[Clinical analysis on effect of retroperitoneoscopic nephrectomy in elderly donors for renal transplantation].

OBJECTIVE: To evaluate the safety and effectiveness of retroperitoneoscopic donor nephrectomy in elderly donors for renal transplantation. METHODS: A retrospective analysis was conducted with 123 cases of retroperitoneoscopic living donor kidney transplantation in 309th Hospital of PLA from March 2011 to March 2014, including 44 elderly donors (age≥55 years) and 79 young to middle-aged donors (age <55 years). Comparisons were made in terms of postoperative complications in both donors and recipients, renal function recovery in the donors and function of graft in the recipients. RESULTS: The clinical baseline data of the two groups shows that glomerular filtration rate (GFR) of donors in the elderly donor group was lower than the young donor group (P=0.04). The 123 donors all underwent retroperitoneoscopic donor nephrectomy successfully. Postoperative complications in donors and recipients of both groups had no significant differences (P=0.60; P=1.00). In the elderly donor group, the mean serum creatinine level of donors was significantly higher than that in the young donors group [(115.8±22.3) vs (102.5±16.3) µmol/L, P<0.01] 3 days after operation; and estimated GFR (eGFR) was lower [(53.0±9.1)vs(59.6±8.3)ml·min(-1)·(1.73 m(2))(-1,) P<0.01]. Serum creatinine and eGFR of the two groups showed no significant differences one week and six months after surgery (all P>0.05). Four recipients in the elderly donor group had delayed graft function (DGF), 3 had acute rejection; 8 recipients in the young donor group had DGF, 5 had acute rejection; no statistically significant differences were observed between the 2 groups (both P=1.00). Recipients' eGFR were higher in the young donor group than in the elderly donor group at 1 week, 1 month, 3 months, 6 months and 12 months after surgery, but with no statistically significant differences(all P>0.05). After (27.8±12.6) months follow-up, 1 recipient in the elderly donor group died from pulmonary infection; two recipients in the young donor group had kidney dysfunction. Graft survival in the two groups showed no significant difference(P=0.95). CONCLUSIONS: Retroperitoneoscopic donor nephrectomy is safe and feasible for elderly donors. With careful preoperative evaluation, precise operation, and close postoperative monitoring and follow-up, it could provide satisfactory clinical outcome.

Clinical significance of monitoring serum level of matrix metalloproteinase 9 in patients with acute kidney allograft rejection.

This study was designed to explore the clinical significance of dynamically monitoring the serum level of matrix metalloproteinase 9 (MMP-9) before and after renal transplantation. Before transplantation and 1, 3, 5, 7, 10, 15, and 20 days after transplantation, the peripheral blood was collected from 102 renal transplant recipients, including 8 with acute rejection (ARs) and 94 non-ARs. The serum MMP-9 level was detected by Luminex 200 analyzer (Luminex Corporation, Austin, TX, USA). By day 3 post-transplantation, the serum MMP-9 level in non-ARs had significantly reduced as compared to the pretransplantation level, and reached the lowest value on day 20 post-transplantation. In contrast, the serum MMP-9 level in ARs had significantly increased by day 3, reached the highest value on day 7, and remained significantly higher on day 20 as compared to the pretransplantation level. The receiver operating characteristic curve was plotted to evaluate the power of serum MMP-9 level on day 20 post-transplantation to differentiate the non-AR and AR groups. Our data revealed that with a threshold of 8473.26 pg/mL, the area under the curve was 0.758 (0.661, 0.856); the sensitivity and specificity of the diagnostic were 78.40% and 61.30%, respectively; the positive and the negative predictive values were 74.60% and 66.67%, respectively; and the accuracy rate was up to 71.57%. Taken together, the results indicated that dynamically monitoring serum MMP-9 levels in renal allograft recipients might be a convenient and safe method to diagnose ARs.

Antigen-specific suppression by induced CD4+CD25high regulatory T cells in kidney recipients.

The biology and function of induced CD4(+)CD25(high) regulatory T (Treg) cells have not been clarified for their specificity to a foreign antigen. To test whether the regulatory functions of the induced CD4(+)CD25(high) Treg cells after transplantation require antigen-specific triggering, we analyzed the capacity of induced CD4(+)CD25(high) Treg cells to inhibit the proliferation of conventional CD4(+)CD25(-) T cells in response to T-cell receptor stimulation using donor cells or HLA-mismatched third-party cells in vitro. CD4(+)CD25(high) Treg cells did not proliferate in response to allogeneic stimulation and suppressed proliferation of the co-cultured autologous CD4(+)CD25(-) populations in a dose-dependent manner. The proliferation of CD4(+)CD25(-)T cells from the same donor in mixed lymphocyte reactions was significantly inhibited at a 1:8 ratio of conventional T cells:Treg cells: 14,404 +/- 673 cpm without CD4(+)CD25(high) Treg cells versus 10,781 +/- 539 cpm with CD4(+)CD25(high) Treg cells P = .01). At the same 1:8 ratio, the proliferation of CD4(+)CD25(-) cells derived from major histocompatibility complex-mismatched patients was not significantly inhibited: 14,404 +/- 673 cpm without CD4(+)CD25(high) Treg cells versus 12,471 +/- 709 cpm with CD4(+)CD25(high) Treg cells (P = .06). Antigen specificity of the induced CD4(+)CD25(high) Treg cells was demonstrated, after transplantation, supporting the use of antigen-specific Treg cells as a therapeutic strategy.

Molecular modelling study of the mechanism of high-potency inhibition of human catechol-O-methyltransferase by (-)-epigallocatechin-3-O-gallate.

The molecular mechanism of inhibition of human catechol-O-methyltransferase (COMT) by (-)-epigallocatechin-3-O-gallate (EGCG), which is a modest substrate of COMT but an ultra-potent inhibitor of this enzyme, was studied. EGCG has an IC(50) value of 70 nM for inhibiting human liver COMT-mediated O-methylation of 2-hydroxyestradiol, which was 210-760 times more potent than catechin, epigallocatechin and epicatechin. Kinetic analyses showed that EGCG had a strong component of non-competitive inhibition of the O-methylation of 2-hydroxyestradiol. Computational molecular modelling studies showed that the B- and D-rings of EGCG can bind tightly to the human COMT in four different modes (i.e. D-para-OH, D-meta-OH, B-para-OH, and B-meta-OH). The binding geometry of EGCG in these binding modes was found to be less than ideal to form perfect Mg(2+) coordination for the catalysis of its own methylation. It is concluded that the very tight binding interaction of EGCG with COMT makes it a potent non-competitive inhibitor, but its imperfect geometry makes it a poor substrate for methylation by this enzyme.

Does endothelial chimerism correlate with renal allograft rejection?

BACKGROUND: The blood vessels of a transplanted organ are an interface between the donor and the recipient. The endothelium is believed to be a major target for graft rejection. After transplantation endothelial cells of a transplanted organ may be of recipient origin. OBJECTIVES: In this study we sought to determine whether endothelial chimerism correlates with graft rejection. METHODS: Biopsy samples from 34 renal transplants of female recipients who received kidneys from male donors were studied for the presence of endothelial cells of recipient origin. Formalin-fixed, paraffin-embedded tissue sections of renal biopsy samples were examined by fluorescence in situ hybridization (FISH) for the presence of endothelial cells containing two X chromosomes, using a biotinylated Y-chromosome probe and digoxigenin-labeled X-chromosome probe. RESULTS: The FISH methods identified endothelial cells of recipient origin. Endothelial chimerism was common, irrespective of rejection. Its presence was focal with these elements, coexisting in the biopsy. CONCLUSIONS: We observed no correlation between the percentage of recipient endothelial cells among vascular elements and the type of graft rejection (P > .05).

[Design of blood-pressure parameter auto-acquisition circuit].

This paper presents the realization and design of a kind of blood-pressure parameter auto-acquisition circuit. The auto-acquisition of blood-pressure parameter controlled by 89C2051 single chip microcomputer is accomplished by collecting and processing the driving signal of LCD. The circuit that is successfully applied in the home unit of telemedicine system has the simple and reliable properties.

Influence of host cell infiltration on the glycolipid content of mouse brain tumors.

Previous studies showed that levels of some glycosphingolipids (GSLs) expressed in solid brain tumors grown in vivo were reduced or undetectable in cultured cells prepared from the tumors. This phenomenon has been attributed either to suppressed glycolipid synthesis from unknown forces of the tissue culture environment or to the absence of host cells that normally infiltrate the solid tumors growing in vivo. To test further the host cell hypothesis, we examined host cell markers in two experimental mouse brain tumors, the ependymoblastoma and the CT-2A, that were grown as subcutaneous solid tumors in the flank of C57BL/6J (B6) mice or as cultured cells in vitro. The markers included ganglioside N-glycolylneuraminic acid (NeuGc), GA1 (asialo-GM1), and Fc receptor-bearing cells. NeuGc-containing gangliosides, GA1, and Fc receptors are expressed by macrophages and lymphoid-type cells of the mouse host immune system but are not normally expressed by mouse neural cells. Differences in the relative content of Fc receptor-bearing cells in ependymoblastoma and CT-2A tumors grown in vivo (8.3 and 16.8%, respectively) were proportional to differences in the relative content of NeuGc-containing gangliosides (25.5 and 45.1%) and GA1 (8.5 and 13.8%), respectively. Neither cultured tumor cell line expressed Fc receptors, GA1, or NeuGc-containing gangliosides. These findings suggest that non-neoplastic host infiltrating cells (macrophages) contribute significantly to the GSL composition of solid tumors growing in vivo.