52 research outputs found

    Connecting continuum poroelasticity with discrete synthetic vascular trees for modeling liver tissue

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    Computational simulations have the potential to assist in liver resection surgeries by facilitating surgical planning, optimizing resection strategies, and predicting postoperative outcomes. The modeling of liver tissue across multiple length scales constitutes a significant challenge, primarily due to the multiphysics coupling of mechanical response and perfusion within the complex multiscale vascularization of the organ. In this paper, we present a modeling framework that connects continuum poroelasticity and discrete vascular tree structures to model liver tissue across disparate levels of the perfusion hierarchy. The connection is achieved through a series of modeling decisions, which include source terms in the pressure equation to model inflow from the supplying tree, pressure boundary conditions to model outflow into the draining tree, and contact conditions to model surrounding tissue. We investigate the numerical behaviour of our framework and apply it to a patient-specific full-scale liver problem that demonstrates its potential to help assess surgical liver resection procedure

    Effect of Protocol of Care on Clinical Outcomes of Patients with Chest Tube Post Cardiothoracic Surgery

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    Cardiothoracic surgery is a surgical specialty, which deals with the diagnosis and management of surgical conditions of the heart, lungs and esophagus (1) .Chest tube (CT) is an invasive procedure which inserted post cardiothoracic surgery to facilitate lung expansion and allowing  the drainage of fluids from the chest cavity. Aim: this study aimed to evaluate the effect of protocol of care on clinical outcomes of patients with chest tube post cardiothoracic surgery. Materials and method a quasi-experimental research design was conducted at Cardiothoracic Surgery Department at Tanta University hospital. A purposive sample of 80 adult patients with chest tube based on statistical power analysis were selected and divided into two equal group 40 patients in each group as follows: Group 1: (Study group): consist of 40 adult patients were received protocol of care implemented by the researcher. Group 2: (Control group): consists of 40 adult patients who were received routine nursing care by hospital nursing staff. Three Tools were used to collect the data .Tool (I) Biosocio-demographic characteristics. Tool (II) Chest tube assessment, Tool (III) Pain assessment. Results:- The mean duration of ICU stay in control group (6.77) was higher than in the study group (4.97) days, more than half (52.6%)of the patients in the control group at the 7th day of the study had elevated body temperature comparing to none  in the study group, nearly two third (62.5%) of patients has  a positive culture swab in the control group at the  7th day of the study group ,compared to about  third(35%) of patients in the study group. More than half of patients (52.5%) in the control group had a severe pain during removal of chest tube compared to small percentage (5.0%) in the study group. Conclusions and recommendations:-Protocol of nursing care which was composed of deep breathing and coughing   exercises, sterile technique during chest tube dressing, and cold application, are recommended for all cardiothoracic surgical patients with chest tube. Keywords: Protocol of Care, Clinical Outcomes, Cardiothorathic Surger

    Efficacy of mRNA anti-SARS-CoV-2 vaccination and dynamics of humoral immune response in patients with solid tumors: results from the institutional registry of an italian tertiary cancer center

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    Background: Systemic immunosuppression characterizing cancer patients represents a concern regarding the efficacy of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, and real-world evidence is needed to define the efficacy and the dynamics of humoral immune response to mRNA-based anti-SARS-CoV-2 vaccines. Methods: We conducted an observational study that included patients with solid tumors who were candidates for mRNA anti-SARS-CoV-2 vaccination at the Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. The primary objective was to monitor the immunologic response to the mRNA anti-SARS-CoV-2 vaccination in terms of anti-spike antibody levels. All the patients received two doses of the mRNA-1273 vaccine or the BNT162b2 vaccine. Healthcare workers served as a control group of healthy subjects. Results: Among the 243 patients included in the present analysis, 208 (85.60%) and 238 (97.94%) resulted seroconverted after the first and the second dose of vaccine, respectively. Only five patients (2.06%) had a negative titer after the second dose. No significant differences in the rate of seroconversion after two vaccine doses were observed in patients as compared with the control group of healthy subjects. Age and anticancer treatment class had an independent impact on the antibody titer after the second dose of vaccination. In a subgroup of 171 patients with available data about the third timepoint, patients receiving immunotherapy with immune checkpoint inhibitors seem to have a higher peak of antibodies soon after the second dose (3 weeks after), but a more pronounced decrease at a late timepoint (3 months after). Conclusions: The systemic immunosuppression characterizing cancer patients did not seem to dramatically affect the humoral response to anti-SARS-CoV-2 mRNA vaccines in our population of patients with solid tumors. Further investigation is needed to dissect the interplay between immunotherapy and longitudinal dynamics of humoral response to mRNA vaccines, as well as to analyze the cellular response to mRNA vaccines in cancer patients

    Betacellulin Induces Increased Retinal Vascular Permeability in Mice

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    BACKGROUND: Diabetic maculopathy, the leading cause of vision loss in patients with type 2 diabetes, is characterized by hyper-permeability of retinal blood vessels with subsequent formation of macular edema and hard exudates. The degree of hyperglycemia and duration of diabetes have been suggested to be good predictors of retinal complications. Intervention studies have determined that while intensive treatment of diabetes reduced the development of proliferative diabetic retinopathy it was associated with a two to three-fold increased risk of severe hypoglycemia. Thus we hypothesized the need to identify downstream glycemic targets, which induce retinal vascular permeability that could be targeted therapeutically without the additional risks associated with intensive treatment of the hyperglycemia. Betacellulin is a 32 kD member of the epidermal growth factor family with mitogenic properties for the retinal pigment epithelial cells. This led us to hypothesize a role for betacellulin in the retinal vascular complications associated with diabetes. METHODS AND FINDINGS: In this study, using a mouse model of diabetes, we demonstrate that diabetic mice have accentuated retinal vascular permeability with a concomitant increased expression of a cleaved soluble form of betacellulin (s-Btc) in the retina. Intravitreal injection of soluble betacellulin induced retinal vascular permeability in normoglycemic and hyperglycemic mice. Western blot analysis of retinas from patients with diabetic retinopathy showed an increase in the active soluble form of betacellulin. In addition, an increase in the levels of A disintegrin and metalloproteinase (ADAM)-10 which plays a role in the cleavage of betacellulin was seen in the retinas of diabetic mice and humans. CONCLUSIONS: These results suggest that excessive amounts of betacellulin in the retina may contribute to the pathogenesis of diabetic macular edema

    Prediction Models Based on Soil Characteristics for Evaluation of the Accumulation Capacity of Nine Metals by Forage Sorghum Grown in Agricultural Soils Treated with Varying Amounts of Poultry Manure

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    Predictive models were generated to evaluate the degree to which nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were absorbed by the leaves, stems and roots of forage sorghum in growing media comprising soil admixed with poultry manure concentrations of 0, 10, 20, 30 and 40 g/kg. The data revealed that the greatest contents of the majority of the metals were evident in the roots rather than in the stems and leaves. A bioaccumulation factor (BAF)  1. Translocation factor values were < 1 for all metals with the exception of Co, Cr and Ni, which displayed values of 1.20, 1.67 and 1.35 for the leaves, and 1.12, 1.23 and 1.24, respectively, for the stems. The soil pH had a negative association with metal tissues in plant parts. A positive relationship was observed with respect to plant metal contents, electrical conductivity and organic matter quantity. The designed models exhibited a high standard of data precision; any variations between the predicted and experimentally observed contents for the nine metals in the three plant tissue components were nonsignificant. Thus, it was concluded that the presented predictive models constitute a pragmatic tool to establish the safety from risk to human well-being with respect to growing forage sorghum when cultivating media fortified with poultry manure.The authors extend their appreciation to the Deputyship for Research and Innovation, Ministry of Education in Saudi Arabia for funding this research work through the project number IFP-KKU-2020/3.Peer reviewe

    A peptide derived from TIMP-3 inhibits multiple angiogenic growth factor receptors and tumour growth and inflammatory arthritis in mice

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    The binding of vascular endothelial growth factor (VEGF) to VEGF receptor-2 (VEGFR-2) on the surface of vascular endothelial cells stimulates many steps in the angiogenic pathway. Inhibition of this interaction is proving of value in moderating the neovascularization accompanying age-related macular degeneration and in the treatment of cancer. Tissue inhibitor of metalloproteinases-3 (TIMP-3) has been shown to be a natural VEGFR-2 specific antagonist—an activity that is independent of its ability to inhibit metalloproteinases. In this investigation we localize this activity to the C-terminal domain of the TIMP-3 molecule and characterize a short peptide, corresponding to part of this domain, that not only inhibits all three VEGF-family receptors, but also fibroblast growth factor and platelet-derived growth factor receptors. This multiple-receptor inhibition may explain why the peptide was also seen to be a powerful inhibitor of tumour growth and also a partial inhibitor of arthritic joint inflammation in vivo

    Modeling of Growth using an Immersed Finite Element Method

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    To prevent remeshing, we explore the use of a non‐boundary‐fitted finite element method for the computational modeling of growth including contact mechanics. Accordingly, we utilize a mesh‐related mapping procedure for the use of implicit geometry description by a level set function within the framework of immersed methods. Hence, our framework provides a setting to include patient‐specific geometries based on imaging data as we use a level set function for the implicit geometry description. In this contribution, we show that the proposed approach is a viable alternative for problems with mesh‐related obstacles, in particular when large growth simulations on complex patient‐specific geometries are of primary interest

    Prediction Models for Evaluating the Uptake of Heavy Metals by the Invasive Grass Vossia cuspidata (Roxb.) Griff. in the River Nile, Egypt: A Biomonitoring Approach

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    This study aimed to develop new prediction models that include sediment properties (pH, organic matter, and silt and clay concentrations) for estimating the potential uptake of heavy metals (HMs) by the invasive grass Vossia cuspidata. Plant and sediment samples were collected from the microsites that represent the natural distribution of the species in two Nile islands in Cairo, Egypt. The results show that the root was the main accumulating organ for the analyzed HMs (Fe, Mn, Zn, Cu, Ni, and Pb). The mean concentrations of Fe and Mn and the maximum concentrations of Cu, Ni, and Pb were phytotoxic. The values of the bioconcentration factor were &gt;1, while the translocation factor was &gt;1 for Zn and Cu in rhizome and stem, Mn in leaf, and Ni and Pb in stem and leaf. There were no significant differences between the measured and the predicted HM concentrations in all organs of the species. This indicates the excellent robustness of the developed regression models. Sixteen equations (out of 24) had high R2 values. Thus, V. cuspidata could be considered a biomonitor for HM pollution, and the developed equations will benefit the prediction of HM uptake by the species in the River Nile ecosystem
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