1,720,982 research outputs found
Ex-Vivo Evaluation of “First Tip Closing” Radiofrequency Vessel Sealing Devices for Swine Small Intestinal Transection
Get PDFSIMPLE SUMMARY: The study observed the burst pressure (BP), number of activations, and histological evaluation of ex vivo swine small intestinal loops transected by stapler, a single fulcrum radiofrequency vessel sealing (RFVS—Ligasure Atlas) device, and the newly-invented jaws RFVS (Caiman). Caiman5, Caiman Maryland, Caiman12, Ligasure Atlas, and Stapler were employed as experimental groups, with Stapler serving as the control group. Caiman5, Caiman12, and the stapler needed just one activation to complete the seal. The Caiman5 and Caiman Maryland groups had considerably lower mean blood pressures than the Stapler group. The RFVS Caiman12 and Ligasure Atlas generated mean BP results that were comparable to the Stapler and did not vary. Caiman12 and Ligasure Atlas generate equivalent mechanical capabilities as well as stapled intestinal closure, while Caiman12 requires just one activation to complete the transection. ABSTRACT: This study compared burst pressure (BP), number of activations, and histological assessment of ex vivo swine small intestine loops transected by stapler, a single fulcrum radiofrequency vessel sealing (RFVS) device, and the newly-developed jaws RFVS. Fifty (n = 50) 20 cm long jejunal loops were randomly assigned to be transected with RFVS devices and linear stapler (Caiman5, Caiman Maryland, Caiman12, Ligasure Atlas, and Stapler group as control respectively). Caiman5, Caiman12 and stapler required only one activation to complete the sealing. The mean BP in Caiman5 and Caiman Maryland groups were significantly lower (p < 0.05) than the S group as control and the other RFVS devices studied. RFVS Caiman12 and Ligasure Atlas produced mean BP values that were close to the Control and did not differ between them. The lumen was totally closed in the Caiman12 and Ligasure Atlas groups. The findings of this investigation were promising; we discovered that Caiman12 and Ligasure Atlas produce comparable mechanical capabilities as well as stapled intestinal closure, however Caiman12 need a single activation to complete the transection
Treatment of Monolateral Legg-Calvé-Perthes Disease with Autologous Bone Marrow Mononuclear Cells in 32 Dogs
Get PDFObjective In the present study, we report our results of the use of autologous bone marrow mononuclear cells (BMMCs) as a minimally invasive treatment for Legg-Calvé-Perthes in dogs.
Study Design In accordance with Ljunggren's scale, inclusion criteria were determined by clinical condition and radiographic features of the disease, resulting in 32 dogs enrolled in this retrospective study from 2007 to 2019. Bone marrow was collected from each dog from the iliac crest and the mononuclear fraction was separated with density gradient centrifugation. The mean number of BMMCs was 104.7 ± 46.5 × 106 cells. The mean BMMC colony-forming units were 71.6 ± 51.9 × 102/mL.
Cells were suspended in fibrin glue before BMMC administration and implanted via transcutaneous injection under computed tomography or radiographic guidance, using a Jamshidi needle inserted through the femoral head and neck.
Results A progressive reduction of pain within 3 weeks after BMMC administration was observed in 28 patients, with gradually increased weight bearing on the affected limb. In four dogs, however, pain and lameness persisted and at 3 months post-BMMC injection, femoral head and neck resection was performed. Histological and immunohistochemical studies were done on samples from those four dogs, which showed evidence of formation of new cartilage and subchondral bone in the area where cells were implanted.
Clinical Significance Based on these results, BMMC therapy may be considered as effective and minimally invasive treatment option for LCPD in dogs
PS2.3: 3D biomimetic PLGA scaffolds engineered with amniotic epithelial stem cells promote in vitro and in vivo tendon regeneration via paracrine and immunomodulatory mechanisms
No full textIntroduction: Tendon injuries still represent a medical challenge due to their limited healing capacity and the risk of chronic inflammation and fibrosis. Tissue engineering represents a promising strategy to support tendon regeneration. Bioinspired scaffolds mimicking native tendon architecture may offer a functional solution by supporting tenogenic differentiation and modulating immune responses. This study investigated the regenerative potential of electrospun poly(lactide-co-glycolide) (PLGA) 3D tendon biomimetic scaffolds engineered with amniotic epithelial stem cells (AECs), in vitro and in vivo.
Methods: PLGA scaffolds were fabricated via electrospinning to mimic tendon hierarchical architecture. AECs were engineered on 3D scaffolds and the resulting conditioned media (CM) were collected and characterised. In vitro, CM effects were tested on angiogenesis (HUVECs), immune modulation (PBMCs and Jurkat cells), and tenogenesis (co-cultured naïve AECs). Expression of tendon markers (SCX, COL1, TNMD, THBS4) was assessed at gene and protein levels. For in vivo validation, the AEC-engineered 3D scaffolds were allotransplanted into a validated sheep Achilles tendon defect model. Explanted tissues (n=10) at day 14 (d14) were evaluated for scaffold biocompatibility, engraftment, teno-differentiation, and local immune modulation.
Results: AECs cultured on 3D scaffolds exhibited enhanced secretion of VEGF-D, PDGF-BB, b-FGF, and RANTES compared to control groups (p < 0.0001). CM significantly reduced PBMC proliferation and Jurkat NF-κB activation (p < 0.001), indicating a strong immunosuppressive effect, without promoting HUVECs proliferation and tubule formation. Naïve AECs co-cultured with AEC-3D scaffolds exhibited robust teno-differentiation, with significant upregulation of COL1, TNMD, and THBS4 (p < 0.01) and TNMD protein expression (p < 0.01). In vivo, the scaffolds were well tolerated, successfully engrafted, and induced in situ teno-differentiation of the transplanted AECs. Histological and molecular analyses, differently from control tendons, revealed an organised COL1 deposition, modulation of local inflammation and preferential M2 macrophages recruitment, indicating a regenerative response.
Conclusion: AEC-engineered 3D PLGA scaffolds embody a next-generation approach to tendon regeneration, offering a smart, biomimetic platform that actively instructs stem cell fate and orchestrates immune modulation. By simultaneously guiding tenogenic differentiation and modulating the immune response, these constructs shift from passive supports into dynamic drivers of tissue regeneration. Their efficacy, demonstrated in vitro and in a large-animal tendon injury model, paves the way for their application in regenerative medicine. Beyond structural integration, they established a pro-regenerative niche that promoted organized extracellular matrix deposition and M2 macrophage recruitment. Future preclinical studies will focus on long-term functional recovery as a proof of concept for translational feasibility and clinical scalability in tendon therapies.
This research has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement ID 955685—Perspective for Future Innovation in Tendon Repair H2020MSCA-ITN-EJD-P4 FIT. European Union—NextGenerationEU—under the Italian Ministry of University and Research (MUR) National Innovation Ecosystem grant no. ECS00000041 – VITALITY – CUP C43C22000380007. Progetti di Rilevante Interesse Nazionale (PRIN) – Smart Biomimetic Device for Tendon Tissue Engineering – CUP C53D23005440006
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Respiratory effects of low versus high tidal volume with or without positive end-expiratory pressure in anesthetized dogs with healthy lungs
No full textOBJECTIVE To evaluate the impact of 2 tidal volumes (TVs) with or without positive end-expiratory pressure (PEEP) on lung mechanics, aeration, and gas exchange in healthy anesthetized dogs. ANIMALS 40 mixed-breed dogs with healthy lungs. PROCEDURES Anesthetized dogs were randomly assigned to 4 groups (n = 10/group) with different ventilatory settings: TVof 8 mL/kg and PEEP of 0 cm H2O (low TVgroup), TVof 8 mL/kg and PEEP of 5 cm H2O (low TVplus PEEP group), TVof 15 mL/kg and PEEP of 0 cm H2O (high TVgroup), or TVof 15 mL/kg and PEEP of 5 cm H2O (high TVplus PEEP group). Expired CO2and respiratory rate were titrated on the basis of a predetermined stepwise protocol. Gas exchange, respiratory mechanics, and pulmonary aeration were evaluated by means of CT 30 minutes after starting mechanical ventilation at the assigned setting. RESULTS Partial pressures of arterial and expired CO2were higher in the low TVand low TVplus PEEP groups than in the high TVand high TVplus PEEP groups. Peak and plateau airway pressures were higher in the PEEP group than in the other groups. Static lung compliance was higher in the high TVplus PEEP group than in the low TVgroup. Relative percentages of atelectatic and poorly aerated lung were lower in the high TVplus PEEP group than in the other groups. Oxygenation was similar among groups. CONCLUSIONS AND CLINICAL RELEVANCE Differences in TVand PEEP application during mechanical ventilation may affect respiratory function in anesthetized dogs with healthy lungs. Ventilation with a TVof 15 mL/kg and PEEP of 5 cm H2O significantly improved lung compliance and reduced the amount of atelectatic and poorly aerated lung
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