Search results for "Plate"
showing 10 items of 1689 documents
Early implant healing: promotion of platelet activation and cytokine release by topographical, chemical and biomimetical titanium surface modificatio…
2011
Abstract Objectives: Platelet releasate has been shown to promote osteogenetic cell proliferation and differentiation. Topography and chemistry of biomaterials have high impact on platelet activation. More specifically, the bioactive cell adhesive peptide sequence Arg–Gly–Asp (RGD) triggers platelet activation mediated by the αIIbβ3 integrin receptor. Accordingly, topographical, chemical and biomimetical (immobilized RGD peptide) modifications of titanium (Ti) surfaces may enhance early platelet activation and bony healing of implants. Therefore, the aim of the study was to evaluate platelet activation with subsequent platelet-derived cytokine release by accordingly modified Ti surfaces. Ma…
Bacteria of the Genus Roseobacter Associated with the Toxic Dinoflagellate Prorocentrum lima
1998
The dinoflagellate Prorocentrum lima is known to produce diarrhetic shellfish poisons. However, it is yet unclear if the dinoflagellates themselves or the bacteria associated with them produce the toxins. Here we analyze the toxicity as well as the spectrum of bacteria in two cultures of P. lima, namely P. lima-SY and P. lima-ST, which initially derived from the same P. lima strain PL2V. Toxicity tests, applying the Artemia bioassay revealed in both cultures high levels of toxins. The bacteria, associated with the two cultures, were identified by PCR/nucleotide sequence analysis of the 16S rRNA gene. From cultures of P. lima-SY the dominant sequence was found to share a 93.7% similarity wit…
Staphylococcus aureus alpha-toxin attack on human platelets promotes assembly of the prothrombinase complex.
1990
alpha-Toxin, the major cytolysin of Staphylococcus aureus, promotes blood coagulation by its attack on human platelets (Bhakdi S., Muhly, M., Mannhardt, U., Hugo, F., Klapettek, K., Mueller-Eckhardt, C., and Roka, L. (1988) J. Exp. Med. 168, 527-542). In the present study we demonstrate that toxin attack on gel-filtered human platelets initiates the assembly of prothrombinase complexes at rates up to 10-fold of controls. Treatment of platelets with 0.1 microgram/ml alpha-toxin resulted in generation of 1.4 units of thrombin/10(8) platelets. A similar rate of thrombin generation was noted when platelets were subjected to three cycles of freezing and thawing. However, the alpha-toxin-induced …
In vivo assembly of chromatin on pBR322 sequences cloned into yeast plasmids
1989
Abstract In order to study the in vivo assembly of chromatin on prokaryotic DNA templates, we have transformed yeast cells with plasmids pAJ50 and pRB58, which contain pBR322 sequences. In both cases nucleosomes are assembled in vivo on pBR322 DNA, although the nucleosomes are not homogeneous in size. To explore whether there is any preference for nucleosome assembly along pBR322 sequences, we have used an indirect end labeling method. The results indicate that most nucleosomes are placed at random on pBR322, although the probability for histone octamers to interact with some short regions is somewhat reduced. These regions coincide with sequences in which the frequency distribution of nucl…
Immune Thrombocytopenia: Recent Advances in Pathogenesis and Treatments
2021
Immune thrombocytopenia (ITP) is a rare autoimmune disease due to both a peripheral destruction of platelets and an inappropriate bone marrow production. Although the primary triggering factors of ITP remain unknown, a loss of immune tolerance—mostly represented by a regulatory T-cell defect—allows T follicular helper cells to stimulate autoreactive splenic B cells that differentiate into antiplatelet antibody-producing plasma cells. Glycoprotein IIb/IIIa is the main target of antiplatelet antibodies leading to platelet phagocytosis by splenic macrophages, through interactions with Fc gamma receptors (FcγRs) and complement receptors. This allows macrophages to activate autoreactive T cells …
Cellular effects of HMG-CoA reductase inhibitors on blood cells (monocytes, macrophages, platelets)
2002
Atherosclerosis is the primary cause of ischaemic heart disease (IHD) and stroke and the leading cause of death and long-term disabilities in westernized societies. Several important environmental and genetic risk factors are associated with atherosclerosis. Over the past decade, it has become evident that atherosclerosis is not simply an inevitable degenerative consequence of ageing, but rather a chronic inflammatory condition connecting altered cholesterol metabolism and other risk factors to the development and progression of the atherosclerotic lesion and its sequelae like plaque rupture, fibrosis, calcification and thrombosis [1].
Validation of the ISTH/SSC bleeding assessment tool for inherited platelet disorders: A communication from the Platelet Physiology SSC
2020
Background: Careful assessment of bleeding history is the first step in the evaluation of patients with mild/moderate bleeding disorders, and the use of a bleeding assessment tool (BAT) is strongly encouraged. Although a few studies have assessed the utility of the ISTH-BAT in patients with inherited platelet function disorders (IPFD) none of them was sufficiently large to draw conclusions and/or included appropriate control groups. Objectives: The aim of the present study was to test the utility of the ISTH-BAT in a large cohort of patients with a well-defined diagnosis of inherited platelets disorder in comparison with two parallel cohorts, one of patients with type-1 von Willebrand disea…
The EasyTube during general anesthesia for minor surgery
2017
BACKGROUND The EasyTube (EzT) is a supraglottic airway device that is used for emergency airway situations. Ventilation during general anesthesia should also be feasible, but literature on the EzT is scarce. We evaluated the EzT in comparison with the endotracheal tube (ETT) in its use during general anesthesia in a comparative study. METHODS A total of 400 patients with American Society of Anesthesiologists (ASA) physical status I to II scheduled for minor surgery in 4 centers were randomized for ventilation via the ETT or EzT. RESULTS In all patients, the EzT and the ETT could be inserted within 3 attempts. In all EzT patients, the inspiratory and expiratory minute volumes (6.64 ± 0.71 an…
Endodontic management of single rooted immature mandibular second molar with single canal using MTA and platelet-rich fibrin membrane barrier: A case…
2011
An immature tooth with pulpal necrosis and periapical pathology imposes a great difficulty to the endodontists. Endodontic treatment options for such teeth consist of conventional apexification procedure with and without apical barriers. Various materials have been tried as apical matrix in the past. This article demonstrates the newer concept of using platelet rich fibrin membrane as an apical matrix barrier for stabilization of MTA in root end apexification procedure. Platelet Rich Fibrin is an autologous fibrin matrix containing a large quantity of platelet and leukocyte cytokines, which enhance healing by release of growth factors. This case report represents successful management of a …