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2.
Bioact Mater ; 8: 559-572, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34541420

RESUMO

We demonstrate a simple, effective and feasible method to address the shrinkage of Poly (lactic-co-glycolic acid) (PLGA) through a core-shell structure fiber strategy. The results revealed that introducing size-stable poly-caprolactone (PCL) as the core fiber significantly improved the PLGA-based fibrous scaffold's dimensional maintenance. We further utilized fish collagen to modify the PLGA shell layer (PFC) of coaxial fibers and loaded baicalin (BA) into the PCL core layer (PCL-BA) to endow fibrous scaffold with more functional biological cues. The PFC/PCL-BA fibrous scaffold promoted the osteogenic differentiation of bone mesenchymal stem cells and stimulated the RAW264.7 cells to polarize into a pro-reparative phenotype. Importantly, the in vivo study demonstrated that the PFC/PCL-BA scaffold could regulate inflammation and osteoclast differentiation, favor neovascularization and bone formation. This work tactfully combined PLGA and PCL to establish a drug release platform based on the core-shell fibrous scaffold for vascularized bone regeneration.

3.
J Biomed Mater Res B Appl Biomater ; 110(1): 7-17, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34142745

RESUMO

Periodontitis would cause dental tissue damage locally. Biomaterials substantially affect the surrounding immune microenvironment through treatment-oriented local inflammatory remodeling in dental periodontitis. This remodeling process is conducive to wound healing and periodontal tissue regeneration. Recent progress in understanding the foreign body response (FBR) and immune regulation, including cell heterogeneity, and cell-cell and cell-material interactions, has provided new insights into the design criteria for biomaterials applied in treatment of periodontitis. This review discusses recent progress and perspectives in the immune regulation effects of biomaterials to augment or reconstruct soft and hard tissue in an inflammatory microenvironment of periodontitis.

4.
Bioact Mater ; 11: 206-217, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34938924

RESUMO

Topographical properties, such as pattern and diameter, of biomaterials play important roles in influencing cell activities and manipulating the related immune response during wound healing. We prepared aligned electrospinning membranes with different fiber diameters, including 319 ± 100 nm (A300), 588 ± 132 nm (A600), and 1048 ± 130 nm (A1000), by adjusting the distance from the tip to the collector, the injection rate, and the concentration of the solution. The A300 membranes significantly improved cell proliferation and spreading and facilitated wound healing (epithelization and vascularization) with the regeneration of immature hair follicles compared to the other membranes. Transcriptomics revealed the underlying molecular mechanism that A300 could promote immune-related processes towards a pro-healing direction, significantly promoting keratinocyte migration and skin wound healing. All the results indicated that wound healing requires the active participation of the immune process, and that A300 was a potential candidate for guided skin regeneration applications.

5.
Microbiol Spectr ; : e0151921, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34851152

RESUMO

Salmonella enterica serovar Typhimurium is the leading cause of invasive nontyphoidal salmonellosis. Additionally, the emergence of multidrug-resistant S. Typhimurium has further increased the difficulty of controlling its infection. Previously, we showed that an antipsychotic drug, loxapine, suppressed intracellular Salmonella in macrophages. To exploit loxapine's antibacterial activity, we simultaneously evaluated the anti-intracellular Salmonella activity and cytotoxicity of newly synthesized loxapine derivatives using an image-based high-content assay. We identified that SW14 exhibits potent suppressive effects on intramacrophagic S. Typhimurium with an 50% effective concentration (EC50) of 0.5 µM. SW14 also sensitized intracellular Salmonella to ciprofloxacin and cefixime and effectively controlled intracellular multidrug- and fluoroquinolone-resistant S. Typhimurium strains. However, SW14 did not affect bacterial growth in standard microbiological broth or minimal medium that mimics the phagosomal environment. Cellular autophagy blockade by 3-methyladenine (3-MA) or shATG7 elevated the susceptibility of intracellular Salmonella to SW14. Finally, reactive oxygen species (ROS) scavengers reduced the antibacterial efficacy of SW14, but the ROS levels in SW14-treated macrophages were not elevated. SW14 decreased the resistance of outer membrane-compromised S. Typhimurium to H2O2. Collectively, our data indicated that the structure of loxapine can be further optimized to develop new antibacterial agents by targeting bacterial resistance to host oxidative-stress defense. IMPORTANCE The incidence of diseases caused by pathogenic bacteria with resistance to common antibiotics is consistently increasing. In addition, Gram-negative bacteria are particularly difficult to treat with antibiotics, especially those that can invade and proliferate intracellularly. In order to find a new antibacterial compound against intracellular Salmonella, we established a cell-based high-content assay and identified SW14 from the derivatives of the antipsychotic drug loxapine. Our data indicate that SW14 has no effect on free bacteria in the medium but can suppress the intracellular proliferation of multidrug-resistant (MDR) S. Typhimurium in macrophages. We also found that SW14 can suppress the resistance of outer membrane compromised Salmonella to H2O2, and its anti-intracellular Salmonella activity can be reversed by reactive oxygen species (ROS) scavengers. Together, the findings suggest that SW14 might act via a virulence-targeted mechanism and that its structure has the potential to be further developed as a new therapeutic against MDR Salmonella.

6.
Chem Sci ; 12(43): 14519-14530, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34881003

RESUMO

A thermally activated delayed fluorescence (TADF) white organic light-emitting diode (WOLED) holds great promise for low-cost, large-scale lighting applications. Nevertheless, manipulating exciton allocation in a white TADF single layer is still a challenge. Herein, we demonstrate that the exciton kinetic process of dually doped white TADF films is strongly dependent on the grid regularity of the host matrix. Intermolecular hydrogen bonds (IHBs) are used to weave the matrices of two host molecules DPEQPO and DPSQPO featuring four phosphine oxide (PO) groups and different IHB orientations. The DPSQPO matrix forms regular grids to uniformly disperse and separate dopants, while DPEQPO exhibits chaotic IHBs, in turn inducing a heterogeneous dopant distribution. As a consequence, in both photoluminescence and electroluminescence processes, in contrast to DPEQPO hosted systems with comparable singlet Förster resonance energy transfer and triplet Dexter energy transfer, DPSQPO provides a FRET-predominant exciton allocation between blue and yellow dopants, which markedly suppresses triplet quenching and improves the white color purity, resulting in a state-of-the-art external quantum efficiency up to 24.2% of its single-emissive-layer pure-white TADF diode, in contrast to 16.0% for DPEQPO based analogs. These results indicate the significance of host engineering for exciton kinetics and suggest the feasibility of host grid design for developing high-performance TADF lighting.

7.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(6): 718-723, 2021 Dec 01.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34859634

RESUMO

OBJECTIVES: To investigate the clinical effect of Er:YAG laser combined with ethylenediamine tetra acetic acid (EDTA) on three-walled periodontal intrabony defects adjacent to implant sites. METHODS: A total of 30 patients with three-walled periodontal intrabony defects adjacent to implant sites were treated with the combination therapy. Patients with three-walled intrabony defects were divided into two groups according to the depth of the intrabony pocket between the implant and natural teeth. Evaluation of wound healing was performed 10 days after the operation, and bone augmentation was evaluated 6 months after the operation. RESULTS: Primary healing in group 1 was 92.31%, primary healing in group 2 was 82.35%. No significant difference was observed between the two groups (P>0.05). Bone augmentation in group 1 and group 2 were (2.85±1.81), (4.92±2.22) mm. There was significant difference between the two groups (P<0.05). New bone growth occurred more slowly in group 1 (0.70 mm±0.32 mm) than in group 2 (1.25 mm±0.47 mm) (P>0.05). Probe depths (PD), clinical attachment levels (CAL), and sulcus bleeding indices (SBI) showed no statistically significant difference between the two groups (P>0.05). The one-year survival rate of natural tooth in group 1 and group 2 were 100%, 94.2%, and the one-year survival rate of implants in both groups was 100%. CONCLUSIONS: The effect of bone augmentation with combination therapy was more ideal in group 2 than in group 1. Implant placement with combination therapy may be a viable technique to reconstruct three-walled intrabony defects due to the space maintenance provided by implants and bone grafts and the good root surface biocompatibility provided by the Er:YAG laser and EDTA.

8.
BMC Oral Health ; 21(1): 655, 2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34922521

RESUMO

BACKGROUND: To evaluate a cross-shaped incision technique for thick-gingiva and thin-gingiva patients treated with implant-supported fixed prosthesis. METHODS: Total 55 patients receiving cross-shaped incision were assigned into thick-gingiva group (29 cases) and thin-gingiva group (26 cases). Follow-up was performed at 3 and 12-month after final restoration. RESULTS: Mesial and distal papilla height was significantly greater in thick-gingiva group than thin-gingiva group at 3 and 12 months, while periodontal depth and crestal marginal bone level around implant had no significant difference between the two groups during follow-up. No case of recession of buccal marginal gingiva was observed in thick-gingiva group. However, the recession of marginal gingiva of buccal aspect of the crown was found in 5 patients (19.2%) with thin-gingiva. CONCLUSIONS: The cross-shaped incision may be applied to reconstruct gingival papillae and avoid the gingival recession in patients with thick-gingiva phenotype. Trial registration This study was registered at ClinicalTrials.gov (registration number NCT04706078, date 12 January 2021, Retrospectively registered).

9.
Int J Mol Sci ; 22(22)2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34830417

RESUMO

As sessile organisms, plants must directly deal with an often complex and adverse environment in which hyperosmotic stress is one of the most serious abiotic factors, challenging cellular physiology and integrity. The plasma membrane (PM) is the hydrophobic barrier between the inside and outside environments of cells and is considered a central compartment in cellular adaptation to diverse stress conditions through dynamic PM remodeling. Endocytosis is a powerful method for rapid remodeling of the PM. In animal cells, different endocytic pathways are activated in response to osmotic stress, while only a few reports are related to the endocytosis response pathway and involve a mechanism in plant cells upon hyperosmotic stress. In this study, using different endocytosis inhibitors, the microdomain-specific dye di-4-ANEPPDHQ, variable-angle total internal reflection fluorescence microscopy (VA-TIRFM), and confocal microscopy, we discovered that internalized Clathrin Light Chain-Green Fluorescent Protein (CLC-GFP) increased under hyperosmotic conditions, accompanied by decreased fluorescence intensity of CLC-GFP at the PM. CLC-GFP tended to have higher diffusion coefficients and a fraction of CLC-GFP molecules underwent slower diffusion upon hyperosmotic stress. Meanwhile, an increased motion range of CLC-GFP was found under hyperosmotic treatment compared with the control. In addition, the order of the PM decreased, but the order of the endosome increased when cells were in hyperosmotic conditions. Hence, our results demonstrated that clathrin-mediated endocytosis and membrane microdomain-associated endocytosis both participate in the adaptation to hyperosmotic stress. These findings will help to further understand the role and the regulatory mechanism involved in plant endocytosis in helping plants adapt to osmotic stress.

10.
Org Biomol Chem ; 19(43): 9369-9372, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34757357

RESUMO

A unique C30 steroid, solitumergosterol A (1), was isolated from the deep-sea-derived fungus Penicillium solitum MCCC 3A00215. The planar structure and relative configuration of 1 were established mainly on the basis of extensive analysis of its 1D and 2D NMR as well as HRESIMS data, while its absolute configuration was clarified by comparison of the experimental and theoretical ECD spectra. Noteworthily, 1 is a Diels-Alder adduct of a heterogeneous steroid bearing a 6/6/6/6/5 pentacyclic carbon skeleton. Solitumergosterol A (1) exhibited weak in vitro anti-tumor activity against MB231 cells by a RXRα-dependent mechanism.

11.
Int J Oral Implantol (Berl) ; 14(4): 435-451, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34726851

RESUMO

PURPOSE: To introduce a novel and efficient procedure to solve a multidisciplinary issue connected to implant-related surgery in areas near periapical lesions of adjacent teeth using single-stage combined surgery while exploring a new way to prevent retrograde peri-implantitis. MATERIALS AND METHODS: A 31-year-old woman diagnosed with a Kennedy III dentition defect in the maxillary right central incisor and posttreatment apical periodontitis in the maxillary right lateral incisor was treated using a multidisciplinary procedure. First, the preoperative data were collected from intraoral, extraoral facial and CBCT scans. Then, the aesthetic appearance of the anterior teeth was planned digitally and implant insertion was simulated. Next, virtual bone augmentation was carried out with reference to the simulated implant position, and according to the virtual augmentation, the templates for bone shell harvesting (also used for apical osteotomy and root tip resection during endodontic microsurgery) and bone shell grafting of the edentulous area were designed and fabricated. The templates for combined surgery (endodontic microsurgery and horizontal bone augmentation) consisted of one basal template and multiple interchangeable attachments via a plugin design to make guided endodontic microsurgery and digitally guided bone augmentation more efficient. Combined surgery was then carried out using the templates for guidance. During surgery, the apical inflammation affecting the maxillary right lateral incisor was first removed and its preserved apical bony window was prepared as an autogenous bone shell for bone augmentation of the maxillary right central incisor site. Guided bone regeneration of the edentulous area and guided tissue regeneration were then performed for the adjacent tooth. Six months after the combined surgery, digital guided implant surgery was carried out for the edentulous area. The final prosthesis was delivered in accordance with the preoperative aesthetic design and achieved using an implant-supported restoration for the maxillary right central incisor, full crown restoration for the maxillary right lateral incisor, and ceramic veneers for the maxillary left central and lateral incisors for space closure. RESULTS: The horizontal bone augmentation in the edentulous area and endodontic microsurgery on the neighbouring tooth were performed successfully in a single-stage surgical procedure; thus, augmentation of the resorbed alveolar bone and removal of infection in the adjacent site were achieved simultaneously. At the 1-year follow-up after combined surgery, the healing of the natural maxillary right lateral incisor and the area having undergone bone augmentation showed promising results with no postoperative complications. CONCLUSIONS: This novel digital workflow appears effective in addressing the problem of periapical lesions in retained teeth adjacent to the edentulous area that requires horizontal bone augmentation in one surgical procedure, providing an efficient way of resolving the problem using endodontics and implantology, and preventing retrograde peri-implantitis.


Assuntos
Microcirurgia , Boca Edêntula , Adulto , Feminino , Seguimentos , Humanos , Incisivo/diagnóstico por imagem , Maxila/diagnóstico por imagem
12.
Mar Drugs ; 19(10)2021 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-34677479

RESUMO

A systematic chemical investigation of the deep-sea-derived fungus Penicillium solitum MCCC 3A00215 resulted in the isolation of one novel polyketide (1), two new alkaloids (2 and 3), and 22 known (4-25) compounds. The structures of the new compounds were established mainly on the basis of exhaustive analysis of 1D and 2D NMR data. Viridicatol (13) displayed moderate anti-tumor activities against PANC-1, Hela, and A549 cells with IC50 values of around 20 µM. Moreover, 13 displayed potent in vitro anti-food allergic activity with an IC50 value of 13 µM, compared to that of 92 µM for the positive control, loratadine, while indole-3-acetic acid methyl ester (9) and penicopeptide A (10) showed moderate effects (IC50 = 50 and 58 µM, respectively).

13.
Oral Oncol ; 122: 105539, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34547555

RESUMO

BACKGROUND: The goal of this study was to explore the benefits of S-1/capecitabine as maintenance therapy in locoregionally advanced nasopharyngeal carcinoma (NPC) patients with different risks of treatment failure. METHODS: A total of 2205 eligible, locoregionally advanced NPC patients were recruited for this retrospective study. Multivariate Cox regression analysis was performed to identify optimal predictors of overall survival (OS) and distant metastasis-free survival (DMFS) for constructing the nomograms. Patients were stratified into high-risk or low-risk groups based on the total score of the nomograms. Propensity score matching (PSM) was performed to match the maintenance and non-maintenance cohorts in different risk groups. A log-rank test was performed to evaluate correlations between maintenance therapy and survival. RESULTS: A nomogram for OS was established (C-index, 0.664; 95% confidence interval, 0.635-0.693). The 5-year OS rate was significantly higher in the low-risk group than in the high-risk group (83.5% vs. 67.2%, P < 0.001). Patients in the high-risk group who received S-1/capecitabine maintenance therapy achieved significant improvement in the 5-year OS rate (82.8% vs. 67.1%, p = 0.034), whereas patients in the low-risk group did not (86.7% vs. 80.9%, P = 0.081). There was no significant difference in OS, DMFS, progression-free survival (PFS), or toxicities between the S-1 and capecitabine groups (all P > 0.05), and overall treatment-related adverse events (AEs) were not severe (grade 1-2). CONCLUSION: S-1/capecitabine maintenance therapy could prolong OS for locoregionally advanced NPC patients in the high-risk group. The toxicities of S-1/capecitabine maintenance therapy were mild and tolerable. Our findings can help guide maintenance therapy in locoregionally advanced NPC.

14.
J Plant Physiol ; 265: 153491, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34399121

RESUMO

Analysis of codon usage bias (CUB) in different species can reveal the patterns of genetic information transfer across those species. To better understand the characteristics of MYB10-a key regulator of anthocyanin biosynthesis-and identify the true (functional) MYB10 gene among the two candidates in Populus, we analysed the coding sequences of MYB10 genes in 10 different species using Codon W, CHIPS, CUSP, and CAI. Majority of the optimal amino acid codons of MYB10 genes ended with A/U, and GGA, UCA, GCA, AGA, and CCA were over-represented in all plant species studied. Among the two most promising MYB10 gene candidates in Populus, Potri.17G125700 shared a higher similarity of codon usage with MYB10 genes from other plant species, suggesting that it encodes the functional MYB10 in Populus. We verified this speculation by cloning both candidate MYB10 genes from Populus into vectors to produce transiently transformed seedlings. Colour phenotypes and anthocyanin content of the transiently transformed seedlings indicated that Potri.17G125700 encodes the true MYB10 transcription factor, which positively regulates anthocyanin accumulation in Populus. Furthermore, CUB analysis was used to select the most promising MYB12 candidate in Malus sp. (crabapple). Our results demonstrate the effectiveness of CUB analysis as a promising method to identify the functional gene from a set of candidates in long-living plants with complex genetics.


Assuntos
Antocianinas/biossíntese , Antocianinas/genética , Uso do Códon , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Populus/genética , Variação Genética , Genótipo , Fenótipo , Análise de Sequência
15.
Materials (Basel) ; 14(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443183

RESUMO

The chemically cross-linking 1-ethyl-3-(3-dimethylaminopropylcarbodiimide hydrochloride/N-hydroxy-succinimide (EDC/NHS) collagen membrane endows such natural polymers with promising mechanical properties. Nevertheless, it is inadequate to advance the modulation of foreign body response (FBR) after implantation or guidance of tissue regeneration. In previous research, macrophages have a strong regulatory effect on regeneration, and such enhanced membranes underwent the modification with Epigallocatechin-3-gallate (EGCG) could adjust the recruitment and phenotypes of macrophages. Accordingly, we develop EGCG-EDC/NHS membranes, prepared with physical immersion, while focusing on the surface morphology through SEM, the biological activity of collagen was determined by FTIR, the activity and adhesion of cell culture in vitro, angiogenesis and monocyte/macrophage recruitment after subcutaneous implantation in vivo, are characterized. It could be concluded that it is hopeful EGCG-EDC/NHS collagen membrane can be used in implant dentistry for it not only retains the advantages of the collagen membrane itself, but also improves cell viability, adhesion, vascularization, and immunoregulation tendency.

16.
J Leukoc Biol ; 110(3): 591-604, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34231923

RESUMO

As the most successful therapy for missing teeth, dental implant has become increasingly prevalent around the world. A lot of papers have reported diverse local risk factors affecting the success and survival rate of dental implants, either for a short or a long period. However, there are also many types of systemic disorders or relatively administrated medicine that may jeopardize the security and success of dental implant treatment. Additionally, the coronavirus disease 2019 pandemic also poses a challenge to dental implant clinicians. Some of these risk factors are clinically common but to some extent unfamiliar to dentists, thus optimal measurements are often lacking when they occur in dental clinics. In this review, we analyze potential systemic risk factors that may affect the success rate of dental implants. Some of them may affect bone mineral density or enhance the likelihood of local infection, thus impeding osseointegration. Others may even systemically increase the risk of the surgery and threaten patients' life. In order to help novices receive high-risk patients who need to get dental implant treatment in a more reasonable way, we accordingly review recent research results and clinical experiments to discuss promising precautions, such as stopping drugs that impact bone mineral density or the operation, and addressing any perturbations on vital signs.


Assuntos
Densidade Óssea , Implantes Dentários/normas , Falha de Restauração Dentária/estatística & dados numéricos , Osseointegração , Humanos , Fatores de Risco
17.
Artigo em Inglês | MEDLINE | ID: mdl-34181031

RESUMO

We investigated the ability of triticale uptake of Mercury (Hg), clarified whether triticale root uptake of Hg2+ via Zinc (Zn2+) transports, using hydroponic experiments. At 25℃, when Hg exposure in solution was lower than 20 µM, Hg concentration in the roots can be better described by a hyperbolic function, which shows a saturable characteristic. Under ice-cold (< 2℃) conditions, a nonsaturable (linear) component was found. Low exposure of Zn2+ (0-1 µM) inhibited plant Hg uptake when Hg exposure in the solution ranged from 1 to 10 µM, it showed an antagonistic effect of Zn on plant uptake of Hg. When Hg exposure was 20 µM, it revealed a synergistic effect of Zn on plant uptake of Hg, Hg in the root increased at the Zn (1 µM) exposure in the solution. Our results will deepen the understanding of Hg transfer in the soil-plant system.

18.
Acta Biomater ; 129: 148-158, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34082097

RESUMO

The fate of biomaterials is orchestrated by biocompatibility and bioregulation characteristics, reported to be closely related to topographical structures. For the purpose to investigate the topography of fibrous membranes on the guided bone regeneration performance, we successfully fabricated poly (lactate-co-glycolate)/fish collagen/nano-hydroxyapatite (PFCH) fibrous membranes with random, aligned and latticed topography by electrospinning. The physical, chemical and biological properties of the three topographical PFCH membranes were systematically investigated by in vitro and in vivo experiments. The subcutaneous implantation of C57BL6 mice showed an acceptable mild foreign body reaction of all three topological membranes. Interestingly, the latticed PFCH membrane exhibited superior abilities to recruit macrophage/monocyte and induce angiogenesis. We further investigated the osteogenesis of the three topographical PFCH membranes via the critical-size calvarial bone defect model of rats and mice and the results suggested that latticed PFCH membrane manifested promising performance to promote angiogenesis through upregulation of the HIF-1α signaling pathway; thereby enhancing bone regeneration. Our research illustrated that the topological structure of fibrous membranes, as one of the characteristics of biomaterials, could regulate its biological functions, and the fibrous structure of latticed topography could serve as a favorable surface design of biomaterials for bone regeneration. STATEMENT OF SIGNIFICANCE: In material-mediated regeneration medicine, the interaction between the biomaterial and the host is key to successful tissue regeneration. The micro-and nano-structure becomes one of the most critical physical clues for designing biomaterials. In this study, we fabricated three topological electrospun membranes (Random, Aligned and Latticed) to understand how topological structural clues mediate bone tissue regeneration. Interestingly, we found that the Latticed topographical PFCH membrane promotes macrophage recruitment, angiogenesis, and osteogenesis in vivo, indicating the fibrous structure of latticed topography could serve as a favorable surface design of biomaterials for bone regeneration.


Assuntos
Regeneração Óssea , Osteogênese , Animais , Materiais Biocompatíveis , Durapatita , Imunidade , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Tecidos Suporte
19.
Oral Oncol ; 120: 105378, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34174518

RESUMO

OBJECTIVE: The aim of this study was to establish a nomogram for predicting radiation-induced hypothyroidism (RHT) based on an equivalent dose at 2 Gy per fraction (EQD2) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT) with or without chemotherapy. METHODS: Two hundred forty-four eligible patients with NPC were recruited for this study. Patients' clinical factors and dose-volume parameters of the thyroid gland were retrieved from medical records and the IMRT treatment planning system, respectively. The irradiation doses were converted into EQD2 for analysis. Least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate logistic regression analysis were performed to identify optimal predictors of RHT for constructing the nomogram. RESULTS: With a median follow-up of 63.0 months, the cumulative incidence rates of RHT at 3 months and 1-, 2-, 3-, 4- and 5- year after IMRT were 10.2%, 36.2%, 47.6%, 54.2%, 58.8% and 69.4%, respectively. Four independent factors for predicting RHT, including gender, age, pretreatment volume of the thyroid gland and V35Gy(3Gy) of the thyroid gland, were identified and incorporated into the nomogram. The area under the ROC curve of the nomogram was 0.747 (95% confidence interval 0.685 - 0.809). Calibration curves and DCA curves showed that the nomogram was in good agreement with the actual observations and clinical usefulness. CONCLUSIONS: The nomogram proposed in this study provides a reliable estimate of RHT risk in patients with NPC after IMRT and appears to have the potential to be a useful tool for widespread clinical applications.

20.
Elife ; 102021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34028354

RESUMO

What factors constrain the arrangement of the multiple fields of a place cell? By modeling place cells as perceptrons that act on multiscale periodic grid-cell inputs, we analytically enumerate a place cell's repertoire - how many field arrangements it can realize without external cues while its grid inputs are unique - and derive its capacity - the spatial range over which it can achieve any field arrangement. We show that the repertoire is very large and relatively noise-robust. However, the repertoire is a vanishing fraction of all arrangements, while capacity scales only as the sum of the grid periods so field arrangements are constrained over larger distances. Thus, grid-driven place field arrangements define a large response scaffold that is strongly constrained by its structured inputs. Finally, we show that altering grid-place weights to generate an arbitrary new place field strongly affects existing arrangements, which could explain the volatility of the place code.


Assuntos
Sinais (Psicologia) , Hipocampo/fisiologia , Modelos Neurológicos , Células de Lugar/fisiologia , Percepção Espacial , Animais , Simulação por Computador , Hipocampo/citologia , Humanos , Redes Neurais de Computação , Plasticidade Neuronal , Análise Numérica Assistida por Computador
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