Effects of vehicles on the physical properties and biocompatibility of premixed calcium silicate cements

Premixed calcium silicate cements (pCSCs) contain vehicles which endow fluidity and viscosity to CSCs. This study aimed to investigate the effects of three vehicles, namely, polyethylene glycol (PEG), propylene glycol (PG), and dimethyl sulfoxide (DMSO), on the physicochemical properties and biocompatibility of pCSCs. The setting time, solubility, expansion rate, and mechanical strength of the pCSCs were evaluated, and the formation of calcium phosphate precipitates was assessed in phosphate-buffered saline (PBS). The effects of pCSC extracts on the osteogenic differentiation of mesenchymal stem cells (MSCs) were investigated. Finally, the tissue compatibility of pCSCs in rat femurs was observed. CSC containing PEG (CSC-PEG) exhibited higher solubility and setting time, and CSC-DMSO showed the highest expansion rate and mechanical strength. All pCSCs generated calcium phosphate precipitates. The extract of CSC-PG induced the highest expressions of osteogenic markers along with the greatest calcium deposites. When implanted in rat femurs, CSC-PEG was absorbed considerably, whereas CSC-PG remained relatively unaltered inside the femur.

Effects of RGD-grafted phosphatidylserine-containing liposomes on the polarization of macrophages and bone tissue regeneration

Phosphatidylserine-containing liposomes (PSLs) can mimic the anti-inflammatory effects of apoptotic cells by binding to the phosphatidylserine receptors of macrophages. MGF-E8, a bridge molecule between phosphatidylserine and macrophages, can promote M2 polarization by activating macrophage integrin with its arginine-glycine-aspartic acid (RGD) motif. In this study, to mimic MGF-E8, PSLs presenting RGD peptide (RGD-PSLs) were prepared, and their immunomodulatory effects on macrophages and the bone tissue regeneration of rat calvarial defects were investigated. RGD peptides enhanced the phagocytosis of PSLs by macrophages, especially when the PSLs contained 3% RGD. RGD-PSLs were also more effective than PSLs for the suppression of lipopolysaccharide-induced gene expression of proinflammatory cytokines (i.e., IL-1β, IL-6, and TNF-α) as well as CD86 (M1 marker) expression. Furthermore, RGD promoted PSL-induced M2 polarization: 3%-RGD-PSLs significantly enhanced the mRNA expression of Arg-1, FIZZ1, and YM-1, as well as CD206 (M2 marker) expression. In a calvarial defect model, a significant increase in M2 with a decrease in M1 macrophages was observed with 3%-RGD-PSL treatment compared with the effects of PSLs alone. Finally, new bone formation was also accelerated by 3%-RGD-PSLs. Thus, these results suggest that the intensive immunomodulatory effect of RGD-PSLs led to the enhancement of bone tissue regeneration.

Lympho-Vascular Invasion by Detecting D2-40 Was the Potent Prognostic Predictor in Breast Cancer Patients

(Introduction) Distant metastasis and recurrence are the major factors of prognosis in breast cancer patients. Both of lymphovascular invasion (LVI) and blood vascular invasion (BVI) are known to be the important route for metastasis to regional lymph nodes and systemic metastasis. Despite the importance of vascular invasion as a prognostic factor, the application of vascular invasion as a histopathologic criterion is controversial. The aims of this study were to distinguish between LVI and BVI for the role of prognosis and recurrence in breast cancer patients by using an endothelial subtype specific immunohitochemical stain (podoplanin, D2-40 and CD31)Methods) Sections from 80 paraffin-embedded archival specimens of invasive breast cancer were stained for expression of podoplanin, D2-40, and CD31. The results of immunohistochemical staining were correlated with clinicopathologic features, such as tumor size, the status of lymph node metastases, estrogen receptor status, progesterone receptor status and HER2 expression, and recurrence. The patients with ductal carcinoma in situ and stage 4 breast cancer were excluded.Results) A significant correlation was found in the higher expression of D2-40, and lymph node metastasis. (P=0.02) We found a significant correlation between the expression of D2-40 and the recurrence of breast cancer. (P=0.04) However, there was no significant correlation between BVI and recurrence. A poorer disease free survival was shown in the higher expression of D2-40. (P<0.01) In multivariate analysis, the higher expression of D2-40 revealed a significant association with decreased disease-free survival.Conclusion) The higher expression of D2-40 was the more prognostic predictor than blood vascular invasion in breast cancer patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6171.

Nuclear factor {kappa}B inactivation in the rat liver ameliorates short term total warm ischaemia/reperfusion injury

BACKGROUND

In hepatic ischaemia/reperfusion injury, activated liver macrophages (Kupffer cells) are dominantly regulated by a transcription factor, nuclear factor kappaB (NFkappaB), with respect to expression of inflammatory cytokines, acute phase response proteins, and cell adhesion molecules.

AIMS

We assessed whether inactivation of NFkappaB in the liver could attenuate total hepatic warm ischaemia/reperfusion injury.

METHODS

We studied rats with hepatic overexpression of inhibitor kappaBalpha super-repressor (IkappaBalpha SR) caused by a transgene introduced using an adenoviral vector. Hepatic ischaemia/reperfusion injury was induced under warm conditions by total occlusion of hepatoduodenal ligament structures for 20 minutes, followed by reperfusion. Controls included uninfected and control virus (AdLacZ) infected rats.

RESULTS

IkappaBalpha SR was overexpressed in Kupffer cells as well as in hepatocytes, blocking nuclear translocation of NFkappaB (p65) into the nucleus after reperfusion. Gene transfection with IkappaBalpha SR, but not with LacZ, markedly attenuated ischaemia/reperfusion injury, suppressing inducible nitric oxide synthase and nitrotyrosine expression in the liver. Moreover, no remarkable hepatocyte apoptosis was detected under IkappaBalpha SR overexpression.

CONCLUSIONS

Adenoviral transfer of the IkappaBalpha SR gene in the liver ameliorates short term warm ischaemia/reperfusion injury, possibly through attenuation of hepatic macrophage activation.

Numerical simulation and experimental validation of the dynamics of multiple bubble merger during pool boiling under microgravity conditions

Numerical simulation and experimental validation of the growth and departure of multiple merging bubbles and associated heat transfer on a horizontal heated surface during pool boiling under variable gravity conditions have been performed. A finite difference scheme is used to solve the equations governing mass, momentum, and energy in the vapor liquid phases. The vapor-liquid interface is captured by a level set method that is modified to include the influence of phase change at the liquid-vapor interface. Water is used as test liquid. The effects of reduced gravity condition and orientation of the bubbles on the bubble diameter, interfacial structure, bubble merger time, and departure time, as well as local heat fluxes, are studied. In the experiments, multiple vapor bubbles are produced on artificial cavities in the 2-10 micrometer diameter range, microfabricated on the polished silicon wafer with given spacing. The wafer was heated electrically from the back with miniature strain gage type heating elements in order to control the nucleation superheat. The experiments conducted in normal Earth gravity and in the low gravity environment of KC-135 aircraft are used to validate the numerical simulations.

Thoracoscopic parasternal lymph node dissection for the staging of breast cancer

With the advent of advanced thoracoscopic techniques, new applications have been expanding their roles in thoracic surgery. The aim of this paper is to introduce our new thoracoscopic approach in performing parasternal lymph node dissection of advanced breast cancer for its staging. This technique does not need the removal of any costal cartilage which is usually done in the conventional classical technique after radical mastectomy. Thoracoscopic procedure, in which wide and complete parasternal lymph node dissection is done, is minimally invasive and easy to perform. Therefore, the thoracoscopic technique may be a suitable alternative to the conventional approach in the future.

Dynamics of single and multiple bubbles and associated heat transfer in nucleate boiling under low gravity conditions

Experimental studies and numerical simulation of growth and lift-off processes of single bubbles formed on designed nucleation sites have been conducted under low-gravity conditions. Merging of multiple bubbles and lift-off processes during boiling of water in the parabola flights of KC-135 aircraft were also experimentally studied. The heating area of the flat heater surface was discretized and equipped with a number of small heating elements that were separately powered in the temperature-control mode. As such, the wall superheat remained nearly constant during the growth and departure of the bubbles, whereas the local heat flux varied during the boiling process. From numerical calculation it is found that peak of heat flux occurs locally at the contact line of bubble and heater surface. Dry conditions exist inside the bubble base area, which is characterized through a zero heat flux region in the numerical calculation and a lower heat flux period in the experimental results. During the merger of multiple bubbles, dry-out continues. In both the numerical calculations and experimental results, the bubble lift-off is associated with an apparent increase in heat flux. Wall heat flux variation with time and spatial distribution during the growth of a single bubble from numerical simulations are compared with experimental data.

[A case of advanced gastric cancer with multiple liver metastases in an elderly patient that responded dramatically to UFT therapy]

An 88-year-old female patient suffering from Borrmann type 3 advanced gastric cancer complicated by multiple hepatic metastases underwent a total gastrectomy. A small dose of 200 mg/day of UFT was administered orally every day postoperatively. At postoperative month 6, a marked diminishment of the hepatic metastatic lesions was noted. Resection of the primary lesion with a regimen of a small oral dose of UFT was remarkably effective in this elderly gastric cancer patient with complications from multiple hepatic metastases.