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1.
Neurol Sci ; 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38969962

RESUMO

BACKGROUND: Menkes Disease (MD) is a fatal X-linked recessive disorder caused by mutations in the ATP7A gene. Severe cases typically die before the age of three. Mild MD and occipital horn syndrome are variants of MD characterized by a less severe phenotype and longer survival. OBJECTIVE: This case series aims to validate previous findings, expand the clinical phenotype, identify novel ATP7A mutations of MD patients. METHODS: Observational data with follow-up were collected from 17 genetically diagnosed Chinese MD patients. RESULTS: All 17 patients exhibited neurological symptoms, including delayed motor milestones (100%) and seizures (58.8%). Unspecific pregnancy or delivery complications occurred in 9 patients (52.9%). The most prevalent connective tissue problems were abnormal hair (76.5%), followed by skeletal and dental abnormalities (52.9%), skin problems (41.2%) and hernia (35.3%). Sensorineural hearing loss (17.6%) was previously unreported. Coronary artery aneurysm and patent foramen ovale (5.9%) were infrequent. One 16-year-old boy carries pathological exon 3-4 deletion, presents novel mild phenotype including short stature and cerebellar ataxia. Out of 13 patients with follow-up (median: 24 months), 7 patients (53.8%) died with median survival of 40 months (range: 21-48 months), 3 patients (23.1%) show severe motor development delay and 2 (15.4%) have refractory epilepsy, only the mild MD patient shows improved cerebellar ataxia. Sixteen ATP7A mutations were identified including 6 small indels (37.5%), 5 nonsense mutations (31.2%), 2 missense mutations (12.5%), 2 exon deletions (12.5%), and 1 splice site mutation (6.25%). Fourteen mutations were novel. CONCLUSIONS: Our study further broadens the phenotypic and genotypic spectrums of Menkes disease.

2.
Gastroenterology ; 162(4): 1183-1196, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34968454

RESUMO

BACKGROUND & AIMS: N6-methyladenosine (m6A) governs the fate of RNAs through m6A readers. Colorectal cancer (CRC) exhibits aberrant m6A modifications and expression of m6A regulators. However, how m6A readers interpret oncogenic m6A methylome to promote malignant transformation remains to be illustrated. METHODS: YTH N6-methyladenosine RNA binding protein 1 (Ythdf1) knockout mouse was generated to determine the effect of Ythdf1 in CRC tumorigenesis in vivo. Multiomic analysis of RNA-sequencing, m6A methylated RNA immunoprecipitation sequencing, YTHDF1 RNA immunoprecipitation sequencing, and proteomics were performed to unravel targets of YTHDF1 in CRC. The therapeutic potential of targeting YTHDF1-m6A-Rho/Rac guanine nucleotide exchange factor 2 (ARHGEF2) was evaluated using small interfering RNA (siRNA) encapsulated by lipid nanoparticles (LNP). RESULTS: DNA copy number gain of YTHDF1 is a frequent event in CRC and contributes to its overexpression. High expression of YTHDF1 is significantly associated with metastatic gene signature in patient tumors. Ythdf1 knockout in mice dampened tumor growth in an inflammatory CRC model. YTHDF1 promotes cell growth in CRC cell lines and primary organoids and lung and liver metastasis in vivo. Integrative multiomics analysis identified RhoA activator ARHGEF2 as a key downstream target of YTHDF1. YTHDF1 binds to m6A sites of ARHGEF2 messenger RNA, resulting in enhanced translation of ARHGEF2. Ectopic expression of ARHGEF2 restored impaired RhoA signaling, cell growth, and metastatic ability both in vitro and in vivo caused by YTHDF1 loss, verifying that ARHGEF2 is a key target of YTHDF1. Finally, ARHGEF2 siRNA delivered by LNP significantly suppressed tumor growth and metastasis in vivo. CONCLUSIONS: We identify a novel oncogenic epitranscriptome axis of YTHDF1-m6A-ARHGEF2, which regulates CRC tumorigenesis and metastasis. siRNA-delivering LNP drug validated the therapeutic potential of targeting this axis in CRC.


Assuntos
Neoplasias Colorretais , Regulação Neoplásica da Expressão Gênica , Adenosina/análogos & derivados , Adenosina/metabolismo , Animais , Carcinogênese/genética , Neoplasias Colorretais/patologia , Humanos , Lipossomos , Camundongos , Nanopartículas , RNA Interferente Pequeno , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Fatores de Troca de Nucleotídeo Guanina Rho/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismo
3.
Sensors (Basel) ; 22(12)2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35746111

RESUMO

Curved pedestrian bridges are important urban infrastructure with the desired adaptability to the landscape constraints and with aesthetic benefits. Pedestrian bridges feature thin cross-sections, which provide sufficient load capacities but lead to low natural frequencies that make the bridges susceptible to vibration under pedestrian excitation. This study investigates the lateral vibration of a curved bridge with a small radius down to 20 m, proposes an approach to mitigate the lateral vibration of bridges with large curvatures using distributed multiple tuned mass dampers (MTMD), and conducts in-situ bridge tests to evaluate the vibration mitigation performance. The lateral vibration was investigated through in-situ tests and finite element analysis as well as the code requirements. The key parameters of the distributed MTMD system were improved by strategically selecting the mass ratio, bandwidth, center frequency ratio, and damper number. The results showed that the curved bridge was subjected to significant lateral vibration due to the coupling of torque and moment, and the recommended design parameters for the studied bridge were derived, i.e., the total mass ratio is 0.02, bandwidth is 0.15, center frequency ratio is 1.0, and damper number is 3. The proposed approach effectively improves the deployment of MTMD for lateral vibration control of the curved bridge. The field tests showed that the vibration was reduced by up to 82% by using the proposed approach.


Assuntos
Pedestres , Vibração , Análise de Elementos Finitos , Humanos , Rádio (Anatomia) , Aço
4.
Macromol Rapid Commun ; 40(4): e1800648, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30485580

RESUMO

As one of the most important smart materials, fluorescent hydrogel actuators can produce both color and shape changes under external stimuli. In the present work, an effective approach to develop a novel fluorescent hydrogel actuator with pH and thermo dual responsiveness is proposed. Through incorporating pH-responsive perylene tetracarboxylic acid (PTCA), which is a typical fluorescent moiety with aggregation-caused quenching (ACQ) effect, into an anisotropic poly(N-isopropylacrylamide)-polyacrylamide (PNIPAm-PAAm) structure, the obtained hydrogel exhibits stable thermoresponsive shape deformation and switchable fluorescence performance upon a pH trigger. Therefore, fluorescence-quenching-based and actuation-based information can be revealed when exposed to UV light and immersed into warm water, respectively. Moreover, the thermoresponsive actuating behavior can be applied to further hide the fluorescence-quenching-based images. The present work may provide new insights into the design and preparation of novel stimuli-responsive hydrogel actuators.


Assuntos
Corantes Fluorescentes/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Temperatura , Fluorescência , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Propriedades de Superfície
5.
ACS Omega ; 8(23): 20739-20754, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37323396

RESUMO

Periodontitis is a progressive inflammatory skeletal disease characterized by periodontal tissue destruction, alveolar bone resorption, and tooth loss. Chronic inflammatory response and excessive osteoclastogenesis play essential roles in periodontitis progression. Unfortunately, the pathogenesis that contributes to periodontitis remains unclear. As a specific inhibitor of the mTOR (mammalian/mechanistic target of rapamycin) signaling pathway and the most common autophagy activator, rapamycin plays a vital role in regulating various cellular processes. The present study investigated the effects of rapamycin on osteoclast (OC) formation in vitro and its effects on the rat periodontitis model. The results showed that rapamycin inhibited OC formation in a dose-dependent manner by up-regulating the Nrf2/GCLC signaling pathway, thus suppressing the intracellular redox status, as measured by 2',7'-dichlorofluorescein diacetate and MitoSOX. In addition, rather than simply increasing the autophagosome formation, rapamycin increased the autophagy flux during OC formation. Importantly, the anti-oxidative effect of rapamycin was regulated by an increase in autophagy flux, which could be attenuated by blocking autophagy with bafilomycin A1. In line with the in vitro results, rapamycin treatment attenuated alveolar bone resorption in rats with lipopolysaccharide-induced periodontitis in a dose-dependent manner, as assessed by micro-computed tomography, hematoxylin-eosin staining, and tartrate-resistant acid phosphatase staining. Besides, high-dose rapamycin treatment could reduce the serum levels of proinflammatory factors and oxidative stress in periodontitis rats. In conclusion, this study expanded our understanding of rapamycin's role in OC formation and protection from inflammatory bone diseases.

6.
PLoS One ; 17(8): e0271050, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35925917

RESUMO

The realization of poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) from laboratory to clinical applications remains slow, partly because of the lack of precise control of each condition in the preparation process and the rich selectivity of nanoparticles with diverse characteristics. Employing PLGA NPs to establish a large range of size-controlled drug delivery systems and achieve size-selective drug delivery targeting remains a challenge for therapeutic development for different diseases. In this study, we employed a microfluidic device to control the size of PLGA NPs. PLGA, poly (ethylene glycol)-methyl ether block poly (lactic-co-glycolide) (PEG-PLGA), and blend (PLGA + PEG-PLGA) NPs were engineered with defined sizes. Blend NPs exhibit the widest size range (40-114 nm) by simply changing the flow rate conditions without changing the precursor (polymer molecular weight, concentration, and chain segment composition). A model hydrophobic drug, paclitaxel (PTX), was encapsulated in the NPs, and the PTX-loaded NPs maintained a large range of controllable NP sizes. Furthermore, size-controlled NPs were used to investigate the effect of particle size of sub-200 nm NPs on tumor cell growth. The 52 nm NPs showed higher cell growth inhibition than 109 nm NPs. Our method allows the preparation of biodegradable NPs with a large size range without changing polymer precursors as well as the nondemanding fluid conditions. In addition, our model can be applied to elucidate the role of particle sizes of sub-200 nm particles in various biomedical applications, which may help develop suitable drugs for different diseases.


Assuntos
Nanopartículas , Neoplasias , Portadores de Fármacos/química , Humanos , Ácido Láctico/química , Microfluídica , Nanopartículas/química , Neoplasias/tratamento farmacológico , Paclitaxel/uso terapêutico , Tamanho da Partícula , Polietilenoglicóis/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
7.
Dent Mater J ; 40(2): 322-330, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33116001

RESUMO

This study aimed to investigate the effect of Deoxyribonuclease I (DNase I) coating on initial adhesion and biofilm formation of peri-implant bacteria. Titanium (Ti), Ti-polydopamine (Ti-PDOP), Ti-PDOP-DNase I and Ti-PDOP-inactivated DNase I samples were studied. The FE-SEM, EDS and XPS were used to confirm that DNase I was coated onto Ti. The initial adhesion and biofilm formation of Aggregatibacter actinomycetemcomitans (A.a) and Fusobacterium nucleatum (F.n) were observed by CLSM. The osteogenic induction of Ti-PDOP-DNase I on MC3T3-E1 cells was investigated by ALP activity and RT-PCR. The adhesion clearance rate of viable bacteria on the surfaces of Ti-PDOP-DNase I was 91.95% for A.a, and 96.37% for F.n, and the 24 h biofilm formation of the bacteria was significantly inhibited. In addition, on DNase I coating, the mRNA level of osteogenic marker genes (alp, opn, bsp, sp7) and the activity of ALP were both up-regulated. Therefore, DNase I coating could be an alternative approach for preventing implant-related infection.


Assuntos
Infecções Bacterianas , Titânio , Aderência Bacteriana , Biofilmes , Desoxirribonuclease I , Fusobacterium nucleatum , Humanos , Polímeros , Propriedades de Superfície
8.
ACS Appl Mater Interfaces ; 12(38): 42511-42520, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32897691

RESUMO

Photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as highly prospective therapeutic modalities in cancer therapy. Notwithstanding, a critical challenge still remains in the exploration of an effective strategy to maximize the synergistic efficacy of PTT and PDT due to low photoconversion efficiency. Herein, inspired by the phospholipid bimolecular structure of the cell membrane, bionic cell membrane polymeric vesicles with photothermal/photodynamic synergy for prostate cancer therapy at one wavelength's excitation are constructed in one step by the coordination of hexadecyl trimethyl ammonium bromide (CTAB) from the surface of hydrophobic gold nanorods (AuNRs) with indocyanine green (ICG) and polycaprolactone (PCL), achieving their self-assembly in aqueous solutions. Importantly, the aggregation of the assembly improves the stability of the vesicles, realizing the synergistic effect of PTT and PDT for prostate cancer therapy. After being assembled within polymeric vesicles, bifunctional photosensitizer ICG can generate reactive oxygen species (ROS) and photothermal effect under light treatment. Their ROS not only induce PDT efficacy but also destroy the integrity of the lysosomal membrane, promoting the translocation of ICG and another photosensitizer called gold nanorods (AuNRs) into the cytosol. Moreover, their photothermal effects produced by both photosensitizers are able to engender greater damage to the tumor cells because of the close distance with organelles. This structure manifests good cellular uptake, highly effective tumor accumulation, high photothermal conversion efficiency, and excellent properties of enhanced photobleaching resistance, which are beneficial to ICG-based fluorescence tumor imaging. Using the same near-infrared (NIR) wavelength for excitation, the AuNR/ICG vesicles can reduce the side effect rate of photodamage on the skin. In addition, by generating reactive oxygen species (ROS) and double photothermal effect, the vesicles under NIR excitation can promote the apoptosis of PC3 tumor cells. Taken together, the spontaneous self-assembled AuNR/ICG vesicles exhibit huge potential in advanced-stage prostate cancer therapy, especially for the prostate-specific membrane antigen (PSMA)-negative castration-resistant subtype.


Assuntos
Antineoplásicos/farmacologia , Membrana Celular/química , Fármacos Fotossensibilizantes/farmacologia , Polímeros/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Ouro/química , Ouro/farmacologia , Humanos , Verde de Indocianina/química , Verde de Indocianina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Células PC-3 , Tamanho da Partícula , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Terapia Fototérmica , Polímeros/química , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície
9.
Orthop Surg ; 11(2): 325-329, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30884151

RESUMO

Fractures of the tibia represent a common class of injuries in orthopedics. The blood supply to the tibia is poor due to the small subcutaneous muscle tissues inside. Consequently, the tibia is prone to delayed fracture healing and nonunion of the fracture after surgery. In this case, we used porous tantalum metal plate to treat nonunion of a tibial fracture and achieved satisfactory therapeutic effects. For the first time in the field, we used 3D printing technology to fabricate porous tantalum metal plates for the treatment of tibial fractures. The resulting porous tantalum metal exhibited excellent mechanical and biological properties, and improved the therapeutic effects for the treatment of a tibial fracture nonunion. Porous tantalum metal plates have great application potential as a new implant material for internal fixation.


Assuntos
Materiais Biocompatíveis , Placas Ósseas , Tantálio , Fraturas da Tíbia/cirurgia , Adulto , Fixação Interna de Fraturas/instrumentação , Fixação Interna de Fraturas/métodos , Consolidação da Fratura , Humanos , Masculino , Impressão Tridimensional , Radiografia , Fraturas da Tíbia/diagnóstico por imagem
10.
World J Pediatr ; 14(5): 437-447, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30280313

RESUMO

BACKGROUND: Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awareness and effective treatments, to further standardize and strengthen the clinical management and to reduce the mortality of HFMD, the guidelines for diagnosis and treatment have been developed. METHODS: National Health Commission of China assembled an expert committee for a revision of the guidelines. The committee included 33 members who are specialized in diagnosis and treatment of HFMD. RESULTS: Early recognition of severe cases is utmost important in diagnosis and treatment of patients with HFMD. The key to diagnosis and treatment of severe cases lies in the timely and accurate recognition of stages 2 and 3 of HFMD, in order to stop progression to stage 4. Clinicians should particularly pay attention to those EV-A71 cases in children aged less than 3 years, and those with disease duration less than 3 days. The following indicators should alert the clinician of possible deterioration and impending critical disease: (1) persistent hyperthermia; (2) involvement of nervous system; (3) worsening respiratory rate and rhythm; (4) circulatory dysfunction; (5) elevated peripheral WBC count; (6) elevated blood glucose and (7) elevated blood lactic acid. For treatment, most mild cases can be treated as outpatients. Patients should be isolated to avoid cross-infection. Intense treatment modalities should be given for those severe cases. CONCLUSION: The guidelines can provide systematic guidance on the diagnosis and management of HFMD.


Assuntos
Controle de Doenças Transmissíveis/organização & administração , Infecções por Coxsackievirus/diagnóstico , Doença de Mão, Pé e Boca/diagnóstico , Doença de Mão, Pé e Boca/terapia , Isolamento de Pacientes/métodos , Criança , Pré-Escolar , Terapia Combinada , Infecções por Coxsackievirus/epidemiologia , Infecções por Coxsackievirus/terapia , Feminino , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Incidência , Lactente , Masculino , Guias de Prática Clínica como Assunto , Prognóstico , Medição de Risco , Estações do Ano , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do Tratamento
11.
Beijing Da Xue Xue Bao Yi Xue Ban ; 39(1): 64-6, 2007 Feb 18.
Artigo em Zh | MEDLINE | ID: mdl-17304330

RESUMO

OBJECTIVE: To evaluate the effect of core:dentin thickness ratio on the flexure strength, fracture mode and origin of bilayered IPS Empress II ceramic composite specimens. METHODS: IPS Empress II core ceramic, dentin porcelain and bilayered composite specimens with core:dentin thickness ratio of 2:1 and 1:1 were tested in three-point flexure strength. Mean strengths and standard deviations were determined. The optical microscopy was employed for identification of the fracture mode and origin. RESULTS: The flexure strength of dentin porcelain was the smallest(62.7 MPa), and the strength of bilayered composite specimens was smaller than single-layered core ceramic(190.2 MPa). The core: dentin ratio did not influence the strength of bilayered composite specimens. The frequency of occurrence of bilayered specimen delaminations was higher in the group of core: dentin thickness ratio of 1:1 than in the group of 2:1. CONCLUSION: IPS Empress II core ceramic was significantly stronger than veneering dentin porcelain. Core:dentin thickness ratio could significantly influence the fracture mode and origin, and bilayered IPS Empress II ceramic composite specimens showed little influence in the fracture strength.


Assuntos
Silicatos de Alumínio/química , Cerâmica/química , Porcelana Dentária/química , Teste de Materiais/métodos , Força Compressiva , Elasticidade , Maleabilidade , Estresse Mecânico , Resistência à Tração
12.
Int J Nanomedicine ; 9: 4035-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25187707

RESUMO

A large number of studies have shown that bufalin can have a significant antitumor effect in a variety of tumors. However, because of toxicity, insolubility in water, fast metabolism, short half-life, and other shortcomings, its application is limited in cancer therapy. In this study, we explored the anti-metastatic role of bufalin-loaded pluronic polyetherimide nanoparticles on HCT116 colon cancer-bearing mice. Nanoparticle size, shape, drug loading, encapsulation efficiency, and in vitro drug release were studied. Also, cellular uptake of nanoparticles, in vivo tumor targeting, and tumor metastasis were studied. The nanoparticles had a particle size of about 60 nm and an encapsulation efficiency of 75.71%, by weight. The in vitro release data showed that free bufalin was released faster than bufalin-loaded pluronic polyetherimide nanoparticles, and almost 80% of free bufalin was released after 32 hours. Nanoparticles had an even size distribution, were stable, and had a slow release and a tumor-targeting effect. Bufalin-loaded pluronic polyetherimide nanoparticles can significantly inhibit the growth and metastasis of colorectal cancer.


Assuntos
Antineoplásicos/química , Bufanolídeos/química , Neoplasias Colorretais/metabolismo , Nanopartículas/química , Poloxâmero/química , Polímeros/química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Bufanolídeos/farmacocinética , Bufanolídeos/farmacologia , Neoplasias Colorretais/patologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Células HCT116 , Humanos , Fígado/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Nus , Tamanho da Partícula , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Int J Oral Sci ; 4(2): 101-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22699263

RESUMO

The objective of this study was to investigate the mechanical characteristics of implant-abutment interface design in a dental , using nonlinear finite element analysis (FEA) method. This finite element simulation study was applied on three commonly used commercial dental implant systems: model I, the reduced-diameter 3i implant system (West Palm Beach, FL, USA) with a hex and a 12-point double internal hexagonal connection; model II, the Semados implant system (Bego, Bremen, Germany) with combination of a conical (450 taper) and internal hexagonal connection; and model III, the Brinemark implant system (Nobel Biocare, Gothenburg,Sweden) with external hexagonal connection. In simulation, a force of 170 N with 45" oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum von Mises stress, principal stress and displacement while the Br Bnemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution, and produced a smaller displacement than the other two implant systems.


Assuntos
Desenho Assistido por Computador , Projeto do Implante Dentário-Pivô/estatística & dados numéricos , Planejamento de Prótese Dentária , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Simulação por Computador , Humanos , Estresse Mecânico
14.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 28(2): 185-9, 2010 Apr.
Artigo em Zh | MEDLINE | ID: mdl-20480665

RESUMO

OBJECTIVE: To explore the multi-differentiated capability of human periodontal ligament cell population (hPDLP), and provide a theoretical basis for the periodontal regeneration by tissue engineering technique. METHODS: hPDLP was cultured from periodontium of human tooth by the outgrowth method. STRO-1 and CD 146 expression were investigated by flow cytometry. hPDLP was induced to odontogenic/osteogenic-like and adipogenic-like cell. The multilineage differentiation capacities of hPDLP were evaluated by alizarin red stain, oil red O stain, anti-CD146 and STRO-1 immunocytochemistry, and reverse-transcriptase polymerase chain reaction analysis. RESULTS: hPDLP was isolated from human periodontium and most of the cells retained their fibroblastic spindle shape. hPDLP can be induced into osteoblast-like cells and adipocyte-like cells, and calcium deposition and lipid droplets were detected perspectively. And the eighth generation of hPDLP had weaker potential into adipocyte-like cells than the first passage, however, there was no difference to the aspect of calcification ability between the two passages. CONCLUSION: hPDLP cultured in vitro can differentiate into adipocytes and osteoblasts, and the first to third passage cells may have the predominance of differentiation potential.


Assuntos
Diferenciação Celular , Ligamento Periodontal , Adipócitos , Células Cultivadas , Fibroblastos , Citometria de Fluxo , Humanos , Técnicas In Vitro , Odontogênese , Osteoblastos , Regeneração , Engenharia Tecidual
15.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 43(9): 561-3, 2008 Sep.
Artigo em Zh | MEDLINE | ID: mdl-19087610

RESUMO

OBJECTIVE: To analyze the effects of core material and design on the fracture mechanism of veneered all-ceramic crowns. METHODS: The fracture process of 6 veneered alumina or zirconia crowns with different core design (well-distributed core, not well distributed core, and core with cervical ring) under load was analyzed by RFPA'2D finite element analysis software. RESULTS: All the six tested crowns fractured due to tension failure, and the crack started at the porcelain in the cusp and spread along the interface between core and porcelain. Under the conditions of this test, the break was only related to the porcelain and not the core, and the crack of porcelain took place earlier in zirconia crowns than in alumina crowns. Minimum stress distribution in cervical ring core design crown and maximum stress distribution in not well distributed core design crown could be seen at the neck area. CONCLUSIONS: Zirconia crowns presented greater stress at the interface between core and porcelain than alumina crowns. The not well distributed core design did not increase the rise of break. The neck area was the weak area with tensile stress concentration in the cervical ring core design.


Assuntos
Falha de Restauração Dentária , Análise do Estresse Dentário , Análise de Elementos Finitos , Ligas Metalo-Cerâmicas , Planejamento de Prótese Dentária , Teste de Materiais
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