Papers by Keyword: Histology

Abstract: Biodegradable magnesium-based alloys shows good prospects in their use as biodegradable orthopedic materials. The aim of this study is to demonstrate good biocompatibility and lack of local and systemic toxicity of some experimental implants made by magnesium alloy type Mg-Ca 0,8 [%wt]. The study was conducted by implanting some experimental pins made by magnesium alloy type Mg-Ca 0,8 [%wt] in bone, proximal femur and intramedullary tibia, and in thigh muscle of the rabbits. Also, we follow the evolution of blood levels of Mg, Ca, blood counts, liver and kidney function. The evolution of the experience animals was followed for 6 weeks by radiologic imaging, and taking blood samples. After 6 weeks, we obtain after euthanasia of animal experience the harvest blood samples, and musculoskeletal tissue samples for histopathological examination. The histopathology results have not demonstrated peri-implant cytotoxicity, bone and muscle cells being viable. Fibrosis at tissue implant border was minimal showing a good integration. There were no pathological increases in blood levels of Mg and Ca, or changes in blood counts, as well as no change in renal or hepatic function. All this experimental results demonstrates that the magnesium alloy type Mg-Ca 0,8 [%wt] represent a promising solution in orthopedic surgery, proving to be safe, with a high degree of biocompatibility, and without toxic effects.

Abstract: We analyzed histological data statistically describing the distribution of orientations of vascular smooth muscle cells (VSMC) within porcine aorta. The data were correlated with the fractions of actin, desmin, vimentin, elastin and collagen within the same samples. In samples with more contractile VSMC and less elastin, the symmetrical helices of VSMC were arranged closely to each other and they were more concentrated than in samples with fewer actin-and desmin-positive VSMC and more elastin. The findings are suitable for microstructurally-motivated biomechanical modeling of porcine aorta under normal conditions.

Abstract: The retrograde filling is a critical step to a successful outcome of the endodontic surgery. Despite the progress in the technology of novel root-end filling materials, zinc oxide-eugenol cement superEBA is still preserving its clinical value on long-term basis. The study aimed to reconsider the tissue response to the initial irritating effect of this material. Silicon tubes filled with superEBA were subcutaneously implanted for 120 days in white Wistar rats which were afterwards sacrificed. The connective tissue surrounding the superEBA implants revealed fibroblast proliferation and a definite reparatory process without inflammatory reaction. A non-specific tissue healing in progress around the implants, without calcifications, necrosis, and apoptosis was also described after 4 months. SuperEBA proved on animal model that its cytotoxicity is reducing gradually in time until no adverse reaction is observed. The reduced content in eugenol compared to other surgical zinc oxide cements and the benefic effect of o-ethoxybenzoic acid are the support to reconsider SuperEBA as a biocompatible retrograde filling material.

Abstract: Bone graft substitute materials play an important role in oral rehabilitation and understanding the biological effects of these materials is important for an optimum use. Many bone graft substitutes have been approved for clinical use but this large variability make it hard to select a graft materials. The present study aimed to evaluate the methods that we can today use to assess the degree of osseointegration of the synthetic bone augmentation materials.For this study we made three study groups, each of them consisting of six laboratory rats. On the maxilla of this animals 3-mm diameter experimental cavities were carried out. For the first study group the cavities were augmented with the collagen fleece Alveoprotect, for the second group with the synthetic bone graft Ossceram nano, and in the third group the experimental cavities were left unaugmented. The obtained samples were subjected to three examination methods: clinical and radiological examination, Optical Coherence Tomography (OCT), and a histological study.The evaluation methods of bone graft materials may be divided in two categories: in vivo and in vitro methods. In vivo methods include clinical evaluation and imagistic such as radiological or computer tomography (CT) evaluation. Even a minimal but careful direct clinical observation allows observing the appearance of the bone defect healing at its different stages. CBCT scan is the imaging method of choice in the graft materials repairment of the osseous defects because provides 3D volumetric measurements of newly formed hard tissues.Optical Coherence Tomography (OCT) is a constantly growing imaging method characterized by high spatial resolution and noninvasive subsurface detection. The OCT allowed us to evaluate the surface and subsurface of the ongoing healing bone defects in a non-destructive manner.For the in vitro methods histological methods represents the classical evaluation of the bone graft materials biological integration. On the histological samples we generally noticed the experimental defects filling with connective tissue with various bone ingrowths from the surrounding bone tissue.However new emerging methods give new opportunities to a more accurate research of this materials. The microcomputed tomography analysis may determine the relationships and differences in three-dimensional bone mineral density and microtrabecular structures between bone grafts and their adjacent native boneTo design and produce an efficient bone graft, the researchers and clinicians should have sufficient knowledge of the characteristics of grafts such as osteogenesis, osteoinductivity, and osteoconductivity, and their other advantages and disadvantages.

Abstract: A foreign body is any object originating outside the body. It may migrate from its entry site and cause pain, inflammation and infection. This study aims to examine in vitro cytotoxicity and in vivo tissue response at different implantation sites of two iron-based foreign body (FeFB) specimens: pure Fe wire, Cr-coated Fe wire, and SS316L wire as control. In vitro cytotoxicity was assessed towards rat smooth muscle cells with direct method of methyl thiazolyl tetrazolium (MTT) assay. In vivo tissue response was examined using mice animal model until day 14 after surgical implantation in subcutaneous nape area and intramuscular right femoral muscle. Cell viability, surface morphology and Fe ion release were examined. Implant density and tissue response were examined by using radiographic imaging and histology, respectively. Results showed that both FeFB specimens exhibited similar cell viability with SS316L. Iron ion concentration was higher in both FeFB medium compared to that of SS316L and with oxide layer formation on their surface. Radiographic analysis showed that the density of both FeFB implants end-side was increased. Meanwhile, histological tissue response at intramuscular sites for FeFB specimens showed a prominent inflammatory response compared to SS316L. Detailed analysis on cell and tissue-material interactions of the iron-based foreign body specimens is discussed further in this article.

Abstract: The inflation-extension test was performed in order to obtain the mechanical response (stress-strain curves) of the human vein - vena saphena magna (usually used for coronary artery bypass graft surgery). Tubular samples of the vein were inflated four times up to the pressure approx. 4 kPa (vein pressure) and then four times up to approx. 16 kPa (systolic pressure). The experiments were recorded by the CCD camera. The longitudinal and circumferential deformations of the tube were evaluated using the edge detection method. The experimental data were fitted by anisotropic, nonlinear, constitutive model in order to obtain model parameters, especially the parameter which can be explained as collagen fibres orientation approximation. This parameter was then compared with the findings from histology. The histology analyses based on label-free imaging were performed additionally to the mechanical testing. Collagen (most important load-bearing component of the vein wall) was visualized using second harmonic generation imaging (SHG, excitation at 860 nm by a tunable IR pulse laser, detection at 430±10 nm). This method enabled us to observe collagen through the vein wall. It was found that the collagen fibres are helically aligned within the vein at an angle 37±6° measured from circumferential axis. The results of collagen orientation angle show a good agreement of findings obtained from histology and from constitutive model.

Abstract: Using light microscopy to observe the Carassius auratus, Pelophylax nigromaculata and Oryctolagus cuniculus lens on morphology and histology, measuring the thickness of each layer, layers and density of epithelial cell and the diameter of nucleus, et al. Results show that: Carassius auratus, Pelophylax nigromaculata and Oryctolagus cuniculus are siginificantly different in lens organizational structure, its visual ability shows a gradual and improving trend, it shows that the three animals have consistency on structure and function of lens with Behavioral characteristics.

Abstract: The association of TricOsTM (Macroporous Biphasic Ceramic Phosphate MBCP granules) and the fibrin sealant FS VH S/D 4, has been developed to answer a challenging request of orthopaedic surgeons: a biocompatible, osteogenic, mouldable, and self-hardening bone substitute able to fill randomly shaped bone defects. The aims of this study was the evaluation of the performance and safety of the bioactive bone substitute TricOs™ associated with a fibrin sealant in regeneration of functional bone. The pre-clinical tests were conducted to optimize MBCP granules size and ratio MBCP–FS VH S/D 4 (sheep maxillary sinus grafting, femoral epiphysis defect in rabbits, long bone defects in sheep). A clinical study design was set up as an exploratory prospective French multicentric phase II study sponsored by INSERM (Institut National de la Santé et de la Recherche Médicale). The application was the TOV (Tibial Osteotomy of Valgisation) using osteosynthesis and bone substitute: TricOs™ mixed with the fibrin sealant (FS VH S/D 4) for filling the space created. The follow up is 13 months with safety checks, clinical assessments, highsensitivity X-ray, and CT-scan imaging. A bone sample will be collected from the reconstructed area at 12 months, during the osteosynthesis material removal surgery. The principal criterion is CT-scan imaging performed 12 months after TOV surgery, before material removal, to assess qualitative and quantitative bone reconstruction. Animals’ studies demonstrate that the biomaterial is safe to use and shows osteoconductive properties, granules resorption and bone ingrowth at the expenses of the implants. As for clinical trial, 7 patients are today included in the study: This paper present the first results obtained from X-ray imaging during follow up.

Abstract: In this study, we report human clinical and histological data on the use of micromacroporous biphasic calcium phosphate wedges in combination with osteosynthesis with adjustable screws for open tibial osteotomy. 42 patients were operated for open tibial osteotomy for valgisation due to incipient medial gonarthrosis. The population was composed of 43 knees (25 right knees and 18 left knees) in 13 women and 29 men, with a mean age of 46 years. Radiological follow-up at D+1, D+90 and D+360, and 12 biopsies for histology were processed after the removal of the osteosynthesis. Consolidation was obtained in 100 % of cases (except one, because of failure of the osteosynthesis). Regular bone ingrowth was observed on X-ray, with maintain of the corrections at one year in 98.5 % of cases. Only 8 % of cases showed a radiolucent interface after D+360. Histological examinations demonstrated resorption of the MBCP and large bone ingrowth. Polarised microscopy confirmed the lamellar bone, and the X-rays and microscanner revealed well mineralised and organised newly-formed bone.

Abstract: We evaluated the differences of histological findings of the retrieved specimens from the different areas in the same hip with interposing HA granules and without interposing HA granules between the bone and bone cement interface. In the area existing HA, bone ingrowth into the spaces of HA granules was very dense and a thick bone layer with HA granules contacted around the bone cement. In the area not-existing HA, bone formation at the base was seen poorly and bone formation at the area adjacent to the bone cement was not seen.