Quality of functional haematopoietic stem/progenitor cells from cryopreserved human umbilical cord blood.

BACKGROUND AND OBJECTIVES: Transplantation of cryopreserved umbilical cord blood (UCB) can be used to treat a multitude of haematologic and immunological diseases. In this study, we examined the quality of UCB cryopreserved for 2 (group I), 4 (group II) and 6 (group III) years. METHODS: The following parameters and procedures were used to test individual units of cryopreserved UCB: the number of total nucleated cells (TNC), cell viability, CFU-GM assay, T-cell activation in vitro and haematopoietic stem cell engraftment in NOD/SCID mice in vivo. RESULTS: The TNC recovery rates for groups I, II and III were 106·2 ± 6·17%, 96·69 ± 6·39% and 100·38 ± 5·27%, respectively, and the mean percentages of viable cells after thawing were 86·88%, 86·38% and 87·43%. When TNC were plated at 5 × 10(3), the number of CFU-GM was 13·6 (group I), 13·8 (group II), 14·2 (group III) and 14·7 (fresh UCB). We confirmed that the huCD4(+) and huCD8(+) T cells within cryopreserved UCB are functionally responsive by assessment of activated huCD25(+) cells. Moreover, the percentage of huCD45(+) cells in the bone marrow was 4·32 ± 1·29% (group I), 4·48 ± 1·11% (group II), 4·40% ± 1·12% (group III) and 4·50% ± 0·66% (fresh UCB), and that in the peripheral blood was 14·69 ± 3·08% (group I), 15·24 ± 4·05% (group II), 15·74 ± 3·43% (group III) and 17·48 ± 3·74% (fresh UCB) in NOD/SCID mice infused with isolated huCD34(+) cells. CONCLUSION: These results indicated that cryopreserved UCB units efficiently retrieve in functionally competent form and are suitable for transplantation.

Identification of differentially expressed genes by 2,3,7,8-tetrachlorodibenzo-p-dioxin in human bronchial epithelial cells.

Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD) is one of the most powerful environmental toxins and causes a variety of toxic effects in humans. Since it makes first contact with bronchial epithelial cells as an atmospheric contaminant, we identified differentially expressed genes (DEGs) in TCDD-treated human bronchial epithelial cells (HBE4-E6/E7) using an annealing control primer (ACP) system. Six genes, five upregulated and one downregulated, were isolated and their expression patterns were confirmed by reverse dot blot analysis. Their genomic sequences were used for identification, and the upregulated proteins were found to be acyl-coenzyme A dehydrogenase (VLCAD), S100 calcium binding protein A6 (S100A6), nuclear receptor co-repressor 2 (NCOR2), ribosomal protein, large, P1 (RPLP1), and tubulin α 1c, and the downregulated protein was shown to be tubulin ß2. Among them, the expression of the S100A6 was further analysed by northern hybridization because of its relationship with TCDD. These results suggest that this new method was simple and convenient to identify DEGs regulated by a specific agent. Moreover, these isolated genes may provide important information to better understand the mechanisms of TCDD toxicity in human bronchial epithelial cells.

Differential effects of corticosteroids on the expression of cyclooxygenase-2, tumour necrosis factor-alpha and matrix metalloproteinase-9 in an animal model of migraine.

Nitric oxide (NO) directly activates trigeminal afferents innervating the dura mater and up-regulates inflammatory mediators. We evaluated NO-mediated up-regulation of cyclooxygenase-2 (COX-2), tumour necrosis factor-alpha (TNF-alpha) and matrix metalloproteinase-9 (MMP-9), and the effect of glucocorticoid administration in an experimental animal model of migraine. COX-2 and TNF-alpha expression and MMP-9 activity were increased after continuous intravenous infusion of glyceryl trinitrate (GTN), a NO donor. Immunofluorescence staining demonstrated strong expression of these inflammatory mediators in the meningeal blood vessels. Methylprednisolone (MP) down-regulated MMP-9, which was reversed by RU486, a glucocorticoid receptor antagonist. COX-2 and TNF-alpha expression was not affected by MP or RU486 administration. These results suggest proinflammatory mediators are involved in the NO-mediated cascade of migraine pathogenesis. Further understanding of the activation of these inflammatory mediators at the transcriptional level may have therapeutic implications for future migraine treatments.

Characterisation of pore structures in nanoporous materials for advanced bionanotechnology.

Porous materials are potential candidates for applications in various fields, such as bionanotechnology, gas separation, catalysts and micro-electronics. In particular, their applications in bionanotechnology include biosensors, biomedical implants and microdevices, biosupporters, bio-encapsules, biomolecule separations and biomedical therapy. All these bionanotechnology applications utilise the shape, size and size distribution of pores in porous materials. Therefore the controlled creation of pores with desired shape, size and size distribution is most important in the development of nanoporous materials. Accordingly, the accurate evaluation of pore structure is necessary in the development of nanoporous materials and their applications. This article reviews recent developments in analytical techniques to characterise the pore structures of nanoporous materials.