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1.
Int J Mol Sci ; 24(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37834077

RESUMO

Fracture-healing is a highly complex and timely orchestrated process. Non-healing fractures are still a major clinical problem and treatment remains difficult. A 16 Hz extremely low-frequency pulsed electromagnetic field (ELF-PEMF) was identified as non-invasive adjunct therapy supporting bone-healing by inducing reactive oxygen species (ROS) and Ca2+-influx. However, ROS and Ca2+-influx may stimulate neutrophils, the first cells arriving at the wounded site, to excessively form neutrophil extracellular traps (NETs), which negatively affects the healing process. Thus, this study aimed to evaluate the effect of this 16 Hz ELF-PEMF on NET formation. Neutrophils were isolated from healthy volunteers and exposed to different NET-stimuli and the 16 Hz ELF-PEMF. NETs were quantified using Sytox Green Assay and immunofluorescence, Ca2+-influx and ROS with fluorescence probes. In contrast to mesenchymal cells, ELF-PEMF exposure did not induce ROS and Ca2+-influx in neutrophils. ELF-PEMF exposure did not result in basal or enhanced PMA-induced NET formation but did reduce the amount of DNA released. Similarly, NET formation induced by LPS and H2O2 was reduced through exposure to ELF-PEMF. As ELF-PEMF exposure did not induce NET release or negatively affect neutrophils, the ELF-PEMF exposure can be started immediately after fracture treatment.


Assuntos
Campos Eletromagnéticos , Peróxido de Hidrogênio , Humanos , Espécies Reativas de Oxigênio , Campos Eletromagnéticos/efeitos adversos , Consolidação da Fratura
2.
Biology (Basel) ; 12(8)2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37626968

RESUMO

Diabetes is a worldwide evolving disease with many associated complications, one of which is delayed or impaired wound healing. Appropriate wound healing strongly relies on the inflammatory reaction directly after injury, which is often altered in diabetic wound healing. After an injury, neutrophils are the first cells to enter the wound site. They have a special defense mechanism, neutrophil extracellular traps (NETs), consisting of released DNA coated with antimicrobial proteins and histones. Despite being a powerful weapon against pathogens, NETs were shown to contribute to impaired wound healing in diabetic mice and are associated with amputations in diabetic foot ulcer patients. The anti-diabetic drugs metformin and liraglutide have already been shown to regulate NET formation. In this study, the effect of insulin was investigated. NET formation after stimulation with PMA (phorbol myristate acetate), LPS (lipopolysaccharide), or calcium ionophore (CI) in the presence/absence of insulin was analyzed. Insulin led to a robust delay of LPS- and PMA-induced NET formation but had no effect on CI-induced NET formation. Mechanistically, insulin induced reactive oxygen species, phosphorylated p38, and ERK, but reduced citrullination of histone H3. Instead, bacterial killing was induced. Insulin might therefore be a new tool for the regulation of NET formation during diabetic wound healing, either in a systemic or topical application.

4.
Mater Sci Eng C Mater Biol Appl ; 40: 16-23, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24857460

RESUMO

Al2O3 and Al2O3-YSZ composites containing 3 and 5 wt.% TiO2 were prepared by spark plasma sintering at temperatures of 1350-1400°C for 300s under a pressure of 40 MPa. The grain growth of alumina was suppressed by the addition of YSZ. Al2O3-YSZ composites showed higher hardness than monolithic Al2O3. There was not a considerable difference in hardness values for Al2O3-YSZ composites containing 10 and 20 vol.% YSZ and the addition of TiO2 decreased the hardness of the composites. The fracture toughness of Al2O3 increased from 2.8 MPa·m(1/2) to 4.3 MPa·m(1/2) with the addition of 10vol.% YSZ, further addition resulted in higher fracture toughness values. The fracture toughness values were increased with TiO2 addition and the highest value of fracture toughness, 5.3 MPa·m(1/2), was achieved with the addition of 20 vol.% YSZ and 5 wt.% TiO2. Preliminary in vivo tests demonstrated the biocompatibility and osseointegration of the composites after 6 week post-implantation in femur of Wistar rats.


Assuntos
Óxido de Alumínio/química , Materiais Biocompatíveis/química , Titânio/química , Ítrio/química , Zircônio/química , Animais , Materiais Biocompatíveis/farmacologia , Fêmur/efeitos dos fármacos , Fêmur/patologia , Dureza , Temperatura Alta , Osseointegração/efeitos dos fármacos , Pressão , Próteses e Implantes , Ratos , Ratos Wistar
5.
J Biomed Mater Res A ; 85(1): 236-41, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17688268

RESUMO

The biological properties of calcium phosphate-derived materials are strongly influenced by changes in Ca/P stoichiometry and grain size, which have not yet been fully elucidated to date. For this reason, the objective of this in vitro study was to understand osteoblast (bone forming cells) adhesion on nanoparticulate calcium phosphates of various Ca/P ratios. A group of calcium phosphates with Ca/P ratios between 0.5 and 2.5 were obtained by adjusting the Ca/P stoichiometry of the initial reactants necessary for calcium phosphate precipitation. For samples with 0.5 and 0.75 Ca/P ratios, tricalcium phosphate (TCP) and Ca(2)P(2)O(7) phases were observed. In contrast, for samples with 1.0 and 1.33 Ca/P ratios, the only stable phase was TCP. For samples with 1.5 Ca/P ratios, the TCP phase was dominant, however, small amounts of the hydroxyapatite (HA) phase started to appear. For samples with 1.6 Ca/P ratios, the HA phase was dominant. Last, for samples with 2.0 and 2.5 Ca/P ratios, the CaO phase started to appear in the HA phase, which was the dominant phase. Moreover, the average nanometer grain size, porosity (%), and the average pore size decreased in general with increasing Ca/P ratios. Most importantly, results demonstrated increased osteoblast adhesion on calcium phosphates with higher Ca/P ratios (up to 2.5). In this manner, this study provided evidence that Ca/P ratios should be maximized (up to 2.5) in nanoparticulate calcium phosphate formulations to increase osteoblast adhesion, a necessary step for subsequent osteoblast functions such as new bone deposition.


Assuntos
Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Osteoblastos/fisiologia , Cálcio/química , Adesão Celular/fisiologia , Linhagem Celular , Durapatita/química , Humanos , Fósforo/química
6.
Wien Klin Wochenschr ; 118(7-8): 217-23, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16794759

RESUMO

BACKGROUND: The Women's Health Office of the State of Tyrol, Austria, provides cardiovascular disease (CVD) prevention programs for women. However, local Turkish women have not participated in our programs. The aim of the so-called Mosque Campaign was to conduct a Turkish-language, culture-sensitive CVD prevention program tailored to the needs of Turkish women to improve their knowledge of CVD risk factors and to minimize ethnic differences in participation rates for preventive programs. METHODS: The pilot program was conducted in all 28 mosques in Tyrol during the years 1999/00, 2000/01 and 2001/02. A Turkish educational lecture and the opportunity for a private medical consultation were provided, and 2,446 Turkish women completed a questionnaire on their personal knowledge of CVD. In addition a total of 1,992 blood pressure readings were taken. RESULTS: Most of the women belonged to the first generation of female immigrants and reported not using German-language media. About one-third of the women considered themselves to be obese. More than 13 % had raised systolic and/or diastolic blood pressure. We observed a significant decrease in unawareness of the main CVD risk factors from 1999/00 to 2001/02: unawareness of cholesterol level decreased from 57.4 % to 32.4 % (p < 0.001), of blood pressure from 41.3 % to 29.6 % (p < 0.001) and of blood glucose from 49.7 % to 25.2 % (p < 0.001). CONCLUSIONS: Even though Austria provides free access to healthcare services, a large number of Turkish women were not aware of their CVD risk factors. The Mosque Campaign reached female Turkish migrants and was effective in reducing their level of unawareness about CVD. Language-adapted and culture-sensitive programs are necessary to ensure greater equality for ethnic minority groups.


Assuntos
Atitude Frente a Saúde/etnologia , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Emigração e Imigração/estatística & dados numéricos , Promoção da Saúde/organização & administração , Educação de Pacientes como Assunto/métodos , Medição de Risco/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Áustria/epidemiologia , Feminino , Humanos , Islamismo , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Educação de Pacientes como Assunto/estatística & dados numéricos , Medicina Preventiva/organização & administração , Fatores de Risco , Turquia/epidemiologia , Saúde da Mulher
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