Evaluation of total greenhouse gas emissions during sewage sludge composting by the different dicyandiamide added forms: Mixing, surface broadcasting, and their combination.

The aim of this work was to compare the impact of different adding forms of dicyandiamide (DCD) on NH3 and greenhouse gas (GHG) emissions during sewage sludge (SS) composting. Four treatments were set up using SS mixed with sawdust, to which DCD was then added by mixing (M), surface broadcasting (B), and a combination of the two (M+B). The treatment without DCD applied was used as the control. The results indicate that the addition of DCD slightly inhibited the organic matter (OM) degradation, but that it had no significant effect on CO2 emission. The surface mulching of DCD has no significant effect on NH3, N2O, and CH4 emissions. The mixing addition of DCD significantly increased the NH3 emission by 32.5% compared to that of the control. The N2O emission for the M and M+B treatments significantly decreased by 35.1% and 51.8%, respectively. The CH4 emission for the M and M+B treatments decreased by 33.9% and 31.8%, respectively. In addition, the total GHG emissions for the M and M+B treatments were significantly reduced by 16.7-25.7% (P < 0.05) compared to those of the control. Therefore, to reduce the total GHG emissions of the SS composting process, the addition of DCD by a combination of mixing and surface mulching is strongly recommended as a highly efficient solution.

Methylation of secreted frizzled related protein gene in acute leukemia patients in China.

BACKGROUND: DNA methylation of CpG islands within the promoters of specific genes may play roles in tumor initiation and progression. It has been suggested such events may serve as critical check points. METHODS: The present study analyzed the methylation status of CpG islands within the promoters of secreted frizzled-related proteins (SFRPs) in 87 acute leukemia (AL) patients, 20 normal controls, and four AL cell lines. 5-aza-2'- deoxycytidine (5-Aza-CdR), an inhibitor of DNA methylation, was employed to determine its effect on SFRP expression. RESULT: Methylation of at least one SFRP promoter was observed in 69% of the AL patients analyzed. In addition, methylation of all four SFRP promoters was observed in Molt-4, Jurkat, HL60 and NB4 cells. In Jurkat cells, methylation levels of four SFRP promoters decreased in a dose-dependent manner upon treatment with 5-Aza-CdR, which coincided with increased mRNA expression. With increasing 5-Aza-CdR concentrations, the expression of DNA methyltransferases, DNMT3A and DNMT3B, significantly decreased in a dose-dependent manner. CONCLUSION: The present study demonstrated that SFRP gene methylation may be involved in AL progression, with a possible epigenetic mechanism influencing Wnt signaling.

[Role of dendritic cells in graft rejection after penetrating keratoplasty].

OBJECTIVE: To gain insight into the role of dendritic cells in graft rejection following penetrating keratoplasty by investigating their distribution in rat cornea. METHODS: Orthotopical corneal transplantation was performed and immunohistochemical staining of the whole-mount cornea and the spleen tissue specimen employed to determine the distribution of the dendritic cells in the cornea. RESULTS: Graft rejection occurred in all rats following the transplantation. No OX-62(+) dendritic cells were found in normal cornea but they were present in the epithelium of the cornea graft with allograft rejection. CONCLUSION: OX-62(+) dendritic cells presenting in the rejected cornea may be related to acute graft rejection after penetrating keratoplasty.

[Effects of 1alpha, 25-dihydroxyvitamin D3 on the acute immune rejection and corneal neovascularization in high-risk penetrating keratoplasty in rats].

OBJECTIVE: To investigate the effects of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), a hormone that has immunosuppressive properties, on acute rejection and corneal neovascularization in rat keratoplasty model, so as to assess the therapeutic effects and explore the mechanism of 1,25(OH)(2)D(3) as an immunosuppressant in corneal transplantation. METHODS: High risk corneal transplantation was performed orthotopically in SD rat models of high risk penetrating keratoplasty established by placing three 10-0 nylon sutures in the central corneas for two weeks, with the Wistar rats as the donors. The SD rat models were randomly assigned into 5 groups and treated with 1,25(OH)(2)D(3) at varied concentrations and cyclosporine A (CsA). The expressions of interleukin (IL)-1alpha, tumor necrosis factor (TNF)-alpha, and vascular endothelial growth factor (VEGF) mRNA were detected by in situ hybridization (ISH). RESULTS: 1,25(OH)(2)D(3) significantly suppressed acute graft rejection and inhibited corneal neovascularization as compared with saline. 1,25(OH)(2)D(3) showed better immunomodulatory effects when administered along with CsA in rat corneal allotransplants. ISH study demonstrated that 1,25(OH)(2)D(3) strongly suppressed mRNA and protein expressions of the cytokines IL-1alpha and TNF-but not those of VEGF. CONCLUSION: Topical administration of 1,25(OH)(2)D(3) can be effective in suppressing acute corneal graft rejection by inhibiting the expression of proinflammatory cytokines (IL-1alpha and TNF-alpha).

[Immunohistochemical study of in situ CD86 expression in rejected rat corneal graft after penetrating keratoplasty].

OBJECTIVE: To investigate the expression of CD86 co-stimulatory molecules in rejected rat corneal graft in situ after penetrating keratoplasty. METHODS: Rat models of orthotopical corneal transplantation were established, and after the occurrence of graft rejection, immunohistochemical staining was performed on the corneal whole-mounts and the spleen tissue of the recipient rats. RESULTS: CD86(+) cells were detected in the epithelium of the corneal graft during allograft rejection but not in normal cornea. CONCLUSION: In situ expression of costimulatory molecules in the corneal allograft may be related to the acute immune rejection after penetrating keratoplasty.

[Subconjunctival interleukin-1 receptor antagonist inhibits graft rejection following high-risk penetrating keratoplasty in rats].

OBJECTIVE: To observe the roles of subconjunctival administration of interleukin-1 receptor antagonist (IL-1ra) promoting corneal graft survival in rat models of high-risk penetrating keratoplasty. METHODS: Corneal vascularization was induced in 40 Sprague-Dawley rats (40 eyes) by passing 10-0 silk suture through the corneal stroma, and 30 of these rats received corneal grafts from Wistar rats to establish high-risk keratoplasty models and were divided into 3 groups to receive their respective treatment with IL-1ra eye drops (50 microg/ml), 1% CsA eye drops, administered 3 times a day, or no treatment. All the rats were treated by Tobra Dex eye drops and Tropicamid eye drops, 3 times a day for 14 consecutive days after the operation. During the 30-day observation, the survival of the grafts was recorded, and all the grafts were evaluated for signs of rejection. RESULTS: The mean survival times (MST) of the grafts of the treatment groups with IL-1ra and CsA were 12.00+/-1.50 d and 10.44+/-1.13 d respectively, significantly longer than that in the untreated model group (8.00+/-1.25 d, t=0.00, P<0.01), and the difference in the MST between the 2 treatment groups was also significant (t=0.00, P<0.01). CONCLUSION: Treatment with IL-1ra may significantly prolong high-risk corneal allograft survival.