Cieľ: Oboznámenie sa s problematikou detského keratokónusu s dôrazom na význam rutinného vyšetrenia rohovkovou topografiou a tomografiou detí a adolescentov z predisponovaných skupín. Cieľom je včasná detekcia keratokónusu a jeho subklinickej formy čo umožní skorú liečbu s predpokladanými lepšími pooperačnými výsledkami. Materiál a metodika: Rohovkovým tomografom Pentacam AXL boli vyšetrené deti a adolescenti s astigmatizmom rovným alebo väčším ako 2 dioptrie (aspoň na jednom oku) a pacienti s aspoň jedným rizikovým faktorom ako je šúchanie očí pri alergických ochoreniach, pozitívna rodinná anamnéza na keratokónus alebo niektorá z foriem sietnicových dystrofií. Celkovo sme do súboru zahrnuli 231 očí (116 pacientov), z čoho bolo 54 dievčat a 62 chlapcov. Výsledky: Vyhodnotený bol parameter Belin-Ambrósio deviation index kde sme ako subklinický keratokónus zaradili spolu 41 očí a ako klinický keratokónus sme označili 12 očí. Ďalej boli rohovkové mapy hodnotené individuálne kde sme ako subklinický keratokónus zaradili spolu 15 očí a ako klinický keratokónus sme označili 6 očí. V našom súbore, v porovnaní s kontrolnou skupinou sa subklinický a klinický keratokónus vyskytoval najčastejšie v skupine pacientov s astigmatizmom a v skupine tzv. šúchačov očí. Po individuálnom zhodnotení sa v našom súbore vyskytoval keratokónus častejšie u chlapcov ako u dievčat. Záver: Väčšina pacientov s keratokónusom je zachytená až keď dôjde k zníženiu zrakovej ostrosti, ktorá vzniká v dôsledku zmien na prednej ploche rohovky. Rohovková topografia a tomografia nám umožňuje sledovať aj počiatočné zmeny na zadnej ploche rohovky a tým nám pomáha detegovať subklinickú formu keratokónusu a dáva možnosť jeho skorého ošetrenia. Preto je dôležité určiť si, ktoré skupiny sú rizikové a u ktorých by sa mala vykonávať rohovková topografia a tomografia rutinne.
Aim: To introduce the topic of pediatric keratoconus, highlighting the importance of routine corneal topography and tomography in children and adolescents from predisposed groups. To attempt to ensure the early detection of keratoconus and its subclinical form, enabling early treatment, which brings better expected postoperative results. Material and methods: Using the corneal tomograph Pentacam AXL we examined children and adolescents with astigmatism equal or greater than 2 diopters (in at least one eye) and patients with at least one risk factor such as eye rubbing in the case of allergic pathologies, positive family history of keratoconus or certain forms of retinal dystrophy. In total, we included 231 eyes (116 patients), of which 54 were girls and 62 were boys. Results: The Belin-Ambrósio deviation index parameter was evaluated, in which we classified a total of 41 eyes as subclinical keratoconus and 12 eyes as clinical keratoconus. Next, the corneal maps were evaluated individually, in which we included a total of 15 eyes as subclinical keratoconus and 6 eyes as clinical keratoconus. In our group, compared to the control group, subclinical and clinical keratoconus occurred most often in the group of patients with astigmatism and in the group of so-called “eye rubbers”. After individual evaluation, keratoconus occurred more frequently in boys than in girls in our cohort. Conclusion: Most patients with keratoconus are diagnosed when there is a deterioration of visual acuity and changes on the anterior surface of the cornea. Corneal topography and tomography allows us to monitor the initial changes on the posterior surface of the cornea, and helps us to detect the subclinical form of keratoconus and the possibility of its early treatment. Therefore, it is important to determine which groups are at risk and groups in which corneal topography and tomography should be performed routinely.
Fourierova analýza je metoda umožňující dokonalý popis povrchu rohovky. U souboru 50 náhodně vybraných pacientů, u kterých byla provedena PRK, jsme zjišťovali předoperační hodnoty a pooperační vývoj sférického ekvivalentu, cylindru, decentrace a nepravidelného astigmatismu získaných Fourierovou analýzou topografických dat 1, 3, 6 a 12 měsíců po operaci. Pooperační decentrace vrcholu rohovky vzhledem ke středu zornice je oproti předoperační hodnotě statisticky významně vyšší. Hodnota nepravidelného astigmatismu před a po operaci se statisticky významně neliší. Byl zjištěn silný stupeň korelace mezi hodnotami sférického ekvivalentu získanými Fourierovou analýzou a simulovanou keratometrií. Klinický význam má korelace mezi parametry decentrace a nepravidelného astigmatismu s výslednou pooperační nejlépe korigovanou zrakovou ostrostí. Pomocí Fourierova rozkladu můžeme získat informace, které by mohly vysvětlit horší výsledek některých operací.
Fourier analysis is a powerful method of evaluating the surface of the cornea. In 50 patients after photorefractive keratectomy included in our study we measured spherical equivalent, regular astigmatism, irregular astigmatism and decentration retrospectively acquired by Fourier series analysis of corneal topography data 1, 3, 6 and 12 months after operation. Postoperative decentration increased significantly froma mean preoperative value.The preoperative andpostoperative values are not significantly different. The Fourier spherical equivalent and the values of keratometric spherical (equivalent) are highly correlated. Correlation among decentration, irregular astigmatism and best corrected visual acuity is important for clinical practice. Due to Fourier analysis we obtain information, which could explain worse results of some surgeries.
- MeSH
- Astigmatism MeSH
- Photorefractive Keratectomy methods instrumentation MeSH
- Fourier Analysis MeSH
- Humans MeSH
- Postoperative Period MeSH
- Preoperative Care MeSH
- Cornea surgery MeSH
- Corneal Topography methods MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Review MeSH
- Comparative Study MeSH
The objective of this study was to evaluate and compare titanium surfaces: machined (MA); sintered ceramic-blasted (HAS); sintered ceramic-blasted and acid-etched (HAS DE) and to determine the effects of surface topography, roughness and chemical composition on human osteoblast cell reaction. Titanium surface samples were analyzed with respect to surface chemical composition, topography, and roughness. The effects of material surface characteristics on osteoblasts was examined by analyzing osteoblast morphology, viability and differentiation. Osteoblasts cultured on these materials had attached, spread and proliferated on every sample. The viability of osteoblasts cultured on HAS and HAS DE samples increased more intensively in time comparing to MA sample. The viability of osteoblast cultured on HAS samples increased more intensively in the early phases of culture while for cells cultured on HAS DE the cells viability increased later in time. Alkaline phosphate activity was the highest for the cells cultured on HAS sample and statistically higher than for the MA sample. The least activity occurred on the smooth MA sample along with the rougher HAS DE samples. All the examined samples were found to be biocompatible, as indicated by cell attachment, proliferation, and differentiation. Titanium surfaces modification improved the dynamics of osteoblast viability increase. Osteoblast differentiation was found to be affected by the etching procedure and presence of Ca and P on the surface.
- MeSH
- Alkaline Phosphatase metabolism MeSH
- Cell Differentiation MeSH
- Cell Line MeSH
- Phosphorus pharmacology MeSH
- Ceramics MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Osteoblasts physiology ultrastructure MeSH
- Osteogenesis drug effects MeSH
- Surface Properties MeSH
- Cell Proliferation MeSH
- Titanium chemistry MeSH
- Calcium pharmacology MeSH
- Cell Survival MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The excellent mechanical, tribological and biochemical properties of diamond coatings are promising for improving orthopedic or stomatology implants. A crucial prerequisite for such applications is an understanding and control of the biological response of the diamond coatings. This study concentrates on the correlation of diamond surface properties with osteoblast behavior. Nanocrystalline diamond (NCD) films (grain size up to 200 nm, surface roughness 20 nm) were deposited on silicon substrates of varying roughnesses (1, 270 and 500 nm) and treated by oxygen plasma to generate a hydrophilic surface. Atomic force microscopy was used for topographical characterization of the films. As a reference surface, tissue culture polystyrene (PS) was used. Scanning electron microscopy and immunofluorescence staining was used to visualize cell morphological features as a function of culture time. Metabolic activity, alkaline phosphatase activity, and calcium and phosphate deposition was also monitored. The results show an enhanced osteoblast adhesion as well as increased differentiation (raised alkaline phosphatase activity and mineral deposition) on NCD surfaces (most significantly on RMS 20 nm) compared to PS. This is attributed mainly to the specific surface topography as well as to the biocompatible properties of diamond. Hence the controlled (topographically structured) diamond coating of various substrates is promising for preparation of better implants, which offer faster colonization by specific cells as well as longer-term stability.
- MeSH
- Biocompatible Materials chemistry MeSH
- Cell Differentiation MeSH
- Cell Culture Techniques methods MeSH
- Cell Line MeSH
- Diamond chemistry MeSH
- Humans MeSH
- Molecular Conformation MeSH
- Nanostructures chemistry ultrastructure MeSH
- Osteoblasts cytology physiology MeSH
- Osteogenesis physiology MeSH
- Surface Properties MeSH
- Cell Proliferation MeSH
- Tissue Engineering methods MeSH
- Cell Size MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
Boron-doped nanocrystalline diamond (BNCD) films exhibit outstanding electrochemical properties that make them very attractive for the fabrication of electrodes for novel neural interfaces and prosthetics. In these devices, the physicochemical properties of the electrode materials are critical to ensure an efficient long-term performance. The aim of this study was to investigate the relative contribution of topography and doping to the biological performance of BNCD films. For this purpose, undoped and boron-doped NCD films were deposited on low roughness (LR) and high roughness (HR) substrates, which were studied in vitro by means of protein adsorption and fibroblast growth assays. Our results show that BNCD films significantly reduce the adsorption of serum proteins, mostly on the LR substrates. As compared to fibroblasts cultured on LR BNCD films, cells grown on the HR BNCD films showed significantly reduced adhesion and lower growth rates. The mean length of fibronectin fibrils deposited by the cells was significantly increased in the BNCD coated substrates, mainly in the LR surfaces. Overall, the largest influence on protein adsorption, cell adhesion, proliferation, and fibronectin deposition was due to the underlying sub-micron topography, with little or no influence of boron doping. In perspective, BNCD films displaying surface roughness in the submicron range may be used as a strategy to reduce the fibroblast growth on the surface of neural electrodes.
- MeSH
- 4-Aminopyridine analogs & derivatives metabolism MeSH
- Actins physiology MeSH
- Boron chemistry MeSH
- Cell Adhesion physiology MeSH
- Diamond chemistry MeSH
- Fibroblasts physiology MeSH
- Blood Proteins chemistry MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Membranes, Artificial MeSH
- Nanoparticles * MeSH
- Surface Properties MeSH
- Cell Proliferation MeSH
- Materials Testing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Cells communicate with their environment via surface receptors, but nanoscopic receptor organization with respect to complex cell surface morphology remains unclear. This is mainly due to a lack of accessible, robust and high-resolution methods. Here, we present an approach for mapping the topography of receptors at the cell surface with nanometer precision. The method involves coating glass coverslips with glycine, which preserves the fine membrane morphology while allowing immobilized cells to be positioned close to the optical surface. We developed an advanced and simplified algorithm for the analysis of single-molecule localization data acquired in a biplane detection scheme. These advancements enable direct and quantitative mapping of protein distribution on ruffled plasma membranes with near isotropic 3D nanometer resolution. As demonstrated successfully for CD4 and CD45 receptors, the described workflow is a straightforward quantitative technique to study molecules and their interactions at the complex surface nanomorphology of differentiated metazoan cells.
- MeSH
- Cell Membrane metabolism MeSH
- Nanotechnology * MeSH
- Receptors, Cell Surface * metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
PURPOSE OF THE STUDY By 7th December 2016, 4,755 Bicon-Plus cups in total were implanted in the Czech Republic. Some of them have been continuously re-operated, while the most frequent reason of failure is polyethylene wear and aseptic loosening. The present study is focused on surface analysis of retrieved polyethylene Bicon-Plus cups and the determination of the roughness of their bearing surfaces. MATERIAL AND METHODS In this study, we had 13 high molecular weight polyethylene cups with the average time in situ of 8.11 years (3.6-13.7, SD 3.2) before the retrieval. The study population was composed of 3 men, 10 women, with the mean age of 53.31 years. An optical scanning method, based on the principle of active triangulation, was used to determine wear rate. The rate of wear was identified by means of an obtained scan subsequently processed with the use of the GOM Inspect software. The roughness of surfaces was analysed with the application of Contour GT-X8 profiler using the principle of phase shifting interferometry. Measurements of surface topography of the retrieved cups were performed on the entire bearing surfaces. For the individual surface changes, a typical range of surface roughness, describing the particular wear character, was determined. By means of morphology analysis of the tested implants, three areas were identified: unworn area; area representing the worn part of the cup; and the area roughened by parallel grooving. The total surface roughness was evaluated as an arithmetic mean of the measured values. Subsequently, the values were sorted based on frequency and were classified into categories defining the particular wear mechanisms. RESULTS Wear rate of the retrieved acetabular cups was evaluated based on the wear direction vector and the size of linear wear. The average linear wear was equal to 0.13 mm/year (ranging from 0.26 to 2.29 mm/year), and the mean value of total volumetric material loss was 44.37 mm3/year (the range being from 51.80 to 1,119.7 mm3/year). Using the optical profilometer, a map of roughness distribution of the individual cups was obtained. For each implant, 76 values of roughness were evaluated. With the respect to average roughness, the samples were sorted to various categories describing: surface polishing; abrasiveadhesive wear; surfaces with preserved grooving; substantial plastic deformation. DISCUSSION The results clearly showed an increase of wear depending on implant survival; however, the tendency is not linear. This fact can be attributed to a larger amount of abrasive particles, causing an increase of wear or occurrence of surface wear in terms of micro cracks and oxidation degradation of polyethylene. This study indicates that geometry, positioning, and cup alignment during the implantation have a fundamental impact on the cup durability. Further correlation, which was observed in the case of the cup with prevailing roughness in the range from 0.1 to 0.3 μm, is a relatively wide wear vector angle determined with the use of the optical method. Considering the implants with the longest survival time with no loosening of the acetabular cup, the mean angle of direction vector was 56.8° (SD 2.1°). CONCLUSIONS The present study provides the results of morphology analysis of the retrieved Bicon-Plus cups. In general, relatively high wear rate, mainly of abrasive-adhesive character was identified. The dependence between wear and implant in situ longevity was not clearly linear, which suggests the influence of other parameters on the polyethylene wear rate. An important role of implant positioning on survival was also revealed. Moreover, it seems that it can be a more important parameter than the characteristics of the patient. Key words: total hip arthroplasty, Bicon-Plus cup, retrieval analysis, surface analysis, wear measurement, roughness, deformation, survivorship.
- MeSH
- Equipment Failure Analysis MeSH
- Hip Prosthesis * MeSH
- Middle Aged MeSH
- Humans MeSH
- Arthroplasty, Replacement, Hip instrumentation MeSH
- Polyethylene MeSH
- Surface Properties MeSH
- Prosthesis Design MeSH
- Prosthesis Failure * MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
- MeSH
- Antigens, Surface genetics drug effects MeSH
- Apoptosis genetics radiation effects MeSH
- Fusion Proteins, bcr-abl genetics MeSH
- Cell Differentiation physiology drug effects MeSH
- Cell Nucleus genetics metabolism drug effects MeSH
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive genetics metabolism pathology MeSH
- Down-Regulation MeSH
- Research Support as Topic MeSH
- Humans MeSH
- Molecular Sequence Data MeSH
- Cell Line, Tumor MeSH
- Gene Expression Regulation, Leukemic MeSH
- RNA Interference physiology MeSH
- Tetradecanoylphorbol Acetate analogs & derivatives pharmacology MeSH
- Blotting, Western MeSH
- Check Tag
- Humans MeSH
- Publication type
- Comparative Study MeSH
