20 research outputs found
Effects of immunomodulatory drugs on TNF-α and IL-12 production by purified epidermal langerhans cells and peritoneal macrophages
<p>Abstract</p> <p>Background</p> <p>Langerhans cells constitute a special subset of immature dendritic cells localized in the epidermis that play a key role in the skin's immune response. The production of cytokines is a key event in both the initiation and the regulation of immune responses, and different drugs can be used to remove or modify their production by DC and, therefore, alter immune responses in a broad spectrum of diseases, mainly in human inflammatory and autoimmune diseases. In the present study, we examined the effects of prednisone, thalidomide, cyclosporine A, and amitriptyline, drugs used in a variety of clinical conditions, on the production of TNF-α, IL-10, and IL-12 by purified epidermal Langerhans cells and peritoneal macrophages in BALB/c mice.</p> <p>Findings</p> <p>All drugs inhibited TNF-α production by Langerhans cells after 36 hours of treatment at two different concentrations, while prednisone and thalidomide decreased IL-12 secretion significantly, amitriptyline caused a less pronounced reduction and cyclosporine A had no effect. Additionally, TNF-α and IL-12 production by macrophages decreased, but IL-10 levels were unchanged after all treatments.</p> <p>Conclusions</p> <p>Our results demonstrate that these drugs modulate the immune response by regulating pro-inflammatory cytokine production by purified epidermal Langerhans cells and peritoneal macrophages, indicating that these cells are important targets for immunosuppression in various clinical settings.</p
Very Small Embryonic-Like Stem Cells Purified from Umbilical Cord Blood Lack Stem Cell Characteristics
Very small embryonic-like (VSEL) cells have been described as putatively pluripotent stem cells present in murine bone marrow and human umbilical cord blood (hUCB) and as such are of high potential interest for regenerative medicine. However, there remain some questions concerning the precise identity and properties of VSEL cells, particularly those derived from hUCB. For this reason, we have carried out an extensive characterisation of purified populations of VSEL cells from a large number of UCB samples. Consistent with a previous report, we find that VSEL cells are CXCR4+, have a high density, are indeed significantly smaller than HSC and have an extremely high nuclear/cytoplasmic ratio. Their nucleoplasm is unstructured and stains strongly with Hoechst 33342. A comprehensive FACS screen for surface markers characteristic of embryonic, mesenchymal, neuronal or hematopoietic stem cells revealed negligible expression on VSEL cells. These cells failed to expand in vitro under a wide range of culture conditions known to support embryonic or adult stem cell types and a microarray analysis revealed the transcriptional profile of VSEL cells to be clearly distinct both from well-defined populations of pluripotent and adult stem cells and from the mature hematopoietic lineages. Finally, we detected an aneuploid karyotype in the majority of purified VSEL cells by fluorescence in situ hybridisation. These data support neither an embryonic nor an adult stem cell like phenotype, suggesting rather that hUCB VSEL cells are an aberrant and inactive population that is not comparable to murine VSEL cells
Using fibers in the reinforcement of concrete
The main target of the present research is to study the possibility of utilizing used (recycled) polypropylene (PP) packages in the reinforcement of concrete as an alternate for the virgin mono-filament and mesh PP currently in use in Fiber-Reinforced Concrete (FRC). The over-arching benefits of loading concrete with used PP may be summarized as: reducing the cost of FRC as a step towards wider range of applications, as well as utilizing a solid waste as a step towards a cleaner environment. In the present work PP fibers of different geometry (mesh, monofilament and recycled) are added to concrete in different concentrations namely: 0.1% by volume, equivalent to 900 gm fiber/m3 concrete and 0.2% by volume equivalent to 1800 gm fiber/m3 concrete. The concrete specimens are subjected to both normal (soaking in water) and severe (soaking in acids at various concentrations) conditions, for periods of time: 7, 14 and 21 days. Compressive strength test was applied for all prepared blocks after soaking for 7, 14 and 21 days and the average values are recorded. The results obtained for the FRC are compared with those of the blank sample. Results showed that incorporating PP to concrete blocks leads to an enhancement in the compressive strength with increasing the incorporated-fiber concentration up till 0.1%, above which the compressive strength decreased significantly. On soaking in H2SO4, the highest strength for the three types of PP fibers was recorded after 14 days, after which the strength deteriorated rapidly until it reached the lowest value after 21 days. X-Ray analysis was applied in an attempt to interpret the obtained results.</jats:p
Optimization of a saturated gas plant: Meticulous simulation-based optimization – A case study
Effects of aramid fibers and colloidal particle fillers in composite ethylene propylene diene monomer rubber thermal insulators for rocket motor insulation
In this study, we develop and characterize an asbestos-free rubber composite for potential use as a rocket motor insulator. The insulator is based on ethylene propylene diene monomer blended with aramid fiber (Kevlar) in the pulp form (KP), together with alumina and/or silica as reinforcement. Different formulations based on these fillers were prepared. The fillers were dispersed in the ethylene propylene diene monomer polymeric matrix to obtain a homogenous master batch for curing. We analyzed and compared physical, mechanical and thermal properties of different compositions (density, hardness, tensile strength, elongation, ablation resistance and mass loss on heating). Reinforcement of ethylene propylene diene monomer with Kevlar improves the performance of the material with respect to mechanical and thermal properties, while not improving well the performance with respect to ablation resistance. Using hybrid reinforcement (KP + alumina + silica) within ethylene propylene diene monomer improves the performance of ethylene propylene diene monomer with respect to mechanical properties, thermal properties, ablation resistance and thermal decomposition resistance. The optimum performance of the insulation material was achieved when the formulation consisted of 10 part per hundred ratio KP with even amounts of alumina and silica. A novel composite engineered for improved insulation of solid rocket motors using the hybrid reinforcements was developed for the first time, which can be applied in future space missions. </jats:p
Ethane integration project—a study for Egyptian NGLs plants and their economics
Abstract For Egypt, ethane is a vital chemical precursor, with the potential to significantly attract financial resources and drive economic growth. Enhancing its added value necessitates efficient recovery of ethane before it enters the national grid without processing. This research investigates the technical and economic feasibility of integrating natural gas liquids (NGLs) from three Egyptian NGLs plants—South Western Desert NGLs (SWD NGLs), North Western Desert NGLs (NWD NGLs), and East Mediterranean NGLs (EMD NGLs)—to improve ethane recovery from natural gas fields. The study focuses on revamping these NGLs plants using various NGLs recovery techniques, conducting a comprehensive comparison to identify the most effective methods for processing rich feed gas. Detailed design of the NGLs recovery processes was developed using HYSYS V.14 simulation software and supplementary calculation sheets. The design criteria encompass both technical and economic parameters to ensure a holistic approach in meeting project requirements. Results indicate a significant increase in ethane recovery: 16% for SWD NGLs, 10% for NWD NGLs (A, B, C), and 85% for EMD NGLs. This improvement will boost ethane feedstock for petrochemical companies from 2000 ton/day to 3500 ton/day, enabling increased polyethylene production. Economic analysis for the base case shows an expected internal rate of return (IRR) of 26%, a net present value (NPV) of USD 73 million, and a payback period of approximately 3 years. Sensitivity analysis on product prices, feed gas prices, and total capital investment confirms the project’s economic viability, with all cases showing feasibility (IRR ≥ 15%) except when product prices fall below USD 225/ton for propane, USD 215/ton for liquefied petroleum gas (LPG), and USD 25/bbl for condensate. This study highlights the potential for enhanced ethane recovery, offering substantial economic benefits and supporting the growth of Egypt’s petrochemical industry
004 Caractérisation des cellules obtenues lors de la culture des explants limbiques humains
CD4+ CD25+ cells in type 1 diabetic patients with other autoimmune manifestations
AbstractThe existence of multiple autoimmune disorders in diabetics may indicate underlying primary defects of immune regulation. The study aims at estimation of defects of CD4+ CD25+high cells among diabetic children with multiple autoimmune manifestations, and identification of disease characteristics in those children. Twenty-two cases with type 1 diabetes associated with other autoimmune diseases were recruited from the Diabetic Endocrine and Metabolic Pediatric Unit (DEMPU), Cairo University along with twenty-one normal subjects matched for age and sex as a control group. Their anthropometric measurements, diabetic profiles and glycemic control were recorded. Laboratory investigations included complete blood picture, glycosylated hemoglobin, antithyroid antibodies, celiac antibody panel and inflammatory bowel disease markers when indicated. Flow cytometric analysis of T-cell subpopulation was performed using anti-CD3, anti-CD4, anti-CD8, anti-CD25 monoclonal antibodies. Three cases revealed a proportion of CD4+ CD25+high below 0.1% and one case had zero counts. However, this observation did not mount to a significant statistical difference between the case and control groups neither in percentage nor absolute numbers. Significant statistical differences were observed between the case and the control groups regarding their height, weight centiles, as well as hemoglobin percentage, white cell counts and the absolute lymphocytic counts. We concluded that, derangements of CD4+ CD25+high cells may exist among diabetic children with multiple autoimmune manifestations indicating defects of immune controllers
