1,555 research outputs found

    unfixed and fixed human chromosomes show different staining patterns after restriction endonuclease digestion

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    Restriction endonucleases (REs) have been widely used to produce banding patterns on chromosomes, but it remains uncertain to what extent the patterns are due to the sequence specificity of the enzymes, and to what extent chromatin structure influences the pattern of digestion. To throw light on this question, we have digested with restriction endonucleases unfixed chromosomes prepared in two different ways (isolated, and whole metaphase cells spread with a cytocentrifuge) and compared the results with those obtained on conventionally fixed chromosomes. Unfixed isolated chromosomes are easily destroyed by REs; after fixation with cold methanol, which produced minimal alteration to the chromatin structure, the chromosomes are resistant to the action of REs, and conventional methanol-acetic acid fixation is required to permit the induction of banding patterns by REs. Unfixed cytocentrifuge preparations, in which the chromosomes are still surrounded by cytoplasm, are much more resistant to the action of REs, and again banding patterns were only induced after methanol-acetic acid fixation. We conclude that the action of restriction endonucleases on chromosomes is strongly influenced by chromatin organisation, and that methanol-acetic acid fixation is required to permit the induction of conventional banding patterns on chromosomes

    Response of human engineered cartilage based on articular or nasal chondrocytes to interleukin-1? and low oxygen

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    Previous studies showed that human nasal chondrocytes (HNC) exhibit higher proliferation and chondrogenic capacity as compared to human articular chondrocytes (HAC). To consider HNC as a relevant alternative cell source for the repair of articular cartilage defects it is necessary to test how these cells react when exposed to environmental factors typical of an injured joint. We thus aimed this study at investigating the responses of HNC and HAC to exposure to interleukin (IL)-1? and low oxygen. For this purpose HAC and HNC harvested from the same donors (N=5) were expanded in vitro and then cultured in pellets or collagen-based scaffolds at standard (19%) or low oxygen (5%) conditions. Resulting tissues were analyzed after a short (3 days) exposure to IL-1?, mimicking the initially inflammatory implantation site, or following a recovery time (1 or 2 weeks for pellets and scaffolds, respectively). After IL-1? treatment, constructs generated by both HAC and HNC displayed a transient loss of GAG (up to 21.8% and 36.8%, respectively) and, consistently, an increased production of metalloproteases (MMP)-1 and -13. Collagen type II and the cryptic fragment of aggrecan (DIPEN), both evaluated immunohistochemically, displayed a trend consistent with GAG and MMPs production. HNC-based constructs exhibited a more efficient recovery upon IL-1? withdrawal, resulting in a higher accumulation of GAG (up to 2.6-fold) compared to the corresponding HAC-based tissues. On the other hand, HAC displayed a positive response to low oxygen culture, while HNC were only slightly affected by oxygen percentage. Collectively, under the conditions tested mimicking the postsurgery articular environment, HNC retained a tissue-forming capacity, similar or even better than HAC. These results represent a step forward in validating HNC as a cell source for cartilage tissue engineering strategies

    Genetics in orthopaedic practice

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    DNA holds genetic information in the nucleus of eukaryotic cells; and has three different functions: replication, storage of hereditary information, and regulation of cell division. Most studies described the association of single nucleotide polymorphism (SNP) to common orthopaedics diseases and the susceptibility to develop musculoskeletal injuries. Several mutations are associated with osteoporosis, musculoskeletal ailments and other musculoskeletal deformity and conditions. Several strategies, including gene therapy and tissue engineering with mesenchymal stem cells (MSC), have been proposed to enhance healing of musculoskeletal tissues. Furthermore, a recent technique has revolutionized gene editing: clustered regulatory interspaced short palindromic repeat (CRISPR) technology is characterized by simplicity in target design, affordability, versatility, and high efficiency, but needs more studies to become the preferred platform for genome editing. Predictive genomics DNA profiling allows to understand which genetic advantage, if any, may be exploited, and why a given rehabilitation protocol can be more effective in some individual than others. In conclusion, a better understanding of the genetic influence on the function of the musculoskeletal system and healing of its ailments is needed to plan and develop patient specific management strategies

    3‐D GPR Imaging of Complex Fluvial Stratigraphy at the Boise Hydrogeophysical Research Site

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    A series of three-dimensional (3-D) ground-penetrating radar (GPR) data sets were acquired over the central wellfield area at the Boise Hydrogeophysical Research Site (BHRS). The survey region is 30 m x 18 m and encompasses 13 wells. The goal of the surveys is to image the complex fluvial (cobble-and-sand) stratigraphy around the wellfield. These images will be used to construct 3-D models of the sedimentary architecture and to help constrain fine-scale models of hydrologic and geophysical parameters at the site. The data sets were acquired using 25 MHz, 50 MHz, 100 MHz and 200 MHz antennas. Depth of penetration ranges from -9.6 m for the 200 MHz data to -22 m for the 25 MHz data. Processing significantly improves the reliability and interpretability of the images. The images suggest that the deposit can be subdivided laterally and vertically into several distinct units or radar architectural elements; these elements are typically separated by erosional bounding surfaces. Horizontal bedding, cross-bedding and channel structures are clearly evident in the 100 MHz and 200 MHz data, and a clay layer that underlies the cobble-and-sand aquifer at -20 m depth is successfully imaged in the 25 MHz and 50 MHz data. The water table, at a depth of l-2 m, is imaged in the 100 MHz and 200 MHz data. Time slices and vertical cuts through the data volumes are used to identify the shape and orientation of the different architectural elements, and to accurately locate important hydrostratigraphic boundaries. These data are being used to construct a 3-D model of the hydrogeologic zonation of the aquifer. Hydrologic and geophysical parameter values associated with each zone will be determined from additional field measurements (e.g., hydraulic tests in wells, crosshole radar and seismic tomography, transient electromagnetics, and well logs). The 3-D GPR surveys provide valuable information about the location, scale and geometry of different stratigraphic units at the BHRS

    Treatment of simple bone cyst with bone marrow concentrate and equine-derived demineralized bone matrix injection versus methylprednisolone acetate injections: A retrospective comparative study

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    Objective: The aim of this study was to compare the outcome of intra-lesional autologous bone marrow concentrate (BMC) and equine derived demineralized bone matrix (EDDBM) injections with methylprednisolone acetate injections in patients with simple bone cyst. Methods: Clinical records and radiographs of 53 consecutive patients (37 females, and 16 males; mean age: 10.61 +/- 1.53 years) treated between 2006 and 2016 were retrospectively reviewed. Healing was assessed by an independent radiologist according to Neer scoring system. Functional outcome was assessed with the Activity Scale for Kids (ASK). Thirty-four cysts were in the humerus, 13 in the femur and 6 in other locations. Twenty-nine patients were included in Steroid Group and treated with 3 cycles of injections of methylprednisolone acetate, while 24 patients were treated with injection of autologous bone marrow concentrate and equine derived demineralized bone matrix (BMC + EDDBM Group). The two groups were homogenous for the mean age, sex distribution, cysts location and their clinical presentation. Results: At a minimum follow-up of 24 months, success rate (Neer/Cole score 3 and 4) was higher in EDDBM+BMC group (83.3% vs 58.6%; p=0.047). Female patients had higher healing rates in both groups (p=0.002). No association was found between healing and age (p=0.839), cyst activity (p=0.599), cyst localization (p=0.099) and clinical presentation (p=0.207). BMC+EDDBM group showed higher ASK score (p=0.0007). Conclusion: Treatment with BMC+EDDBM injections may provide better results with a single procedure than 3 methylprednisolone acetate injections and represent an interesting alternative for the treatment of unicameral bone cysts

    Narrow Band Imaging and High Definition Television in endoscopic evaluation of upper aero-digestive tract cancer.

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    Narrow band imaging and high definition television are recent innovations in upper aero-digestive tract endoscopy. Aim of this prospective, non-randomized, unblinded study was to establish the diagnostic advantage of these procedures in the evaluation of squamous cell cancer arising from various upper aero-digestive tract sites. Between April 2007 and January 2010, 444 patients affected by upper aero-digestive tract squamous cell cancer, or previously treated for it, were evaluated by white light and narrow band imaging ± high definition television endoscopy, both in the pre-/intra-operative setting and during follow-up. Tumour resection was performed taking into account narrow band imaging and high definition television information to obtain histopathologic confirmation of their validity. Endoscopic and pathologic data were subsequently matched to obtain sensitivity, specificity, positive, negative predictive values, and accuracy. Overall, 110 (25%) patients showed adjunctive findings by narrow band imaging ± high definition television when compared to standard white light endoscopy. Of these patients, 98 (89%) received histopatological confirmation. The sensitivity, specificity, positive, negative predictive values, and accuracy for white light-high definition television were 41%, 92%, 87%, 82%, and 67%, for narrow band imaging alone 75%, 87%, 87%, 74%, and 80%, and for narrow band imaging-high definition television 97%, 84%, 88%, 96%, and 92%. The highest diagnostic gain was observed in the oral cavity and oropharynx (25%). Narrow band imaging and high definition television were of value in the definition of superficial tumour extension, and in the detection of synchronous lesions in the pre-/intra-operative settings. These technologies also played an important role during post-treatment surveillance for early detection of persistences, recurrences, and metachronous tumours

    Narrow Band Imaging and High Definition Television in the endoscopic evaluation of upper aero-digestive tract cancer

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    Narrow band imaging and high definition television are recent innovations in upper aero-digestive tract endoscopy. Aim of this prospective, non-randomized, unblinded study was to establish the diagnostic advantage of these procedures in the evaluation of squamous cell cancer arising from various upper aero-digestive tract sites. Between April 2007 and January 2010, 444 patients affected by upper aero-digestive tract squamous cell cancer, or previously treated for it, were evaluated by white light and narrow band imaging ± high definition television endoscopy, both in the pre-/intra-operative setting and during follow-up. Tumour resection was performed taking into account narrow band imaging and high definition television information to obtain histopathologic confirmation of their validity. Endoscopic and pathologic data were subsequently matched to obtain sensitivity, specificity, positive, negative predictive values, and accuracy. Overall, 110 (25%) patients showed adjunctive findings by narrow band imaging ± high definition television when compared to standard white light endoscopy. Of these patients, 98 (89%) received histopatological confirmation. The sensitivity, specificity, positive, negative predictive values, and accuracy for white light-high definition television were 41%, 92%, 87%, 82%, and 67%, for narrow band imaging alone 75%, 87%, 87%, 74%, and 80%, and for narrow band imaging-high definition television 97%, 84%, 88%, 96%, and 92%. The highest diagnostic gain was observed in the oral cavity and oropharynx (25%). Narrow band imaging and high definition television were of value in the definition of superficial tumour extension, and in the detection of synchronous lesions in the pre-/intra-operative settings. These technologies also played an important role during post-treatment surveillance for early detection of persistences, recurrences, and metachronous tumours

    Simple mindreading abilities predict complex theory of mind: developmental delay in autism spectrum disorders

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    Theory of Mind (ToM) is impaired in individuals with Autism Spectrum Disorders (ASD). The aims of this study were to: i) examine the developmental trajectories of ToM abilities in two different mentalizing tasks in children with ASD compared to TD children; and ii) to assess if a ToM simple test known as Eyes-test could predict performance on the more advanced ToM task, i.e. Comic Strip test. Based on a sample of 37 children with ASD and 55 TD children, our results revealed slower development at varying rates in all ToM measures in children with ASD, with delayed onset compared to TD children. These results could stimulate new treatments for social abilities, which would lessen the social deficit in ASD
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