Regulational effects of breast cancer stromal cells and normal breast stromal cells on MCF-7 mammosphere formation

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Background: It is well known that microenvironment plays an important role in tumor progression so we investigated the regulatory effects of breast cancer stromal cells (BCSCs) and normal breast stromal cells (NBSCs) as microenvironment on MCF-7 mammosphere formation. Methods: MCF-7 cells were cultured in suspension to generate mammospheres. The proportion of CD44+CD24- cells was assessed by flow cytometry and the expression of Wint1, notch1, β-catenin, CXCR4, SOX2, and ALDH3A1 was detected by real-time PCR. The stromal cells were purified and identified by immumohistochemistry. BCSCs or NBSCs and MCF-7 cells were co-cultured via Transwell system, the volumes and numbers of mammospheres and the mammosphere-forming efficiency (MFE) were calculated and the expression of Wnt1, β-catenin, Notch1 were detected. Results: The proportion of CD44+CD24- cells in mammospheres and MCF-7 cells was 10.4% and 2.1% (p < 0.05), respectively. Real-time PCR analysis suggested that Wint1, notch1, β-catenin, CXCR4, SOX2, and ALDH3A1 genes in the mammosphere cells were with higher levels than MCF-7 cells by about 2.25, 2.45, 1.72, 4.68, 4.25, 5.38 fold, respectively (p < 0.01). The stromal cells purified were identified as fibroblasts by α-SMA,Vimentin and fibroblast special protein antibody via immumohistochemistry. The time of mammosphere's formation was earlier, the volumes of mammospheres were bigger, and the MFE was higher than control group. The expressions of Wnt1 in co-culture group were significantly upregulated 1.27, 3.18 folds than control group, respectively, while the β-catenin was 1.22, 1.75 folds; Notch1 was 1.31, 2.09 folds; and CXCR4 was 1.73, 2.77 folds, respectively. Conclusions: Mammosphere cells contained higher propotion of breast cancer stem cells and expressed higher levels of cancer stem cell related genes. BCSCs can promote the mammosphere-forming efficiency and upregulate the expression of cancer stem cell related genes.

No significant financial relationships to disclose.

Role of E1B protein-dificient oncolytic virus in breast cancer stem cells

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Background: Cancer stem cells have been indicated in the initiation of tumors and are even found to be responsible for relapses after apparently curative therapies have been undertaken. In breast cancer, they may reside in the CD44+CD24−/low population. Oncolytic adenoviruses enter cells through infection and can kill both proliferating and quiescent cells. We investigated the role of E1B protein- dificient oncolytic adenovirus in breast cancer stem cells. Methods: MCF-7 cells were infected by E1B protein-dificient oncolytic adenovirus as infected group (MOI=100) and cultured routinely as control group simultaneously. The proportion of CD44+CD24- cells was assessed by flow cytometry (FCM) in two groups respectively. Meanwhile, mammosphere culture was done in two groups' cells to observe the size and number of mammospheres, calculate the mammosphere- forming efficiency (MFE). The proportion of CD44+CD24- cells in two groups' mammospheres was assessed by FCM. Results: The percentages of CD24-,CD44+, CD44+CD24- in the infected gruop were 43.9%, 63.26%, 22.19%, respectively. While in the control group, the percentages were 6.74%, 88.30%, 2.30%. In the infected group, the time of mammosphere's formation was earlier, the volumes of mammospheres were bigger and the MFE was higher than the control group (1.26%:0.9%). In two mammospheres' groups, the proportion of CD44+CD24- cells in experiment group and control group was 38.08% and 23.35%, respectively. Conclusions: E1B protein-dificient oncolytic adenovirus can kill MCF-7 cells in short time, mainly breast cancer differentiated cells. It maybe promote the growth of the breast cancer stem cells. It maybe accelerate the speed of self-renewed and differentiation of the breast cancer stem cells.

No significant financial relationships to disclose.

Electroluminescent devices based on amorphous SiN/Si quantum dots/amorphous SiN sandwiched structures

A single layer of dense Si quantum dots with average size of 4 nm sandwiched in amorphous SiN layers was prepared by laser crystallization of ultrathin amorphous Si film followed by subsequently thermal annealing. The electroluminescent diodes were fabricated by evaporating Al electrodes on back sides of p-Si substrates and the top surface of samples. Room temperature electroluminescence can be detected with applying the negative voltage around 10V on the top gate electrode and the luminescent intensity is increased with increasing the applied voltage. It was found that the integrated luminescent intensity is linearly proportional to the injection current which suggested the intensity depends on the concentrations of injected carriers after Fowler-Nordheim tunneling through amorphous SiN barriers. The influence of the amorphous SiN with different band gap on the device performance was also discussed briefly.

Establishment of an enzyme-linked immunosorbent assay system for determining soluble CD96 and its application in the measurement of sCD96 in patients with viral hepatitis B and hepatic cirrhosis

CD96, previously named T cell activation increased late expression (Tactile), is a transmembrane molecule that functions as an activated receptor on natural killer cells. It is well known that many transmembrane molecules have soluble forms, which were either shed from the cell surface or spliced at mRNA level. In many cases, the levels of soluble forms in the circulation could be used as biomarkers of lymphocyte activation in bacterial or virus infection, tumour, transplantation and autoimmune disease. To investigate whether CD96 could be released into the sera and the possible biological function of soluble hCD96 (sCD96), we generated and characterized five clones of anti-hCD96 mouse monoclonal antibodies (mAb) and developed a sandwich enzyme-linked immunosorbent assay (ELISA) system based on two anti-hCD96 mAbs with different epitope specificities. Using this ELISA system, sCD96 in serum samples from 99 healthy individuals could be detected. Furthermore, we found that the level of sCD96 in serum samples from patients with chronic viral hepatitis B or classes B and C of hepatic cirrhosis classified using the Child-Pugh score was much higher (P < 0.001 versus healthy individuals; P = 0.006 versus healthy individuals respectively) than that from healthy individuals (0.98 ng/ml). Our study demonstrates for the first time that sCD96 existed in sera, and suggests that sCD96 may be used as a serous marker for some diseases such as chronic viral hepatitis B infection or hepatic cirrhosis in classes B and C. The level of sCD96 in patients' serum may have some relationship with a chronic inflammatory reaction.

Picovoltmeter for probing vortex dynamics in a single weak-pinning Corbino channel

We have developed a picovoltmeter using a Nb dc superconducting quantum interference device for measuring the flux-flow voltage from a small number of vortices moving through a submicron weak-pinning superconducting channel. We have applied this picovoltmeter to measure the vortex response in a single channel arranged in a circle on a Corbino disk geometry. The circular channel allows the vortices to follow closed orbits without encountering any sample edges, thus eliminating the influence of entry barriers.

First observation of the Greisen-Zatsepin-Kuzmin suppression

The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy cosmic rays shows a sharp suppression at an energy of 6 x 10(19) eV, consistent with the expected cutoff energy. We observe the ankle of the cosmic-ray energy spectrum as well, at an energy of 4 x 10(18) eV. We describe the experiment, data collection, and analysis and estimate the systematic uncertainties. The results are presented and the calculation of the statistical significance of our observation is described.

Risk factors for rejection and infection in pediatric liver transplantation

Rejection and infection are important adverse events after pediatric liver transplantation, not previously subject to concurrent risk analysis. Of 2291 children (<18 years), rejection occurred at least once in 46%, serious bacterial/fungal or viral infections in 52%. Infection caused more deaths than rejection (5.5% vs. 0.6% of patients, p < 0.001). Early rejection (<6 month) did not contribute to mortality or graft failure. Recurrent/chronic rejection was a risk in graft failure, but led to retransplant in only 1.6% of first grafts. Multivariate predictors of bacterial/fungal infection included recipient age (highest in infants), race, donor organ variants, bilirubin, anhepatic time, cyclosporin (vs. tacrolimus) and era of transplant (before 2002 vs. after 2002); serious viral infection predictors included donor organ variants, rejection, Epstein-Barr Virus (EBV) naivety and era; for rejection, predictors included age (lowest in infants), primary diagnosis, donor-recipient blood type mismatch, the use of cyclosporin (vs. tacrolimus), no induction and era. In pediatric liver transplantation, infection risk far exceeds that of rejection, which causes limited harm to the patient or graft, particularly in infants. Aggressive infection control, attention to modifiable factors such as pretransplant nutrition and donor organ options and rigorous age-specific review of the risk/benefit of choice and intensity of immunosuppressive regimes is warranted.

Non-resonant and resonant x-ray scattering studies on multiferroic TbMn2O5

Comprehensive x-ray scattering studies, including resonant scattering at Mn L, Tb L, and M edges, were performed on single crystals of TbMn2O5 for crystallographic data to elucidate the nature of its commensurate and incommensurate phases. The scattering results provide direct evidence of symmetry lowering to the ferroelectric phase driven by magnetically induced lattice modulations and show the presence of multiple magnetic orders. The competing orders under spin-frustrated geometry are believed to cause discommensuration and result in the commensurate-to-incommensurate phase transition around 24 K. It is proposed that the low temperature incommensurate phase consists of commensurate domains separated by antiphase domain walls which change both signs of spontaneous polarizations and x-ray scattering amplitudes for forbidden reflections.

In vitro evaluation of fibrin mat and Tegaderm wound dressing for the delivery of keratinocytes--implications of their use to treat burns

The effectiveness of fibrin mat and Tegaderm delivery systems to maintain clonogenic keratinocytes in culture were evaluated using in vitro methods. A fibrin mat was found to provide a culture environment that is conducive for the proliferation of keratinocytes and supporting their ability to form colonies of good growth potential in vitro. This confirms that the fibrin mat is a good delivery system for cultured epithelial autograft (CEA). In our unit, fibrin-CEA is limited only for the treatment of severe burns due to the high cost of fibrin glue. However, this substrate is able to maintain the regenerative properties of the CEA which is crucial for the treatment of extensive and full thickness burns. Tegaderm, a cost-effective polyurethane wound dressing is able to support keratinocyte cell growth but at a slower rate and with fewer colonies formed compared to the fibrin system. This suggests that Tegaderm can be an alternative approach of delivering autologous cells, limited to treat chronic wounds and less extensive burns. The use of simple and relatively inexpensive bench techniques can potentially serve as a quality control to check for keratinocytes cultured and delivered to every patient in the clinical setting.

Use of skin allograft and its donation rate in Singapore: an 11-year retrospective review for burns treatment

An 11-year retrospective review (1993 to 2003) of 102 severe burn patients (>40% total body surface area and undergone wound excision surgery) was performed to determine the efficacy of early wound debridement and coverage of large burns with skin allografts, a treatment introduced here in 1998 with the establishment of a skin banking facility. While there was no significant reduction in mortality, length of hospital stay decreased by 15.7 days (P < .05) during the post-skin-banking period. Skin allograft donation rates from multiorgan donors were consistently fewer compared with corneal donation, mainly due to strong cultural beliefs and public misconceptions regarding skin harvesting. The overall tissue donation rate in Singapore may improve if efforts focus on deceased cases sent to the state coroner where retrieval and counseling can be centralized.

Resonant X-ray scattering study of quadrupole-strain coupling in DyB4

X-ray and neutron scattering studies were performed on DyB4 which exhibits both a quadrupolar ordering and a macroscopic lattice distortion. A forbidden reflection at 7.792 keV near the Dy L3 absorption edge is identified as a quadrupolar ordering peak, and the quadrupolar order and a monoclinic structural distortion develop concomitantly below 12.3 K as second-order-type phase transitions. Coupling between the quadrupolar order and the strain in DyB4 is directly demonstrated by observing that both order parameters are proportional to each other.

Enhancement of electrical and ferromagnetic properties by additional Al doping in Co:ZnO thin films

Several properties of Al-doped Zn(0.95)Co(0.05)O thin films prepared by radio frequency (RF) magnetron co-sputtering have been systematically investigated. The experimental results indicate that Co(2+) steadily substitutes for tetrahedrally coordinated Zn(2+) in the ZnO wurtzite lattice without any segregated secondary phase formation, and that a trace amount of additional Al doping has a profound influence on the enhancement of electrical and magnetic properties of Co:ZnO films. All the films show room-temperature ferromagnetism, and a giant magnetic moment of 3.36 μ(B)/Co is obtained in the Zn(0.948)Co(0.05)Al(0.002)O thin film. The ferromagnetic ordering is seen to be correlated with the structural defects. Moreover, a phenomenon of band gap broadening and absorption edge blueshift can be achieved by additional Al doping into the Co:ZnO films.

Baicalin reduces the severity of experimental autoimmune encephalomyelitis

Scutellaria baicalensis Georgi is one of the important medicinal herbs widely used for the treatment of various inflammatory diseases in Asia. Baicalin (BA) is a bioactive anti-inflammatory flavone found abundantly in Scutellaria baicalensis Georgi. To explore the therapeutic potential of BA, we examined the effects of systemic administration of the flavone (5 and 10 mg/kg, ip) on relapsing/remitting experimental autoimmune encephalomyelitis (EAE) induced by proteolipid protein 139-151 in SJL/J mice, an experimental model of multiple sclerosis. The mice treated with PBS or BA at day -1 and for 3 consecutive days were observed daily for clinical signs of disease up to 60 days after immunization. In the PBS-EAE group, neurological scores were: incidence (100%), mean day of onset (8.0 +/- 0.73), peak clinical score (3.0 +/- 0.4), and cumulative disease index (141.8 +/- 19.4). In the BA-EAE group (5 or 10 mg kg(-1) day(-1), respectively), incidence (95 or 90%), mean day of onset (9.0 +/- 0.80 or 9.2 +/- 0.75; P = 0.000), peak clinical score (2.2 +/- 0.3 or 2.0 +/- 0.3; P = 0.000), and cumulative disease index (75.9 +/- 10.1 or 62.9 +/- 8.4; P = 0.000) decreased, accompanied by the histopathological findings (decrease of dense mononuclear infiltration surrounding vascellum) for the spinal cord. Additionally, the in vitro effects of BA (5, 10, and 25 microM) on mononuclear cells collected from popliteal and inguinal lymph nodes of day-10 EAE mice were evaluated using an MTT reduction assay for cell proliferation, and ELISA to measure IFN-gamma and IL-4 cytokines. Compared with the control group, BA caused an increase in IL-4 (EAE-DMSO: 3.56 +/- 0.42 pg/mL vs EAE-BA (5, 10, and 25 microM): 6.03 +/- 1.1, 7.83 +/- 0.65, 10.54 +/- 1.13 pg/mL, respectively; P < 0.001); but inhibited IFN-gamma (EAE-DMSO: 485.76 +/- 25.13 pg/mL vs EAE-BA (5, 10, and 25 microM): 87.08 +/- 9.24, 36.27 +/- 5.44, 19.18 +/- 2.93 pg/mL, respectively; P < 0.001) and the proliferation of mononuclear cells (EAE-DMSO: 0.73 +/- 0.021 vs EAE-BA (5, 10, and 25 microM): 0.41 +/- 0.015, 0.31 +/- 0.018, 0.21 +/- 0.11, respectively; P < 0.001) in a concentration-dependent manner. The results suggest that BA might be effective in the treatment of multiple sclerosis.