Behaviour of Zirconia Based Fuel Material Under Xe Irradiation

The behaviour of ZrO2-10%YO1.5-5%ErO1.5-( 10%ThO2) (At %) cubic solid solutions under low and high energy Xe ion irradiation up to a fluence of 1.8·1016 Xe.cm−2 was investigated by TEM. Low energy (60 keV) Xe ions did not yield amorphization. From the observed bubble formation, swelling values of less than one volume per cent were estimated to be 0.19–0.72% during irradiation at room temperature or at high temperature (925 K). Furthermore, no amorphization was obtained by Xe irradiation under extreme conditions such as high energy (1.5 MeV) Xe ion and low temperature (20 K). This confirms the robustness of this material and argues in favour of the selection of zirconia based material as an advanced nuclear fuel for plutonium disposition.

Vitrification of High-Level Radioactive Waste by Sintering Under Pressure

Sintered silicate glass waste forms with a continuous glass phase and embedded but not completely dissolved waste particles were prepared by powder technology. We used a typical defense waste compositions, containing 38 wt.% of ZrO2 and prepared sinter glass samples with 30, 35, and 40 wt.% waste loading at 830°C and 27.6 MPa, by hot isostatic pressing. The glass former was amorphous silica powder. Simulated waste was added as calcine. Samples were characterized using scanning and transmission electron microscopy. The results show that extensive sintering took place, particularly with the 40 wt.% samples. Waste components, such as Na2O, CaO, MnO2, La203, Fe2O3, NiO, Cr2O3, and P2O5, dissolved completely in the continuous glass phase. ZrO2 was partly dissolved and occurred as aggregates of tiny baddeleyite crystals. The porosity of the samples was 2-3%, indicating that the optimum sintering conditions have not been met to reach porosities <1%.

Chemical durability tests were carried out with sintered glass with 35 wt.% waste loading in deionized water at 90°C under static conditions, showing that the glass is at least as chemically durable as a borosilicate glass with 31 wt.% melted at 1350°C.

+Antisense oligonucleotide targeting survivin inhibits growth by inducing apoptosis in human osteosarcoma cells MG-63

Survivin may play an important role in the development of osteosarcoma. In this study, we chose osteosarcoma cell line MG-63, which highly expressed survivin, to observe the effects of antisense oligonucleotide targeting survivin on the apoptosis induction and proliferation inhibition. It was shown in our results that the apoptosis rate and the proliferation inhibition rate increased significantly in survivin-positive cells MG-63 by using MTT and flow cytometry methods. We found that the growth inhibition rate and apoptosis rate were changed in a dose-dependent way. When the concentration of antisurvivin oligonucleotide was 600 nM, the effects reached the peak. RT-PCR and western-blot methods were used to detect the mRNA and protein expression of survivin in MG-63. We observed that the mRNA and protein expression of survivin reduced after transfected with antisurvivin oligonucleotides at the concentration of 200 nM, 400 nM and 600 nM. At the same time, we found that the mRNA and protein expression of Fas were up-regulated with the concentration of antisurvivin oligonucleotides from 200 nM to 600 nM. It was negative associated with the expression change of survivin. These data suggested that survivin should play an important role in the development of osteosarcoma and the survivin blockaded by using antisurvivin oligonucleotide could inhibit the proliferation and induce apoptosis of osteosarcoma by decreasing the expression of survivin and activate the Fas-mediated apoptosis. Down-regulation of survivin by antisense oligonucleotide might be an effective strategy to the treatment of osteosarcoma and might improve the therapeutic effect.

KEYWORDS

osteosarcoma, Survivin, apoptosis, Fas.

Cell-based osteoprotegerin therapy for debris-induced aseptic prosthetic loosening on a murine model

Exogenous OPG gene modification appears a therapeutic strategy for osteolytic aseptic loosening. The feasibility and efficacy of a cell-based OPG gene delivery approach were investigated using a murine model of knee prosthesis failure. A titanium pin was implanted into mouse proximal tibia to mimic a weight-bearing knee arthroplasty, followed by titanium-particles challenge to induce periprosthetic osteolysis. Mouse fibroblast-like synoviocytes were transduced in vitro with either AAV-OPG or AAV-LacZ before transfused into the osteolytic prosthetic joint 3 weeks post surgery. Successful transgene expression at the local site was confirmed 4 weeks later after sacrifice. Biomechanical pull-out test indicated a significant restoration of implant stability following the cell-based OPG gene therapy. Histology revealed that inflammatory pseudo-membranes existed ubiquitously at bone-implant interface in control groups, while only observed sporadically in OPG gene-modified groups. TRAP+ osteoclasts and TNFα, IL-1β, CD68+ expressing cells were significantly reduced in periprosthetic tissues of OPG gene-modified mice. No transgene dissemination or tumorigenesis was detected in remote organs and tissues. Data suggest that cell based ex vivo OPG gene therapy was comparable in efficacy with in vivo local gene transfer technique to deliver functional therapeutic OPG activities, effectively halted the debris-induced osteolysis and regained the implant stability in this model.

An evaluation of the diabetic kidney disease definition in chinese patients diagnosed with type 2 diabetes mellitus

The concomitant presence of retinopathy may be helpful in discriminating kidney pathology in type 2 diabetes. This cross-sectional study evaluated the ability to predict the likelihood of patients having diabetic kidney disease (DKD) by comparing the percentage incidence of diabetic retinopathy in different subgroups of Chinese patients with type 2 diabetes (n = 668). The prevalence of chronic kidney disease in the patients was 63.3% (6.6% with DKD, 41.0% with possible DKD and 15.7% with non-diabetic renal disease [NDRD]). The percentage of patients with diabetic retinopathy in the DKD group (63.6%) was significantly higher than in the possible DKD group (24.9%) and the NDRD group (19.0%). DKD was independently associated with diabetic retinopathy based on logistic regression analysis. The likelihood of DKD occurrence as defined by the National Kidney Foundation-Kidney Disease Outcomes Quality Initiative of the USA is applicable to Chinese patients with diabetes. Diabetic retinopathy was more prevalent in patients with DKD compared with patients with possible DKD or NDRD.

Short communication: Genetic parameters of production traits in Chinese Holsteins using a random regression test-day model

The objective of this study was to estimate genetic parameters of production traits in the first 3 parities in Chinese Holsteins. Data were a random sample of complete herds (109,005 test-day records of 9,706 cows from 54 herds) extracted from the original data set, which included 362,304 test-day records of 30,942 Holstein cows from 105 herds. A test-day animal model with multiple-trait random regression and the Gibbs sampling method were used for parameter estimation. Regression curves were modeled using Legendre polynomials of order 4. The multiple-trait analysis included milk, fat, and protein yield, and somatic cell score (SCS). Average daily heritabilities ranged between 0.222 and 0.346 for the yield traits and between 0.092 and 0.187 for SCS. Heritabilities were higher in the third lactation for all traits. Within-parity genetic correlations were very high among the yield traits (>0.806) and were close to zero between SCS and yield traits, especially for first-parity cows. Results were similar to previous literature estimates from studies that used the same model as applied to this study. The estimates found in this study will be used to perform breeding value estimation for national genetic evaluations in Chinese Holsteins.

The Association of Dysglycaemia and Cardiovascular Disease in Patients with Metabolic Syndrome

The objective of this study was to investigate the relationship between increased prevalence of cardiovascular disease and glucose regulation status in Chinese patients with metabolic syndrome (MetS). All patients underwent an oral glucose tolerance test (2-h post-load plasma glucose) to determine their glucose regulation status and had their brachial–ankle pulse wave velocity (baPWV) measured. Of the 590 patients included in the study, 115 (19.5%) had normal glucose tolerance, 114 (19.3%) had impaired fasting glucose (IFG) alone, 38 (6.4%) had impaired glucose tolerance (IGT) alone, 197 (33.4%) had diabetes mellitus and 126 (21.4%) had combined glucose intolerance (CGI; IFG plus IGT). Patients with diabetes mellitus had a significantly higher baPWV compared with all other groups and patients with CGI had a significantly higher baPWW compared with patients with IFG. Dysglycaemia was common in patients with MetS. An increased prevalence of cardiovascular disease in patients with MetS was related to their glucose regulation status.

High weight differences between donor and recipient affect early kidney graft function--a role for enhanced IL-6 signaling

The frequency of delayed function of kidney transplants varies greatly and is associated with quality of graft, donor age and the duration of cold ischemia time. Furthermore, body weight differences between donor and recipient can affect primary graft function, but the underlying mechanism is poorly understood. We transplanted kidney grafts from commensurate body weight (L-WD) or reduced body weight (H-WD) donor rats into syngeneic or allogeneic recipients. Twenty-four hours posttransplantation, serum creatinine levels in H-WD recipients were significantly higher compared to L-WD recipients indicating impaired primary graft function. This was accompanied by upregulation of IL-6 transcription and increased tubular destruction in grafts from H-WD recipients. Using DNA microarray analysis, we detected decreased expression of genes associated with kidney function and an upregulation of other genes such as Cyp3a13, FosL and Trib3. A single application of IL-6 into L-WD recipients is sufficient to impair primary graft function and cause tubular damage, whereas immediate neutralization of IL-6 receptor signaling in H-WD recipients rescued primary graft function with well-preserved kidney graft architecture and a normalized gene expression profile. These findings have strong clinical implication as anti-IL6R treatment of patients receiving grafts from lower-weight donors could be used to improve primary graft function.

Potentiation of NF-kappaB-dependent transcription and inflammatory mediator release by histamine in human airway epithelial cells

BACKGROUND AND PURPOSE

In asthma, histamine contributes to bronchoconstriction, vasodilatation and oedema, and is associated with the late phase response. The current study investigates possible inflammatory effects of histamine acting on nuclear factor kappaB (NF-kappaB)-dependent transcription and cytokine release.

EXPERIMENTAL APPROACH

Using BEAS-2B bronchial epithelial cells, NF-kappaB-dependent transcription and both release and mRNA expression of IL-6 and IL-8 were examined by reporter assay, ELISA and quantitative RT-PCR. Histamine receptors were detected using qualitative RT-PCR and function examined using selective agonists and antagonists.

KEY RESULTS

Addition of histamine to TNFalpha-stimulated BEAS-2B cells maximally potentiated NF-kappaB-dependent transcription 1.8 fold, whereas IL-6 and IL-8 protein release were enhanced 7.3- and 2.7-fold respectively. These responses were, in part, NF-kappaB-dependent and were associated with 2.6- and 1.7-fold enhancements of IL-6 and IL-8 mRNA expression. The H(1) receptor antagonist, mepyramine, caused a rightward shift in the concentration-response curves of TNFalpha-induced NF-kappaB-dependent transcription (pA(2)=9.91) and release of IL-6 (pA(2)=8.78) and IL-8 (pA(2)=8.99). Antagonists of histamine H(2), H(3) and H(4) receptors were without effect. Similarly, H(3) and H(4) receptor agonists did not affect TNFalpha-induced NF-kappaB-dependent transcription, or IL-6 and IL-8 release at concentrations below 10 microM. The anti-inflammatory glucocorticoid, dexamethasone, inhibited the histamine enhanced NF-kappaB-dependent transcription and IL-6 and IL-8 release.

CONCLUSIONS AND IMPLICATIONS

Potentiation of NF-kappaB-dependent transcription and inflammatory cytokine release by histamine predominantly involves receptors of the H(1) receptor subtype. These data support an anti-inflammatory role for H(1) receptor antagonists by preventing the transcription and release of pro-inflammatory cytokines.

Efficacy of hyperbaric oxygen on survival of random pattern skin flap in diabetic rats

OBJECTIVES

This study was designed to determine if hyperbaric oxygen improved random pattern skin flap survival in diabetic rats.

METHODS

Cranially-based, 4 x 10 cm dorsal skin flaps were raised in 38 diabetic rats induced by streptozocin (STZ). The animals were randomly divided equally into two groups. Group A was a control group observed in the room air and Group B was the experimental group, which received hyperbaric oxygen (HBO2) therapy. The HBO2 regimen consisted of 90 minutes of treatment with 100% O2 at 2.5 ATA (atmosphere absolute ATA) per day for 7 consecutive days. On the 7th postoperative day, we measured the necrotic flap area and the new growth number of capillary vessel and the granulation tissue thickness.

RESULTS

The percentage of necrosis flap area for group A was 50.5 +/- 10.5%; for group B it was 38.5 +/- 9.3%. The reduction in necrosis flap area was highly significant (p < 0.01) compared with controls. Also, new-growth capillary vessel and granulation tissue thickness were statistically different between the two groups.

CONCLUSIONS

The findings of this study demonstrated beneficial effects of HBO2 in improving diabetic rat dorsal skin flap survival.

Amylin deposition in the kidney of patients with diabetic nephropathy

Amylin (islet amyloid peptide) plays a critical role in islet amyloidosis and in the development of beta-cell dysfunction in patients with diabetes; however, the involvement of amylin in renal amyloidosis has not been studied. For this reason, we surveyed 149 patients with biopsy-proven diabetic nephropathy (DN). The results were compared to 95 renal disease control patients, which included membranoproliferative glomerulonephritis, light-chain deposition, IgA nephropathy, and obesity-related glomerulopathy (ORG). Seventy-two of the 149 patients with DN showed amylin deposition in their renal tissue. Amylin was mainly distributed in the expanded mesangial area, Kimmelstiel-Wilson nodules, Bowman's capsule, and in blood vessels. The frequencies of mesangial proliferation, glomerular nodule lesions, and glomerular sclerosis were higher in DN patients with amylin deposits. Furthermore, the tubular interstitial lesions were more severe in these patients. Of the 95 disease-control patients, four with ORG were positive for renal amylin deposits. Our study has found renal amylin deposition in patients with DN and that the deposition was associated with disease severity. We suggest that strict metabolic control and reversing insulin resistance in patients with diabetes may blunt the process of amylin deposition in the kidney and possibly protect renal function in these patients.

Aberrant FoxM1B expression increases matrix metalloproteinase-2 transcription and enhances the invasion of glioma cells

We recently showed that FoxM1 is overexpressed in human glioblastomas and that forced FoxM1B expression in anaplastic astrocytoma cells leads to the formation of highly invasive glioblastoma multiforme (GBM) in nude mice. However, the molecular mechanisms by which FoxM1 enhances glioma invasion are unknown. In this study, we found that FoxM1 overexpression increased matrix metalloproteinase (MMP)-2 expression in glioma cells, whereas blockade of FoxM1 expression suppressed MMP-2 expression. Transfection of FoxM1 into glioma cells directly activated the MMP-2 promoter, whereas inhibition of FoxM1 expression by FoxM1-siRNA suppressed its activation. We identified a FoxM1-binding site in the MMP-2 promoter and demonstrated that FoxM1 protein bound directly to it. Mutation of this FoxM1-binding site significantly attenuated MMP-2 promoter activity. Furthermore, FoxM1 overexpression increased the invasiveness of glioma cells, whereas inhibition of FoxM1 expression suppressed the invasiveness of GBM cells. Inhibition of MMP-2 by a specific MMP-2 inhibitor reversed the invasive phenotype of glioma cells overexpressing FoxM1. Finally, immunohistochemical analysis of 45 human GBM specimens showed a significant correlation between FoxM1 overexpression and elevated MMP-2 expression. Collectively, these findings provide evidence that FoxM1 contributes to glioma progression by enhancing MMP-2 gene transcription and thus tumor-cell invasion.