[Brand-New Ge20Ga5Sb10S65 Prism Biosensor Based on Inverted SPR].

Based on inverted surface plasmon resonance (ISPR) a novel biosensor consisting of Ge20Ga5Sb10S65-palladium-graphene layer-biomolecule layer is proposed. The refractive index of biomolecule layer alters as biomolecule experience interactions, thus leading to a shift of ISPR angle. On this basis, the spectrum output of sensor is derived by transfer matrix method. The sensitivity, the resolution, the dynamic detection range and the signal to noise ratio of the presented sensor are discussed and compared with the performance of traditional sensors. Moreover, the influences of grapheme layer thickness on sensors are analyzed with comparative study. Finally, near infrared is used as the incident light of the presented sensor. The results show that, the best thickness of grapheme layer is monolayer; the peak intensity of the ISPR reflection is about 80%~90% of intensity of incident light, guaranteeing a high signal to noise ratio; In the visible light, when λ = 632.8 nm, the presented sensor is 1.9 times the resolution of the sensor based on SiO2 coupling inverted surface plasmon resonance, is 3. 5 times the resolution of the sensor based on surface plasmon resonance(SPR), and is 2 times the dynamic detection range of pre-existing biosensor based on SPR. The application of Ge20Ga5Sb10S65 prism extends the detection light wavelength from the visible region to the near infrared region. When λ = 1,000 nm, the sensor is 3-4 times of the sensor in visible region. The research greatly contributes to the realization and application of biosensor based on inverted surface plasmon resonance.

[Up-regulation of the sHLA-G5 level by human-mouse chimeric anti-IL-2R monoclonal antibody treatment in kidney transplantation].

OBJECTIVE: To find whether the up-regulation of soluble human leucocyte antigen-G5 (sHLA-G5) levels is a new function mechanism of anti-interleukin-2 receptors (anti-IL-2R) monoclonal antibody treatment in kidney transplantation. METHODS: A total of 215 recipients at our centre from January 2006 to December 2007 were divided into antibody use group (n = 141) and antibody non-use group (n = 74) and another healthy group (n = 69). The sHLA-G5 level in peripheral blood was detected by enzyme-linked immunosorbent assay (ELISA). And the expression of HLA-G5 was confirmed by Western blot and Real-time polymerase chain reaction (PCR). RESULTS: sHLA-G5 levels was (56 ± 30) µg/L in using anti-IL-2 receptor monoclonal antibody before transplantation, It was higher than that before use antibody [(34 ± 20) µg/L], also higher than healthy group [(35 ± 17) µg/L] and antibody non-use group [(36 ± 19) µg/L, P < 0.05, respectively]. At Day 1, Day 4, Week 1, Week 2 post-transplantation, the level of sHLA-G5 of recipients with antibody use was significantly higher than that of those with antibody non-use. The values were as follows: (95 ± 35) µg/L vs (54 ± 16) µg/L, (131 ± 24) µg/L vs (75 ± 22) µg/L, (167 ± 44) µg/L vs (62 ± 17) µg/L, (172 ± 35) µg/L vs (45 ± 16) µg/L (all P < 0.01). And the results of Western blot and RT-PCR corresponded to those of ELISA. CONCLUSION: The preoperative use of first dose of anti-IL-2R monoclonal antibodies results in the up-regulated level of sHLA-G5. Thus it is beneficial for protecting the kidney survival and reducing the risks of acute rejection.

[Applications of monitoring human leukocyte antigen G and its inhibitory receptors in post-renal transplantation].

OBJECTIVE: to study the feasibility of human leucocyte antigen-G (HLA-G) as a post-transplantation prognostic biomarker and discuss the correlation of its receptor expression and the mechanisms. METHODS: a total of 215 recipients in our centre from February 2006 to June 2008 were divided into stable kidney function group (n = 173) and acute rejection group (n = 42). The soluble human leucocyte antigen-G5 (sHLA-G5) level in peripheral plasma was detected by ELISA. And the HLA-G receptor ILT-2, KIR2DL4 on T, B, NK lymphocytes were analyzed by flow cytometry (FCM). The sHLA-G5 cutoff level by ROC curve was employed to predict the events of acute post-transplantation rejection. And regression analysis was used to determine the association of sHLA-G5 with acute rejection. RESULTS: an optimal cutoff value of 139.0 microg/L could be defined for sHLA-G5 (sensitivity: 63.6%, specificity: 82.1%, AUC: 0.780). Binary regression analysis showed that sHLA-G5 played an independent role on acute rejection (P = 0.019, OR = 0.039, 95%CI: 2.091 - 5.661). The rate of HLA-G receptor ILT-2 on CD4(+)T cell, CD8(+)T cell and B cell in acute rejection group was statistically lower than that in stable kidney function group (21% ± 7% vs 52% ± 17%, 23% ± 6% vs 39% ± 16%, 21% ± 7% vs 39% ± 16%, all P < 0.05). The expression of KIR2DL4 on NK cells in acute rejection group was statistically lower than that in stable kidney function group (31% ± 10%vs 57% ± 21%, P < 0.05). CONCLUSION: sHLA-G5 level may be predicted for acute rejection with a high sensitivity and specificity. The up-regulated expression of ILT-2 and KIR2DLT may contribute to immunology tolerance in peripheral circulation.

[Expression of human leucocyte antigen G in peripheral blood of kidney transplantation recipients].

OBJECTIVE: To investigate the expression of non-classical major histocompatibility complex (MHC)-I molecule, human leucocyte antigen (HLA) G, including membrane-bound HLA-G (mHLA-G), intracellular HLA-G (iHLA-G) and soluble HLA-G (sHLA-G), in peripheral blood of surviving kidney transplantation recipients and understand the relevance between HLA-G and the function of transplanted organ, as well as the onset of acute rejection. METHODS: A longitudinal study was performed on 175 kidney transplantation recipients. Three groups were involved in this study, including acute rejection group (n = 36), function stable group (n = 139) and healthy control group (n = 30). The expression of mHLA-G1 and iHLA-G1 in the T lymphocytes of peripheral blood was detected by flow cytometry analysis and the sHLA-G5 level detected by ELISA. RESULTS: The average rate of CD4(+)mHLA-G1(+), CD8(+)mHLA-G1(+), CD4(+)iHLA-G1(+), CD8(+)iHLA-G1(+) in T lymphocytes of healthy control group was 0.43% +/- 0.19%, 1.23% +/- 0.41%, 27% +/- 13% and 36% +/- 14% respectively. That of acute rejection group was 0.57% +/- 0.34%, 1.31% +/- 0.56%, 26% +/- 8% and 37% +/- 17%; that of function stable group was 0.61% +/- 0.43%, 1.39% +/- 0.47%, 26% +/- 9% and 37% +/- 17% respectively. There was no significant difference among the three groups (all P > 0.05). The average of sHLA-G5 levels in plasma of control group was (25 +/- 14) ng/ml, acute rejection group (24 +/- 15) ng/ml (pre-operative) and (34 +/- 21) ng/ml (post-operative), function stable group (25 +/- 11) ng/ml (pre-operative) and (56 +/- 32) ng/ml (post-operative). There was no significant difference among the three groups (pre-operative, P > 0.05). The average of sHLA-G5 levels in plasma of function stable group was higher than that of acute rejection group (post-operative, P < 0.05). CONCLUSION: There is a subset of CD4(+)HLA-G1(+) and CD8(+)HLA-G1(+)T lymphocytes with low percentage in peripheral blood of those surviving kidney transplantation recipients. The expressions of mHLA-G1 and iHLA-G1 have no relevance with the onset of acute rejection. sHLA-G5 is correlated with acute rejection in peripheral blood of surviving transplantation recipients.

HLA-G expression in the peripheral blood of live kidney transplant recipients.

BACKGROUND: The human leukocyte antigen-G (HLA-G) has been considered to be an important tolerogeneic molecule playing an essential role in maternal-fetal tolerance, upregulated in the context of transplantation, malignancy, and inflammation, and has been correlated with various clinical outcomes. The aim of this study was to investigate the clinical relevance of the expression of membrane HLA-G (mHLA-G), intracellular HLA-G (iHLA-G), and soluble HLA-G (sHLA-G) in the peripheral blood of live kidney transplant recipients. METHODS: We compared the expression of the three HLA-G isoforms in three groups, healthy donors (n=20), recipients with acute rejection (n=19), and functioning transplants (n=30). Flow cytometry was used to detect the expression of mHLA-G and iHLA-G in the T lymphocytes of peripheral blood from subjects in the three groups. Enzyme-linked immunosorbent assays were used to detect sHLA-G in the plasma from the three groups. RESULTS: There were no significant differences in mHLA-G and intracellular HLA-G among the three groups, but the sHLA-G plasma level was higher in the functioning group than in the acute rejection or healthy group. We found a subset of CD4(+)HLA-G(+) and CD8(+)HLA-G(+) T lymphocytes with low rates of mHLA-G expression in the peripheral blood of kidney transplantation recipients. Intracellular expression of HLA-G was detected in T lymphocytes. However, there was no correlation between acute rejection and the mHLA-G or intracellular HLA-G expression. CONCLUSION: sHLA-G was the major isoform in the peripheral blood of live kidney transplant recipients and high sHLA-G levels were associated with allograft acceptance.

[Impact of the land-use change on the non-point source nitrogen load in Yunmeng Lake watershed].

Take potable water sources in Linyi City Yunmeng Lake watershed as a case study, it obtains the nutrient export coefficient of land use by the export coefficient model and simulative rainfall experiment. On the basis of GIS and RS, it analyses the effect of the non-point source (NPS) pollution load because of the land-use change during the past 25 years. The result indicates that the TN increased from 3.77 x 10(3) t in 1986, to 4.45 x 10(3) t in 1995, to 5.5 x 10(3) t in 2010; As far as land-use type is concerned, the TN from farm-land increased year by year, the contribution rate is 80.11% in 1986, 82.60% in 1995 and 85.59% in 2010, the forestland and the grass-land load have a little change, but the contribution rate decreased gradually, the residential load increased by a large margin, however, the contribution rate is very little. As for the sub-basin, the higher the proportion of the farm-land is, the more the TN load increased. There is a significant positive correlation between the farm-land and the nitrogen (TN) load, so the farm-land is the sources of the nitrogen. Conversely, there are negative correlations between the forest-land, grass-land and the TN load; therefore, the forest-land and grass-land are the sinks of the nitrogen. Therefore, it can adjust the land-use structure to reduce and control the TN loss to water environmental pollution.