109 research outputs found
Synthesis and characterization of phosphine substituted organometallic chalcones
The current focus in organometallic chalcones is based upon their synthesis, eloectrochemical properties, diverse biological behavior and their facet towards a new field “bioorganometallics’’ concerning both organometallic and coordination chemistry . The organometallic chalcones can be used as precursor for the synthesis of various other important biologically active heterocyclic compounds. Ferrocene based derivatives which are one of the most extensively studied among metallocenes has also been reported for their application to materials particularly in designing molecular sensors, molecular ferromagnet, electrochemical agent, molecular switch and non-linear optical material. Recently, phosphine chemistry has gained attention due to their tremendous applications and aspects in the field of bioorganometallics. In view of their enormous prospect we carried out the synthesis and characterization of phosphine substituted multimetallic organometallic chalcone. The electrochemical and biological properties of synthesized organometallic chalcone is under investigation
Phosphatidylserine-positive erythrocytes bind to immobilized and soluble thrombospondin-1 via its heparin-binding domain
Phosphatidylserine (PS)-dependent erythrocyte adhesion to endothelium and sub-endothelial matrix components is mediated in part via thrombospondin (TSP). While TSP exhibits multiple cell-binding domains, the PS-binding site on TSP is unknown. Since a cell-binding domain for anionic heparin is located at the amino-terminus, we hypothesized that PS-positive red cells (PS+ve-RBCs) bind to this domain. We demonstrate that both heparin and its low-molecular-weight derivative enoxaparin (0.5-50u/ml) inhibited PS+ve-RBC adhesion to immobilized TSP in a concentration-dependent manner (21-77% inhibition, P\u3c0.05). Pre-incubation of immobilized TSP with an antibody against the heparin-binding domain blocked PS+ve-RBC adhesion to TSP. Antibodies that recognize the collagen- and the carboxy-terminal CD47-binding domain on TSP had no effect on this process. While pre-incubation of PS+ve-RBCs with TSP-peptides from the heparin-binding domain containing the specific heparin-binding motif KKTRG inhibited PS+ve-erythrocyte adhesion to matrix TSP (P\u3c0.001), these peptides in the immobilized form supported PS-mediated erythrocyte adhesion. A TSP-peptide lacking the binding-motif neither inhibited nor supported PS+ve-RBC adhesion. Additional experiments show that soluble-TSP also interacted with PS+ve-RBCs via its heparin-binding domain. Our results demonstrate that PS-positive erythrocytes bind to both immobilized and soluble TSP via its heparin-binding domain and that both heparin and enoxaparin, at clinically relevant concentrations, block this interaction. Other studies have shown that heparin inhibited P-selectin- and soluble-TSP-mediated sickle erythrocyte adhesion to endothelial cells. Our results taken together with the previously documented findings provide a rational basis for clinical use of heparin or its low-molecular-weight derivatives as therapeutic agents in treating vaso-occlusive pain in patients with sickle cell disease
Microvascular endothelial cells express a phosphatidylserine receptor: a functionally active receptor for phosphatidylserine-positive erythrocytes
Phosphatidylserine (PS)-positive erythrocytes adhere to endothelium and subendothelial matrix components. While thrombospondin mediates these inter-actions, it is unknown whether PS-associated erythrocyte-endothelial adhesion occurs in the absence of plasma ligands. Using ionophore-treated PS-expressing control HbAA erythrocytes, we demonstrate that PS-positive erythrocytes adhered to human lung microendothelial cells in the absence of plasma ligands, that this adhesion was enhanced following endothelial activation with IL-1alpha, TNF-alpha, LPS, hypoxia, and heme, and that this adhesive interaction was selective to erythrocyte PS. We next explored whether microendothelial cells express an adhesion receptor that recognizes cell surface-expressed PS (PSR) similar to that expressed on activated macrophages. We demonstrate constitutive expression of both PSR mRNA and protein that were up-regulated in a time-dependent manner following endothelial activation. While minimal PSR expression was noted on unstimulated cells, endothelial activation up-regulated PSR surface expression. In antibody-blocking studies, using PS-positive erythrocytes generated either artificially via ionophore treatment of control erythrocytes or from patients with sickle cell disease, we demonstrate that PSR was functional, supporting PS-mediated erythrocyte adhesion to activated endothelium. Our results demonstrate the existence of a novel functional adhesion receptor for PS on the microendothelium that is up-regulated by such pathologically relevant agonists as hypoxia, cytokines, and heme
STATUS GIZI, ASUPAN MAKAN REMAJA AKHIR YANG BERPROFESI SEBAGAI MODEL
Latar Belakang :Ketidakpuasan terhadap bentuk dan ukuran tubuh semakin sering dijumpai di kalangan remaja putri,khususnya di kalangan model. Masalah yang paling umum dihadapi oleh model yakni membatasi asupan jenis makanan tertentu untuk mendapatkan tubuh yang kurus. Penelitian ini bertujuan untuk mengetahui status gizi, asupan makan remaja putri usia 19-20tahun yang berprofesi sebagai model.
Metode : Peneliti menggunakan deskriptif analitis. Penelitian ini diadakan pada 31 subyek remaja putri usia 19-20 tahun di managemen modeling school.Sampel diambil secara non probability sampling. Kriteria inklusi adalah sehat jasmani dan tidak sedang menjalani pengobatan tertentu. Data perilaku makan diperoleh dari Food Frequency Questionner (FFQ). Analisis data dengan menggunakan Nutrisurvey untuk memperoleh hasil asupan karbohidrat, protein, dan lemak dari subyek.
Hasil : Subyek sebanyak (80,6%) dengan status gizi kurang, asupan karbohidrat, protein dan lemak belum sesuai dengan AKG. Sebanyak (12,9 %) dengan status gizi normal Asupan protein sesuai dengan AKG namun karbohidrat dan lemak tidak sesuai AKG. Sebanyak (6,45%) status gizi normal asupan karbohidrat sesuai namun protein dan lemak belum sesuai dengan AKG.
Simpulan : Asupan remaja akhir yang berprofesi sebagai model belum baik, dan sebagian remaja akhir memiliki status gizi kurang
Heme induces endothelial tissue factor expression: Potential role in hemostatic activation in patients with hemolytic anemia
Objectives: We explored the possibility that heme, an inflammatory mediator and a product of intravascular hemolysis in patients with hemolytic anemia including sickle cell disease, could modulate hemostasis by an effect on endothelial tissue factor (TF) expression.
Methods: Levels of TF mRNA, protein and procoagulant activity were measured in heme-treated endothelial cells. Results: Heme induces TF expression on the surface of both macrovascular and microvascular endothelial cells in a concentration-dependent manner, with 12-fold to 50-fold induction being noted (enzyme-linked immunosorbent assay) between 1 and 100 μm heme (P \u3c 0.05). Complementary flow cytometry studies showed that the heme-mediated endothelial TF expression was quantitatively similar to that of tumor necrosis factor-alpha (TNF-α). Heme also upregulated the expression of TF mRNA (8-fold to 26-fold), protein (20-fold to 39-fold) and procoagulant activity (5-fold to 13-fold) in endothelial cells in a time-dependent manner. The time-course of heme-mediated TF antigen expression paralleled the induction of procoagulant activity, with antibody blocking studies demonstrating specificity for TF protein. Interleukin (IL)-1α, and TNF-α are not involved in mediating the heme effect, as antibodies against these cytokines and IL-1-receptor antagonist failed to block heme-induced TF expression. Inhibition of heme-induced TF mRNA expression by sulfasalazine and curcumin suggested that the transcription factor nuclear factor kappaB is involved in mediating heme-induced TF expression in endothelial cells.
Conclusions: Our results demonstrate that heme induces TF expression by directly activating endothelial cells, and that heme-induced endothelial TF expression may provide a pathophysiologic link between the intravascular hemolytic milieu and the hemostatic perturbations previously noted in patients with hemolytic anemia including sickle cell disease
Low-Temperature Thermoelectric Performance and Optoelectronic Properties of Monolayer of WX2N4(X = Si, Ge)
We investigated the thermoelectric properties of the 2D monolayer of WX2N4
using Density Functional Theory combined with Boltzmann Transport Equation. We
obtained an outstanding thermoelectric figure of merit of 0.91 at 400K for
p-type WGe2N4, whether it showed a ZT value of 0.56 for n-type at the same
temperature. On the other hand, the WSi2N4 showed significantly low ZT at room
temperature.Comment: 16 pages, 9 figure
Spontaneous ruptured splenic artery aneurysm: a case report
Splenic artery aneurysms are rare. We discuss a case of a 58-year-old gentleman presenting with collapse and shock secondary to spontaneous splenic artery aneurysm rupture. Patient underwent laparotomy and splenectomy then discharged home within a week of presentation
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