Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 490
Filtrar
1.
J Dent ; 138: 104733, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37783373

RESUMO

OBJECTIVE: To investigate the cross-linking and protective effect of artemisinin (ART), dihydroartemisinin (DHA), and artesunate (AST) on collagen fibers of demineralized dentin surface. METHODS: Molecular docking was used to predict potential interactions of ART, DHA, and AST with dentin type I collagen. Human third molars without caries were completely demineralized and treated with different solutions for 1 min. The molecular interactions and cross-linking degree of ART and its derivatives with dentin collagen were evaluated by FTIR spectroscopy, total extractable protein content, and a ninhydrin assay. Scanning electron microscopy, hydroxyproline release, and ultimate microtensile strength tests (µUTS) were employed to confirm the mechanical properties and anti-collagenase degradation properties of dentin collagen fibers. RESULTS: ART, DHA, and AST combined with dentin type I collagen mainly through hydrogen bonding and hydrophobic interactions, and the cross-linking reaction sites were mainly C=O and CN functional groups. Compared to the control group, ART and its derivatives significantly increased the degree of cross-linking. Additionally, significant increases were observed in resistance to enzymatic digestion and mechanical properties of the artemisinin and its derivatives group. CONCLUSION: ART, DHA, and AST could cross-link with demineralized dentin collagen, through improving the mechanical properties and anti-collagenase degradation properties. CLINICAL SIGNIFICANCE: The study endorses the potential use of ART and its derivatives as a prospective collagen cross-linking agent for degradation-resistant and long-period dentin bonding in composite resin restorations.


Assuntos
Artemisininas , Colagem Dentária , Humanos , Colágeno Tipo I , Reagentes de Ligações Cruzadas/farmacologia , Reagentes de Ligações Cruzadas/análise , Reagentes de Ligações Cruzadas/química , Simulação de Acoplamento Molecular , Estudos Prospectivos , Resistência à Tração , Colágeno/farmacologia , Colágeno/química , Colagenases/análise , Colagenases/farmacologia , Artemisininas/farmacologia , Artemisininas/análise , Dentina , Colagem Dentária/métodos , Adesivos Dentinários/farmacologia , Adesivos Dentinários/química
2.
Oral Dis ; 29(8): 3525-3539, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36437605

RESUMO

OBJECTIVES: Collagen fibrils from carious dentin matrix are prone to enzymatic degradation. This study investigates the feasibility and mechanism of nordihydroguaiaretic acid (NDGA), as a collagen crosslinker, to bio-modify the demineralized dentin matrix. METHODS: The physicochemical properties of the crosslinked dentin matrix were characterized by swelling ratio, ninhydrin assay, Fourier Transform Infrared spectroscopy, and atomic force microscopy. The collagenase degradation resistance was evaluated by measuring loss of dry mass, hydroproline release, loss of elasticity, and micro-nano structure integrity. The cytotoxicity of NDGA-crosslinked dentin collagen was evaluated by flow cytometry. RESULTS: NDGA crosslinked dentin matrix without destroying the integrity of collagen. Mechanistically, NDGA formed bisquinone bond between two adjacent o-quinone groups, resulting in NDGA polymeric matrix in which collagen fibrils were embedded. NDGA modification could significantly enhance the stiffness of dentin matrix at macro-nano scale. The NDGA-crosslinked dentin matrix exhibited remarkably low collagen degradation and sustained bulk elasticity after collagenase challenge, which were attributed to decreased water content, physical masking of collagenase bind sites on collagen, and improved stiffness of collagen fibrils. Notably, NDGA-crosslinked dentin matrix exhibited excellent biocompatibility. CONCLUSION: NDGA, as a biocompatible collagen crosslinker, improves the mechanical properties and biodegradation resistance of demineralized dentin matrix.


Assuntos
Colágeno , Colagenases , Masoprocol/análise , Masoprocol/química , Colagenases/análise , Colagenases/metabolismo , Dentina/química
3.
Nat Prod Res ; 36(18): 4704-4708, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34753359

RESUMO

Leucophyllum frutescens (Scrophulariaceae) is a medicinal plant of Mexican traditional medicine. The aim of this study was to analyse the volatile components from the leaves and flowers by GC/MS and to assess their anti-aging activity for the first time. A total of 30 compounds were identified where 1-octen-3-ol (73.56%) and D-limonene (11.12%) represented the major ingredients in the leaves, while n-heneicosane (32.30%) and dehydroepingaione (15.15%) were the major components in the flowers. In vitro anti-aging activity was measured via assessing collagenase and elastase inhibition. Essential oils from the leaves and flowers showed potential collagenase inhibitory activity with IC50 of 55.7 and 47.4 µg/mL. However, the oils from the leaves and flowers showed moderate anti-elastase activity with IC50 of 60.8 and 97.7 µg/mL. Therefore, the oil of Leucophyllum frutescens could afford a promising natural anti-aging drug.


Assuntos
Óleos Voláteis , Scrophulariaceae , Colagenases/análise , Flores/química , Óleos Voláteis/química , Elastase Pancreática , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química
4.
Regul Toxicol Pharmacol ; 113: 104645, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32278234

RESUMO

A safety assessment was conducted for microbial collagenase (COL) enzyme expressed in Streptomyces violaceoruber. The acute oral toxicity of COL was examined in Sprague-Dawley rats and the LD50 of COL via single oral administration to rats was higher than 2000 mg/kg body weight. A 13-week oral gavage study of COL showed no adverse effects due to the enzyme up to a dose of 234.9 mg total organic solids (TOS)/kg body weight per day (NOAEL). A bacterial reverse mutation test showed no mutagenic activity at the highest dose (4698 µg TOS per plate). In the mouse lymphoma TK assay, a positive result was observed at the highest dose of 4698 µg TOS/mL although it had low reproducibility. To confirm the chromosome aberration potential, an in vivo micronucleus test was conducted that demonstrated the lack of mutagenic potential on the bone marrow of rats at doses up to 1879 mg TOS/kg body weight per day. The results of the genotoxicity studies and acute and subchronic rat studies support the safe use in food production of collagenase produced from S. violaceoruber.


Assuntos
Colagenases/análise , Streptomyces/enzimologia , Administração Oral , Animais , Colagenases/administração & dosagem , Colagenases/metabolismo , Feminino , Masculino , Camundongos , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Medição de Risco , Testes de Toxicidade Aguda , Testes de Toxicidade Subcrônica
5.
Dis Colon Rectum ; 62(8): 972-979, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31283593

RESUMO

BACKGROUND: Bacteria that produce collagen-digesting enzymes (collagenolytic bacteria) have been shown to play a critical and previously unappreciated role in anastomotic leak pathogenesis by breaking down host tissue extracellular matrix proteins. Detection of these bacteria is labor intensive, and no screening method currently exists. OBJECTIVES: We evaluated a rapid screening method developed to detect the presence of these collagenolytic bacteria in clinical samples, such as drain fluid, anastomotic tissue, or feces. DESIGN: We compared a new method of detecting collagenolytic bacterial species with a previously used technique using samples from a murine experimental model and then demonstrated the utility of this screening method in samples from patients with anastomotic complications. SETTINGS: All of the laboratory work and previous murine experiments were performed in Dr Alverdy's laboratory at the University of Chicago under institutional review board-approved protocols. PATIENTS: Samples from patients with challenging wound complications were provided by participating clinicians with verbal patient consent. Given the small number of patients, this was determined to be institutional review board exempt. MAIN OUTCOME MEASURES: Whether this analysis can influence patient management and outcomes will require additional study. RESULTS: This screening method detects numerous strains of bacteria with collagenolytic properties, including the collagenolytic species that have been implicated previously in anastomotic leak. Once collagenolytic strains are identified, they can be speciated and tested for antibiotic resistance using standard laboratory techniques. LIMITATIONS: This study is limited by the small number of patient samples tested. CONCLUSIONS: We demonstrated the potential applicability of this assay to evaluate rare and complex anastomotic complications that often require analysis beyond standard culture and sensitivity assays. Future applications of this method may allow the development of strategies to prevent anastomotic leak related to collagenolytic bacteria. See Video Abstract at http://links.lww.com/DCR/A962.


Assuntos
Fístula Anastomótica/prevenção & controle , Antibioticoprofilaxia/métodos , Bactérias/enzimologia , Colectomia/efeitos adversos , Colagenases/análise , Doenças do Colo/cirurgia , Infecção da Ferida Cirúrgica/prevenção & controle , Fístula Anastomótica/microbiologia , Bactérias/isolamento & purificação , Feminino , Humanos , Masculino , Recidiva , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/microbiologia
6.
J Chromatogr A ; 1529: 1-28, 2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29132826

RESUMO

Elastase, collagenase, hyaluronidase and tyrosinase, are very interesting enzymes due to their direct implication in skin aging and as therapeutic hits. Different techniques can be used to study these enzymes and to evaluate the influence of effectors on their kinetics. Nowadays, analytical techniques have become frequently used tools for miniaturizing enzyme assays. The main intention of this article is to review chromatographic and electrophoretic tools that study the four enzymes above mentioned. More specifically, the use of high-performance liquid chromatography and capillary electrophoresis and their derivative techniques for monitoring these enzymes will be investigated. The advantages and limitations of these assays will also be discussed. The original use of microscale thermophoresis and thin layer chromatography in this domain will also be covered.


Assuntos
Cromatografia , Eletroforese , Ensaios Enzimáticos/instrumentação , Enzimas/análise , Colagenases/análise , Colagenases/química , Colagenases/metabolismo , Enzimas/química , Enzimas/metabolismo , Hialuronoglucosaminidase/análise , Hialuronoglucosaminidase/química , Hialuronoglucosaminidase/metabolismo , Cinética , Monofenol Mono-Oxigenase/análise , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/metabolismo , Oxirredução , Elastase Pancreática/análise , Elastase Pancreática/química , Elastase Pancreática/metabolismo
7.
World J Gastroenterol ; 23(31): 5680-5691, 2017 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-28883693

RESUMO

AIM: To evaluate the effect of local surgical adhesive glue (albumin/glutaraldehyde-Bioglue) on the healing of colonic anastomoses in rats. METHODS: Forty Albino-Wistar male rats were randomly divided into two groups, with two subgroups of ten animals each. In the control group, an end-to-end colonic anastomosis was performed after segmental resection. In the Bioglue group, the anastomosis was protected with extraluminar application of adhesive glue containing albumin and glutaraldehyde. Half of the rats were sacrificed on the fourth and the rest on the eighth postoperative day. Anastomoses were resected and macroscopically examined. Bursting pressures were calculated and histological features were graded. Other parameters of healing, such as hydroxyproline and collagenase concentrations, were evaluated. The experimental data were summarized and computed from the results of a one-way ANOVA. Fisher's exact test was applied to compare percentages. RESULTS: Bursting pressures, adhesion formation, inflammatory cell infiltration, and collagen deposition were significantly higher on the fourth postoperative day in the albumin/glutaraldehyde group than in the control group. Furthermore, albumin/glutaraldehyde significantly increased adhesion formation, inflammatory cell infiltration, neoangiogenesis, and collagen deposition on the eighth postoperative day. There was no difference in fibroblast activity or hydroxyproline and collagenase concentrations. CONCLUSION: Albumin/glutaraldehyde, when applied on colonic anastomoses, promotes their healing in rats. Therefore, the application of protective local agents in colonic anastomoses leads to better outcomes.


Assuntos
Adesivos/uso terapêutico , Anastomose Cirúrgica/efeitos adversos , Fístula Anastomótica/prevenção & controle , Proteínas/uso terapêutico , Deiscência da Ferida Operatória/prevenção & controle , Adesivos Teciduais/uso terapêutico , Cicatrização/efeitos dos fármacos , Fístula Anastomótica/epidemiologia , Fístula Anastomótica/etiologia , Animais , Colagenases/análise , Colo/metabolismo , Colo/cirurgia , Humanos , Hidroxiprolina/análise , Incidência , Masculino , Modelos Animais , Ratos , Ratos Wistar , Deiscência da Ferida Operatória/epidemiologia , Deiscência da Ferida Operatória/etiologia
8.
Methods Mol Biol ; 1626: 71-78, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28608201

RESUMO

Collagenolytic proteases have many potential applications in different areas of science, industry, and medicine. The determination of the activity of such proteins is paramount to their application. Here, we describe methods which can be applied to determine the activity and some basic characteristics of potential collagenases.


Assuntos
Colagenases/metabolismo , Eletroforese em Gel de Poliacrilamida/métodos , Ensaios Enzimáticos/métodos , Animais , Colágeno/metabolismo , Colagenases/análise , Humanos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Inibidores de Metaloproteinases de Matriz/metabolismo , Metais/metabolismo , Temperatura
9.
Methods Mol Biol ; 1626: 115-121, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28608204

RESUMO

In-gel zymography is a commonly employed tool to identify active enzymes in a quantitative and qualitative manner. In this work, apart from the incorporation of substrate which is traditionally employed in zymography, the identification of collagenase by incubation of the enzyme resolved on a polyacrylamide gel with substrate solution is described. The two methods are quite fast and result in specific detection of bacterial collagenase.


Assuntos
Clostridium histolyticum/enzimologia , Colagenases/análise , Ensaios Enzimáticos/métodos , Eletroforese em Gel de Poliacrilamida Nativa/métodos , Clostridium histolyticum/metabolismo , Colágeno/metabolismo , Colagenases/metabolismo , Ensaios Enzimáticos/economia , Eletroforese em Gel de Poliacrilamida Nativa/economia , Fatores de Tempo
10.
Methods Mol Biol ; 1626: 221-228, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28608215

RESUMO

Zymography is a well-standardized protocol for the qualitative assessment and analysis of proteinases under specified conditions. However, analysis of a large number of samples simultaneously becomes a challenge when the zymography is carried out by the usual protocol of electrophoresis. This can be overcome by assaying the matrix-degrading proteinases in substrate-impregnated gels in multiwells. Enzymes are copolymerized with 300 mL of 10% acrylamide impregnated with gelatin substrate and incubated for 16 h. The gels are then stained with Coomassie blue, destained with water, and visualized with the naked eye. The intensity; if needed can be measured with a densitometer or gel documentation system. This method has been tested for bacterial collagenases as well as some matrix-degrading metalloproteinases that were purified from rat mammary gland. It can also be used to characterize the enzymes with respect to the type and concentration of the cations required for activity and the role of other regulatory molecules that may affect the enzyme activity. The added advantage of this method is that the electrophoresis set up and electricity is not needed for the procedure.


Assuntos
Eletroforese em Gel de Poliacrilamida/métodos , Ensaios Enzimáticos/métodos , Peptídeo Hidrolases/metabolismo , Animais , Bactérias/enzimologia , Bactérias/metabolismo , Colagenases/análise , Colagenases/metabolismo , Corantes/análise , Densitometria/métodos , Feminino , Gelatina/metabolismo , Gelatinases/análise , Gelatinases/metabolismo , Glândulas Mamárias Animais/enzimologia , Glândulas Mamárias Animais/metabolismo , Peptídeo Hidrolases/análise , Ratos , Corantes de Rosanilina/análise , Coloração e Rotulagem/métodos
11.
Photomed Laser Surg ; 33(3): 145-53, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25714387

RESUMO

OBJECTIVE: This work aimed to investigate the biochemical changes associated with low-level laser therapy (LLLT) using 660 and 780 nm, on a well-established experimental model of osteoarthritis (OA) in the knees of rats with induced collagenase, using histomorphometry and Raman spectroscopy. MATERIALS AND METHODS: Thirty-six Wistar rats were divided into four groups: control (GCON, n=9), collagenase without treatment (GCOL, n=9), collagenase with LLLT 660 nm treatment (G660, n=8), and collagenase with LLLT 780 nm treatment (G780, n=10). LLLT protocol was: 30 mW power output, 10 sec irradiation time, 0.04 cm(2) spot size, 0.3 J energy, 0.75 W/cm(2) irradiance, and 7.5 J/cm(2) fluence per session per day, during 14 days. Then, knees were withdrawn and submitted to histomorphometry and Raman spectroscopy analysis. Principal components analysis (PCA) and Mahalanobis distance were employed to characterize the spectral findings. RESULTS: Histomorphometry revealed a significant increase in the amount of collagen III for the group irradiated with 660 nm. The Raman bands at 1247, 1273, and 1453 cm(-1) (from principal component score PC2), attributed to collagen type II, and 1460 cm(-1) (from PC3), attributed to collagen type III, suggested that the LLLT causes acceleration in cellular activity, especially on the cells that repair cartilage, accelerating the breakdown of cartilage destroyed by collagenase and stimulating the fibroblast to synthesize repairing collagen III. CONCLUSIONS: LLLT accelerated the initial breakdown of cartilage destroyed by collagenase and stimulated the fibroblast to synthesize the repairing collagen III, suggesting a beneficial effect of LLLT on OA.


Assuntos
Terapia com Luz de Baixa Intensidade , Osteoartrite/radioterapia , Análise Espectral Raman , Animais , Colagenases/análise , Osteoartrite/patologia , Ratos , Ratos Wistar
12.
Invest Ophthalmol Vis Sci ; 55(1): 55-63, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24222300

RESUMO

PURPOSE: Vitreous degeneration contributes to several age-related eye diseases, including retinal detachment, macular hole, macular traction syndrome, and nuclear cataracts. Remarkably little is understood about the molecular interactions responsible for maintaining vitreous structure. The purpose of this study was to measure the structural properties of the vitreous body after enzymatic degradation of selected macromolecules. METHODS: Mechanical properties of plugs of bovine and porcine vitreous were analyzed using a rheometer. Oscillatory and extensional tests measured vitreous stiffness and adhesivity, respectively. Major structural components of the vitreous were degraded by incubation overnight in collagenase, trypsin, or hyaluronidase, singly or in combination. Vitreous bodies were also incubated in hyper- or hypotonic saline. Effects of these treatments on the mechanical properties of the vitreous were measured by rheometry. RESULTS: Enzymatic digestion of each class of macromolecules decreased the stiffness of bovine vitreous by approximately half (P < 0.05). Differential effects were observed on the damping capacity of the vitreous (P < 0.05), which was shown to correlate with material behavior in extension (P < 0.01). Digestion of hyaluronan significantly decreased the damping capacity of the vitreous and increased adhesivity. Collagen degradation resulted in the opposite effect, whereas digestion of proteins and proteoglycans with trypsin did not alter behavior relative to controls. Osmotic perturbations and double-enzyme treatments further implicated hyaluronan and hyaluronan-associated water as a primary regulator of adhesivity and material behavior in extension. CONCLUSIONS: Collagen, hyaluronan, and proteoglycans act synergistically to maintain vitreous stiffness. Hyaluronan is a key mediator of vitreous adhesivity, and mechanical damping is an important factor influencing dynamic vitreous behavior.


Assuntos
Colágeno/análise , Colagenases/análise , Oftalmopatias/metabolismo , Proteoglicanas/análise , Corpo Vítreo/química , Corpo Vítreo/fisiopatologia , Animais , Fenômenos Biomecânicos , Bovinos , Modelos Animais de Doenças , Oftalmopatias/fisiopatologia , Suínos
13.
Caries Res ; 47(6): 591-600, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24080530

RESUMO

Current understanding of dental caries considers this disease a demineralization of the tooth tissues due to the acid produced by sugar-fermenting microorganisms. Thus, caries is considered a diet- and pH-dependent process. We present here the first metagenomic analysis of the bacterial communities present at different stages of caries development, with the aim of determining whether the bacterial composition and biochemical profile are specific to the tissue affected. The data show that microbial composition at the initial, enamel-affecting stage of caries is significantly different from that found at subsequent stages, as well as from dental plaque of sound tooth surfaces. Although the relative proportion of Streptococcus mutans increased from 0.12% in dental plaque to 0.72% in enamel caries, Streptococcus mitis and Streptococcus sanguinis were the dominant streptococci in these lesions. The functional profile of caries-associated bacterial communities indicates that genes involved in acid stress tolerance and dietary sugar fermentation are overrepresented only at the initial stage (enamel caries), whereas other genes coding for osmotic stress tolerance as well as collagenases and other proteases enabling dentin degradation are significantly overrepresented in dentin cavities. The results support a scenario in which pH and diet are determinants of the disease during the degradation of enamel, but in dentin caries lesions not only acidogenic but also proteolytic bacteria are involved. We propose that caries disease is a process of varying etiology, in which acid-producing bacteria are the vehicle to penetrate enamel and allow dentin degrading microorganisms to expand the cavity.


Assuntos
Bactérias/classificação , Cárie Dentária/microbiologia , Metagenoma/genética , Ácidos , Bactérias/genética , Proteínas de Bactérias/análise , Candida/classificação , Colagenases/análise , DNA Bacteriano/análise , Cárie Dentária/classificação , Esmalte Dentário/microbiologia , Placa Dentária/microbiologia , Dentina/microbiologia , Sacarose Alimentar/metabolismo , Progressão da Doença , Fermentação/genética , Humanos , Concentração de Íons de Hidrogênio , Lactobacillus/classificação , Osmose , Peptídeo Hidrolases/análise , Prevotella/classificação , Análise de Sequência de DNA , Streptococcus mitis/enzimologia , Streptococcus mitis/isolamento & purificação , Streptococcus mutans/enzimologia , Streptococcus mutans/isolamento & purificação , Streptococcus sanguis/enzimologia , Streptococcus sanguis/isolamento & purificação
14.
Clin Exp Optom ; 96(2): 214-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23496656

RESUMO

BACKGROUND: Proteases, protease activity and inflammatory molecules in tears have been found to be relevant in the pathogenesis of keratoconus. We sought to determine the influence of eye rubbing on protease expression, protease activity and concentration of inflammatory molecules in tears. METHODS: Basal tears were collected from normal volunteers before and after 60 seconds of experimental eye rubbing. The total amount of matrix metalloproteinase (MMP)-13 and inflammatory molecules interleukin (IL)-6 and tumour necrosis factor (TNF)-α in the tear samples were measured using specific enzyme-linked immunosorbent assays (ELISA). Tear collagenase activity was investigated using a specific activity assay. RESULTS: The concentrations of MMP-13 (51.9 ± 34.3 versus 63 ± 36.8 pg/ml, p = 0.006), IL-6 (1.24 ± 0.98 versus 2.02 ± 1.52 pg/ml, p = 0.004) and TNF-α (1.16 ± 0.74 versus 1.44 ± 0.66 pg/ml, p = 0.003) were significantly increased in normal subjects after eye rubbing. The experimental eye rub did not alter significantly the collagenase activity (5.02 ± 3 versus 7.50 ± 3.90 fluorescent intensity units, p = 0.14) of tears. CONCLUSION: Eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-α in normal study subjects. This increase in protease, protease activity and inflammatory mediators in tears after eye rubbing may be exacerbated even further during persistent and forceful eye rubbing seen in people with keratoconus and this in turn may contribute to the progression of the disease.


Assuntos
Citocinas/análise , Ceratocone/etiologia , Peptídeo Hidrolases/análise , Lágrimas/química , Adulto , Colagenases/análise , Feminino , Humanos , Interleucina-6/análise , Ceratocone/metabolismo , Masculino , Metaloproteinase 13 da Matriz/análise , Fator de Necrose Tumoral alfa/análise
15.
Dent Mater ; 29(4): 485-92, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23434233

RESUMO

OBJECTIVE: To investigate whether proanthocyanidins (PA) is capable of improving dentin collagen's biological stability through cross-linking within time periods that are clinically relevant. MATERIALS AND METHODS: Demineralized dentin collagen slabs were treated with 3.75 wt% PA solution for 10s, 1 min, 30 min, 60 min, 120 min, 360 min, and 720 min, respectively. The resultant cross-linked collagen samples were subject to digestion with 0.1% collagenase at 37°C for 2h, 6h, 12h, 24h, 36 h, and 48 h. The percentage of weight loss after digestion was calculated to evaluate PA-treated collagen's resistance toward enzymatic degradation. Fourier-transformed infrared (FTIR) spectroscopy was used to probe evidences of PA-collagen interactions after various periods of PA treatment. RESULTS: The collagenase digestion assay suggests that PA treatment as short as 10s can enhance collagen's resistance toward enzymatic challenge. The FTIR spectroscopy further verifies that PA is indeed incorporated into collagen regardless of treatment time, possibly via a mechanism involving the chemical interactions between PA and collagen. SIGNIFICANCE: This study confirmed that PA can effectively cross-link collagen and improve its biological stability in time periods as short as 10s. The use of PA as a priming agent is therefore clinically feasible and is a promising approach to improving the durability of current dentin bonding systems.


Assuntos
Colágeno/efeitos dos fármacos , Colagenases/análise , Reagentes de Ligações Cruzadas/farmacologia , Dentina/efeitos dos fármacos , Proantocianidinas/farmacologia , Cimentos de Resina/química , Colágeno/metabolismo , Colagem Dentária/métodos , Dentina/enzimologia , Humanos , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Artigo em Espanhol | LILACS | ID: lil-660046

RESUMO

La periodontitis constituye la infección bacteriana más prevalente a nivel mundial y representa un factor de riesgo para diversas patologías sistémicas. El estado de inflamación y destrucción periodontal se manifiestan a través de la presencia de biomarcadores en el suero y fluidos orales, tales como el fluido gingival crevicular (FGC), saliva y enjuague oral. Enzimas como las metaloproteinasas de matriz (MMP) y mieloperoxidasa, constituyen biomarcadores potenciales para ensayos moleculares complementarios a la clínica de uso en el sillón dental. A continuación se presenta una revisión de la literatura respecto de la aplicación potencial del análisis de metaloproteinasas de matriz extracelular (MMPs) en el diagnóstico complementario de las enfermedades periodontales. Se ha demostrado que los niveles de MMP-9, -13 y particularmente de MMP-8, se asocian con el grado de inflamación periodontal, y pueden diferenciar entre sujetos sanos, con gingivitis, periodontitis y peri-implantitis, mientras que la mejoría de los parámetros clínicos en respuesta al tratamiento periodontal se asocia con la reducción de la activación y niveles de estas enzimas en FGC, como así también en el suero. Se concluye que la determinación, particularmente de MMP-8 en fluidos orales presenta un elevado potencial como complemento de los métodos clínicos tradicionales para identificar a los pacientes con periodontitis o en riesgo de desarrollar la enfermedad, monitorear fases del tratamiento y mejoría de signos periodontales e incluso evaluar el estado de inflamación sistémica.


Periodontal disease is the most common bacterial infection worldwide and it can contribute to enhance the risk for the development of several systemic diseases. The status of periodontal inflammation and destruction can be reflected in biomarker measurement in serum and oral fluids, like gingival crevicular fluid (GCF), saliva and mouth-rinse. Some enzymes, such as matrix metalloproteinases (MMPs) and myeloperoxidase are potential candidates for chair-side point-of-care oral fluid assays. This review is focused on the utility of matrix metalloproteinase (MMP) analysis in oral fluid as a complementary diagnostic method to chronic periodontitis. Levels of MMP-9,-13 and specially of MMP-8, reflect oral inflammatory status and discriminate among healthy, gingivitis, periodontitis and periimplantitis individuals, whereas MMP levels and activation in GCF and serum are in line with the improvement of clinical parameters in response to periodontal treatment. As a conclusion, MMP-8 assessment in GCF could represent a helpful adjunctive method to traditional diagnostics to identify periodontitis or patients at risk to develop the disease, monitor treatment phases, improvement of periodontal signs and even screen the systemic inflammation status.


Assuntos
Humanos , Colagenases/análise , Líquido do Sulco Gengival/enzimologia , Periodontite/diagnóstico , Periodontite/enzimologia , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/enzimologia , Biomarcadores/análise , /análise , Sistemas Automatizados de Assistência Junto ao Leito , Fatores de Tempo
17.
Cell Transplant ; 21(6): 1245-60, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22080793

RESUMO

Human hepatocyte transplantation is gaining acceptance for the treatment of liver diseases. However, the reagents used to isolate hepatocytes from liver tissue are not standardized and show lot-to-lot variability in enzyme activity and endotoxin contamination. For clinical application, highly purified reagents are preferable to crude digest preparations. A purified tissue dissociating enzyme (TDE) preparation (CIzyme(TM) purified enzymes) was developed based on the enzyme compositions found in a superior lot of collagenase previously used by our group for human hepatocyte isolation. The performance of this enzyme preparation was compared to collagenase type XI on 110 liver cases by assessing hepatocyte yield, viability, and seven other functional assays that included plating efficiency, basal and induced CYP450 activities, phase II conjugation activity, and ammonia metabolism. No statistically significant difference was observed between these TDEs when they were used to isolate hepatocytes from liver resections or organ donor tissue on 54 hepatocyte isolations with type XI enzyme and 56 isolations using CIzyme(TM). These results show that a highly purified and defined TDE preparation can be formulated that provides excellent performance with respect to viability, yield, and functional activity of the isolated cells. In addition to reproducible formulation, these purified enzyme products have only 2-3% of the endotoxin of crude enzyme preparations. These results show that purified enzymes such as CIzyme(TM) will be a safe and effective for the isolation of human hepatocytes for clinical transplants.


Assuntos
Colagenases/metabolismo , Hepatócitos/citologia , Separação Celular , Cromatografia Líquida de Alta Pressão , Colagenases/análise , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A2/metabolismo , Citocromo P-450 CYP3A/metabolismo , Hepatócitos/metabolismo , Humanos , Testosterona/metabolismo
18.
Tech Coloproctol ; 15 Suppl 1: S117-20, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21956403

RESUMO

PURPOSE: The purpose of this experimental study is to investigate the effects of iloprost on colonic anastomotic healing in rats, after intraperitoneal administration. METHODS: Forty male Albino-Wistar rats were randomized into two groups of twenty animals each. They all underwent colonic resection followed by an inverted anastomosis. The rats of Group A (control) received 3 ml of NaCl intraperitoneally, while those of Group B (iloprost) received iloprost (2 µg/kg body weight), immediately postoperatively and daily until killed. Each group was further divided into two equal subgroups, depending on the day of killing. The animals of subgroups 1 were killed on the fourth postoperative day, while those of subgroups 2 on the eighth. Macroscopical and histological assessments were performed. Besides, anastomotic bursting pressures and the tissue concentrations in hydroxyproline and collagenase I were also evaluated. RESULTS: No anastomotic dehiscence was noted. The mean bursting pressure was higher in the iloprost group compared with the control group, but a significant difference was revealed only on the fourth postoperative day. Furthermore, iloprost significantly increased the new vessel formation on the fourth, as well as on the eighth postoperative day. CONCLUSION: Iloprost enhances the early phase of colonic anastomotic healing in rats.


Assuntos
Colo/cirurgia , Iloprosta/farmacologia , Vasodilatadores/farmacologia , Cicatrização/efeitos dos fármacos , Anastomose Cirúrgica , Animais , Colagenases/análise , Colagenases/efeitos dos fármacos , Colo/irrigação sanguínea , Colo/química , Colo/patologia , Hidroxiprolina/análise , Hidroxiprolina/efeitos dos fármacos , Iloprosta/efeitos adversos , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Pressão/efeitos adversos , Ratos , Ratos Wistar , Ruptura/etiologia , Fatores de Tempo , Aderências Teciduais/etiologia , Vasodilatadores/efeitos adversos
19.
J Vasc Surg ; 51(6): 1479-87, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20488324

RESUMO

OBJECTIVE: There is remarkable controversy over the processes driving abdominal aneurysm growth. The inherent limitations of animal and human studies hamper elucidation of the key inflammatory and proteolytic processes. Human data are largely derived from surgical specimens that typically reflect the final stages of the disease process and thus do not allow distinction between primary and secondary processes. Clear epidemiologic and genetic associations between abdominal aortic aneurysm (AAA) and popliteal artery aneurysms (PAA) suggest that that these two pathologies share common grounds. On this basis, we reasoned that information of corresponding and discordant processes in these aneurysms might provide critical clues on the processes that are crucial for aneurysm progression. METHODS: Messenger RNA (semi-quantitative real-time polymerase chain reaction) and protein analysis (enzyme-linked immunosorbent assay, multiplex, Western blotting), and histology were performed on aneurysm wall samples obtained during elective PAA and AAA repair. Nonaneurysmal aorta tissue from organ donors was included as reference. RESULTS: Messenger RNA and protein analysis showed that PAA and AAA are both characterized by a marked activation of nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) proinflammatory transcription factors, and hyperexpression of interleukin (IL)-6 and IL-8. Discordant findings were found for other inflammatory markers such as interferon-gamma, interferon-inducible protein 10, tumor necrosis factor-alpha, monocyte chemotactic protein-1, and macrophage inflammatory protein 1alpha and beta, which were all lower in PAA. On the cellular level, both pathologies exhibited profuse infiltration of macrophages, neutrophils, and T-helper cells. Results for B cells, plasma cells, and cytotoxic T cells were discordant, with minimal infiltration of these cell types in PAA. Evaluation of protease expression and activation showed that both conditions are dominated by increased matrix metalloproteinase 8 and 9, and cathepsin K, L and S expression and activation. CONCLUSION: This explorative study characterizes degenerative aneurysmal disease general inflammatory conditions that are dominated by profound activation of the NF-kappaB and AP-1 pathways, hyperexpression of IL-6 and IL-8, and neutrophil involvement. Discordant findings for interferon gamma, cytotoxic T cells, B cells, and plasma cells challenge a critical role for these factors in the process of aneurysm growth. Pharmaceutic strategies targeting the common components in AAA and PAA may prove effective for the stabilization of AAA.


Assuntos
Aneurisma/fisiopatologia , Aorta Abdominal/fisiopatologia , Aneurisma da Aorta Abdominal/fisiopatologia , Artéria Poplítea/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Aneurisma/genética , Aneurisma/metabolismo , Aneurisma/patologia , Aorta Abdominal/química , Aorta Abdominal/patologia , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Western Blotting , Catepsinas/análise , Colagenases/análise , Citocinas/análise , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação da Expressão Gênica , Humanos , Mediadores da Inflamação/análise , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , NF-kappa B/análise , Infiltração de Neutrófilos , Artéria Poplítea/química , Artéria Poplítea/patologia , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T Auxiliares-Indutores/patologia , Fator de Transcrição AP-1/análise
20.
Vet Surg ; 39(1): 65-70, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20210947

RESUMO

OBJECTIVE: To evaluate whether synovial fluid concentrations of an osteoarthritis biomarker in dysplastic canine elbows with medial coronoid disease (MCD) are elevated compared with unaffected elbows and to determine if these concentrations correlate to the degree of articular cartilage damage. STUDY DESIGN: Cross sectional clinical study. ANIMALS: Dogs (n=19; 35 elbows) with MCD and dogs (8; 16 elbows) with unaffected elbows. METHODS: Concentrations of a collagenase-generated cleavage neoepitope of type II collagen (Col2-3/4C(long mono), or C2C) in joint fluid from elbows were analyzed and compared between dogs with MCD and unaffected dogs. Correlation of C2C concentration with subjective grading of articular cartilage surface damage was also evaluated. RESULTS: Mean (+/-SD) C2C concentration from MCD dogs was significantly higher (112.3+/-24.8 ng/mL) than in unaffected dogs (76.1+/-16.9 ng/mL; P<.05). There was a moderate correlation between cartilage damage grade and increasing C2C concentrations (P<.05, r=0.62) CONCLUSION: C2C concentrations are elevated in the synovial fluid of dogs with MCD compared with unaffected elbows, and a moderate, significant correlation was identified between these concentrations and subjective grading of articular cartilage damage. CLINICAL RELEVANCE: This preliminary data suggest that C2C concentrations in synovial fluid may have potential as a biomarker for diagnosis of articular cartilage damage associated with MCD and as a means of objectively determining the degree of articular cartilage damage.


Assuntos
Biomarcadores/análise , Colagenases/análise , Doenças do Cão/diagnóstico , Osteoartrite/veterinária , Líquido Sinovial/química , Animais , Artroscopia/veterinária , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Doenças do Cão/patologia , Cães , Feminino , Membro Anterior , Coxeadura Animal/diagnóstico , Masculino , Osteoartrite/diagnóstico , Osteoartrite/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA