105 research outputs found
Different titanium surfaces modulate the bone phenotype of SaOS-2 osteoblast-like cells.
Commercially pure titanium implants presenting a relatively smooth, machined surface or a roughned endosseous surface show a large percentage of clinical successes. Surface properties of dental implants seem to be important with respect to bone cells response. Implant topography appears to modulate cell growth and differentiation of osteoblasts affecting the bone healing around the titanium implant. The aim of the present study was to examine the effects of three different titanium surfaces on cell morphology, adhesion and bone phenotypic expression of human osteoblast-like cells, SaOS-2. SaOS-2 cells were cultured on commercially pure titanium disks of 1 cm in diameter with three different surface roughness: smooth (S), sandblasted (SB) and titanium plasma sprayed (TPS). Differences in the cell morphology were found on the three surfaces showing an uniform monolayer of shaped cells on the S surfaces, and clusters of multilayered cells with an irregular shape on the rough surfaces. The adhesion of SaOS-2 cells, as measured after 3h of culture, was not affected by surface roughness. ECM components such as collagen I (CoI), fibronectin (FN), vitronectin (VN) and tenascin (TN) were secreted and organized only on SB and TPS surfaces while on S surfaces they remained in the cytoplasm. Osteopontin and BSP-II were largely detected on SB and TPS surfaces, while only minimal production was observed on S surfaces. These data show that titanium surface roughness affects bone differentiation of osteoblast like-cells, SaOS-2, indicating that surface properties may be able to modulate the osteoblast phenotype. These observations also suggest that the bone healing response around dental implants can be affected by surface topography
Evidence That p-Cresol and IL-6 Are Adsorbed by the HFR Cartridge: Towards a New Strategy to Decrease Systemic Inflammation in Dialyzed Patients?
Introduction
Hemodialysis (HD) and hemodiafiltration clear only with a low efficiency the plasma from interleukin-6 and p-cresol, two protein-bound uremic toxins associated with high cardiovascular risk in end stage renal disease. HFR Supra is a double-chamber hemodiafiltration system in which the ultrafiltrate returns to the patient after its regeneration through a resin cartridge that binds hydrophobic and protein-bound solutes. In the present study, we evaluated whether the HFR cartridge can also bind total p-cresol and IL-6 and remove them from the ultrafiltrate.
Methods
We compared the levels of IL-6 and p-cresol in ultrafiltrate samples collected at the inlet (UFin) and at the outlet (UFout) of the cartridge at the start or at the end of a 240 min HFR session in 12 inflamed chronic HD patients. The pro-inflammatory activity of the ultrafiltrate samples was also determined by evaluating the changes that they induced in IL-6 mRNA expression and protein release in peripheral blood mononuclear cells from 12 healthy volunteers. IL-6 and p-cresol circulating levels were also assessed in peripheral plasma blood samples collected before and after HFR and, for comparison, a control HD.
Results
p-Cresol and IL-6 were lower in UFout than in UFin both at the start and at the end of the HFR session, suggesting that they were retained by the cartridge. IL-6 mRNA expression and release were lower in PBMC incubated with UFout collected at the end than with UFin collected at the start of HFR, suggesting that passage through the cartridge reduced UF pro-inflammatory activity. Plasma total p-cresol decreased by about 53% after HFR, and 37% after HD. IL-6 circulating values were unmodified by either these dialysis procedures.
Conclusions
This study shows that the HFR-Supra cartridge retains total p-cresol and IL-6 in the ultrafiltrate and lowers plasma total p cresol but not IL-6 levels.
Trial Registration
ClinicalTrials.gov NCT0186577
The urokinase/urokinase receptor system in mast cells: effects of its functional interaction with fmlf receptors
Mast cell and basophils express the high
affinity receptor for IgE (FcRI) and are primary
effector cells of allergic disorders. The urokinase
(uPA)-mediated plasminogen activation system is
involved in physiological and pathological events
based on cell migration and tissue remodelling, such
as inflammation, wound healing, angiogenesis and
metastasis. uPA is a serine protease that binds uPAR,
a high affinity glycosyl-phosphatidyl-inositol (GPI)-
anchored receptor. uPAR focuses uPA activity at the
cell surface and activates intracellular signaling
through lateral interactions with integrins, receptor
tyrosine kinases and the G-protein-coupled family of
fMLF chemotaxis receptors (FPRs).
We investigated the expression of the uPAuPAR system and its functional interaction with
FPRs in human mast cells (MCs). Differently from
basophils, MCs produced uPA that was able to
induce their chemotaxis. Indeed, MCs also expressed
uPAR, both in the intact and in a cleaved form (DIIDIII-uPAR) that can expose, at the N-terminus, the
SRSRY sequence, able to interact with FPRs and to
mediate cell chemotaxis. MCs also expressed
mRNAs for FPRs that were functionally active;
indeed, uPA and a soluble peptide (uPAR84-95),
containing the SRSRY chemotactic sequence of
uPAR and able to interact with FPRs, were able to
induce MCs chemotaxis.
Thus, uPA is a potent chemoattractant for
MCs acting through the exposure of the chemotactic
epitope of uPAR, that is an endogenous ligand for
FPRs. The same mechanism could be involved in
VEGF-A secretion by human MCs, also induced by
uPA and uPAR84-95 stimulation
Cellule staminali cardiache (MSC) e ingegneria tissutale: studi di nuove matrici naturali e sintetiche per il delivery di MSC nel riparo del tessuto cardiaco
Regolazione della produzione di osteocalcina ed interleuchina 6 da parte del GM-CSF in cellule di osteosarcoma umano.
Comportamento produttivo ed analisi dell'accrescimento di linee aromatiche di tabacco (Nicotiana tabacum L.) "Burley"
Sistemi colturali per l'appennino meridionale: nota IV. Dinamica dei principali nutrienti.
[Evaluation of T-lymphocytic activity tested by E rosettes test for rheumatoid arthritis (author's transl)]
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