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1.
Rozhl Chir ; 100(7): 339-347, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34465110

RESUMO

INTRODUCTION: Ileocolic intussusception is one of the most frequent causes of acute abdomen in infants and toddlers. The purpose of this study was to evaluate the treatment of ileocolic intussusception in the Czech Republic in 2019. METHODS: Fourteen departments of paediatric surgery participated in this multicentre retrospective study. A SurveyMonkey Inc. questionnaire was used for anonymous data collection of patients with ileocolic intussusception. RESULTS: In 2019, ileocolic intussusception was diagnosed in 162 patients; median age was 30 months (3 months to 9.5 years). Contrast enema was indicated in 133 patients, primary surgery in 14 patients and spontaneous reduction was found in 15 patients. All departments using contrast enema had a success rate of 89.5%; 12 departments approached the contrast enema procedure under general anaesthesia (including myorelaxation at 7 departments) and 2 departments under sedation. Contrast enema under general anaesthesia with/without myorelaxation was significantly more successful than contrast enema under sedation (108/113, 95.6% vs 11/20, 55%; p.


Assuntos
Doenças do Íleo , Intussuscepção , Pré-Escolar , República Tcheca , Enema , Humanos , Lactente , Intussuscepção/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
2.
Acta Chir Orthop Traumatol Cech ; 84(2): 133-137, 2017.
Artigo em Tcheco | MEDLINE | ID: mdl-28809631

RESUMO

PURPOSE OF THE STUDY In developing new or modifying the existing surgical treatment methods of spine conditions an integral part of ex vivo experiments is the assessment of mechanical, kinematic and dynamic properties of created constructions. The aim of the study is to create an appropriately validated numerical model of canine cervical spine in order to obtain a tool for basic research to be applied in cervical spine surgeries. For this purpose, canine is a suitable model due to the occurrence of similar cervical spine conditions in some breeds of dogs and in humans. The obtained model can also be used in research and in clinical veterinary practice. MATERIAL AND METHODS In order to create a 3D spine model, the LightSpeed 16 (GE, Milwaukee, USA) multidetector computed tomography was used to scan the cervical spine of Doberman Pinscher. The data were transmitted to Mimics 12 software (Materialise HQ, Belgium), in which the individual vertebrae were segmented on CT scans by thresholding. The vertebral geometry was exported to Rhinoceros software (McNeel North America, USA) for modelling, and subsequently the specialised software Abaqus (Dassault Systemes, France) was used to analyse the response of the physiological spine model to external load by the finite element method (FEM). All the FEM based numerical simulations were considered as nonlinear contact statistic tasks. In FEM analyses, angles between individual spinal segments were monitored in dependence on ventroflexion/ /dorziflexion. The data were validated using the latero-lateral radiographs of cervical spine of large breed dogs with no evident clinical signs of cervical spine conditions. The radiographs within the cervical spine range of motion were taken at three different positions: in neutral position, in maximal ventroflexion and in maximal dorziflexion. On X-rays, vertebral inclination angles in monitored spine positions were measured and compared with the results obtain0ed from FEM analyses of the numerical model. RESULTS It is obvious from the results that the physiological spine model tested by the finite element method shows a very similar mechanical behaviour as the physiological canine spine. The biggest difference identified between the resulting values was reported in C6-C7 segment in dorsiflexion (Δφ = 5.95%), or in C4-C5 segment in ventroflexion (Δφ = -3.09%). CONCLUSIONS The comparisons between the mobility of cervical spine in ventroflexion/dorsiflexion on radiographs of the real models and the simulated numerical model by finite element method showed a high degree of results conformity with a minimal difference. Therefore, for future experiments the validated numerical model can be used as a tool of basic research on condition that the results of analyses carried out by finite element method will be affected only by an insignificant error. The computer model, on the other hand, is merely a simplified system and in comparison with the real situation cannot fully evaluate the dynamics of the action of forces in time, their variability, and also the individual effects of supportive skeletal tissues. Based on what has been said above, it is obvious that there is a need to exercise restraint in interpreting the obtained results. Key words: cervical spine, kinematics, numerical modelling, finite element method, canine.


Assuntos
Vértebras Cervicais/fisiologia , Simulação por Computador , Amplitude de Movimento Articular , Animais , Vértebras Cervicais/diagnóstico por imagem , Cães , Imageamento Tridimensional , Amplitude de Movimento Articular/fisiologia , Tomografia Computadorizada por Raios X
3.
Homo ; 67(6): 433-446, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27890319

RESUMO

During the past twelve centuries, the stature of Central European inhabitants has increased significantly with corresponding changes in the size of lower limb bones. The aim of our study was to determine whether these changes have occurred strictly in relation to size or if the shape of skeletal structures has been altered simultaneously. Diachronic size and shape changes in the proximal part of tibia in a Central European population (Czech Republic) were studied using geometric morphometrics (principal components analysis, Hotelling's test, linear discriminant analysis). The study sample consisted of 183 three-dimensional (3D) models of adult tibiae dating to the early Middle Ages (N=65), early 20th century (N=60), and from a modern Czech population (N=57). A positive secular trend in size manifested only between the two modern Czech populations (the 20th century vs. the 21st century), a time range shorter than one century. By contrast, landmark-based shape analyses revealed significant differences in tibial morphology over the three periods covered in the study. In particular, progressive changes were observed in the position of tibial tuberosity (shifted medially), the inclination of the line connecting tuberosity with anterior edge of the tibial plateau (sloped down), the reshaping of the lower back condyle boundary (shifted posteriorly), and reshaping of the medial contour of the medial condyle (shifted anteriorly). Changes in the shape of the proximal tibial extremity across the chronologically distinct groups indicated the existence of discreet but convincing microevolutionary trends involving this anatomical structure.


Assuntos
Tíbia/anatomia & histologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antropologia Física , Evolução Biológica , República Tcheca , Feminino , História do Século XX , História do Século XXI , História Medieval , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Paleontologia , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
Bratisl Lek Listy ; 116(5): 302-10, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25924639

RESUMO

OBJECTIVES: The study was aimed at the assessment of specific complications depending on the sliding hip screw position. BACKGROUND: The finite element method in the biomechanical analysis of this implant may be used to predict the mechanical failure due to the screw position. METHODS: 380 sliding screw osteosyntheses for stable pertrochanteric fractures of 365 patients were included in the study. We divided and analysed the osteosyntheses with five various screw positions and focused on the specific complications development. For the construction of the finite element model of the femur, the program ABAQUS 6.9 was used. Analyses were performed with evaluation of the bone response to the different screw locations (strain and stress) with maximum low-cycle high stress loading. RESULTS: The specific complication rate was 10 %, with the re-operation rate of 4.2 %. If placing the screw in the middle third of the neck it reduced significantly strain patterns of the plate and screw. A screw position in the superior third of the neck significantly increased the strain of the plate and screw by more than 63 %. CONCLUSIONS: The conformity in the clinical and biomechanical analyses was observed. The finite element model can be considered as valid in predicting sliding screw failures (Tab. 4, Fig. 8, Ref. 30).


Assuntos
Placas Ósseas , Parafusos Ósseos , Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Fraturas do Quadril/cirurgia , Idoso , Idoso de 80 Anos ou mais , Feminino , Análise de Elementos Finitos , Fixação Interna de Fraturas/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
5.
Bratisl Lek Listy ; 115(2): 107-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24601707

RESUMO

BACKGROUND: A comparison between plate and intramedullary osteosynthesis techniques in terms of the biomechanical stability of distal radius fracture fixation. METHODS: Mathematical modelling was used to simulate distal radius fractures, type C1 and type C2, and to compare the stability of osteosynthesis in both techniques under several wrist joint load conditions: axial compressive loading of the radius, bending loads in volar and dorsal flexion and radial and ulnar deviation, and axial torsional loading of the forearm. RESULTS: For both type C1 and type C2 fractures, the stability of intramedullary osteosynthesis was comparable with plate osteosynthesis in dorsal flexion. Plate osteosynthesis proved to be more stable only in ulnar deviation. The intramedullary X-screw technique provided more stability when loads were applied in volar flexion, radial deviation, pronation and supination, and in axial loading of the radius. CONCLUSIONS: The result of mathematical simulations was comparable for both types of fracture. It showed a higher stability of intramedullary osteosynthesis. Although when lower force intensity was applied, both techniques were comparable (Fig. 8, Ref. 16).


Assuntos
Placas Ósseas , Simulação por Computador , Fixação Intramedular de Fraturas/métodos , Fraturas Intra-Articulares/cirurgia , Fraturas do Rádio/cirurgia , Fixação Intramedular de Fraturas/instrumentação , Humanos , Computação Matemática
6.
Comput Methods Biomech Biomed Engin ; 14(8): 673-81, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21797802

RESUMO

The temporomandibular (TM) joint is one of the most used joints in the human body, and any defect in this joint has a significant influence on quality of life. The objective of this study was to create a parametric numerical finite element (FE) analysis to compare the effect of surgical techniques used for total TM joint replacement implantation on loading the TM joint on the other side. Our hypothesis is that for the optimal function of all total TM joint replacements used in clinical practice it is crucial to devise a minimally invasive surgical technique, whereby there is minimum resection of masticatory muscles. This factor is more important than the design of the usually used total TM joint replacements. The extent of muscle resection influences the mechanical loading of the whole system. In the parametric FE analyses, the magnitude of the TM joint loading was compared for four different ranges of muscle resections during bite, using an anatomical model. The results obtained from all FE analyses support our hypothesis that an increasing extent of the muscle resection increased the magnitude of the TM joint overloading on the opposite side. The magnitude of the TM joint overloading increased depending on the muscle resection to 235% for bite on an incisor and up to 491% for bite on molars. Our study leads to a recommendation that muscle resection be minimised during replacement implantation and to a proposal that the attachment of the condylar part of the TM joint replacement be modified.


Assuntos
Artroplastia de Substituição , Força de Mordida , Simulação por Computador , Articulação Temporomandibular/cirurgia , Fenômenos Biomecânicos , Análise de Elementos Finitos , Humanos , Qualidade de Vida , Articulação Temporomandibular/fisiopatologia
7.
Acta Chir Orthop Traumatol Cech ; 77(6): 463-9, 2010.
Artigo em Tcheco | MEDLINE | ID: mdl-21223825

RESUMO

On the basis of current studies, polyaryletherketone (PAEK) polymers appear to be materials with great prospects for medical application. The most important member of this family of semi-crystalline thermoplastics is polyetheretherketone (PEEK) with its composites. The excellent properties of this material find their use in the treatment of various disorders of the skeletal system. At present they are used with advantage to construct spinal implants, and replacements for other orthopaedic applications and for dental and trauma medicine are at advanced stages of clinical testing.


Assuntos
Materiais Biocompatíveis , Cetonas , Polietilenoglicóis , Próteses e Implantes , Benzofenonas , Humanos , Cetonas/química , Polietilenoglicóis/química , Polímeros
8.
Physiol Res ; 59(2): 247-253, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19537937

RESUMO

Materials on the basis of cycloolefin copolymers (COC) are suitable for subchondral defect repairs. The objective of this study was to evaluate the influence of surface modification of COC and COC/LLDPE blends on the viability and gene expression of chondrocytes. Human chondrocytes were incubated on the surface of the studied materials. Half of the materials were plasmatically modified with a subsequent type II collagen application. The gene expression of matrix metalloproteinases (MMP-1,-3,-13), pro-inflammatory cytokines (IL-1, TNF-alpha) and apoptotic molecules (BAX, Bcl-2) was evaluated using quantitative Taq-Man PCR after 48 h incubation. Chondrocyte viability was evaluated by the MTT test after 2, 4 and 8 days of incubation. The synthesis of MMPs was measured by ELISA assay in cell culture medium after 48 h of incubation. Chondrocytes incubated on plasmatically modified in contrast to unmodified materials demonstrated significantly increased gene expression of IL-1 (p<0.05), MMP-1 and MMP-3 (p<0.05 for both comparisons) as well as MMP-13 (p<0.001). Increased gene expression was confirmed by significantly increased production of active forms of particular MMPs into the cell culture medium. Unlike surface unmodified polymers, the modified materials showed time-dependent reduction of chondrocyte viability. The gene expression of TNF-alpha and apoptotic molecules by chondrocytes was not significantly changed by different materials. Cycloolefin copolymers and their blends may represent suitable materials for tissue engineering, however, their surface modification followed by collagen type II application may, at least under in vitro conditions, reduce the viability of chondrocytes and induce their pro-destructive behavior. The potential benefit or disadvantage of surface modifications of materials for osteochondral defect repairs needs to be further elucidated.


Assuntos
Materiais Biocompatíveis/farmacologia , Condrócitos/efeitos dos fármacos , Cicloparafinas/farmacologia , Osteoartrite/tratamento farmacológico , Polímeros/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/fisiologia , Colágeno Tipo II/farmacologia , Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Interleucina-1/genética , Teste de Materiais , Metaloproteinase 1 da Matriz/genética , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 13 da Matriz/genética , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , Osteoartrite/patologia , Próteses e Implantes , Fator de Necrose Tumoral alfa/genética
9.
Prague Med Rep ; 110(1): 79-84, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19591381

RESUMO

The objective of the skeletal defects reconstruction using individual implants is an attempt to replace lost and damaged anatomical bone structures, renew their original function, and at the same time, to restore the original aesthetic visual aspect. This work is focused on a demonstration of the design methods, fabrication and surgical techniques of the custom-made replacement of a large defect of the frontal bone on the skull. The patient was a 30-year-old woman with a defect of the frontal bone in the size of 7 x 3 x 2 cm after a serious polytrauma. The size and character of the defect excluded the use of commonly supplied augmentations. The geometry of the individual replacement was designed on the basis of a 3D model of the defect obtained from a series of CT scans. After verification of the shape accuracy of the defect made from plastic on a 3D printer, the individual replacement was fabricated from an ultra high molecular weight polyethylene (UHMWPE) by machining with the use of the CNC technology. The success of the augmentation depends on the accurate and precise fabrication of the individual replacement, which is highly demanding on the used advanced technologies.


Assuntos
Substitutos Ósseos , Desenho Assistido por Computador , Osso Frontal/cirurgia , Desenho de Prótese , Adulto , Feminino , Osso Frontal/diagnóstico por imagem , Osso Frontal/lesões , Humanos , Imageamento Tridimensional , Polietileno , Procedimentos de Cirurgia Plástica/métodos , Fratura do Crânio com Afundamento/diagnóstico por imagem , Fratura do Crânio com Afundamento/cirurgia , Tomografia Computadorizada por Raios X
10.
Acta Chir Orthop Traumatol Cech ; 76(1): 60-4, 2009 Feb.
Artigo em Tcheco | MEDLINE | ID: mdl-19268051

RESUMO

Reconstruction with the use of custom-made implants aims at optimal replacement of lost or damaged bone structures and restoration of their funkction. In this study the development and construction of a custom-made implant and the operative technique used for the treatment of an extensive tibial defect are described. The patient was a 65-year-old man treated for over 20 years for psoriatic arthritis and severe instability of the right knee, particularly in the frontal plane, with a worsening varus deformity. The radiogram showed an extensive destruction of the medial tibial condyle that also deeply involved the lateral condyle. The extent of defect made it impossible to use any commercial tibial augmentation. The geometry of the custom-designed implant for the medial tibial condyle was constructed on the basis of a 3D defect model and the shape of the medial tibial condyle of the collateral knee seen on CT scans. After its correct shape was verified on a plastic model, its coordinates were set in the software of a machine tool, and a titanium augmentation otherwise compatible with a standard knee replacement was produced.The use of such a custom implant to complete standard total knee arthroplasty has so far been demanding in terms of organisation and manufacture. Its production in the future could be facilitated by substituting titanium for plastic material such as poly-ether-ether-ketone (PEEK). Key words: custom-made implant, tibial augmentation, knee prosthesis.


Assuntos
Artroplastia do Joelho , Desenho Assistido por Computador , Próteses e Implantes , Desenho de Prótese , Idoso , Artrite Psoriásica/cirurgia , Humanos , Imageamento Tridimensional , Masculino , Tíbia/cirurgia
11.
Prague Med Rep ; 108(4): 368-79, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18780649

RESUMO

This project is the beginning of a large research work with a goal to develop a new total replacement of temporomandibular (TM) joint. First aim of this work was to determine the relative displacement of the TM disc and the mandible during mouth opening. The movement of the TM disc was studied using a magnetic resonance imaging. Sagittal static images in revolved sections of the TM joint were obtained in various positions of jaw opening from 0 to 50 mm. The results provided a description of the TM disc displacements as a function of jaw opening. The displacements of the mandible and TM disc were about 16 mm and 10 mm respectively at mouth opening of 50 mm, maximum rotation of the mandible was 34s. The results of these measurements can be used for clinical diagnostics and also they were used as inputs for the follows finite element analysis (FEA). Second aim of this work was to create stress and strain analysis of TM joint using non-linear FEA. Complex of TM joint consists of mandibular disc, half skull and half mandible during normal jaw opening. The results illustrate the stress distributions in the TMJ during a normal jaw opening.


Assuntos
Disco da Articulação Temporomandibular/fisiologia , Adulto , Fenômenos Biomecânicos , Simulação por Computador , Análise de Elementos Finitos , Humanos , Imageamento por Ressonância Magnética , Masculino , Mandíbula/fisiologia , Modelos Biológicos , Movimento
12.
Acta Chir Orthop Traumatol Cech ; 73(4): 243-50, 2006 Aug.
Artigo em Tcheco | MEDLINE | ID: mdl-17026883

RESUMO

PURPOSE OF THE STUDY: Aseptic loosening of implants is the main complication affecting the longevity of joint prostheses. The highest proportion of loosening occurs due to osteolysis produced by the presence of ultra-high molecular weight polyethylene (UHMWPE) wear particles smaller than 1 microm. These can be identified by microscopic, spectroscopic or light-scattering methods. Here we describe our method for counting wear particles, based on the principle of light scattering. MATERIAL AND METHODS: Between 2002 and 2004, we collected samples of polyethylene granuloma in 19 patients who underwent revision total hip arthroplasty (THA) for aseptic loosening. The samples were obtained from strictly defined areas corresponding to the radiographic presentation of periprosthetic zones describes by Gruen and DeLee in THA. The frozen samples were lyophilized and subjected to delipidation and hydrolyzation procedures in 65 % HNO3. The top part of solution containing wear particles was blended with isopropanol, and the mixture was filtered through a 10-microm polycarbon membrane. Subsequently, the filtrate was filtered through a 0.1-microm membrane. Membranes with trapped particles, 0.1 to 1.0 microm in size, were sent for particle characterization and quantification. The number of wear particles was measured by the method based on light scattering with calibration (LSC), using a Beckman Coulter LS230 analyzer that can express particle size distribution in a given volume in percent. The method was based on the fact that each particle reflects rays that can be measured. The medium measured contained an unknown number of UHMWPE particles and a known number of calibration glass beads varying in size. The number of UHMWPE particles was calculated from the known number of calibration beads. RESULTS: Because the collected samples were also used to develop the method, comprehensive data was obtained in six patients only. Particle distribution recorded in the periprosthetic zones in THA varied greatly; up to a five-fold difference in particle concentration was observed between the zones. In five of the six patients, the highest particle concentration was found in zone III. DISCUSSION: Seeking a method that would be exact, quick and cheap and would eliminate particle aggregation remains the subject of study for researchers cooperating with clinical practice. At present methods based on weighing isolated particles are used most frequently. We developed the LSC method that, for quantification, utilizes the ability of particles to disperse light, and allows us to calculate the real numbers of UHMWPE wear particles in a medium containing a known number of calibration particles. Although this is an indirect method, it gives more accurate results than the direct weighing of particles. The advantages of the LSC method involve less demand on sample purity, greater speed and low limits of detection. The method is useful for statistical evaluation of a larger number of samples. The variation in particle distribution in THA found in this study is in agreement with the relevant literature data; it is also in agreement with our assumptions and clinical findings. CONCLUSIONS: The authors developed an original method for assessment of UHMWPE wear particles in tissue samples, which is quicker than the methods so far used. In the periprosthetic tissues studied, particles about 1 microm in size were detected; their numbers (about 1010 particles per gram dry tissue) are in agreement with the literature data. The distribution of particles in periprosthetic zones in THA was uneven. The highest number of particles was found in the neighboring zone III and zone 7, as described by Gruen and DeLee. Key words: wear, polyethylene, total hip arthroplasty, light scattering, aseptic loosening, wear particles.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Polietilenos/análise , Falha de Prótese , Granuloma de Corpo Estranho/diagnóstico , Humanos , Tamanho da Partícula , Polietilenos/efeitos adversos , Reoperação
13.
J Mater Sci Mater Med ; 15(12): 1267-78, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15747178

RESUMO

Ultra-high molecular weight polyethylene (UHMWPE) wear particles are the major cause of total joint replacement (TJR) failures because the wear particles, released from TJR's, cause bone loosening. To simplify the study of the relationship between numbers of particles at various locations around TJR's and extent of bone loosening at these locations, the authors of this work tried to develop a new method for easy and fast determination of number of wear particles. The method, called LSC (Light Scattering with Calibration spheres), is based on light scattering of a suspension of wear particles and calibration spheres, and yields relative numbers of particles. A modified LSC method, called LSCm, requires one additional experiment, a gravimetric analysis of a mixture of all studied samples, to determine absolute numbers of wear particles. LSC and LSCm methods are easy and fast, which make them suitable for processing and comparing high number of samples.


Assuntos
Polietilenos , Varredura Diferencial de Calorimetria , Microscopia/métodos , Microscopia Eletrônica de Varredura , Espalhamento de Radiação , Difração de Raios X
14.
Artigo em Tcheco | MEDLINE | ID: mdl-12764946

RESUMO

PURPOSE OF THE STUDY: The experience obtained during revision surgery and findings of polyethylene granulomas in surrounding tissues of replacement as well as marked differences in the viability of implants resulted in the study of polyethylene disease and its basic mechanisms producing the development of osteoaggressive granulomas. We investigated the morphology of particles and their number in tissues surrounding the implant. The aim of our study was to develop a method for the detection of polyethylene particles in tissues, to identify different types of wear and to assess factors that may influence the viability of joint arthroplasty in general. MATERIAL: Every revizion of joint arthroplasty performed during the last five years was evaluated in terms of the presence of polyethylene granules and the viability state of articular polyethylene inserts. A total of 55 samples were taken from tissues around loosened endoprostheses. The location of each sample was exactly determined. METHOD: A technique was developed to identify wear particles and to visualize them after all organic structures of a polyethylene granuloma were dissolved with nitrogenic acid. RESULTS: The viability of articular polyethylene implants showed extreme differences in relation to different periods of manufacture and probably also to different methods of sterilization. Articular inserts sterilized with formaldehyde (the method used at the beginning of arthroplasty in our country) showed the highest viability and the lowest wear. The polyethylene particles present in tissues surrounding the implant were characterized in terms of morphology and size. DISCUSSION: The comparison of literature data and our results has revealed that there are many unknown facts about the quality and structure of polyethylene. The method of sterilization also appears to play a role. Because the issue is complex, we were not able to identify all factors leading, in some cases, to an early and unexpected failure of the implant and we consider further investigation to be necessary. CONCLUSIONS: Polyethylene disease is an important factor limiting the viability of joint arthroplasty. It results from a complex interaction of polyethylene particles arising by wear with surrounding tissues. The particles, less than 0.5 micron in size, are phagocytized by macrophages and, by complex mechanism of expression of inflammation mediators, they result in the inhibition of osteogenesis and activation of osteoclastic processes. The previous methods of sterilization with formaldehyde vapors apparently reduced wear influenced the resistance of polyethylene to wear to a lesser degree. A method was developed to detect these particles and to characterize their morphology in the tissues of a polyethylene granuloma.


Assuntos
Reação a Corpo Estranho/etiologia , Prótese Articular/efeitos adversos , Polietileno/efeitos adversos , Reação a Corpo Estranho/patologia , Reação a Corpo Estranho/fisiopatologia , Humanos , Tamanho da Partícula , Polietilenos/efeitos adversos , Falha de Prótese
15.
Appl Radiat Isot ; 55(3): 347-54, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11515659

RESUMO

An account is given of the installation and calibration of k0-based NAA--assisted by the DSM Kayzero/Solcoi software package--at the KFKI-AEKI, Budapest, the NPI, Rez and the IJS, Ljubljana. Not only the calibration of the Ge-detectors and the irradiation facilities are discussed, but also other important topics such as gamma-spectrometric hard- and software, QC/QA of the IRMM-530 Al-Au flux monitor and the upgrade of the Kayzero/Solcoi code. The work was performed in the framework of a European Copernicus JRP, coordinated by the Laboratory of Analytical Chemistry, Gent, with DSM Research, Geleen, as the industrial partner.

16.
Fresenius J Anal Chem ; 370(1): 38-41, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11393234

RESUMO

After installation and calibration of k0-assisted NAA in three Central European research institutes (AEKI-Budapest, NPI-Rez, and IJS, Ljubljana), its validation was established via the analysis of three BCR certified reference materials. The matrices of choice were: CRM 277 estuarine sediment, CRM 038 coal fly ash from pulverized coal, and CRM 101 spruce needles. For some elements, e.g. Zn, Cd, and Hg, the analyses were not only performed instrumentally (INAA), but also in the radiochemical mode (RNAA). The work was performed in the framework of a European Copernicus Project.


Assuntos
Carbono/química , Poluentes Ambientais/análise , Sedimentos Geológicos/química , Metais Pesados/análise , Plantas/química , Cinza de Carvão , República Tcheca , Hungria , Material Particulado , Padrões de Referência , Reprodutibilidade dos Testes , Eslovênia
17.
Int J Syst Bacteriol ; 48 Pt 4: 1349-55, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9828436

RESUMO

A new, slow-growing, scotochromogenic mycobacterium was isolated from sputum of a 53-year-old patient with Down's syndrome suffering from tuberculosis. Growth occurred at temperatures between 25 and 40 degrees C with an optimum at 37 degrees C. This strain had surprisingly few enzymic activities (only positive for 68 degrees C heat-stable catalase and weakly positive for urease) and was sensitive to prothionamide, cycloserine, clarithromycin, gentamicin and amikacin but showed resistance to isoniazid, streptomycin, ethambutol, rifampin and ciprofloxacin. These characteristics assign this organism to a novel mycobacterial species characterized by a unique 16S rDNA nucleotide sequence. The name Mycobacterium bohemicum sp. nov. is proposed for this new, slow-growing, scotochromogenic mycobacterium. The type strain is DSM 44277T.


Assuntos
Síndrome de Down/complicações , Mycobacterium/classificação , Tuberculose/microbiologia , Composição de Bases , Sequência de Bases , DNA Bacteriano/química , DNA Ribossômico/química , Ácidos Graxos/análise , Genes de RNAr , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Mycobacterium/fisiologia , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Escarro/microbiologia , Terminologia como Assunto , Tuberculose/complicações
18.
Vnitr Lek ; 43(12): 790-4, 1997 Dec.
Artigo em Tcheco | MEDLINE | ID: mdl-9601891

RESUMO

In 76 patients (66 men and 10 women, age 20-71 years) with stable angina pectoris planar thallium myocardial perfusion scintigraphy, bicycle ergometry and coronary angiography were performed. Thallium scintigraphy was highly sensitive (97%) for detection of ischaemic heart disease, the sensitivity of ergometry was 75%. When comparing patients with affected 1, 2 and 3 coronary arteries perfusion scintigraphy had a sensitivity of 100%, 90% and 100% resp., while bicycle ergometry 62%, 90% and 82% resp. The specificity of perfusion scintigraphy was low (47%), compared with ergometry (60%). The finding of s reversible perfusion defect during scintigraphy indicated significant affection of coronary arteries. The scintigraphic finding of diffuse myocardial ischaemic affection was not significant for assessment of the severity of the coronary artery disease.


Assuntos
Angiografia Coronária , Doença das Coronárias/diagnóstico , Teste de Esforço , Radioisótopos de Tálio , Adulto , Idoso , Circulação Coronária , Doença das Coronárias/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Sensibilidade e Especificidade
19.
Vnitr Lek ; 36(12): 1145-50, 1990 Dec.
Artigo em Tcheco | MEDLINE | ID: mdl-2284712

RESUMO

Using RIA and ELISA methods the authors examined HBsAg, anti-HBc IgM and anti-HAV IgM antibodies in 830 adult patients and 101 children with acute viral hepatitis from the catchment area of the South Moravian region. In these groups also the most frequent hepatotropic infectious agent as the possible cause of hepatitis was examined. It was revealed that in adults viral hepatitis A accounted for 22%, viral hepatitis B for 48.5%, viral hepatitis non-A, non-B for 28.8% of the group. The percentage distribution of viral hepatitis in children is different: hepatitis A predominates (65%), hepatitis B is less frequent (22%) and viral hepatitis non-A, non-B is least frequent (13%). It was demonstrated that viral hepatitis non-A, non-B is under our conditions a very frequent disease, it accounts for one quarter of all cases of viral hepatitis and if we take into account that non-A, non-B hepatitis has frequently permanent serious sequelae, then proper attention must be paid to this disease. The authors demonstrate that differentiation of types of viral hepatitis by routine methods is possible which leads to a substantially more accurate differentiation of hepatitis.


Assuntos
Hepatite D/diagnóstico , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Tchecoslováquia/epidemiologia , Hepatite D/epidemiologia , Hepatite Viral Humana/epidemiologia , Humanos , Pessoa de Meia-Idade
20.
Vnitr Lek ; 36(12): 1151-7, 1990 Dec.
Artigo em Tcheco | MEDLINE | ID: mdl-2126647

RESUMO

Comparison of large groups of patients with acute viral hepatitis A (HA), B (HB) and non-A, non-B (HNANB) revealed that the highest percentage of anicteric forms is found in HA (44.8%) followed by HNANB (27.3%) and the lowest percentage in HB (23.6%). Investigation of mean values of biochemical functional liver tests showed that 1. the highest mean values of bilirubinaemia, ALT and AST were recorded in HB. The differences are statistically significantly higher (p less than 0.01) than in the two remaining types. 2. The difference between the cholesterol serum level, GMT and ALP in HB and HNANB on the one hand and HA on the other hand was at the same level of significance. 3. The transaminase activity is only slightly higher in HA than in HNANB, the differences are not significant (p greater than 0.05). 4. The cholestatic features are more marked in HNANB than in HA. The differences are also significant (p less than 0.01). In the clinical picture in acute HNANB symptoms of influenza predominated (53.33%), followed by digestive complaints (47.5%) and the percentage of articular complaints was lowest (24.17%). Analysis of 24 cases of fulminant forms of viral hepatitis revealed that this course was most frequent in HB (50%), followed by HNANB (41.7%) and least frequent in HA (8.3%).


Assuntos
Hepatite C/diagnóstico , Doença Aguda , Diagnóstico Diferencial , Hepatite A/diagnóstico , Hepatite B/diagnóstico , Hepatite C/patologia , Humanos
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