Initial adhesion of bone marrow stromal cells to various bone graft substitutes

Purpose: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. Methods: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with beta-tricalcium phosphate (TCP), and pure beta-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. Results: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. Conclusions: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment. (C) 2011 Korean Academy of Periodontology.This work was supported by a National Research Foundation of Korea Grant funded by the Government of the Republic of Korea (2008-E00580)

Overexpression of transglutaminase 2 accelerates the erythroid differentiation of human chronic myelogenous leukemia K562 cell line through PI3K/Akt signaling pathway

AbstractTransglutaminase 2 (TG2) is a GTP-binding protein with transglutaminase activity. Despite advances in the characterization of TG2 functions and their impact on cellular processes, the role of TG2 in Human chronic myelogenous leukemia K562 cell line is still poorly understood. To understand the biological significance of TG2 during the differentiation of K562 cells, we established and characterized K562 cells that specifically express TG2. Non-transfected K562 cells showed the increase of membrane-bound-TG2 level after 3 days in the response to Hemin and all trans-retinoic acid (tRA), indicating that membrane recruitment of TG2 is occurred during the erythroid differentiation. However, membrane recruitment of TG2 in TG2-transfected cells revealed within earlier time period, compared with that in vector-transfected cells. The ability of membrane-bound-TG2 to be photoaffinity-labeled with [α-32P]GTP was also increased in TG2-transfected cells. TG2-transfected cells activated Akt phosphorylation and inactivated ERK1/2 phosphorylation, compared with vector-transfected cells. Furthermore, phosphorylation of CREB, one of the Akt substrates, was increased in TG2-transfected cells and this phenomenon was confirmed by RT-PCR analysis of several marker genes related with erythroid lineage in the absence of PI3K specific inhibitor, Wortmannin, indicating that PI3K/Akt signaling pathway also involved in the differentiation of the cell. Finally, as results of benzidine positive staining as well as hemoglobinization analysis, overexpression of TG2 revealed acceleration of the erythroid differentiation of K562 cells. Taken together, there was no increased TG2 expression level in the response of Hemin/tRA and delayed differentiation in vector transfected cells than in TG2-transfected cells, suggesting that suppression of TG2 expression may retard the erythroid differentiation of K562 cells. Therefore, our study may give a new insight for another aspect of the development of this disease

Application of Magneto-Rheological Fluids for Investigating the Effect of Skin Properties on Arterial Tonometry Measurements

Accurate, non-invasive measurements of blood pressure and its continuous monitoring are extremely important for personal health care. Arterial tonometry, a method that is used to provide a detailed image of a patient's cardiovascular health, shows promise for being a non-invasive alternative to current blood pressure measurement methods. However, its measurement accuracy is sensitive to patient variations such as the stiffness of the skin. Thus, this project intends to investigate the effect of skin properties (i.e., stiffness) on the accuracy of tonometric blood pressure measurements. To this end, a test platform, consisting of a pulsatile system and a tunable skin stiffness apparatus (or MR apparatus), is constructed. The cam-follower pulsatile system built based on in vivo testing of human pulses is used to generate realistic pulse waveforms. The MR apparatus is able to adjust its stiffness using Magneto-Rheological (MR) fluid whose apparent viscosity changes with applied magnetic fields. Placed at the surface of the MR apparatus, a cylinder with a frictionless plunger simulates a variable applanation force or “hold-down pressure” of tonometry by adjusting the added weights atop the cylinder. Using this test setup, a series of tests were performed by varying the input magnetic field and the weights, which effectively adjusts the skin stiffness and the hold-down pressure, respectively. The vertical displacement of the plunger caused by the internal pulse pressure was measured using a laser displacement sensor. The output displacement waveforms were analyzed with the focus on the peak amplitude difference of the waveforms, which is related to the augmentation index (a surrogate measure of arterial stiffness). The results show that there exists an “optimal” plunger weight or “hold-down pressure” that provides the most distinct output pulse waveforms. The results further show that the difference in the first two peak values decreases as the skin stiffness increases, indicating that the stiffer the skin property, the less the “hold-down pressure” effects on the accuracy of the tonometry measurements

Flora of Vascular Plants in Ridgelines in the Palgongsa Procincial Park, Korea

AbstractWe investigated and analyzed the flora of vascular plants around ridgelines in the Palgongsan Provincial Park to suggest fundamental data for establishing preservation plans of them. The flora of vascular plants around ridgelines was a total of 587 taxa including 102 familiies, 314 genera, 518 species, 58 varieties, 7 forma, and 4 subspecies. Rare plants designated by Korea Forest Service were 27 taxa including Semiquilegia mandshurica and Aristolochia manshuriensis. Endemic plants were 15 taxa including Clematis trichotoma and Carex okamotoi. Floristic special plants were a total of 100 taxa including all five classes. Naturalized plants were 13 taxa including Phytolacca Americana, ambrosia, and Taraxacum officinale

Probiotics (Lactobacillus rhamnosus R0011 and acidophilus R0052) Reduce the Expression of Toll-Like Receptor 4 in Mice with Alcoholic Liver Disease

Objective The role of lipopolysaccharide (LPS) and toll-like receptor 4 (TLR 4) in the pathogenesis of alcoholic liver disease (ALD) has been widely established. We evaluated the biological effects of probiotics (Lactobacillus rhamnosus R0011 and acidophilus R0052), KRG (Korea red ginseng), and urushiol (Rhus verniciflua Stokes) on ALD, including their effects on normal and high-fat diet in mice. Methods One hundred C57BL/6 mice were classified into normal (N) and high-fat diet (H) groups. Each group was divided into 5 sub-groups: control, alcohol, alcohol+probiotics, alcohol+KRG, and alcohol+urushiol. A liver function test, histology, electron-microscopy, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, and IL-10, and TLR 4 were evaluated and compared. Results In the N group, probiotics, KRG, and urushiol significantly reduced levels of TNF-α (12.3±5.1, 13.4±3.9, and 12.1±4.3 vs. 27.9±15.2 pg/mL) and IL-1β (108.4±39.4, 75.0±51.0, and 101.1±26.8 vs. 162.4±37.5 pg/mL), which were increased by alcohol. Alcohol-induced TLR 4 expression was reduced by probiotics and urushiol (0.7±0.2, and 0.8±0.1 vs. 1.0±0.3, p<0.001). In the H group, IL-10 was significantly increased by probiotics and KRG, compared with alcohol (25.3±15.6 and 20.4±6.2 vs. 7.6±5.6 pg/mL) and TLR 4 expression was reduced by probiotics (0.8±0.2 vs. 1.0±0.3, p = 0.007). Conclusions Alcohol-induced TLR 4 expression was down-regulated by probiotics in the normal and high-fat diet groups. Probiotics, KRG, and urushiol might be effective in the treatment of ALD by regulating the gut-liver axis

Blood transfusion had no influence on the 5-year biochemical recurrence after robot-assisted radical prostatectomy: a retrospective study

Background Although red blood cells (RBC) transfusion is known to be significantly associated with biochemical recurrence in patients undergoing open prostatectomy, its influence on biochemical recurrence after robot-assisted laparoscopic radical prostatectomy remains unclear. Therefore, this study aimed to validate the effect of RBC transfusion on the 5-year biochemical recurrence in patients undergoing robot-assisted laparoscopic radical prostatectomy. Methods This study retrospectively analyzed the medical records of patients who underwent robot-assisted laparoscopic radical prostatectomy at single tertiary academic hospital between October 2007 and December 2014. Univariate and multivariate Cox proportional hazard regression analysis was performed to identify any potential variables associated with 5-year biochemical recurrence. Results A total of 1311 patients were included in the final analysis. Of these, 30 patients (2.3%) were transfused with RBC either during robot-assisted laparoscopic radical prostatectomy or during their hospital stay, which corresponded to 5-year biochemical recurrence of 15.7%. Multivariate Cox proportional hazard regression analysis showed that RBC transfusion had no influence on the 5-year biochemical recurrence. Variables including pathologic T stage (Hazard ratio [HR] 3.5, 95% confidence interval [CI] 2.4–5.1 p < 0.001), N stage (HR 2.3, 95% CI 1.5–3.7, p < 0.001), Gleason score (HR 2.4, 95% CI 1.8–3.2, p < 0.001), and surgical margin (HR 2.0, 95% CI 1.5–2.8, p < 0.001) were independently associated with the 5-year biochemical recurrence. Conclusions RBC transfusion had no significant influence on the 5-year biochemical recurrence in patients undergoing robot-assisted laparoscopic radical prostatectomy