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1.
Kidney Blood Press Res ; 44(5): 1207-1218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31614355

RESUMO

BACKGROUND: Chronic kidney disease (CKD) is the result of a reduced number of nephrons, in which adipose tissue and its metabolites play a significant role. Fibroblast growth factors, FGF19 and FGF21, are involved in lipid and carbohydrate metabolism. The aim of the study was to examine the concentrations of FGF19 and FGF21 in patients with CKD, as well as the correlation between FGF19 and FGF21 and selected biochemical parameters. MATERIALS AND METHODS: The study included 178 subjects: 52 patients with CKD in stages 2-4, without haemodialysis (CKD), 47 haemodialysed patients with CKD (HD), 56 patients with CKD after a renal transplantation (Tx) and 23 healthy subjects as the control group (C). RESULTS: The highest FGF19 serum concentrations were observed in CKD patients and the lowest were observed in the Tx group. Patients in the CKD group had significantly higher serum FGF21 concentrations. There were negative correlations between FGF19 and glomerular filtration rate (GFR), as well as high-density lipoprotein cholesterol levels in patients after kidney transplantation. Negative correlations were also found between serum FGF21 concentrations and GFR in patients after Tx, while positive correlations were observed between FGF21 concentrations and lean body mass in the CKD group, body mass index and total cholesterol in the HD group. CONCLUSIONS: Our results suggest that increased concentrations of FGF19 and FGF21 in patients with CKD may be associated with the metabolism of lipids and carbohydrates. Our results also indicate that haemodialysis and transplantation results in the reduction of FGF19 and FGF21 concentrations in patients with CKD.


Assuntos
Fatores de Crescimento de Fibroblastos/sangue , Insuficiência Renal Crônica/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
J Biomed Mater Res B Appl Biomater ; 107(6): 1889-1897, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30578598

RESUMO

Photo-cross-linked polymers have attracted a lot of attention in the biomedical field. The main benefits of these materials are related to the fact that they are most of the time viscous liquids or pastes that adapt a custom and fixed shape on demand of the user. Present study deals specifically with the biological response upon subcutaneous implantation of four different materials in rabbits. In the study 20 rabbits were divided into four groups (each five rabbits): Groups 1-3 were implanted with tested new obtained by us macromonomers (P1838-DMA; P1838-UR; PDEGA-UR - respectively), while group 4 (control) was implanted with the mesh (PLA) routinely used for surgical treatment of a hernia. The new compounds were polarized earlier using ultraviolet radiation to obtain cross-linked networks. The polymers in the form of discs were then implanted subcutaneously in dorsal region of rabbits. After 28 days polymers were explanted and examined. Microscopic observation evaluated: thickness of the connective tissue capsule around the discs, cells of inflammatory response, disc surface erosion, spectroscopic analysis. The examined materials cause no chronic inflammation, abscesses or tissue necrosis, and the biological response is similar to observed in control group. Therefore, new synthetic materials could be considered as biocompatible and safe. Materials undergo slow degradation of ester bonds and surface erosion and degradation products could be eliminated probably by phagocytosis. On the basis on the afore mentioned knowledge, we formulated hypothesis, that the new polymers are well tolerated by the adjacent tissues. The aim of the following study was to examine reaction of the tissue on new types of prepolymerized material implanted subcutaneously. The obtained results suggest, that the new UV cross-linked polymers do not affect negatively on the connective tissue that is in the contact with the implants. Furthermore, the used materials are in the liquid form, thus they could be easily performed in in minimally invasive laparoscopic treatment of abdominal hernias. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1889-1897, 2019.


Assuntos
Materiais Biocompatíveis , Teste de Materiais , Polímeros , Telas Cirúrgicas , Raios Ultravioleta , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Polímeros/química , Polímeros/farmacologia , Coelhos
4.
Acta Biochim Pol ; 65(4): 479-486, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30451244

RESUMO

Eicosanoids are biologically active molecules that are created in the process of oxidation of arachidonic acid (AA) which is a constituent of the cell membrane phospholipids. Throughout the years it was evidenced by experiments that the lipid and lipid-derived metabolites play an important role in physiological and pathological processes in the kidneys. They are being considered as biomarkers in detecting acute kidney injury, nephrotoxicity, glomerulonephritis and early stages of diabetic nephropathy because of their participation in inflammatory processes and in oxidative stress. They might be also considered as potential novel targets of therapy. However, the role of eicosanoids is still not fully clear and needs to be explored in future studies. In this brief review, studies on the role of eicosanoids in physiological and pathological conditions, e.g. acute kidney injury (AKI) and chronic kidney disease (CKD), and in different renal replacement therapies, including kidney transplantation, are being discussed.


Assuntos
Eicosanoides/fisiologia , Nefropatias/metabolismo , Rim/fisiologia , Ácido Araquidônico/metabolismo , Biomarcadores/metabolismo , Eicosanoides/metabolismo , Humanos , Rim/metabolismo , Nefropatias/tratamento farmacológico , Transplante de Rim
5.
BMC Nephrol ; 18(1): 193, 2017 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-28615054

RESUMO

BACKGROUND: Epidermolysis bullosa is a group of diseases caused by mutations in genes for proteins responsible for cells' anchorage at the dermo-epidermal junction. Their common feature are dysfunctional or even absent connections between cells. The typical clinical sign is the formation of blisters, with possible excessive scarring, in response to minimal skin irritation. End stage renal disease may be one of the comorbidities in patients with epidermolysis bullosa. The implementation of renal replacement therapy may be very difficult in this population. This is mainly due to problems in obtaining the proper dialysis access. The choice of appropriate method may be crucial for patient's survival. CASE PRESENTATION: We present a case of 29-year-old woman with Epidermolysis bullosa caused by laminin 5 gene mutation. The patient suffered from additional conditions: blindness, complete bilateral sensorineural deafness and oesophageal stenosis. When end stage renal disease was diagnosed, the problem of renal replacement therapy had to be faced. There have been few reports concerning ESRD in this specific group of patients in the available literature. In most of them the prognosis was very poor. Nevertheless, we were very determined to overcome all the difficulties. Special procedures and cooperation with the patient's family allowed us to consider kidney transplantation as a treatment option. CONCLUSION: There should be no limitations in renal replacement therapy in patients with epidermolysis bullosa. Haemodialysis, peritoneal dialysis and kidney transplantation are all possible treatment options. Nevertheless, either method requires special procedures.


Assuntos
Epidermólise Bolhosa/diagnóstico , Epidermólise Bolhosa/terapia , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/terapia , Diálise Renal , Adulto , Epidermólise Bolhosa/complicações , Feminino , Humanos , Falência Renal Crônica/complicações , Transplante de Rim/tendências , Diálise Renal/tendências , Resultado do Tratamento
6.
Curr Protein Pept Sci ; 17(8): 821-826, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27226196

RESUMO

The identification of Klotho gene was a major discovery as the gene encodes a protein regulating multiple functions. A defect in Klotho gene expression in mice results in a phenotype of premature aging including shortened life span, growth retardation, hypogonadism, skin and muscle atrophies, vascular calcification, cognition impairment, motor neuron degeneration and others. This phenotype is associated with phosphate balance disorders and underlines the major function of Klotho in mineral metabolism. As another 2 related paralogs were discovered (beta-Klotho, which is involved in bile acid and energy metabolism, and gamma-Klotho, with a yet to be defined function), this led to the revised naming of Klotho as alpha-Klotho. Two forms of alpha-Klotho protein have been reported: a membrane-bound and a soluble one. Membrane Klotho forms a complex with fibroblast growth factor (FGF) receptors and functions as an obligate co-receptor for the FGF-23 phosphatonin in distal tubules. The soluble form of Klotho seems to function as a humoral factor and regulates glycoproteins on the cell surface including ion channels and growth factors. There is data suggesting that soluble Klotho exerts phosphaturic effects independently of FGF-23. Circulating soluble Klotho is produced either by proteolytic cleavage of the extracellular domain of the transmembrane form by two membrane-anchored proteases (ADAM10 and ADAM17) or by alternative mRNA splicing. In animal models Klotho has been shown to exert pleiotropic actions, including cytoprotection, anti-oxidation, anti-apoptosis, protection of vasculature, promotion of angiogenesis and vascularization, inhibition of fibrogenesis and preservation of stem cells. The exact diagnostic and therapeutic role of Klotho in humans is not fully known yet. The article presents the role of Klotho in physiology and different stages of chronic kidney disease (CKD).


Assuntos
Envelhecimento/metabolismo , Glucuronidase/metabolismo , Fosfatos/metabolismo , Insuficiência Renal Crônica/metabolismo , Envelhecimento/genética , Animais , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/metabolismo , Glucuronidase/genética , Humanos , Túbulos Renais Distais/metabolismo , Proteínas Klotho , Camundongos , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Insuficiência Renal Crônica/genética
7.
Curr Protein Pept Sci ; 16(3): 243-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25707472

RESUMO

The incidence and diagnosis of chronic kidney disease (CKD) is on the rise all over the world. CKD is related to ageing of the society and high morbidity due to lifestyle diseases like diabetes, atherosclerosis, and hypertension. CKD is associated with increased oxidative stress generated by uremic toxicity, chronic inflammatory state, lack of vitamins and microelements, parenteral iron administration, and dialysis procedure itself. In terms of cellular physiology, erythrocytes and blood platelets in particular have effective enzymatic and non-enzymatic antioxidative system. The most efficient enzymatic antioxidants include superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase. Glutathione is the leading non-enzymatic free radical scavenger. In CKD, antioxidative defense is impaired and the abnormal activity of the enzymes and glutathione concentration is described in literature. The imbalance between the formation of reactive oxygen species and antioxidative system efficiency takes part in the pathogenesis of cardiovascular complications. It contributes to increased morbidity and mortality in patients with CKD. The severity of these processes depends on the type of renal replacement therapy; haemodialysis (HD) is more predisposing to such disorders than peritoneal dialysis (PD), or even conservative treatment. This can influence the outcome and the possibility of kidney transplantation. Moreover, the early function of kidney allograft seems to be dependent on perioperative antioxidative ability of platelets, which can play a potential protective role in kidney transplantation.


Assuntos
Antioxidantes/metabolismo , Estresse Oxidativo , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/terapia , Terapia de Substituição Renal/métodos , Glutationa/metabolismo , Humanos , Transplante de Rim , Insuficiência Renal Crônica/enzimologia
8.
Histol Histopathol ; 30(1): 105-16, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25029518

RESUMO

AIM: To analyse the impact of the most commonly used immunosuppressive drugs on the occurrence of apoptosis in the native kidneys of Wistar rats. METHOD: The study involved 36 rats. the animals being grouped according to the immunosuppressive regimen used (tacrolimus, mycophenolate mofetil, cyclosporine A, rapamycin and prednisone). The rats in all study groups were treated with a 3-drug protocol for 6 months. The medication dose was adjusted based on available literature data. No drugs were administered to the control group. The rats were then killed. Autopsies of all animals were performed and the kidneys were isolated for histopathology (HE + PAS). To assess cell apoptosis the TUNEL reaction was performed. Blood trough levels of immunosuppressive drugs as well as the parameters of peripheral blood were determined. RESULTS: 1. In rats treated with cyclosporine A distal nephron tubules were characterised by more pronounced apoptosis. 2. In tacrolimus-treated rats a lower intensity of apoptosis was found in the distal tubules. 3. In rapamycin-treated rats the apoptosis was inhibited both in the distal and proximal nephron tubules. 4. In MMF treated rats intense apoptosis was observed in the proximal nephron tubules. 5. There were no significant changes in renal histopathology (HE + PAS). CONCLUSIONS: The apoptosis in nephron tubules caused by immunosuppressive therapy is not accompanied by any histopathological changes (eg fibrosis, inflammation, tubular atrophy, vacuolation of the tubular cells) in light microscopy.


Assuntos
Apoptose/efeitos dos fármacos , Imunossupressores/farmacologia , Rim/efeitos dos fármacos , Animais , Ciclosporina/farmacologia , Masculino , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/farmacologia , Prednisona/farmacologia , Ratos , Ratos Wistar , Sirolimo/farmacologia , Tacrolimo/farmacologia
9.
Drug Des Devel Ther ; 8: 1695-708, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25328384

RESUMO

The structural proteins of renal tubular epithelial cells may become a target for the toxic metabolites of immunosuppressants. These metabolites can modify the properties of the proteins, thereby affecting cell function, which is a possible explanation for the mechanism of immunosuppressive agents' toxicity. In our study, we evaluated the effect of two immunosuppressive strategies on protein expression in the kidneys of Wistar rats. Fragments of the rat kidneys were homogenized after cooling in liquid nitrogen and then dissolved in lysis buffer. The protein concentration in the samples was determined using a protein assay kit, and the proteins were separated by two-dimensional electrophoresis. The obtained gels were then stained with Coomassie Brilliant Blue, and their images were analyzed to evaluate differences in protein expression. Identification of selected proteins was then performed using mass spectrometry. We found that the immunosuppressive drugs used in popular regimens induce a series of changes in protein expression in target organs. The expression of proteins involved in drug, glucose, amino acid, and lipid metabolism was pronounced. However, to a lesser extent, we also observed changes in nuclear, structural, and transport proteins' synthesis. Very slight differences were observed between the group receiving cyclosporine, mycophenolate mofetil, and glucocorticoids (CMG) and the control group. In contrast, compared to the control group, animals receiving tacrolimus, mycophenolate mofetil, and glucocorticoids (TMG) exhibited higher expression of proteins responsible for renal drug metabolism and lower expression levels of cytoplasmic actin and the major urinary protein. In the TMG group, we observed higher expression of proteins responsible for drug metabolism and a decrease in the expression of respiratory chain enzymes (thioredoxin-2) and markers of distal renal tubular damage (heart fatty acid-binding protein) compared to expression in the CMG group. The consequences of the reported changes in protein expression require further study.


Assuntos
Proteínas de Ligação a Ácido Graxo/biossíntese , Imunossupressores/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Tiorredoxinas/biossíntese , Animais , Proteínas de Ligação a Ácido Graxo/metabolismo , Imunossupressores/efeitos adversos , Imunossupressores/química , Rim/patologia , Masculino , Ratos , Ratos Wistar , Tiorredoxinas/metabolismo
10.
Blood Purif ; 37(1): 4-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24481175

RESUMO

BACKGROUND: Patients suffering from chronic kidney disease (CKD) are exposed to increased oxidative stress and disturbances manifesting in the enzymatic and non-enzymatic antioxidative defence system. The object of the research was to assess the differences between conservative treatment, peritoneal dialysis and haemodialysis in moderating cellular antioxidative agents. METHODS: The group examined comprised 145 patients. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase were obtained using kinetic methods. The spectrophotometric method established the concentrations of reduced glutathione, albumin, uric acid, glucose, total protein and lipids. RESULTS: The type of treatment determined significant changes in antioxidative enzyme activities and concentrations of non-enzymatic antioxidative compounds. CONCLUSIONS: Peritoneal dialysis provides better antioxidant protection than other types of therapy in CKD and should be considered as first-choice treatment despite more metabolic disorders.


Assuntos
Estresse Oxidativo , Diálise Renal/métodos , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antioxidantes/metabolismo , Catalase/metabolismo , Feminino , Glucosefosfato Desidrogenase/metabolismo , Glutationa/sangue , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Humanos , Rim/metabolismo , Rim/patologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/patologia , Albumina Sérica/análise , Superóxido Dismutase/metabolismo , Ácido Úrico/sangue
11.
Pol Merkur Lekarski ; 35(207): 179-82, 2013 Sep.
Artigo em Polonês | MEDLINE | ID: mdl-24224459

RESUMO

The development of medicine involves prolongation of human life. In many cases, however, chronic diseases, quite common in the elderly, make the quality of life very poor. We put the question: why we--the doctors--are not able to cope with the problem and whether the pharmacological treatment actually helps? A common medical practice is the use of proton pump inhibitors for various, often nonspecific disorders of the gastrointestinal tract. Statistics point to the overuse of the drugs from this group, also in the elderly. Despite the belief in the safety of such proceedings, proton pump inhibitors may pose a significant threat to older patients contributing to the symptoms worsening, and significantly affecting the mechanisms of acid-base balance. Inhibition of gastric acid secretion in the stomach is not a golden receipt in the case of dyspeptic symptoms, especially in people with the elderly. In many of them achlorhydria or hipochlorhydria is diagnosed. In others, such treatment, may not bring an expected relief in symptoms, while contributing to disturbances of acid-base balance, and--indirectly--have an adverse effect on renal function. We suggest moderation in the use of proton pump inhibitors to bring patients to a real, and not quasi wellness.


Assuntos
Atitude do Pessoal de Saúde , Gastroenteropatias/tratamento farmacológico , Inibidores da Bomba de Prótons/uso terapêutico , Desequilíbrio Ácido-Base/tratamento farmacológico , Idoso , Uso de Medicamentos , Humanos , Inibidores da Bomba de Prótons/efeitos adversos , Procedimentos Desnecessários
12.
Ginekol Pol ; 84(7): 654-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24032281

RESUMO

The paper presents the course of pregnancy delivery and early postpartum period in a 23-year-old woman with lysinuric protein intolerance (LPI). The pregnancy was uneventful and resulted in a caesarean birth to a healthy baby at 37 weeks gestation. Nevertheless, the course of pregnancy in women with LPI is associated with a significantly increased risk of serious complications, including acute hyperammonemia, preeclampsia and postpartum bleeding, as well as fetus intrauterine growth retardation. In many cases, intensive metabolic monitoring and a proper diet with protein limitation and appropriate amino acids supplementation may significantly reduce the risk for both the mother and the newborn.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/terapia , Período Pós-Parto , Complicações na Gravidez/prevenção & controle , Transtornos Puerperais/diagnóstico , Transtornos Puerperais/terapia , Feminino , Humanos , Gravidez , Resultado da Gravidez , Adulto Jovem
13.
Biomaterials ; 34(12): 2920-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23380354

RESUMO

Designing biomaterial surfaces to control the reaction of the surrounding tissue is still considered to be a primary issue, which needs to be addressed systematically. Although numerous in vitro studies have described different nano-metrically textured substrates capable to influence bone cellular response, in vivo studies validating this phenomenon have not been reported. In this study, nano-grooved silicon stamps were produced by laser interference lithography (LIL) and reactive ion etching (RIE) and were subsequently transferred onto the surface of 5 mm diameter Titanium (Ti) discs by nanoimprint lithography (NIL). Patterns with pitches of 1000 nm (500 nm ridge and groove, 150 nm depth), 300 nm (150 nm ridge and groove, 120 nm depth; as well as a 1:3 ratio of 75 nm ridge and 225 nm groove, 120 nm depth) and 150 nm (75 nm ridge and groove, 30 nm depth) were created. These samples were implanted in a rabbit tibia cortical bone. Histological evaluation and histomorphometric measurements were performed, comparing each sample to conventional grit-blasted/acid-etched (GAE) titanium controls. Results showed a significantly higher bone-to-implant contact at 4 weeks for the 300 nm (1:3) specimens, compared to GAE (p = 0.006). At 8 weeks, there was overall more bone contact compared to 4 weeks. However, no significant differences between the nano-textured samples and the GAE occurred. Further studies will need to address biomechanical testing and the use of trabecular bone models.


Assuntos
Próteses e Implantes , Tíbia , Titânio , Animais , Microscopia Eletrônica de Varredura , Coelhos , Propriedades de Superfície
14.
J Aging Res ; 2012: 754739, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22536505

RESUMO

Sarcopenia is a condition of multifaceted etiology arising in many elderly people. In patients with chronic kidney, the loss of muscle mass is much more intensive and the first signs of sarcopenia are observed in younger patients than it is expected. It is associated with the whole-body protein-energy deficiency called protein-energy wasting (PEW). It seems to be one of the major factors limiting patient's autonomy as well as decreasing the quality of life. If it cannot be treated with the simple methods requiring some knowledge and devotion, we will fail to save patients who die due to cardiovascular disease and infection, despite proper conduction of renal replacement therapy. Many factors influencing the risk of sarcopenia development have been evaluated in number of studies. Many studies also were conducted to assess the efficacy of different therapeutic strategies (diet, physical activity, hormones). Nevertheless, there is still no consensus on treatment the patients with PEW. Therefore, in the paper we present the reasons and pathophysiology of sarcopenia as an important element of protein energy wasting (PEW) in elderly patients suffering from chronic kidney disease. We also analyze possible options for treatment according to up-to-date knowledge.

15.
J Mater Sci Mater Med ; 23(7): 1637-44, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22528070

RESUMO

A process of micromolding, delivering micro- and nanopatterned ceramic surfaces for biomaterial applications is described in this work. To create the desired structures, tape casting of ceramic slurries on microfabricated silicon mold was used. Several tape casting slurry compositions were tested to evaluate the feasibility of transferring micro- and nano-features from silicon molds. Used ceramics were alumina (α-Al(2)O(3)) and yttria stabilized zirconia. Three types of polymeric binders for the green tape (PVB, PES, and PVP) were investigated using three different solvents (ethanol, n-methyl-pyrrolidone, water). Well-defined features in shapes of wells with diameters down to 2.4 µm and a depth of 10 µm and pillars with diameters down to 1.7 µm and a height of 3 µm were obtained. Morphology, grain size and porosity of the sintered bodies were characterized. Finally fibroblast cells were cultured on the surfaces in order to observe their morphology under influence of the microstructured surfaces.


Assuntos
Óxido de Alumínio/química , Cerâmica , Nanopartículas , Zircônio/química , Animais , Células Cultivadas , Masculino , Microscopia Eletrônica de Varredura , Ratos , Ratos Wistar
16.
Nanomedicine ; 8(3): 308-17, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21704595

RESUMO

The immune response to an implanted biomaterial is orchestrated by macrophages. In this study various nanogrooved patterns were created by using laser interference lithography and reactive ion etching. The created nanogrooves mimic the natural extracellular matrix environment. Macrophage cell culture demonstrated that interleukin 1ß and TNF-α cytokine production were upregulated on nanogrooved substrates. In vivo subcutaneous implantation in a validated mouse cage model for 14 days demonstrated that nanogrooves enhanced and guided cell adhesion, and few multinucleated cells were formed. In agreement with the in vitro results, cytokine production was found to be nanogroove dependent, as interleukin 1ß, TNF-α, TGF-ß and osteopontin became upregulated. The results indicate that biomaterial surface texturing, especially at the nanometric scale, can be used to control macrophage activation to induce a wound healing response, rather than a profound inflammatory response. From the Clinical Editor: The authors investigate various nano-grooved patterns that mimic the natural extracellular matrix environment and demonstrate (both in macrophage cultures and in vivo) that interleukin 1ß and TNF-α cytokine production is dependent upon surface texturing at the nanometric scale. They propose that modified surfaces may trigger macrophage activation to promote a wound healing response.


Assuntos
Inflamação/patologia , Nanoestruturas/química , Poliestirenos/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Contagem de Células , Linhagem Celular , Forma Celular/efeitos dos fármacos , Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Força Atômica , Implantação de Prótese , Ratos , Tela Subcutânea/efeitos dos fármacos , Propriedades de Superfície/efeitos dos fármacos , Titânio/farmacologia
17.
Tissue Eng Part C Methods ; 17(1): 1-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20594113

RESUMO

With the advance of nanotechnology in biomaterials science and tissue engineering, it is essential that new techniques become available to observe processes that take place at the direct interface between tissue and scaffold materials. Here, Cryo DualBeam focused ion beam-scanning electron microscopy (FIB-SEM) was used as a novel approach to observe the interactions between frozen hydrated cells and nanometric structures in high detail. Through a comparison of images acquired with transmission electron microscopy (TEM), conventional FIB-SEM operated at ambient temperature, and Cryo DualBeam FIB-SEM, the advantages and disadvantages of each technique were evaluated. Ultrastructural details of both (extra)cellular components and cell organelles were best observe with TEM. However, processing artifacts such as shrinkage of cells at the substrate interface were introduced in both TEM and conventional FIB-SEM. In addition, the cellular contrast in conventional FIB-SEM was low; consequently, cells were difficult to distinguish from the adjoining substrate. Cryo DualBeam FIB-SEM did preserve (extra)cellular details like the contour, cell membrane, and mineralized matrix. The three described techniques have proven to be complementary for the evaluation of processes that take place at the interface between tissue and substrate.


Assuntos
Microscopia Crioeletrônica/métodos , Microscopia Eletrônica de Varredura/métodos , Microscopia Eletrônica de Transmissão , Nanotecnologia/métodos , Animais , Artefatos , Materiais Biocompatíveis/química , Imageamento Tridimensional , Masculino , Osteoblastos/metabolismo , Poliestirenos/química , Ratos , Ratos Wistar , Silício/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química
18.
Biomaterials ; 31(30): 7758-65, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20647152

RESUMO

Osteoblasts respond to mechanical stimulation by changing morphology, gene expression and matrix mineralization. Introducing surface topography on biomaterials, independently of mechanical loading, has been reported to give similar effects. In the current study, using a nanotextured surface, and mechanical loading, we aimed to develop a multi-factorial model in which both parameters interact. Mechanical stimulation to osteoblast-like cells was applied by longitudinal stretch in parallel direction to the nanotexture (300 nm wide and 60 nm deep grooves), with frequency of 1 Hz and stretch magnitude varying from 1% to 8%. Scanning electron microscopy showed that osteoblast-like cells subjected to mechanical loading oriented perpendicularly to the stretch direction. When cultured on nanotextured surfaces, cells aligned parallel to the texture. However, the parallel cell direction to the nanotextured surface was lost and turned to perpendicular when parallel stretch to the nanotexture, greater than 3% was applied to the cells. This phenomenon could not be achieved when a texture with micro-sized dimensions was used. Moreover, a significant synergistic effect on upregulation of fibronectin and Cfba was observed when dual stimulation was used. These findings can lead to a development of new biomimetic materials that can guide morphogenesis in tissue repair and bone remodeling.


Assuntos
Osteoblastos/fisiologia , Estresse Mecânico , Animais , Materiais Biocompatíveis/metabolismo , Expressão Gênica , Masculino , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Osteoblastos/ultraestrutura , Ratos , Ratos Wistar , Propriedades de Superfície
19.
Biomaterials ; 31(12): 3307-16, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20122723

RESUMO

To fight bone diseases characterized by poor bone quality like osteoporosis and osteoarthritis, as well as in reconstructive surgery, there is a need for a new generation of implantable biomaterials. It is envisioned that implant surfaces can be improved by mimicking the natural extracellular matrix of bone tissue, which is highly a organized nano-composite. In this study we aimed to get a better understanding of osteoblast response to nanometric grooved substrates varying in height, width and spacing. A throughput screening biochip was created using electron beam lithography. Subsequently, uniform large-scale nanogrooved substrates were created using laser interference lithography and reactive ion etching. Results showed that osteoblasts were responsive to nanopatterns down to 75 nm in width and 33nm in depth. SEM and TEM studies showed that an osteoblast-driven calcium phosphate (CaP) mineralization was observed to follow the surface pattern dimensions. Strikingly, aligned mineralization was found on even smaller nanopatterns of 50 nm in width and 17 nm in depth. A single cell based approach for real time PCR demonstrated that osteoblast-specific gene expression was increased on nanopatterns relative to a smooth control. The results indicate that nanogrooves can be a very promising tool to direct the bone response at the interface between an implant and the bone tissue.


Assuntos
Matriz Extracelular , Nanoestruturas , Osteoblastos/citologia , Animais , Sequência de Bases , Materiais Biocompatíveis , Células Cultivadas , Primers do DNA , Imunofluorescência , Adesões Focais , Expressão Gênica , Masculino , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Osteoblastos/ultraestrutura , Reação em Cadeia da Polimerase , Ratos , Ratos Wistar
20.
Pol Merkur Lekarski ; 26(152): 136-41, 2009 Feb.
Artigo em Polonês | MEDLINE | ID: mdl-19388520

RESUMO

UNLABELLED: In recent years, there has been growing interest in the association between national diet and the possibility of developing various mental disorders, as well as between deficiency of such vitamins as, e.g. folic acid, vitamin B12, B6, and others (e.g., omega-3 fatty acids), elevated serum homocysteine level and the functioning of human brain as well as the occurrence of such disorders as dementia, central nervous system vascular disorders and depression. THE AIM OF THE STUDY: was to present the current state of knowledge about the role of folic acid and homocysteine in the human organism as well as the significance of vitamin deficiency, mainly folic acid and hyperhomocysteinemy for the occurrence of mood disorders. METHOD: The authors conducted the search of the Internet database Medline (www.pubmed.com) using as key words: depression, mood, homocysteine, vitamin deficiencies: folic acid, B6 and 812 and time descriptors: 1990-2007. RESULTS: In depression, folate, vitamins B12 and B6, as well as unsaturated omega-3 fatty acids deficiency affects the biochemical processes in the CNS, as folic acid and vitamin B12, participate in the metabolism of S-adenosylmethionine (SAM), a donator of methyl groups, which play a decisive role in the functioning of the nervous system; they are, among others, active in the formation of neurotransmitters (e.g. serotonin), phospholipids that are a component of neuronal myelin sheaths, and cell receptors. The deficiency of the vitamins in question results in hyperhomocysteinemia (the research shows that approximately 45-55% of patients with depression develop significantly elevated serum homocysteine), which causes a decrease in SAM, followed by impaired methylation and, consequently, impaired metabolism of neurotransmitters, phospholipids, myelin, and receptors. Hyperhomocysteinemia also leads to activation of NMDA receptors, lesions in vascular endothelium, and oxidative stress. All this effects neurotoxicity and promotes the development of various disorders, including depression. Vitamins B12 and B6, folic acid and omega-3 fatty acids supplementation is thus important in patients suffering from their deficiency; national diet as a significant factor in prevention of numerous CNS disorders, including depression, is also worth consideration.


Assuntos
Afeto/efeitos dos fármacos , Afeto/fisiologia , Ácido Fólico/sangue , Homocisteína/sangue , Transtornos do Humor/sangue , Transtornos do Humor/dietoterapia , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Deficiência de Ácido Fólico/complicações , Deficiência de Ácido Fólico/dietoterapia , Homocisteína/administração & dosagem , Homocisteína/deficiência , Humanos , Transtornos do Humor/etiologia , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Deficiência de Vitamina B 12/complicações , Deficiência de Vitamina B 12/dietoterapia , Vitamina B 6/administração & dosagem , Vitamina B 6/sangue , Deficiência de Vitamina B 6/complicações , Deficiência de Vitamina B 6/dietoterapia
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