scholarly journals The Oxidative Response of Human Monocytes to Surface Modified Commercially Pure Titanium

2021 ◽  
Vol 12 ◽  
Author(s):  
Robert P. De Poi ◽  
Michael Kowolik ◽  
Yoshiki Oshida ◽  
Karim El Kholy

Cellular responses to implanted biomaterials are key to understanding osseointegration. The aim of this investigation was to determine the in vitro priming and activation of the respiratory burst activity of monocytes in response to surface-modified titanium. Human peripheral blood monocytes of healthy blood donors were separated, then incubated with surface-modified grade 2 commercially pure titanium (CPT) disks with a range of known surface energies and surface roughness for 30- or 60-min. Secondary stimulation by phorbol 12-myrisate 13-acetate (PMA) following the priming phase, and luminol-enhanced-chemiluminescence (LCL) was used to monitor oxygen-dependent activity. Comparison among groups was made by incubation time using one-way ANOVA. One sample from each group for each phase of the experiment was viewed under scanning electron microscopy (SEM) and qualitative comparisons made. The results indicate that titanium is capable of priming peripheral blood monocytes following 60-min incubation. In contrast, 30 min incubation time lead to reduced LCL on secondary stimulation as compared to cells alone. At both time intervals, the disk with the lowest surface energy produced significantly less LCL compared to other samples. SEM examination revealed differences in surface morphology at different time points but not between differently surface-modified disks. These results are consistent with the hypothesis that the titanium surface characteristics influenced the monocyte activity, which may be important in regulating the healing response to these materials.

2004 ◽  
Vol 37 (2) ◽  
pp. 165-168 ◽  
Author(s):  
Fátima Regina Vilani-Moreno ◽  
Luciana Moreira Silva ◽  
Diltor Vladimir Araújo Opromolla

Studies on host-parasite interaction in Jorge Lobo's disease are scarce, with no report in the literature on the phagocytosis of Lacazia loboi by phagocytic mononuclear cells. Thus, the objective of the present study was to assess the phagocytic activity of blood monocytes in the presence of L. loboi in patients with the disease and in healthy subjects (controls) over 3 and 24 hours of incubation. Statistical analyses of the results showed no significant difference in percent phagocytosis of the fungus between patient and control monocytes. With respect to incubation time, however, there was a significant difference, in that percent phagocytosis was higher at 3 hours than at 24 hours (p <0.01). These results suggest that monocytes from patients with the mycosis are able to phagocyte the fungus, as also observed in control individuals.


Blood ◽  
1987 ◽  
Vol 70 (2) ◽  
pp. 579-582
Author(s):  
LJ Weisberg ◽  
DT Shiu ◽  
PR Conkling ◽  
MA Shuman

Factor XIII is the fibrin-stabilizing factor that covalently cross- links fibrin monomers to form a highly organized, stable fibrin clot. The plasma form of factor XIII is a heterodimer, a2b2, consisting of two a-chains and two b-chains; the intracellular form, such as in platelets and placenta, is a dimer, a2, consisting of a-chains only. The catalytic function of factor XIII, a transglutaminase, resides in the a-chain. To address questions regarding sites of synthesis of factor XIII a-chain, an EcoRI restriction fragment from the protein- coding region of the factor XIII a-chain cDNA was used as a probe for Northern blot analysis. The cDNA probe showed hybridization with a single approximately 4.0-kilobase (kb) message in poly (A)+ mRNA prepared from normal human peripheral blood monocytes and normal human liver. The results demonstrate conclusively that factor XIII a-chains are actively synthesized in circulating monocytes and in liver. To our knowledge, these data represent the first demonstration of synthesis of any blood coagulation factor in primary uncultured and unstimulated monocytes or macrophage cells.


Critical Care ◽  
10.1186/cc29 ◽  
1997 ◽  
Vol 1 (Suppl 1) ◽  
pp. P023
Author(s):  
M Gerlach ◽  
D Keh ◽  
S Spielmann ◽  
T Kerner ◽  
R Peter ◽  
...  

1996 ◽  
Vol 316 (2) ◽  
pp. 593-597 ◽  
Author(s):  
Nicolas J. GOULDING ◽  
L PAN ◽  
Kathleen WARDWELL ◽  
Veronica C. GUYRE ◽  
Paul M. GUYRE

Recombinant human annexin I and a monoclonal antibody specific for this protein (mAb 1B) were used to investigate surface binding of this member of the annexin family of proteins to peripheral blood monocytes. Flow cytometric analysis demonstrated trypsin-sensitive, saturable binding of annexin I to human peripheral blood monocytes but not to admixed lymphocytes. A monoclonal antibody that blocks the anti-phospholipase activity of annexin I also blocked its binding to monocytes. These findings suggest the presence of specific binding sites on monocytes. Furthermore, surface iodination, immunoprecipitation and SDS/PAGE analysis were used to identify two annexin I-binding proteins on the surface of monocytes with molecular masses of 15 kDa and 18 kDa respectively. The identification and characterization of these annexin I-binding molecules should help us to better understand the specific interactions of annexin I with monocytes that lead to down-regulation of pro-inflammatory cell functions.


Sign in / Sign up

Export Citation Format

Share Document