An improved method for rat intubation and thymectomy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Thymokidney has been reported as an approach for a vascularized thymus for transplantation to induce donor specific tolerance. A completely thymectomized model which ensures that the obtained thymus is not injured has not been developed yet and it would be useful for evaluating autologous thymokidney function in rats.</p><p><b>METHODS</b>Adult Sprague-Dawley male rats weighing 150 - 300 g (n = 30) underwent non-invasive intubation with the assistance of an improved self-made wedge-shaped cannula made from a 2-ml plastic syringe and transillumination from the anterior tracheal area by an operation spotlight. The rats then received a thoracotomy while their breathing was supported by a small animal ventilator, and both lobes of the thymus were entirely extirpated under a 10× microscope. The postoperative survival rate of the rats was recorded, and changes in the T-cell reservoir from 9 of 30 rats within 21 days after surgery were monitored using flow cytometry. The complete thymectomy rate was confirmed by autopsy and histological examination on 21 days post-operation.</p><p><b>RESULTS</b>The postoperative survival rate of rats was 100%. The exsected thymus was free of injury and the rate of complete thymectomy was 100%.</p><p><b>CONCLUSIONS</b>This model has a stable survival rate and complete thymectomy is able to be achieved. The obtained thymus tissue is free of injury and can be used for transplantation.</p>

Effect of pre-transplantation hemoglobin concentration on prognosis of renal transplant recipients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>For the renal transplant recipients, anemia is one of the common complications and becomes a major medical issue before transplantation. Haemoglobin (Hb) is used as a prognostic indicator, although the optimal pre-transplantation Hb concentration associated with positive prognosis is still controversial. The aim of this study was to detect the optimal Hb concentration on predicting the graft survival and function.</p><p><b>METHODS</b>A retrospective cohort study was conducted by reviewing the medical records of the patients who received renal transplantations at our center from January 2004 to June 2008. Patients were divided into two groups: high Hb group (≥ 100 g/L, n = 79) and low Hb group (< 100 g/L, n = 63). There was no significant difference between the two groups regarding sex, age, blood type and tissue types. Renal function among the two groups was measured and compared. Panel reacting antigens (PRA) of all the recipients were negative. The effect of preoperative hemoglobin concentration on the postoperative renal function recovery in both groups was further analyzed.</p><p><b>RESULTS</b>A total of 14 acute rejection episodes occurred, including 5 patients in the high Hb group (7.9%) and 9 in the low Hb group (11.4%, P > 0.05). The serum creatinine level at one-year post-transplantation of the low Hb group was significantly higher than that of the high Hb group ((117.8 ± 36.3) µmol/L vs. (103.1 ± 35.5) µmol/L, P < 0.05). For one-year actuarial patient and graft survival, incidence of delayed graft function (DGF), serum creatinine concentrations at 1, 3, 6 months post-transplantation, the incidence of cytomegalovirus (CMV) infection, post-transplantation anemia (PTA) and post-transplantation diabetes mellitus (PTDM) of both groups, there were no statistically significant differences.</p><p><b>CONCLUSION</b>Pre-transplantation Hb concentration has significant effect on one-year creatinine concentration, but can not significantly affect acute rejection episodes, DGF, PTA, CMV infection and PTDM.</p>

Optimal in vitro culture conditions for murine predominant immature CD8a+ dendritic cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The prospects of using immature CD8a(+) dendritic cells (DC2) to establish transplant immunologic tolerance and treatments for autoimmune diseases in the future are promising. However, the methods for inducing DC2 are still being explored. The present study was aimed to investigate the optimal in vitro conditions for preparing large numbers of predominant DC2 from murine bone marrow cells.</p><p><b>METHODS</b>Three groups of bone marrow cells cultured under different conditions were examined, namely a cytokine-induced experimental group (cytokine group), a control group with a low concentration of granulocyte-macrophage colony stimulating factor (GM-CSF, low GM-CSF group) and a control group without endogenous cytokines. The cytokine group was cultured with 5 ng/ml GM-CSF, 25 ng/ml Flt3 ligand (Flt3L), 20 ng/ml interleukin 4 (IL-4) and 100 ng/ml stem cell factor (SCF). The low GM-CSF control group was cultured with 0.4 ng/ml GM-CSF, 25 ng/ml Flt3L and 100 ng/ml SCF, without IL-4. The control group without exogenous cytokines was cultured without additional cytokines. All cells were cultured at 37 degrees C under 5% CO2. On days 3, 7 and 16, 4-color flow cytometry was carried out to analyze the cell phenotypes, and the total cell numbers were counted to analyze the cell yields. Phase-contrast microscopy was used to observe the cell morphologies.</p><p><b>RESULTS</b>The cytokine group exhibited higher proportions of typical immature CD8a(+) DC, especially on day 3, but the total cell number and DC2 proportion decreased during prolonged culture. The low GM-CSF control group showed the same tendencies as the cytokine group on days 16 and 22, but produced higher total cell numbers (P<0.05) with lower DC2 proportions and cell numbers. The control group without exogenous cytokines spontaneously generated a certain proportion of DC2, but with low total cell and DC2 numbers that decreased rapidly, especially during prolonged culture (days 7 and 16, P<0.05).</p><p><b>CONCLUSIONS</b>Culture in the presence of 5 ng/ml GM-CSF, 25 ng/ml Flt3L, 20 ng/ml IL-4 and 100 ng/ml SCF can rapidly induce large quantities of predominant immature CD8a(+) DC from murine bone marrow cells. Therefore, these represent optimal culture conditions for preparing murine immature DC2 in vitro.</p>