Its complex metabolic and non metabolic effects may be a potential therapeutic target and worthy of further study.


Asunto(s)
Carcinogénesis/metabolismo , Glucosa-6-Fosfatasa/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Adulto , Anciano , Animales , Western Blotting , Carcinogénesis/genética , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica , Glucosa-6-Fosfatasa/genética , Células HeLa , Humanos , Inmunohistoquímica , Ratones Endogámicos BALB C , Ratones Desnudos , Persona de Mediana Edad , Pronóstico , Trasplante Heterólogo , Regulación hacia Arriba , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología
12.
J Org Chem ; 87(2): 1194-1207, 2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-35016504

RESUMEN

Density functional theory calculations are used in this study to investigate the product selectivity and mechanism of borane-catalyzed reductive aldehyde amination by a H2 reducing agent. Knowing that different boranes yield different products, two typical boranes, (B(2,6-Cl2C6H3)(p-HC6F4)2 and B(C6F5)3), are studied. Of the seven possible pathways of B(2,6-Cl2C6H3)(p-HC6F4)2-catalyzed aldehyde amination analyzed herein, four are favorable. Three of the four favorable pathways involve imine intermediates, and the fourth is a Lewis acid-base synergistic pathway that involves amine-alcohol condensation. As for the B(C6F5)3 catalyst, it forms a highly stable Lewis adduct with aniline, which impedes the hydrogenation of imine. Therefore, the product of B(C6F5)3-catalyzed reductive amination of benzaldehyde and aniline is an imine. The linear relationship between the charge on the boron atom in the Lewis acid and the relative energies of the Lewis adduct and H2 splitting transition state indicates that this parameter determines product selectivity. Indeed, when the natural charge on boron is larger than 1, an amine is produced, whereas when the charge is less than 1, an imine is produced. Hence, the selectivity of products can be controlled by adjusting the natural charge of the boron atom in the Lewis acid catalyst.

13.
J Biomech Eng ; 144(12)2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36166284

RESUMEN

Computational hemodynamic modeling has been widely used in cardiovascular research and healthcare. However, the reliability of model predictions is largely dependent on the uncertainties of modeling parameters and boundary conditions, which should be carefully quantified and further reduced with available measurements. In this work, we focus on propagating and reducing the uncertainty of vascular geometries within a Bayesian framework. A novel deep learning (DL)-assisted parallel Markov chain Monte Carlo (MCMC) method is presented to enable efficient Bayesian posterior sampling and geometric uncertainty reduction. A DL model is built to approximate the geometry-to-hemodynamic map, which is trained actively using online data collected from parallel MCMC chains and utilized for early rejection of unlikely proposals to facilitate convergence with less expensive full-order model evaluations. Numerical studies on two-dimensional aortic flows are conducted to demonstrate the effectiveness and merit of the proposed method.


Asunto(s)
Aprendizaje Profundo , Teorema de Bayes , Hemodinámica , Método de Montecarlo , Reproducibilidad de los Resultados , Incertidumbre
14.
Molecules ; 27(17)2022 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-36080460

RESUMEN

This study investigates the mechanism of metal-free pyridine phosphination with P(OEt)3, PPh3, and PAr2CF3 using density functional theory calculations. The results show that the reaction mechanism and rate-determining step vary depending on the phosphine and additive used. For example, phosphination of pyridine with P(OEt)3 occurs in five stages, and ethyl abstraction is the rate-determining step. Meanwhile, 2-Ph-pyridine phosphination with PPh3 is a four-step reaction with proton abstraction as the rate-limiting step. Energy decomposition analysis of the transition states reveals that steric hindrance in the phosphine molecule plays a key role in the site-selective formation of the phosphonium salt. The mechanism of 2-Ph-pyridine phosphination with PAr2CF3 is similar to that with PPh3, and analyses of the effects of substituents show that electron-withdrawing groups decreased the nucleophilicity of the phosphine, whereas aryl electron-donating groups increased it. Finally, TfO- plays an important role in the C-H fluoroalkylation of pyridine, as it brings weak interactions.


Asunto(s)
Modelos Teóricos , Piridinas , Catálisis , Electrones , Metales
15.
Biochem Biophys Res Commun ; 574: 78-84, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34438350

RESUMEN

Functional blood vessels are crucial to wound healing, and faster vascularization means faster tissue repair to some extent. Increasing numbers of pro-vascularization wound coverings are being developed and studied. Moreover, mechanical properties of the extracellular matrix can guide the behaviour of related cells to some degree. Studies have shown that the mechanical range of 1-7 kPa contributes to the differentiation of stem cells into endothelial cells and thus to the process of wound vascularization. Unfortunately, the regulatory mechanics of vascularizing wound coverings have been poorly studied. Silk fibroin (SF) has attracted much attention because of its good biocompatibility, degradability and adjustable mechanical properties. In this paper, silk scaffolds with mechanical properties of 2 kPa and 5.9 kPa were prepared by adjusting the mechanics of silk scaffolds in terms of freezing temperature and aligned structure. The mechanical properties of the 5.9 kPa aligned silk scaffold (ASS) showed good vascularization ability. By adjusting the intermediate conformation and physical structure of Silk fibroin (SF), the mechanical strength of the silk scaffold could be increased, enabling us to better understand the mechanical regulation mode. At the same time, the aligned structure of the aligned silk scaffold (ASS) promoted the migration and proliferation of cells related to wound repair to a certain extent. By adjusting the mechanical properties and physical structure of the material, an aligned silk scaffold with vascularization function was constructed, providing more possibilities for faster wound repair.


Asunto(s)
Fibroínas/metabolismo , Neovascularización Patológica/metabolismo , Seda/metabolismo , Animales , Femenino , Ratas , Ratas Sprague-Dawley
16.
Biochem Biophys Res Commun ; 568: 103-109, 2021 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-34214874

RESUMEN

At present, stem cell transplantation has a significant therapeutic effect on spinal cord injury (SCI), however, it is still challenging for the seed cells selection. In this study, in order to explore cells with wide neural repair potentials, we selected the pluripotent stem cells multilineage-differentiating stress-enduring (Muse) cells, inducing the in vitro differentiation of human Muse cells into neural precursor cells (Muse-NPCs) by applying neural induction medium. Here, we found induced Muse-NPCs expressed neural stem cell markers Nestin and NCAM, capable of differentiating into three types of neural cells (neuron, astrocyte and oligodendrocyte), and have certain biological functions. When Muse-NPCs were transplanted into rats suffering from T10 SCI, motor function was improved. These results provide an insight for application of Muse-NPCs in cell therapy or tissue engineering for the repair of SCI in future.


Asunto(s)
Células-Madre Neurales/citología , Células-Madre Neurales/trasplante , Neurogénesis , Traumatismos de la Médula Espinal/terapia , Adulto , Animales , Astrocitos/citología , Células Cultivadas , Femenino , Humanos , Neuronas/citología , Oligodendroglía/citología , Ratas , Ratas Sprague-Dawley
17.
Breast Cancer Res Treat ; 190(2): 213-226, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34471951

RESUMEN

PURPOSE: Meaningful comparison of mutational landscapes across ethnic groups requires the use of standardized platform technology. We have used a harmonized NGS-based liquid biopsy assay to explore the differential genomic landscape of patients with initially hormone receptor-positive (HR+), HER2-negative MBC of first line metastasis or primary Stage IV at diagnosis from the United States (US) and China (CN). METHODS: Plasma circulating tumor DNA (ctDNA) from 27 US patients and 65 CN patients was sequenced using the harmonized CLIA-certified, 152-gene PredicineCare™ liquid biopsy assay. Kaplan-Meier survival analysis was performed to analyze the correlation between genomic alterations and progression-free survival (PFS), and p-values were calculated using the log-rank test. RESULTS: All patients in the CN cohort received chemotherapy and/or hormonal therapy, while 85.2% (23/27) patients in the US cohort received hormonal therapy plus CDK4/6 inhibitors. Mutations were detected in 23 of 27 (85%) US patients and 54 of 65 (83%) CN patients. The prevalence of AKT1 (P = 0.008) and CDH1 (P = 0.021) alterations were both higher in the US vs. CN cohort. In addition, FGFR1 amplification were more frequent in the CN vs. US cohort (P = 0.048). PTEN deletions (P = 0.03) and ESR1 alterations (P = 0.02) were associated with shorter PFS in the CN cohort, neither of these associations were observed in the US cohort. Interestingly, a reduced association between PTEN deletion and PFS was observed in patients receiving CDK4/6 inhibitor treatment. CONCLUSION: The differential prevalence of ctDNA-based alterations such as FGFR1, AKT1, and CDH1 was observed in initially HR+/HER2- MBC patients in the US vs. CN. In addition, the association of PTEN deletions with shorter PFS was found in the CN but not the US cohort. The differential genomic landscapes across the two ethnic groups may reflect biologic differences and clinical implications.


Asunto(s)
Neoplasias de la Mama , Ácidos Nucleicos Libres de Células , ADN Tumoral Circulante , Biomarcadores de Tumor , Ácidos Nucleicos Libres de Células/sangre , Ácidos Nucleicos Libres de Células/genética , China/epidemiología , ADN Tumoral Circulante/sangre , ADN Tumoral Circulante/genética , Femenino , Genómica , Hormonas , Humanos , Metástasis de la Neoplasia , Receptor ErbB-2/genética , Estados Unidos/epidemiología
18.
J Urol ; 206(4): 873-884, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34061567

RESUMEN

PURPOSE: Next-generation sequencing (NGS)-based profiling of both urinary tumor DNA (utDNA) and circulating tumor DNA (ctDNA) shows promise for noninvasive detection and surveillance of urothelial bladder cancer (UBC). However, the analytical performance of these assays remains undefined in the real-world setting. Here, we sought to evaluate the concordance between tumor DNA (tDNA) profiling and utDNA or ctDNA assays using a UBC patient cohort from the intended-use population. MATERIALS AND METHODS: Fifty-nine cases with pathologically confirmed disease and matching tissue/urine pairs were prospectively enrolled. Baseline peripheral blood mononuclear cell and plasma specimens were collected during clinic visits. The PredicineCARETM NGS assay was applied for ultra-deep targeted sequencing and somatic alteration identification in tDNA, utDNA and ctDNA. RESULTS: Diverse quantitative metrics including cancer cell fraction, variant allele frequency and tumor mutation burden were invariably concordant between tDNA and utDNA, but not ctDNA. The mutational landscapes captured by tDNA or utDNA were highly similar, whereas a considerable proportion of ctDNA aberrations stemmed from clonal hematopoiesis. Using tDNA-informed somatic events as reference, utDNA assays achieved a specificity of 99.3%, a sensitivity of 86.7%, a positive predictive value of 67.2%, a negative predictive value of 99.8% and a diagnostic accuracy of 99.1%. Higher preoperative utDNA or tDNA abundance correlated with worse relapse-free survival. Actionable variants including FGFR3 alteration and ERBB2 amplification were identified in utDNA. CONCLUSIONS: Urine-based molecular pathology provides a valid and complete genetic profile of bladder cancer, and represents a faithful surrogate for genotyping and monitoring newly diagnosed UBC.


Asunto(s)
Biomarcadores de Tumor/orina , Carcinoma de Células Transicionales/diagnóstico , ADN Tumoral Circulante/orina , Técnicas de Genotipaje/métodos , Neoplasias de la Vejiga Urinaria/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/genética , Carcinoma de Células Transicionales/sangre , Carcinoma de Células Transicionales/genética , Carcinoma de Células Transicionales/orina , ADN Tumoral Circulante/sangre , ADN Tumoral Circulante/genética , Femenino , Frecuencia de los Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Biopsia Líquida/métodos , Masculino , Persona de Mediana Edad , Mutación , Recurrencia Local de Neoplasia , Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/sangre , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/orina
19.
PLoS Genet ; 14(9): e1007664, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30222779

RESUMEN

CHIP (carboxyl terminus of heat shock 70-interacting protein) has long been recognized as an active member of the cellular protein quality control system given the ability of CHIP to function as both a co-chaperone and ubiquitin ligase. We discovered a genetic disease, now known as spinocerebellar autosomal recessive 16 (SCAR16), resulting from a coding mutation that caused a loss of CHIP ubiquitin ligase function. The initial mutation describing SCAR16 was a missense mutation in the ubiquitin ligase domain of CHIP (p.T246M). Using multiple biophysical and cellular approaches, we demonstrated that T246M mutation results in structural disorganization and misfolding of the CHIP U-box domain, promoting oligomerization, and increased proteasome-dependent turnover. CHIP-T246M has no ligase activity, but maintains interactions with chaperones and chaperone-related functions. To establish preclinical models of SCAR16, we engineered T246M at the endogenous locus in both mice and rats. Animals homozygous for T246M had both cognitive and motor cerebellar dysfunction distinct from those observed in the CHIP null animal model, as well as deficits in learning and memory, reflective of the cognitive deficits reported in SCAR16 patients. We conclude that the T246M mutation is not equivalent to the total loss of CHIP, supporting the concept that disease-causing CHIP mutations have different biophysical and functional repercussions on CHIP function that may directly correlate to the spectrum of clinical phenotypes observed in SCAR16 patients. Our findings both further expand our basic understanding of CHIP biology and provide meaningful mechanistic insight underlying the molecular drivers of SCAR16 disease pathology, which may be used to inform the development of novel therapeutics for this devastating disease.


Asunto(s)
Cognición , Actividad Motora/genética , Dominios Proteicos/genética , Ataxias Espinocerebelosas/genética , Ubiquitina-Proteína Ligasas/genética , Animales , Conducta Animal , Sistemas CRISPR-Cas/genética , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Fenotipo , Mutación Puntual , Multimerización de Proteína/genética , Ratas , Ratas Sprague-Dawley , Ataxias Espinocerebelosas/congénito , Ubiquitina-Proteína Ligasas/metabolismo
20.
J Hum Genet ; 65(9): 797-803, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32313196

RESUMEN

Aksay Kazakhs are the easternmost branch of Kazakhs, residing in Jiuquan city, the forefront of the ancient Silk Road. However, the genetic diversity of Aksay Kazakhs and its relationships with other Kazakhs still lack attention. To clarify this issue, we analyzed the non-recombining portion of the Y-chromosome from 93 Aksay Kazakhs samples, using a high-resolution analysis of 106 biallelic markers and 17 STRs. The lowest haplogroup diversity (0.38) was observed in Aksay Kazakhs among all studied Kazakh populations. The social and cultural traditions of the Kazakhs shaped their current pattern of genetic variation. Aksay Kazakhs tended to migrate with clans and had limited paternal admixture with neighboring populations. Aksay Kazakhs had the highest frequency (80%) of haplogroup C2b1a3a1-F3796 (previous C3*-Star Cluster) among the investigated Eurasian steppe populations, which was now seen as the genetic marker of Kerei clan. Furthermore, NETWORK analysis indicated that Aksay Kazakhs originated from sub-clan Kerei-Abakh in Kazakhstan with DYS448 = 23. TMRCA estimates of three recent descent clusters detected in C2*-M217 (xM48) network, one of which incorporate nearly all of the C2b1a3a1-F3796 Aksay Kazakhs samples, gave the age range of 976-1405 YA for DC1, 1059-1314 YA for DC2, and 1139-1317 YA for DC3, respectively; this is coherent with the 7th to the 11th centuries Altaic-speaking pastoral nomadic population expansion.


Asunto(s)
Pueblo Asiatico/genética , Cromosomas Humanos Y/genética , Etnicidad/genética , China , Marcadores Genéticos , Variación Genética , Genética de Población , Haplotipos , Humanos , Masculino , Filogenia , Polimorfismo de Nucleótido Simple
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA