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1.
Bioorg Med Chem Lett ; 94: 129464, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37634760

RESUMO

Simplified analogues of the myxobacterial polyketide ajudazol were obtained by synthesis and evaluated for their biological activities. Potent simplified 5-lipoxygenase inhibitors were identified. Moreover, strong antiproliferative and apoptotic activities were observed in brain cancer cell lines at low nano- to micromolar concentrations.


Assuntos
Neoplasias Encefálicas , Inibidores de Lipoxigenase , Neuroblastoma , Humanos , Araquidonato 5-Lipoxigenase , Linhagem Celular , Neuroblastoma/tratamento farmacológico , Inibidores de Lipoxigenase/química , Inibidores de Lipoxigenase/farmacologia
2.
Clin Oral Investig ; 27(10): 6187-6197, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37653076

RESUMO

OBJECTIVES: Nano-modified surfaces for dental implants may improve gingival fibroblast adhesion and antibacterial characteristics through cell-surface interactions. The present study investigated how a nanocavity titanium surface impacts the viability and adhesion of human gingival fibroblasts (HGF-1) and compared its response to Porphyromonas gingivalis with those of marketed implant surfaces. MATERIAL AND METHODS: Commercial titanium and zirconia disks, namely, sandblasted and acid-etched titanium (SLA), sandblasted and acid-etched zirconia (ZLA), polished titanium (PT) and polished zirconia (ZrP), and nanostructured disks (NTDs) were tested. Polished titanium disks were etched with a 1:1 combination of 98% H2SO4 and 30% H2O2 (piranha etching) for 5 h at room temperature to produce the NTDs. Atomic force microscopy was used to measure the surface topography, roughness, adhesion force, and work of adhesion. MTT assays and immunofluorescence staining were used to examine cell viability and adhesion after incubation of HGF-1 cells on the disk surfaces. After incubation with P. gingivalis, conventional culture, live/dead staining, and SEM were used to determine the antibacterial properties of NTD, SLA, ZLA, PT, and ZrP. RESULTS: Etching created nanocavities with 10-20-nm edge-to-edge diameters. Chemical etching increased the average surface roughness and decreased the surface adherence, while polishing and flattening of ZrP increased adhesion. However, only the NTDs inhibited biofilm formation and bacterial adherence. The NTDs showed antibacterial effects and P. gingivalis vitality reductions. The HGF-1 cells demonstrated greater viability on the NTDs compared to the controls. CONCLUSION: Nanocavities with 10-20-nm edge-to-edge diameters on titanium disks hindered P. gingivalis adhesion and supported the adhesion of gingival fibroblasts when compared to the surfaces of currently marketed titanium or zirconia dental implants. CLINICAL RELEVANCE: This study prepared an effective antibacterial nanoporous surface, assessed its effects against oral pathogens, and demonstrated that surface characteristics on a nanoscale level influenced oral pathogens and gingival fibroblasts. CLINICAL TRIAL REGISTRATION: not applicable.


Assuntos
Implantes Dentários , Nanoestruturas , Humanos , Titânio/farmacologia , Titânio/química , Peróxido de Hidrogênio , Biofilmes , Antibacterianos/farmacologia , Propriedades de Superfície , Fibroblastos
3.
Biophys J ; 108(4): 918-927, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25692596

RESUMO

The transport channel of nuclear pore complexes (NPCs) contains a high density of intrinsically disordered proteins that are rich in phenylalanine-glycine (FG)-repeat motifs (FG Nups). The FG Nups interact promiscuously with various nuclear transport receptors (NTRs), such as karyopherins (Kaps), that mediate the trafficking of nucleocytoplasmic cargoes while also generating a selectively permeable barrier against other macromolecules. Although the binding of NTRs to FG Nups increases molecular crowding in the NPC transport channel, it is unclear how this impacts FG Nup barrier function or the movement of other molecules, such as the Ran importer NTF2. Here, we use surface plasmon resonance to evaluate FG Nup conformation, binding equilibria, and interaction kinetics associated with the multivalent binding of NTF2 and karyopherinß1 (Kapß1) to Nsp1p molecular brushes. NTF2 and Kapß1 show different long- and short-lived binding characteristics that emerge from varying degrees of molecular retention and FG repeat binding avidity within the Nsp1p brush. Physiological concentrations of NTF2 produce a collapse of Nsp1p brushes, whereas Kapß1 binding generates brush extension. However, the presence of prebound Kapß1 inhibits Nsp1p brush collapse during NTF2 binding, which is dominated by weak, short-lived interactions that derive from steric hindrance and diminished avidity with Nsp1p. This suggests that binding promiscuity confers kinetic advantages to NTF2 by expediting its facilitated diffusion and reinforces the proposal that Kapß1 contributes to the integral barrier function of the NPC.


Assuntos
Núcleo Celular/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , beta Carioferinas/metabolismo , Transporte Ativo do Núcleo Celular , Motivos de Aminoácidos , Animais , Humanos , Cinética , Ligação Proteica , Estrutura Terciária de Proteína , Ratos , Saccharomyces cerevisiae/química
4.
Biophys J ; 106(8): 1751-62, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24739174

RESUMO

Intrinsically disordered Phe-Gly nucleoporins (FG Nups) within nuclear pore complexes exert multivalent interactions with transport receptors (Karyopherins (Kaps)) that orchestrate nucleocytoplasmic transport. Current FG-centric views reason that selective Kap translocation is promoted by alterations in the barrier-like FG Nup conformations. However, the strong binding of Kaps with the FG Nups due to avidity contradicts rapid Kap translocation in vivo. Here, using surface plasmon resonance, we innovate a means to correlate in situ mechanistic (molecular occupancy and conformational changes) with equilibrium (binding affinity) and kinetic (multivalent binding kinetics) aspects of Karyopherinß1 (Kapß1) binding to four different FG Nups. A general feature of the FxFG domains of Nup214, Nup62, and Nup153 is their capacity to extend and accommodate large numbers of Kapß1 molecules at physiological Kapß1 concentrations. A notable exception is the GLFG domain of Nup98, which forms a partially penetrable cohesive layer. Interestingly, we find that a slowly exchanging Kapß1 phase forms an integral constituent within the FG Nups that coexists with a fast phase, which dominates transport kinetics due to limited binding with the pre-occupied FG Nups at physiological Kapß1 concentrations. Altogether, our data reveal an emergent Kap-centric barrier mechanism that may underlie mechanistic and kinetic control in the nuclear pore complex.


Assuntos
Glicina/análogos & derivados , Complexo de Proteínas Formadoras de Poros Nucleares/química , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Poro Nuclear/metabolismo , beta Carioferinas/metabolismo , Animais , Glicina/metabolismo , Humanos , Cinética , Modelos Moleculares , Ligação Proteica , Estrutura Terciária de Proteína , Ressonância de Plasmônio de Superfície , Xenopus laevis
5.
J Biomed Mater Res A ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38925622

RESUMO

This study investigates nanostructured titanium surfaces (Ti2 spikes) that promote the viability of osteoblasts and fibroblasts and prevent bacterial colonisation. Helium ion irradiation was adopted to produce nanometric-sized cones on titanium. Human osteoblasts (hFOB) and human gingiva fibroblasts (hGF) were used for analysis. A viability and a cytotoxicity assay were conducted to evaluate the lactate dehydrogenase (LDH) activity and assess cell damage in Ti2 spikes compared to titanium discs with a sandblasted and acid-etched (Ti2 SLA) surface. The antibacterial activity was investigated against Escherichia coli, Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis. In the course of the cultivation, both hGF and hFOB demonstrated significantly reduced viability on the Ti2 spikes surface. hGF cells exhibited a slight but significant increase in LDH release. In contrast, hFOB showed reduced cytotoxicity on this surface. On the Ti2 spikes surface, hGF cells exhibited a significant reduction in gene expression of VCL, Src-1, and ITGα5. However, the integrin subunits ITGα1 and ITGα3 showed upregulation on the Ti2 spikes surface. The Ti2 spikes surface significantly increased the expression of almost all osteogenic markers. The results of conventional culturing demonstrated a statistically significant decrease in the number of viable cells for S. mutans, F. nucleaum, and greater quantities of P. gingivalis on Ti2 spikes surface compared to control. However, no such reduction was detected for E. coli. The long-term success of implants relies on establishing and maintaining hard and soft peri-implant tissues. Ti2 spikes represent a novel and promising approach to enhance osseointegration and optimize biocompatibility.

7.
Micromachines (Basel) ; 14(2)2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36838142

RESUMO

In the past few years, object detection has attracted a lot of attention in the context of human-robot collaboration and Industry 5.0 due to enormous quality improvements in deep learning technologies. In many applications, object detection models have to be able to quickly adapt to a changing environment, i.e., to learn new objects. A crucial but challenging prerequisite for this is the automatic generation of new training data which currently still limits the broad application of object detection methods in industrial manufacturing. In this work, we discuss how to adapt state-of-the-art object detection methods for the task of automatic bounding box annotation in a use case where the background is homogeneous and the object's label is provided by a human. We compare an adapted version of Faster R-CNN and the Scaled-YOLOv4-p5 architecture and show that both can be trained to distinguish unknown objects from a complex but homogeneous background using only a small amount of training data. In contrast to most other state-of-the-art methods for bounding box labeling, our proposed method neither requires human verification, a predefined set of classes, nor a very large manually annotated dataset. Our method outperforms the state-of-the-art, transformer-based object discovery method LOST on our simple fruits dataset by large margins.

8.
Org Lett ; 25(45): 8089-8094, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37930187

RESUMO

A versatile titanocene-catalyzed radical allyl transfer reaction on epoxides is reported. Epoxide opening occurs regioselectively at the more hindered side, and variously substituted allyl sulfone may be coupled to this position in an efficient manner, enabling a rapid access to quaternary carbon centers with useful functionalities for further elaboration. Furthermore, the procedure can be expanded to stereoselective variants. This new radical allyl transfer expands the scope of allylation in organic synthesis.

9.
Sci Data ; 10(1): 271, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-37169791

RESUMO

Medical Assisted Reproduction proved its efficacy to treat the vast majority forms of infertility. One of the key procedures in this treatment is the selection and transfer of the embryo with the highest developmental potential. To assess this potential, clinical embryologists routinely work with static images (morphological assessment) or short video sequences (time-lapse annotation). Recently, Artificial Intelligence models were utilized to support the embryo selection procedure. Even though they have proven their great potential in different in vitro fertilization settings, there is still considerable room for improvement. To support the advancement of algorithms in this research field, we built a dataset consisting of static blastocyst images and additional annotations. As such, Gardner criteria annotations, depicting a morphological blastocyst rating scheme, and collected clinical parameters are provided. The presented dataset is intended to be used to train deep learning models on static morphological images to predict Gardner's criteria and clinical outcomes such as live birth. A benchmark of human expert's performance in annotating Gardner criteria is provided.


Assuntos
Inteligência Artificial , Blastocisto , Fertilização in vitro , Humanos , Benchmarking , Aprendizado Profundo , Feminino , Gravidez
10.
Colloids Surf B Biointerfaces ; 206: 111940, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34265541

RESUMO

Titanium (Ti)-based implants are broadly applied in the medical field, but their related infections can lead to implant failure. Photo-irradiation of metal materials to generate antimicrobial agents, an alternative to antibiotics, is a promising method to reduce bacterial infection and antibiotic usage. It is therefore important to understand how bacterial pathogens respond to Ti surfaces. Here, Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus, the most prevalent pathogens linked to healthcare-associated infections, were used as model strains. Two different kinds of Ti surfaces respectively stored in dry condition and 0.9 % NaCl solution were applied. Upon UV irradiation and in the absence of bacteria, both tested surfaces exhibited similar bactericidal activity, even though the surfaces stored in 0.9 % NaCl solution generated a slightly higher level of reactive oxygen species (ROS). Interestingly, P. aeruginosa and S. aureus responded to the irradiated Ti surfaces differently regarding interaction time: the number of viable P. aeruginosa was reduced up to 90 % after 30 min interaction with the treated surfaces compared to the untreated ones, but this reduction is lessened to 69 %-81 % after 240 min. By contrast, UV treatment of surfaces did not impact the viability of S. aureus after 30 min interaction, however, led to more than 99 % reduction after 240 min incubation. These results provide first experimental evidence that Gram negative and positive bacterial species respond to ROS with different inactivation kinetics. This work also demonstrated that treatment with photo-irradiation in the absence of bacteria conferred Ti surfaces with efficient bactericidal activity.


Assuntos
Staphylococcus aureus , Titânio , Antibacterianos/farmacologia , Bactérias , Pseudomonas aeruginosa , Titânio/farmacologia
11.
Biology (Basel) ; 10(5)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922217

RESUMO

Due to the rising demand for zirconia (Zr) based implant systems, it is important to understand the impact of Zr and titanium (Ti) implants and particularly their topography on soft tissue healing. As human gingival fibroblasts (hGFs) are the predominant cells in peri-implant soft tissue, we focused on examining the effect of implant material and surface roughness on hGFs' initial attachment, growth and the expression of proteins involved in the focal adhesion. hGFs isolated from eight healthy donors were cultured on the following surfaces: smooth titanium machined surface (TiM), smooth zirconia machined surface (ZrM), moderately rough titanium surface (SLA), or moderately rough zirconia surface (ZLA) for up to 14 days. The initial attachment of hGFs was evaluated by scanning electron microscopy. Cell proliferation/viability was assessed by cell counting kit 8. Focal adhesion and cytoskeleton were visualized by a focal adhesion staining kit. The gene expression of focal adhesion kinase (FAK), α-smooth muscle actin (α-SMA), and integrin subunits ITG-ß1, ITG-ß4, ITG-α4, ITG-α5, ITG-α6, was evaluated by qPCR. Cell proliferation/viability was slightly decreased by moderately rough surfaces, whereas no effect of surface material was observed. Cell morphology was strikingly different between differently treated surfaces: on machined surfaces, cells had elongated morphology and were attached along the grooves, whereas on moderately rough surfaces, cells were randomly attached. Surface roughness had a more pronounced effect on the gene expression compared to the surface material. The expression of FAK, α-SMA, ITG-ß4, ITG-α5, and ITG-α6 was enhanced by moderately rough surfaces compared to smooth surfaces. Within the limitations of this in vitro study, it can be concluded that the behavior of primary hGFs is primarily affected by surface structure, whereas no apparent advantage of Zr over Ti could be observed.

12.
Dent Mater ; 36(6): e194-e205, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32360041

RESUMO

OBJECTIVES: The impact of the implant surface material and roughness on inflammatory processes in peri-implantitis is not entirely clear. Hence, we investigated how titanium and zirconia surfaces with different roughness influence the susceptibility of primary human gingival fibroblasts to different inflammatory stimuli. METHODS: Primary human gingival fibroblasts were isolated from 8 healthy individuals and cultured on following surfaces: smooth titanium machined surface (TiM), smooth zirconia machined surface (ZrM), moderately rough titanium surface (SLA), or moderately rough zirconia surface (ZLA). Subsequently, stimulation with one of the following stimuli was performed: Porphyromonas gingivalis lipopolysaccharide (LPS), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß. The resulting production of IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1 was measured by qPCR and ELISA. RESULTS: P. gingivalis LPS induced IL-6 and MCP-1 production was slightly higher on titanium surfaces compared to zirconia surfaces. IL-1ß induced IL-6 production was not affected by any surface characteristic. The production of MCP-1 in response to IL-1ß was higher on smooth compared to rough surfaces and was not affected by the material. The production of IL-6 and MCP-1 in response to TNF-α was most strongly affected by surface characteristics. Higher production of these cytokine was observed on smooth compared to rough surfaces and on titanium compared to zirconia surfaces. Surface characteristics had only minor effects on IL-8 production. SIGNIFICANCE: The susceptibility of primary gingival fibroblasts to inflammation depends on various factors, such as surface material, surface roughness and the nature of inflammatory stimuli. All these factors might determine susceptibility to peri-implantitis.


Assuntos
Fibroblastos , Gengiva , Células Cultivadas , Materiais Dentários , Humanos , Propriedades de Superfície , Titânio
13.
J Occup Health Psychol ; 4(1): 63-71, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10100114

RESUMO

Members of 2 nurses' associations (N = 71) were assessed using 2 mail questionnaires, a telephone questionnaire, the Diagnostic Interview Schedule, and medical records. Physicians reviewed participants to determine whether they met current criteria for chronic fatigue syndrome (CFS). Stepwise multivariate regression analyses were conducted to identify predictors of functional status scores. Impairments in physical, role, and social functioning increased as fatigue severity increased. Bodily pain increased as fatigue severity increased, and ratings of overall health increased as severity of fatigue decreased. Nurses with a current psychiatric diagnosis reported more impairments in emotional functioning than nurses with a lifetime diagnosis or no psychiatric diagnosis. Quality of life decreased as fatigue severity increased. Nurses with fatigue not meeting CFS criteria reported better quality of life than those with CFS or medical exclusions.


Assuntos
Síndrome de Fadiga Crônica/diagnóstico , Transtornos Mentais/diagnóstico , Enfermeiras e Enfermeiros/psicologia , Adulto , Esgotamento Profissional/psicologia , Síndrome de Fadiga Crônica/psicologia , Feminino , Humanos , Masculino , Transtornos Mentais/psicologia , Análise Multivariada , Valor Preditivo dos Testes , Qualidade de Vida , Índice de Gravidade de Doença , Inquéritos e Questionários
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