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1.
J Appl Stat ; 51(7): 1359-1377, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38835823

RESUMEN

Compared with the conditional mean regression-based scalar-on-function regression model, the scalar-on-function quantile regression is robust to outliers in the response variable. However, it is susceptible to outliers in the functional predictor (called leverage points). This is because the influence function of the regression quantiles is bounded in the response variable but unbounded in the predictor space. The leverage points may alter the eigenstructure of the predictor matrix, leading to poor estimation and prediction results. This study proposes a robust procedure to estimate the model parameters in the scalar-on-function quantile regression method and produce reliable predictions in the presence of both outliers and leverage points. The proposed method is based on a functional partial quantile regression procedure. We propose a weighted partial quantile covariance to obtain functional partial quantile components of the scalar-on-function quantile regression model. After the decomposition, the model parameters are estimated via a weighted loss function, where the robustness is obtained by iteratively reweighting the partial quantile components. The estimation and prediction performance of the proposed method is evaluated by a series of Monte-Carlo experiments and an empirical data example. The results are compared favorably with several existing methods. The method is implemented in an R package robfpqr.

2.
Int J Mol Sci ; 25(10)2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38791411

RESUMEN

Melon (Cucumis melo L.) is a global commercial crop that is sensitive to seed-borne wilt infections caused by Fusarium oxysporum f. sp. melonis (Fom). To address the challenge of detecting Fom contamination, we designed a probe-based real-time PCR method, TDCP2, in combination with rapid or column-based DNA extraction protocols to develop reliable molecular detection methods. Utilizing TDCP2, the detection rate reached 100% for both artificially Fom-inoculated (0.25-25%) and pod-inoculated melon seeds in conjunction with DNA samples from either the rapid or column-based extraction protocol. We performed analyses of precision, recall, and F1 scores, achieving a maximum F1 score of 1 with TDCP2, which highlights the robustness of the method. Additionally, intraday and interday assays were performed, which revealed the high reproducibility and stability of column-based DNA extraction protocols combined with TDCP2. These metrics confirm the reliability of our developed protocols, setting a foundation for future enhancements in seed pathology diagnostics and potentially broadening their applicability across various Fom infection levels. In the future, we hope that these methods will reduce food loss by improving the control and management of melon diseases.


Asunto(s)
Fusarium , Enfermedades de las Plantas , Reacción en Cadena en Tiempo Real de la Polimerasa , Semillas , Fusarium/genética , Fusarium/aislamiento & purificación , Semillas/microbiología , Enfermedades de las Plantas/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Cucurbitaceae/microbiología , ADN de Hongos/genética , ADN de Hongos/aislamiento & purificación , Cucumis melo/microbiología , Reproducibilidad de los Resultados
3.
J Hazard Mater ; 458: 132010, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37423132

RESUMEN

Traditional polymeric fibrous membranes have been extensively used to reduce the health risks caused by airborne particulate matter (PM), leading to the dramatically increasing pollution of plastics and microplastics. Although great efforts have been made to develop poly(lactic acid) (PLA)-based membrane filters, they are frequently dwarfed by their relatively poor electret properties and electrostatic adsorptive mechanisms. To resolve this dilemma, a bioelectret approach was proposed in this work, strategically involving the bioinspired adhesion of dielectric hydroxyapatite nanowhiskers as a biodegradable electret to promote the polarization properties of PLA microfibrous membranes. In addition to significant improvements in tensile properties, the incorporation of hydroxyapatite bioelectret (HABE) enabled remarkable increase in the removal efficiencies of ultrafine PM0.3 in a high-voltage electrostatic field (10 and 25 kV). This was exemplified by the largely increased filtering performance (69.75%, 23.1 Pa) for PLA membranes loaded with 10 wt% HABE at the normal airflow rate (32 L/min) compared to the pristine PLA counterpart (32.89%, 7.2 Pa). Although the filtration efficiency of PM0.3 for the counterpart dramatically decreased to 21.6% at 85 L/min, the increment was maintained at nearly 196% for the bioelectret PLA, while an ultralow pressure drop (74.5 Pa) and high humidity resistance (RH 80%) were achieved. The unusual property combination were ascribed to the HABE-enabled realization of multiple filtration mechanisms, including the simultaneous enhancement of physical interception and electrostatic adsorption. The significant filtration applications, unattainable with conventional electret membranes, demonstrate the bioelectret PLA as a promising biodegradable platform that allows high filtration properties and humidity resistance.

4.
J Colloid Interface Sci ; 645: 850-859, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37178562

RESUMEN

Multivalent ion batteries have attracted great attention because of their abundant reserves, low cost and high safety. Among them, magnesium ion batteries (MIBs) have been regarded as a promising alternative for large-scale energy storage device owing to its high volumetric capacities and unfavorable dendrite formation. However, the strong interaction between Mg2+ and electrolyte as well as cathode material results in very slow insertion and diffusion kinetics. Therefore, it is highly necessary to develop high-performance cathode materials compatible with electrolyte for MIBs. Herein, the electronic structure of NiSe2 micro-octahedra was modulated by nitrogen doping (N-NiSe2) through hydrothermal method followed by a pyrolysis process and this N-NiSe2 micro-octahedra was used as cathode materials for MIBs. It is worth noting that N-NiSe2 micro-octahedra shows more redox active sites and faster Mg2+ diffusion kinetics compared with NiSe2 micro-octahedra without nitrogen doping. Moreover, the density functional theory (DFT) calculations indicated that the doping of nitrogen could improve the conductivity of active materials on the one hand, facilitating Mg2+ ion diffusion kinetics, and on the other hand, nitrogen dopant sites could provide more Mg2+ adsorption sites. As a result, the N-NiSe2 micro-octahedra cathode exhibits a high reversible discharge capacity of 169 mAh g-1 at the current density of 50 mA g-1, and a good cycling stability over 500 cycles with a maintained discharge capacity of 158.5 mAh g-1. This work provides a new idea to improve the electrochemical performance of cathode materials for MIBs by the introduction of heteroatom dopant.

5.
Int J Biol Macromol ; 226: 1273-1283, 2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36442566

RESUMEN

Biomimetic mineralization of high-strength apatite structure essentially relies on mimicking the inorganic building blocks of naturally occurring bones. However, conventional routes still have substantial function gaps in providing precision control over the geometrical dimensions and crystalline morphology of biomineralized apatite. Herein, we conceived the concept of microwave-assisted biomineralization (MAB) to customize 1D hydroxyapatite nanowhiskers (HANWs) at graphene templates, rendering the formation of graphene-hydroxyapatite (Gr-HA) nanohybrids. The HANWs essentially resembled bone apatite in elemental composition (Ca/P = 1.74), diameter (~20 nm), crystallinity (63 %), and rodlike geometry (aspect ratio of ~6). The Gr-HA nanohybrids were uniformly incorporated into poly(lactic acid) (PLA) microfibers (~1 µm) by electrospinning, engendering fibrous membranes with a set of Gr-HA loadings (10, 20 and 30 wt%). Intimate interactions were generated between Gr-HA and PLA matrix, contributing to significant promotion of the mechanical properties for PLA composite membranes. For example, the yield strength and elastic modulus of the PLA composite membranes loaded with 30 wt% Gr-HA achieved 5.4 and 66.4 MPa, increasing nearly 182 % and over 94 % compared to those of pure PLA, respectively. Moreover, the bone-like HANWs endowed PLA membranes with excellent cytocompatibility and good bioactivity, as demonstrated by over 38 % increase in cell viability and rapid apatite formation in mineral solution. The impressive combination of mechanical properties and biological characteristics make the PLA/Gr-HA scaffolds promising for guided tissue/bone regeneration therapy.


Asunto(s)
Durapatita , Grafito , Durapatita/química , Andamios del Tejido/química , Biomineralización , Ingeniería de Tejidos/métodos , Poliésteres/química
6.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-36362048

RESUMEN

We developed an insulated isothermal PCR (iiPCR) method for the efficient and rapid detection of Fusarium oxysporum (Fo), which is a fungus that infects various hosts and causes severe crop losses. The Fo iiPCR method was sensitive enough to detect up to 100 copies of standard DNA template and 10 fg of Fo genomic DNA. In addition, it could directly detect 1 pg of mycelium and 10 spores of Fo without DNA extraction. Our study compared the performance of Fo iiPCR to that of three published in planta molecular detection methods-conventional PCR, SYBR green-based real-time PCR, and hydrolysis probe-based real-time PCR-in field detection of Fo. All diseased field samples yielded positive detection results with high reproducibility when subjected to an Fo iiPCR test combined with a rapid DNA extraction protocol compared to Fo iiPCR with an automated magnetic bead-based DNA extraction protocol. Intraday and interday assays were performed to ensure the stability of this new rapid detection method. The results of detection of Fo in diseased banana pseudostem samples demonstrated that this new rapid detection method was suitable for field diagnosis of Fusarium wilt and had high F1 scores for detection (the harmonic mean of precision and recall of detection) for all asymptomatic and symptomatic Fo-infected banana samples. In addition, banana samples at four growth stages (seedling, vegetative, flowering and fruiting, and harvesting) with mild symptoms also showed positive detection results. These results indicate that this new rapid detection method is a potentially efficient procedure for on-site detection of Fo.


Asunto(s)
Fusarium , Musa , Fusarium/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Musa/genética , ADN
7.
Int J Biol Macromol ; 222(Pt A): 927-937, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36183756

RESUMEN

The past decades have witnessed the archetypal shift from petroleum-based to bioplastics including poly(lactic acid) (PLA) for multifunctional packaging. Here we disclose a microwave-assisted functionalization (MAF) approach to functionalize wood fibers (FWFs) at minute level and high yields (approaching 99 %), conferring high affinity to PLA matrix and significant promotion of mechanical properties. By incorporating of 10 wt% FWFs, the tensile strength and toughness of PLA composite films were elevated to 54.5 MPa and 1.6 MJ/m3, increasing nearly 28 % and over 45 % compared to those of the counterpart loaded pristine wood fibers (PWFs), respectively. It is of significance to note the FWF-enabled unique optical properties for PLA, as exemplified by approximately 100 % UV-blocking ratio (UVR) in the whole UV region with the addition of 20 wt% FWFs. By contrast, the UVR values of PWF-filled PLA (5 %-20 %) gradually decreased as the fiber contents increased, mainly ascribed to the UV reflection at the poorly bonded interfaces and relatively inferior functionality of PWFs. This distinction allowed us to fabricate UV-barrier packaging for preservation of fresh fruits, which were perishable under the UV light of sunshine. The impressive mechanical robustness and high UVR, may prompt affordable and ecofriendly PLA/FWF composites appropriate for packaging.


Asunto(s)
Embalaje de Alimentos , Rayos Ultravioleta , Frutas , Poliésteres
8.
Int J Biol Macromol ; 220: 827-836, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-35998855

RESUMEN

The application of poly(lactic acid) (PLA) in the packaging area is frequently dwarfed by the inadequate gas/water barrier properties, low heat resistance and high UV transmittance. Herein, an environmentally friendly and high-efficiency microwave-assisted functionalization (MAF) approach was proposed to aqueous grafting waste bamboo fibers with the bridging agent. It permitted significant promotion of interfacial interactions between the MAF bamboo fibers (MAFBs) and neighboring PLA chains, contributing to uniform dispersion and intimate interphase. Featuring the morphological features, the MAFB-reinforced (5, 10 and 20 wt%) PLA biocomposites achieved an unexpected combination of high mechanical properties, exceptional resistance to heat deflection and UV irradiation, and excellent water barrier performance. Upon addition of only 5 wt% MAFBs, the tensile strength and toughness of PLA composite films were increased to 46.5 MPa and 0.6 MJ/m3, increasing over 52 % and nearly 107 % compared to those of the counterpart loaded pristine bamboo fibers (PBFs), respectively. This was favorably accompanied by the remarkably reduced water vapor permeability, falling down to the lowest value of 3.5 × 10-11 g∙m/Pa∙s∙m2 for PLA/MAFB (80/20) with a decrease of nearly 79 % compared to the counterpart. It is of interest to note the MAFB-enabled nearly 100 % UV-blocking ratio for PLA loaded 10 and 20 wt% fibers, as well as excellent resistance to heat deflection even at high temperatures like 120 °C. This effort paves the way to multifunctional natural fibers with high affinity to PLA for elegant implementation of high-heat and UV-resistant packaging materials in an ecofriendly manner.


Asunto(s)
Calor , Vapor , Microondas , Poliésteres
9.
Int J Biol Macromol ; 216: 114-123, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35793741

RESUMEN

The anisotropic hierarchical structures of naturally derived materials have offered useful design principles for the fabrication of high-strength and functional materials. Herein, we unraveled a structure-by-bionics approach to construction of pea pod-mimicking architecture for poly(lactic acid) (PLA) composites impregnated with hydroxyapatite nanowhiskers (HANWs). The HANWs (length of 80-120 nm, diameter of ~30 nm) were customized using microwave-assisted aqueous biomineralization at minute level, which were incorporated into PLA microfibers by electrospinning with filler loadings of 10-30 wt%. The membranes comprising HANW-modified PLA microfibers were stacked and structured into composite films, strategically involving high-pressure compression at a relatively low temperature to impart the confined structuring mechanisms. It thus allowed partial melting and thinning of PLA microfibers into nanofibers, onto which the discrete HANWs were tightly adhered and embedded, showing distinguished architectural configurations identical with pea pod. More importantly, the mechanical properties and bioactivity were remarkably promoted, as demonstrated by the increments of over 54 % and nearly 72 % for the yield strength and elastic modulus (71.6 and 2547 MPa) of the structured composite loaded 30 wt% HANWs compared to those of pure PLA (46.4 and 1484 MPa), as accompanied by significant improvements in the bioactivity to nucleate and create apatite entities in mineral solution. The unusual combination of excellent biological characteristics and bone-like mechanical elasticity and extensibility make the structured PLA composites promising for guided bone/tissue regeneration therapy.


Asunto(s)
Durapatita , Pisum sativum , Durapatita/química , Ácido Láctico/química , Poliésteres/química
10.
J Appl Stat ; 49(5): 1179-1202, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35707515

RESUMEN

The bootstrap procedure has emerged as a general framework to construct prediction intervals for future observations in autoregressive time series models. Such models with outlying data points are standard in real data applications, especially in the field of econometrics. These outlying data points tend to produce high forecast errors, which reduce the forecasting performances of the existing bootstrap prediction intervals calculated based on non-robust estimators. In the univariate and multivariate autoregressive time series, we propose a robust bootstrap algorithm for constructing prediction intervals and forecast regions. The proposed procedure is based on the weighted likelihood estimates and weighted residuals. Its finite sample properties are examined via a series of Monte Carlo studies and two empirical data examples.

11.
Sci Rep ; 12(1): 8749, 2022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35610243

RESUMEN

Pineapples are an important agricultural economic crop in Taiwan. Considerable human resources are required to protect pineapples from excessive solar radiation, which could otherwise lead to overheating and subsequent deterioration. Note that simple covering all of the fruit with a paper bag is not a viable solution, due to the fact that it makes it impossible to determine whether the fruit is ripe. This paper proposes a system by which to automate the detection of ripe pineapples. The proposed deep learning architecture enables detection regardless of lighting conditions, achieving accuracy of more than 99.27% with error of less than 2% at distances of 300 ~ 800 mm. This proposed system using an Nvidia TX2 is capable of 15 frames per second, thereby making it possible to mount the device on machines that move at walking speed.


Asunto(s)
Ananas , Aprendizaje Profundo , Ananas/crecimiento & desarrollo , Ananas/fisiología , Ananas/efectos de la radiación , Frutas/crecimiento & desarrollo , Frutas/fisiología , Frutas/efectos de la radiación , Humanos , Protección Radiológica/instrumentación , Protección Radiológica/métodos , Luz Solar/efectos adversos , Taiwán
12.
Plant Dis ; 2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35171641

RESUMEN

Jabuticaba (Plinia cauliflora (Mart.) Kausel) was originated from Brazil (Lorenzi 2000). The production of jabuticaba is growing globally as its value in the food and pharmaceutical industries (Benvenutti 2021). In August 2019, jabuticaba plants with symptoms of leaf blight were observed in the field at the Meinong of Kaohsiung City, Taiwan. Disease incidence was 40%. Symptoms first presented as small, water-soaked lesions on young leaves, and then dark brown lesions of 1-3 cm in diameter on mature leaves. Six symptomatic leaves were collected from 6 jabuticaba plants for verifying the causal agents. Tissues (5 × 5 mm2) were cut from the margin of symptomatic leaf. Samples were sterilized in 1% sodium hypochlorite for 60 s, rinsed with sterile distilled water three times and then placed in 1% water agar in the dark for 5 days at room temperature. Resultant fungal colonies were purified by subculturing fungal hyphal tips on potato dextrose agar in a growth chamber (28°C, 12 h photoperiod) until fungal conidia appeared. The fungi initially produced white, cottony, aerial mycelium, after which concentric black conidiomata appeared on the plates after 7 days of incubation. The 5-celled conidia were fusiform to ellipsoid, straight to slightly curved, with sizes of 24.00-44.00 µm × 6.00-13.00 µm (avg. size, 32.00 × 9.37 µm, n = 120). The apical and basal cells were hyaline, and 3 median cells were pale brown and versicolorous. Conidia had 2-3 apical appendages and a conical basal cell with a truncate base. Based on the characteristics, which were common among isolates from diseased samples, the causal pathogen was identified as Neopestalotiopsis sp. (Solarte et al. 2018). Internal transcribed spacer (ITS), translation elongation factor 1α (TEF), ß-tubulin, and large ribosomal subunit (LSU) DNA sequences were obtained from these isolates and deposited in GenBank (MN723897, ITS; MN813055, TEF; MN813054, ß-tubulin; MN860104, LSU). Sequences demonstrated high sequence identity with those of Neopestalotiopsis formicarum ex-type cultures CBS 362.72 (Maharachchikumbura et al. 2014): 99.44% for ITS (KM199358), 99.38% for TEF (KM199517), 98.86% for ß-tubulin (KM199455), and 100.00% for LSU (KM116248). The phylogenetic relationship in Neopestalotiopsis species supported the identification of our isolates as N. formicarum. Three independent 3-isolate inoculation experiments were performed to fit Koch's postulates. Surface-sterilized leaves on live plants were punctured with a needle and inoculated with 5 µL of conidial suspension (1 × 105 conidia/mL). Inoculated plants were kept in a growth chamber (25°C, 70% relative humidity) for 7 days. Control plants were inoculated with sterile distilled water and kept under the same conditions. Inoculated leaves developed brown lesions around wounds after seven days. The pathogen was re-isolated from diseased plants, following the steps used for the original procedure, with identical characteristics as the initial isolates. This is the first report of leaf brown blight caused by N. formicarum on jabuticaba in Taiwan. N. formicarum was recently considered as a new threat to jabuticaba (Gualberto et al. 2021). In addition, it has a broad host range on many tropical crops, such as guarana and banana (Gualberto et al. 2021). Neopestalotiopsis spp. have been reported to cause important economic fruit diseases (Gualberto et al. 2021). Therefore, N. formicarum may become the potential risk for fruit production of tropical crops.

13.
J Popul Res (Canberra) ; 39(4): 557-565, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33758578

RESUMEN

Emerging at the end of 2019, COVID-19 has become a public health threat to people worldwide. Apart from deaths with a positive COVID-19 test, many others have died from causes indirectly related to COVID-19. Therefore, the COVID-19 confirmed deaths underestimate the influence of the pandemic on society; instead, the measure of 'excess deaths' is a more objective and comparable way to assess the scale of the epidemic and formulate lessons. One common practical issue in analysing the impact of COVID-19 is to determine the 'pre-COVID-19' period and the 'post-COVID-19' period. We apply a change point detection method to identify any change points using excess deaths in Belgium.

14.
J Appl Stat ; 48(4): 583-604, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35706989

RESUMEN

This study examines the optimal selections of bandwidth and semi-metric for a functional partial linear model. Our proposed method begins by estimating the unknown error density using a kernel density estimator of residuals, where the regression function, consisting of parametric and nonparametric components, can be estimated by functional principal component and functional Nadayara-Watson estimators. The estimation accuracy of the regression function and error density crucially depends on the optimal estimations of bandwidth and semi-metric. A Bayesian method is utilized to simultaneously estimate the bandwidths in the regression function and kernel error density by minimizing the Kullback-Leibler divergence. For estimating the regression function and error density, a series of simulation studies demonstrate that the functional partial linear model gives improved estimation and forecast accuracies compared with the functional principal component regression and functional nonparametric regression. Using a spectroscopy dataset, the functional partial linear model yields better forecast accuracy than some commonly used functional regression models. As a by-product of the Bayesian method, a pointwise prediction interval can be obtained, and marginal likelihood can be used to select the optimal semi-metric.

15.
J Clin Endocrinol Metab ; 104(12): 6345-6356, 2019 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-31369093

RESUMEN

CONTEXT: Our previous study demonstrated that the expression of long noncoding RNA (lncRNA) H19 was frequently downregulated in human primary pituitary adenomas and negatively correlated with tumor progression. However, the role of exosomal lncRNA H19 in the inhibition of pituitary tumor growth remains unclear. OBJECTIVE: To investigate whether exosomal H19 could be transported across the cell membrane to exert its inhibitory effect on pituitary tumor growth. DESIGN: Empty lentivirus GH3 cells with or without H19 overexpression were used to establish a xenograft model. Isolated exosomes were identified by transmission electron microscopy, nanoparticle tracking, and Western blotting. The expression levels of serum exosomal H19 from 200 healthy subjects and 206 patients with various subtypes of pituitary tumors were detected by ultracentrifugation and quantitative real-time PCR. RESULTS: The growth of distal tumor cells was inhibited by transferring exosomal H19, which could be transported through cell membrane and exert its inhibitory effect. Cabergoline increased H19 expression and played a synergic therapeutic effect with exosomal H19. Exosomal H19 inhibited phosphorylation of the mTORC1 substrate 4E-BP1. Of note, the expression level of exosomal H19 in the patients with all subtypes of pituitary tumors was significantly lower than that in the healthy subjects. The change of plasma exosomal H19 level may be correlated with the prognosis or drug response of the patients. CONCLUSION: Exosomal H19 inhibits the growth of distal pituitary tumors through inhibiting 4E-BP1 phosphorylation. Plasma exosomal H19 may serve as an important biomarker for predicting medical responses of patients with prolactinomas.


Asunto(s)
Adenoma/prevención & control , Biomarcadores de Tumor/genética , Exosomas/metabolismo , Neoplasias Hipofisarias/prevención & control , ARN Largo no Codificante/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adenoma/genética , Adenoma/metabolismo , Adenoma/patología , Animales , Apoptosis , Biomarcadores de Tumor/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferación Celular , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Ratones Desnudos , Fosforilación , Neoplasias Hipofisarias/genética , Neoplasias Hipofisarias/metabolismo , Neoplasias Hipofisarias/patología , Pronóstico , ARN Largo no Codificante/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Cancer Lett ; 459: 135-144, 2019 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-31176743

RESUMEN

DEP domain-containing mechanistic target of rapamycin (mTOR)-interacting protein (DEPTOR) is an important modulator of mTOR, a highly conserved kinase whose hyperactivation is critically involved in a variety of human tumors. The role of DEPTOR playing in pituitary adenoma (PA) is largely unknown. Here, we reported that DEPTOR was downregulated in PA tissues, especially dopamine-resistant prolactinomas. Consistently, overexpression of DEPTOR inhibited pituitary tumor GH3 and MMQ cells proliferation in vitro and in vivo, and sensitized GH3 and MMQ cells to cabergoline (CAB), a dopamine agonist (DA). Conversely, knockdown of DEPTOR promoted GH3 and MMQ cells proliferation, and conferred cells resistance to CAB. Mechanistically, DEPTOR inhibited both mTOR Complex 1 (mTORC1) and 2 (mTORC2) activities in PA cells. In addition, DEPTOR expression level was increased to suppress mTOR kinase activity via decreasing E3 ubiquitin ligase, ßTrCP1, in response to CAB. Furthermore, DEPTOR enhanced autophagy-dependent cell death to confer cells sensitivity to CAB. Taken together, our results suggest that DEPTOR may be a potential target for the treatment of PAs.


Asunto(s)
Adenoma/tratamiento farmacológico , Adenoma/metabolismo , Agonistas de Dopamina/farmacología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neoplasias Hipofisarias/tratamiento farmacológico , Neoplasias Hipofisarias/metabolismo , Adenoma/patología , Adulto , Animales , Autofagia/efectos de los fármacos , Autofagia/fisiología , Proliferación Celular/efectos de los fármacos , Proliferación Celular/fisiología , Regulación hacia Abajo , Resistencia a Antineoplásicos , Femenino , Xenoinjertos , Humanos , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/antagonistas & inhibidores , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Ratones , Ratones Desnudos , Persona de Mediana Edad , Hipófisis/metabolismo , Neoplasias Hipofisarias/patología , Prolactinoma/tratamiento farmacológico , Prolactinoma/metabolismo , Prolactinoma/patología , Ratas
17.
Phytochemistry ; 161: 97-106, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30822625

RESUMEN

Antrodia cinnamomea, an endemic fungus species of Taiwan, has long been used as a luxurious dietary supplement to enhance liver functions and as a remedy for various cancers. Antroquinonol (AQ), identified from the mycelium of A. cinnamomea, is currently in phase II clinical trials in the USA and Taiwan for the treatment of non-small-cell lung cancer. In the previous studies, we have demonstrated that AQ and 4-acetylantroquinonol B (4-AAQB) utilize orsellinic acid, via polyketide pathway, as the ring precursor, and their biosynthetic sequences are similar to those of coenzyme Q. In order to test 4-hydroxybenzoic acid (4-HBA), synthesized via shikimate pathway, is the ring precursor of AQ analogs, the strategy of metabolic labeling with stable isotopes was applied in this study. Here we have confirmed that 4-HBA serves as the ring precursor for AQ but not a precursor of 4-AAQB. Experimental results indicated that A. cinnamomea preferentially utilizes endogenous 4-HBA via shikimate pathway for AQ biosynthesis. Exogenous tyrosine and phenylalanine can be utilized for AQ biosynthesis when shikimate pathway is blocked by glyphosate. The benzoquinone ring of 4-AAQB is synthesized only via polyketide pathway, but that of AQ is synthesized via both polyketide pathway and shikimate pathway. The precursor-products relationships diagram of AQ and 4-AAQB in A. cinnamomea are proposed based on the experimental findings.


Asunto(s)
Antrodia/química , Parabenos/metabolismo , Ubiquinona/análogos & derivados , Antrodia/metabolismo , Estructura Molecular , Parabenos/química , Ubiquinona/biosíntesis , Ubiquinona/química
18.
Nat Commun ; 9(1): 4624, 2018 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-30397197

RESUMEN

Aberrant expression of long noncoding RNA H19 has been associated with tumour progression, but the underlying molecular tumourigenesis mechanisms remain largely unknown. Here, we report that H19 expression is frequently downregulated in human primary pituitary adenomas and is negatively correlated with tumour progression. Consistently, upregulation of H19 expression inhibits pituitary tumour cell proliferation in vitro and tumour growth in vivo. Importantly, we uncover a function of H19, which controls cell/tumour growth through inhibiting function of mTORC1 but not mTORC2. Mechanistically, we show that H19 could block mTORC1-mediated 4E-BP1 phosphorylation without affecting S6K1 activation. At the molecular level, H19 interacted with 4E-BP1 at the TOS motif and competitively inhibited 4E-BP1 binding to Raptor. Finally, we demonstrate that H19 is more effective than cabergoline treatment in the suppression of pituitary tumours. Together, our study uncovered the role of H19-mTOR-4E-BP1 axis in pituitary tumour growth regulation that may be a potential therapeutic target for human pituitary tumours.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/efectos de los fármacos , Fosfoproteínas/metabolismo , Neoplasias Hipofisarias/metabolismo , ARN Largo no Codificante/antagonistas & inhibidores , ARN Largo no Codificante/metabolismo , Animales , Cabergolina/farmacología , Carcinogénesis , Proteínas Portadoras , Proteínas de Ciclo Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Progresión de la Enfermedad , Regulación hacia Abajo , Femenino , Células HEK293 , Xenoinjertos , Humanos , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Ratones , Fosforilación/efectos de los fármacos , Neoplasias Hipofisarias/tratamiento farmacológico , ARN Largo no Codificante/genética , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Regulación hacia Arriba
19.
Genus ; 74(1): 19, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30595607

RESUMEN

BACKGROUND: Model averaging combines forecasts obtained from a range of models, and it often produces more accurate forecasts than a forecast from a single model. OBJECTIVE: The crucial part of forecast accuracy improvement in using the model averaging lies in the determination of optimal weights from a finite sample. If the weights are selected sub-optimally, this can affect the accuracy of the model-averaged forecasts. Instead of choosing the optimal weights, we consider trimming a set of models before equally averaging forecasts from the selected superior models. Motivated by Hansen et al. (Econometrica 79(2):453-497, 2011), we apply and evaluate the model confidence set procedure when combining mortality forecasts. DATA AND METHODS: The proposed model averaging procedure is motivated by Samuels and Sekkel (International Journal of Forecasting 33(1):48-60, 2017) based on the concept of model confidence sets as proposed by Hansen et al. (Econometrica 79(2):453-497, 2011) that incorporates the statistical significance of the forecasting performance. As the model confidence level increases, the set of superior models generally decreases. The proposed model averaging procedure is demonstrated via national and sub-national Japanese mortality for retirement ages between 60 and 100+. RESULTS: Illustrated by national and sub-national Japanese mortality for ages between 60 and 100+, the proposed model-averaged procedure gives the smallest interval forecast errors, especially for males. CONCLUSION: We find that robust out-of-sample point and interval forecasts may be obtained from the trimming method. By robust, we mean robustness against model misspecification.

20.
J Clin Endocrinol Metab ; 102(10): 3692-3703, 2017 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-28973192

RESUMEN

Context: The dopamine agonist cabergoline (CAB) has been used widely in the treatment of prolactinomas and other types of pituitary adenomas, but its clinical use is hampered by intolerance in some patients with prolactinoma and lack of effectiveness in other pituitary tumor types. Chloroquine (CQ) is an old drug widely used to treat malaria. Recent studies, including our own, have revealed that CAB and CQ are involved in induction of autophagy and activation of autophagic cell death. Objective: To test whether CAB and CQ can function cooperatively to suppress growth of pituitary adenomas as well as other cancers. Results: In vitro studies using the rat pituitary tumor cell lines MMQ and GH3, human pituitary tumor cell primary cultures, and several human cancer cell lines showed that CQ enhanced suppression of cell proliferation by CAB. These results were confirmed in in vivo xenograft models in nude mice and estrogen-induced rat prolactinomas. To understand the mechanism of combined CAB and CQ action, we established a low-CAB-dose condition in which CAB was able to induce autophagy but failed to suppress cell growth. Addition of CQ to low-dose CAB blocked normal autophagic cycles and induced apoptosis, evidenced by the further accumulation of p62/caspase-8/LC3-II. Conclusion: The data suggest that combined use of CAB and CQ may increase clinical effectiveness in treatment of human pituitary adenomas, as well as other cancers, making it an attractive option in tumor and cancer therapies.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cloroquina/administración & dosificación , Ergolinas/administración & dosificación , Neoplasias Hipofisarias/tratamiento farmacológico , Prolactinoma/tratamiento farmacológico , Animales , Cabergolina , Muerte Celular/efectos de los fármacos , Células Cultivadas , Femenino , Células Hep G2 , Humanos , Ratones , Ratones Desnudos , Neoplasias Hipofisarias/patología , Prolactinoma/patología , Ratas , Ratas Endogámicas F344 , Ensayos Antitumor por Modelo de Xenoinjerto
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