Polyglycolic Acid-islet grafts improve blood glucose and insulin concentrations in rats with induced diabetes

Pancreatic islet transplantation is a promising therapeutic treatment for type 1 diabetes mellitus. In the present study, we cocultured islets with or without a polyglycolic acid (PGA) fibrous scaffold for 5 days and transplanted the PGA-islet grafts into the leg muscles of Wistar rats with streptozotocin-induced diabetes; controls were injected with saline. The results showed that the blood glucose concentrations of the group given islets embedded with the PGA scaffold were lower than those without the scaffold or controls. On the other hand, the insulin content of the PGA-islet group was higher at all 5 time points compared with the insulin contents of the other 2 groups. After transplantation, many islets in the PGA-islet grafts showed normal morphology (as seen under the scanning electron microscope) and were surrounded by red blood cells. A fibrous extracellular matrix was visible around the PGA-islet grafts. These results demonstrated that PGA-islet grafts improved blood glucose and insulin concentrations in rats with induced diabetes.

Imbalance between pro- and anti-inflammatory cytokines, and between Th1 and Th2 cytokines in depressed patients: the effect of electroacupuncture or fluoxetine treatment

BACKGROUND

An increase in inflammatory response and an imbalance between T-helper (Th) 1 and 2 functions have been implicated in major depression. The aims of the present study were to 1) study the relationship between pro- and anti-inflammatory cytokines and between Th1 and Th2 produced cytokines in depressed patients and 2) evaluate and compare the effect of treatments with electroacupuncture (EA) and fluoxetine on these cytokines.

METHODS

95 outpatients with major depressive disorder were treated for 6 weeks with EA, fluoxetine or placebo. Hamilton Depression Rating Scale (HDRS) and Clinical Global Impression (CGI) were used to assess severity and therapeutic effects. 30 volunteers served as controls. Serum cytokine concentrations were measured by ELISA.

RESULTS

Increased proinflammatory cytokine interleukin (IL)-1beta and decreased anti-inflammatory cytokine IL-10 were found in the depressed patients. By contract, Th1 produced proinflammatory cytokines, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma were decreased, and Th2 produced cytokine IL-4 was significantly increased in depressed patients. The ratio of IFN/IL-4 was also increased. Both acupuncture and fluoxetine treatments, but not the placebo, reduced IL-1beta concentrations in responders. However, only acupuncture attenuated TNF-alpha concentration and INF-gamma/IL-4 ratio towards the control level.

DISCUSSION

These results suggest that an imbalance between the pro- and anti-inflammatory cytokines (IL-1 and IL-10), and between Th1 and Th2 cytokines (INF-gamma or TNF-alpha and IL-4) occurred in untreated depressed patients. Both EA and fluoxetine had an anti-inflammatory effect by reducing IL-1beta. EA treatment also restored the balance between Th1 and Th2 systems by increasing TNF-alpha and decreasing IL-4.

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.