Search results for "physiologic"
showing 10 items of 2593 documents
Two-Armed Activation of Bone Mineral Deposition by the Flavones Baicalin and Baicalein, Encapsulated in Polyphosphate Microparticles
2017
In this study, we investigated the effect of the two flavonoids, baicalin (baicalein 7-O-[Formula: see text]- d-glucuronic acid) and its aglycone, baicalein (5,6,7-trihydroxyflavone), after encapsulation into amorphous calcium polyphosphate (Ca-polyP) microparticles on mineralization of primary human osteoblasts (phOSB). Both flavonoids, which come from root extracts of Scutellaria baicalensis Georgi, are used in Traditional Chinese Medicine, and are nontoxic in cells up to a concentration of 3[Formula: see text][Formula: see text]g/ml. The morphogenetically active, energy-rich Ca-polyP particles with a stoichiometric P:Ca ratio of 1:2 are degraded by cellular alkaline phosphatase (ALP) to…
An injectable bone substitute composed of beta-tricalcium phosphate granules, methylcellulose and hyaluronic acid inhibits connective tissue influx i…
2011
In this study, the in vivo tissue reaction to a new triphasic and injectable paste-like bone-substitute material composed of beta-tricalcium phosphate (β-TCP), methylcellulose and hyaluronic acid was analyzed. Using a subcutaneous implantation model, the interaction of these materials and the peri-implant tissue reaction were tested in Wistar rats for up to 60 days by means of established histological methods, including histomorphometrical analysis. The study focused on tissue integration, classification of the cellular inflammatory response and the degradation of the material. Groups composed of animals injected only with β-TCP granules, sham-operated animals and animals injected with sali…
Mineralization of SaOS-2 cells on enzymatically (silicatein) modified bioactive osteoblast-stimulating surfaces.
2005
There is a demand for novel bioactive supports in surgery, orthopedics, and tissue engineering. The availability of recombinant silica-synthesizing enzyme (silicatein) opens new possibilities for the synthesis of silica-containing bioactive surfaces under ambient conditions that do not damage biomolecules like proteins. Here it is shown that growth of human osteosarcoma SaOS-2 cells on cluster plates precoated with Type 1 collagen is not affected by additional coating of the plates with the recombinant silicatein and incubation with its enzymatic substrate, tetraethoxysilane (TEOS). However, the enzymatic modification of the plates by biosilica deposition on the protein-coated surface cause…
Collagen-embedded hydroxylapatite–beta-tricalcium phosphate–silicon dioxide bone substitute granules assist rapid vascularization and promote cell gr…
2010
In the present study we assessed the biocompatibility in vitro and in vivo of a low-temperature sol-gel-manufactured SiO(2)-based bone graft substitute. Human primary osteoblasts and the osteoblastic cell line, MG63, cultured on the SiO(2) biomatrix in monoculture retained their osteoblastic morphology and cellular functionality in vitro. The effect of the biomaterial in vivo and its vascularization potential was tested subcutaneously in Wistar rats and demonstrated both rapid vascularization and good integration within the peri-implant tissue. Scaffold degradation was progressive during the first month after implantation, with tartrate-resistant acid phosphatase-positive macrophages being …
Influence of β-tricalcium phosphate granule size and morphology on tissue reaction in vivo.
2010
In this study the tissue reaction to five different β-tricalcium phosphate (β-TCP)-based bone substitute materials differing only in size, shape and porosity was analyzed over 60 days, at 3, 10, 15, 30 and 60 days after implantation. Using the subcutaneous implantation model in Wistar rats both the inflammatory response within the implantation bed and the resulting vascularization of the biomaterials were qualitatively and quantitatively assessed by means of standard and special histological staining methods. The data from this study showed that all investigated β-TCP bone substitutes induced the formation of multinucleated giant cells. Changes in size, shape and porosity influenced the int…
Oxygen isotope composition of North American bobcat (Lynx rufus) and puma (Puma concolor) bone phosphate: implications for provenance and climate rec…
2015
Feline carnivores are threatened by illegal wildlife trade. Tracing the provenance of unknown felid tissues via stable isotope analysis could provide important information in wildlife crime investigations. The oxygen isotope composition of mammalian skeletal phosphate (δ(18)Op) is widely applied to trace the origin of animal remains and to reconstruct migratory patterns in palaeontological, archaeological, ecological and wildlife forensic applications. Teeth and bones of terrestrial mammals form at constant body temperature in isotope equilibrium with body water, which is predominantly controlled by ingested meteoric water (δ(18)Ow) that varies systematically with latitude, altitude and cli…
Inhibition of HSP70: a challenging anti-cancer strategy.
2012
HSP70 is a chaperone that accumulates in the cells after many different stresses promoting cell survival in response to the adverse conditions. In contrast to normal cells, most cancer cells abundantly express HSP70 at the basal level to resist to various insults at different stages of tumorigenesis and during anti-cancer treatment. This cancer cells addiction for HSP70 is the rational for its targeting in cancer therapy. Much effort has been dedicated in the last years for the active search of HSP70 inhibitors. Additionally, the recent clinical trials on highly promising inhibitors of another stress protein, HSP90, showed compensatory increase in HSP70 levels and raised the question of nec…
Tumor Hypoxia: Causative Factors, Compensatory Mechanisms, and Cellular Response
2004
Abstract Learning Objectives After completing this course, the reader will be able to: Explain the effect of hypoxia on resistance to treatment. Describe the causes of tumor hypoxia. Characterize cellular response to hypoxia. Access and take the CME test online and receive 1 hour of AMA PRA category 1 credit at CME.TheOncologist.com Hypoxia is a characteristic feature of locally advanced solid tumors resulting from an imbalance between oxygen (O2) supply and consumption. Major causative factors of tumor hypoxia are abnormal structure and function of the microvessels supplying the tumor, increased diffusion distances between the nutritive blood vessels and the tumor cells, and reduced O2 tra…
Selectivity analysis of protein kinase CK2 inhibitors DMAT, TBB and resorufin in cisplatin-induced stress responses.
2009
Udgivelsesdato: 2009-Nov Targeting protein kinases as a therapeutic approach to treat various diseases, especially cancer is currently a fast growing business. Although many inhibitors are available, exhibiting remarkable potency, the major challenge is their selectivity. Here we show that the protein kinase CK2 inhibitors DMAT, TBB and resorufin differ in their selectivity against PI3K family members, since PI3K and DNA-PK are subject to inhibition by DMAT and TBB, however, not by resorufin. TBB and DMAT treatment together with cisplatin lead to an inhibition of cisplatin-induced stress signaling (as detected by phosphorylation of JNK and H2AX). In the case of resorufin no interference wit…
Nupr1-Aurora Kinase A Pathway Provides Protection against Metabolic Stress-Mediated Autophagic-Associated Cell Death
2012
Abstract Purpose: The limited supply of oxygen and nutrients is thought to result in rigorous selection of cells that will eventually form the tumor. Experimental Design: Nupr1 expression pattern was analyzed in human tissue microarray (TMA) and correlated with survival time of the patient. Microarray analysis was conducted on MiaPaCa2 cells subjected to metabolic stress in Nupr1-silenced conditions. DNA repair and cell cycle–associated gene expression was confirmed by real-time quantitative PCR (qRT-PCR). Nupr1 and AURKA protective role were analyzed using RNA interference (RNAi) silencing or overexpression. DNA damage and autophagy were analyzed by Western blot analysis and immunofluoresc…