Effect of stem cell factor (SCF), Flt3 Ligand (FL) and thrombopoietin (TPO) on ex vivo expansion of mononuclear cells derived from umbilical cord blood under hypoxic conditions / 中华器官移植杂志

Objective To explore the effect of stem cell factor (SCF), Flt3 Ligand (FL) and Thrombopoietin (TPO) on the expansion of the mononuclear cells derived from umbilical cord blood ex vivo under hypoxic conditions.Method Human fresh CB mononuclear cells were isolated and cultured with different combinations of cytokine for 7 days under normoxic or hypoxic conditions (3 ％ O2).At day 0 and 7 of culture, total nucleated cells (TNC), CD34+ , CD34+ CXCR4+ , CD34+ CD49d+ and CD34+ CD62L+ cells were assayed by flow cytometry, and colony forming unit (CFU) was determined.The experiment was divided into four groups: group A (cells were cultured in single mononuclear cells under normoxic conditions);group B (cells were cultured in single mononuclear cells under hypoxic conditions);group C (cells were cultured with SCF, FL and TPO under normoxic conditions);group D (cells were cultured with SCF, FL and TPO under hypoxic conditions).Result At 7th day of culture, TNC, CD34+ cells and CFU expansion were significantly increased in groups B, C and D, and the expansion effect in group D was superior to that in groups B and C, but there was no significant difference between groups B and C (P＞0.05).At 7th day of culture, the expression levels of CD49d, CD62L and CXCR4 on expanded CD34 + cells were significantly reduced in group A as compared with those at day 0, and those in groups B, C and D were significantly increased as compared with those in group A, those in group D were significantly higher than in group D than in groups B and C (P＜0.05),but there was no significant difference between groups B and C (P＞ 0.05).Conclusion Hypoxic conditions could enhance the expansion and expression of CD49d, CD62L and CXCR4 of mononuclear cells derived from umbilical cord blood with SCF, FL and TPO.

Ultrastructural Analysis of in vivo Expanded Corneal Epithelium on Amniotic Membrane

The purpose of this study is to characterize and compare the ultrastructural changes occurring during the in vivo cultivation of corneal epithelium on amniotic membrane (AM) at several different time points. Corneal burn patients (n=7) with a corneal epithelial defect and severe limbal damage were selected. Initially, AM transplantation with limbal autograft was performed at the acute stage of corneal burn to reconstruct the damaged ocular surface. One to six (mean interval; 3.3+/-1.2) months later, the central part of AM containing an in vivo expanded corneal epithelium was excised and retransplanted in adjacent lesions. The excised epithelium with AM was examined by electron microscopy and immunohistochemical study. By electron microscopy, one and two months after expansion, cultivated epithelium on AM showed an undifferentiated epithelium and an incomplete basement membrane (BM). But, after three months, the cultivated epithelium began to differentiate into a multilayered epithelium with a continuous BM with increased hemidesmosomes. These findings were further confirmed by immunohistochemical study, that cytokeratin K3 was expressed in the cultivated corneal epithelium and newly formed BM was partially positive of collagen IV at three months. At least 3 months may be needed for the proliferation and differentiation of in vivo cultivated corneal epithelium on AM.

The Change of Ocular Aberration after LASIK Surgery

PURPOSE: To evaluate the change of ocular aberration after LASIK using Zernike's polynomial expansions. METHODS: Sixty eyes of thirty consecutive patients that underwent LASIK were examined prospectively. The ocular aberration was measured with Hartman-Shack aberrometer (WASCA Wavefront Analyzer, USA) at postoperative 30, 90, and 180 days. The postoperative values were compared with that of preoperation. RESULTS: The average age is 27.6 years old. The range of preoperative refractory error were from -3.00 Diopter (D) to -11.00 D. The increase of spherical and triangular coma aberrations (4.7- fold and 3.5- fold, respectively), with respect to preoperative values. There were statistically significant differences between preoperative and postoperative high order RMS at the postoperative 180 days (p<0.05). CONCLUSIONS: The postoperative increases of RMS in higher order aberration, coma aberration, triangular aberration was observed.

Discrepancy in T cell clonal expansions in synovial fluid and peripheral blood from rheumatoid arthritis patients

Rheumatoid arthritis (RA) is an autoimmune disease involving the synovial membrane of peripheral joints. T cells specific for self antigens may play a critical role. Identification of T cell receptors (TCR) of such specific T cell clones is very important for treatment, prevention and identification of relevant autoantigens. To identify specific T cells, TCR V beta family repertoire and the clonal expansion of T cells were analyzed in this study. The percentage of V beta 5+ or V beta 8+ cells in the synovial fluid mononuclear cells (SFMCs) was similar to that in the peripheral blood mononuclear cells (PBMCs). However, the percentage of DR+ T cells in the SFMCs was higher (p< 0.01). Analyzing the clonality of T cells in 8 V beta families (V beta 1, V beta 5, V beta 8, V beta 14, V beta 16, V beta 17, V beta 18, V beta 20), clonal expansions in CD8+ T cells from the SFMCs were found more frequently than in the PBMCs. The patterns of clonal expansions were discrepant between the SFMCs and the PBMCs even in the same patient, which suggests several inflamed tissue specific T cell clonal expansions in the SFMCs. These T cell clones might be activated by autoantigens which are not identified yet and responsible for the RA pathogenesis.