92 research outputs found

    The formation of secondary arylphosphines in the reaction of organonickel sigma-complex [NiBr(Mes)(bpy)], where Mes = 2,4,6-trimethylphenyl, bpy = 2,2′-bipyridine, with phenylphosphine

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    © 2016 Taylor & Francis Group, LLC.The reactivity of organonickel sigma-complex [NiBr(Mes)(bpy)], where Mes = 2,4,6-trimethylphenyl, bpy = 2,2’-bipyridine towards phenylphosphine (PhPH2) has been investigated. It was found that this interaction leads to secondary mesitylphenylphosphine and dimesitylphosphine by formation of new carbon-phosphorus bond involving mesityl fragment of starting organonickel sigma-complex

    Эффект интрамиокардиального введения аллогенного биоматериала на уровень ангиогенеза и ремоделирования постишемического рубца у крыс

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    Scar smoothing out, angiogenesis stimulation and cardiomyogenesis in myocardial infarction still remain pressing issues despite the variety of existing methods. One of the ways to correct them is intramyocardial implantation of an alloplant biomaterial (ABM) suspension. ABM serves as an inhibitor of fibroneogenesis in various tissues with chronic inflammatory processes. No studies have been carried out with regards to acute myocardial infarction. Objective: to assess the dynamics of the number of bFGF-1 + cells and CD68 macrophages, the degree of angiogenesis amidst the use of ABM in the formation of postinfarction scar in the experiment. Materials and methods. Experimental studies were performed on 100 male Wistar rats weighing 0.18–0.25 kg. Coronary artery ligation was performed on all animals. In the experimental group, the ABM suspension (12 mg) was injected intramyocardially. We used histological, electron microscopic, immunohistochemical (CD68, bFGF-1), morphometric and statistical research methods. Hearts were procured at day 3, 7, 14, 30, and 45. Results. The use of an allogeneic biomaterial immediately after coronary artery stenosis could reduce the area of cicatricial myocardial degeneration by two fold by accelerating inflammatory response and the onset of early proliferative phase. In the reactive zone after ABM implantation, macrophage myocardial infiltration significantly decreased in comparison to the control group. The use of ABM ensures significant predominance of bFGF-1+ cells in the initial period of inflammation (3–14 days). Subsequently (14–45 days), inflammatory cytokine expression became several times less, which corresponded to biodegradation and resorption of the biomaterial. In the control group, during the acute phase of inflammation (3–14 days), bFGF-1+ cells were low in number. Subsequently (14–45 days), cytokine expression increased significantly, causing rapid accumulation of collagen fibers and scarring. In myocardial regeneration after a heart attack in the experiment, ABM stimulated angiogenesis, whose level was three times higher than in the control group. It was noted that ABM serves as a regulator of the neofibrillogenesis-fibroclasia balance in tissue. Conclusion. Macrophage migration inhibition and suppression of pro-inflammatory orientation of macrophages should be indicated as one of the directions of therapeutic correction strategy for ischemic myocardial injuries. Alloplant biomaterial used in the acute phase of myocardial inflammation can serve as such alternative.Проблемы нивелирования рубца, стимуляция ангиогенеза и кардиомиогенеза при инфаркте миокарда не теряют своей актуальности, несмотря на многообразие существующих методов. Одним из способов их коррекции предлагается интрамиокардиальная имплантация суспензии децеллюляризированного биоматериала (ДЦБМ), изготовленного из волокнистых соединительно-тканных образований аллогенного происхождения. ДЦБМ служит ингибитором фибронеогенеза в различных тканях с хроническими воспалительными процессами. В отношении острого инфаркта миокарда исследования не проводились. Цель. Оценка динамики численности bFGF-1 позитивных клеток, макрофагов CD 68, степени ангиогенеза в условиях применения ДЦБМ при формировании постинфарктного рубца в эксперименте. Материалы и методы. Экспериментальные исследования были проведены на 100 крысах-самцах породы Вистар массой 0,18–0,25 кг. Всем животным проведено лигирование коронарной артерии. В опытной группе интрамиокардиально вводили суспензию ДЦБМ (12 мг). В работе использовали гистологические, электронно-микроскопические, иммуногистохимические (CD 68, bFGF-1), морфометрические и статистические методы исследования. Забор сердец проводили через 3, 7, 14, 30, 45 суток. Результаты. Использование аллогенного биоматериала сразу после стенозирования коронарной артерии позволяет более чем в 2 раза уменьшить площадь рубцового перерождения миокарда за счет ускорения течения воспалительного ответа и наступления ранней пролиферативной фазы. В реактивной зоне после имплантации ДЦБМ значительно снижалась инфильтрация миокарда макрофагами по сравнению с контрольной группой. Использование ДЦБМ обеспечивало значительное преобладание bFGF-1+-клеток в начальный период воспаления (3–14 суток). В последующем (14–45 суток) экспрессия фиброкина становилась в разы меньше, что соответствовало биодеградации и резорбции биоматериала. В контрольной же группе в период острой фазы воспаления (3–14 суток) уровень bFGF-1+-клеток был низким, а в последующем (14–45 суток) экспрессия цитокина значительно увеличивалась, что вызывало стремительное накопление коллагеновых волокон и рубцевание. В процессе формирования постинфарктного регенерата в эксперименте ДЦБМ стимулировал ангиогенез, уровень которого превышал показатели контрольной группы в три раза. Отмечено, что биоматериал служил регулятором баланса неофибриллогенеза-фиброклазии в ткани. Заключение. Одним из направлений стратегии терапевтической коррекции при ишемических повреждениях миокарда следует указать ингибирование миграции макрофагов и подавление их провоспалительной направленности. В качестве такой альтернативы может являться аллогенный децеллюляризированный биоматериал, изготовленный из экстраклеточного матрикса, примененный в острой фазе воспаления миокарда

    Quantitative super-resolution solid immersion microscopy via refractive index profile reconstruction

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    Solid Immersion (SI) microscopy is a modern imaging modality that overcomes the Abbe diffraction limit and offers novel applications in various branches of visible, infrared, terahertz, and millimeter-wave optics. Despite the widespread use, SI microscopy usually results in qualitative imaging. Indeed, it presents only the raw distributions (in the image plane) of the backscattered field intensity, while unlocking the information about the physical properties of an imaged object, such as its complex refractive index (RI) distribution, requires resolving the inverse problem and remains a daunting task. In this paper, a method for resolving the SI microscopy inverse problem is developed, capable of reconstructing the RI distribution at the object imaging plane with subwavelength spatial resolution, while performing only intensity measurements. The sample RI is retrieved via minimization of the error function that characterizes discrepancy between the experimental data and the predictions of analytical model. This model incorporates all the key features of the electromagnetic-wave interaction with the SI lens and an imaged object, including contributions of the evanescent and ordinary-reflected waves, as well as effects of light polarization and wide beam aperture. The model is verified numerically, using the finite-element frequency-domain method, and experimentally, using the in-house reflection-mode continuous-wave terahertz SI microscope. Spatial distributions of the terahertz RIs of different low-absorbing optical materials and highly absorbing biological objects were studied and compared to a priori known data to demonstrate the potential of the novel SI microscopy modality. Given the linear nature of the Maxwell’s equations, the developed method can be applied for subwavelength-resolution SI microscopy at other spectral ranges

    Bone Marrow-Derived Cells from Male Donors Do Not Contribute to the Endometrial Side Population of the Recipient

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    Accumulated evidence demonstrates the existence of bone marrow-derived cells origin in the endometria of women undergoing bone marrow transplantation (BMT). In these reports, cells of a bone marrow (BM) origin are able to differentiate into endometrial cells, although their contribution to endometrial regeneration is not yet clear. We have previously demonstrated the functional relevance of side population (SP) cells as the endogenous source of somatic stem cells (SSC) in the human endometrium. The present work aims to understand the presence and contribution of bone marrow-derived cells to the endometrium and the endometrial SP population of women who received BMT from male donors. Five female recipients with spontaneous or induced menstruations were selected and their endometrium was examined for the contribution of XY donor-derived cells using fluorescent in situ hybridization (FISH), telomapping and SP method investigation. We confirm the presence of XY donor-derived cells in the recipient endometrium ranging from 1.7% to 2.62%. We also identify 0.45–0.85% of the donor-derived cells in the epithelial compartment displaying CD9 marker, and 1.0–1.83% of the Vimentin-positive XY donor-derived cells in the stromal compartment. Although the percentage of endometrial SP cells decreased, possibly being due to chemotherapy applied to these patients, they were not formed by XY donor-derived cells, donor BM cells were not associated with the stem cell (SC) niches assessed by telomapping technique, and engraftment percentages were very low with no correlation between time from transplant and engraftment efficiency, suggesting random terminal differentiation. In conclusion, XY donor-derived cells of a BM origin may be considered a limited exogenous source of transdifferentiated endometrial cells rather than a cyclic source of BM donor-derived stem cells

    Characteristics of Stem Cells Derived from the Degenerated Human Intervertebral Disc Cartilage Endplate

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    Mesenchymal stem cells (MSCs) derived from adult tissues are an important candidate for cell-based therapies and regenerative medicine due to their multipotential differentiation capability. MSCs have been identified in many adult tissues but have not reported in the human intervertebral disc cartilage endplate (CEP). The initial purpose of this study was to determine whether MSCs exist in the degenerated human CEP. Next, the morphology, proliferation capacity, cell cycle, cell surface epitope profile and differentiation capacity of these CEP-derived stem cells (CESCs) were compared with bone-marrow MSCs (BM-MSCs). Lastly, whether CESCs are a suitable candidate for BM-MSCs was evaluated. Isolated cells from degenerated human CEP were seeded in an agarose suspension culture system to screen the proliferative cell clusters. Cell clusters were chosen and expanded in vitro and were compared with BM-MSCs derived from the same patient. The morphology, proliferation rate, cell cycle, immunophenotype and stem cell gene expression of the CESCs were similar to BM-MSCs. In addition, the CESCs could be induced into osteoblasts, adipocytes, chondrocytes, and are superior to BM-MSCs in terms of osteogenesis and chondrogenesis. This study is first to demonstrate the presence of stem cells in the human degenerated CEP. These results may improve our understanding of intervertebral disc (IVD) pathophysiology and the degeneration process, and could provide cell candidates for cell-based regenerative medicine and tissue engineering

    It is time to define an organizational model for the prevention and management of infections along the surgical pathway: a worldwide cross-sectional survey

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    Background: The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants’ perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. Methods: A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. Results: Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. Conclusion: Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened

    Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

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    Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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