Ex vivo expansion of hematopoietic stem cells was suggested as the best way of overcoming problems caused by limited hematopoietic cell number for cord blood transplantation. In this study, we quantified and characterized an ex vivo expansion capacity of umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) as a cell feeder layer for support of UCB-derived committed hematopoietic progenitor cells (HPCs) in the absence or presence of recombinant cytokines. The UCB-derived MSCs used in the study differentiated into osteoblast, chondrocytes, and adipocytes under proper conditions. Frequencies in colony forming unit-granulocyte, macrophage, colony forming unit-granulocyte, erythrocyte, macrophage, megakaryocyte, burst forming unit-erythrocyte, and colony forming unit-erythrocyte increased to 3.46-, 9.85-, 3.64-, and 2.03-folds, respectively, only in culture supplemented by UCB-derived MSCs as a cell feeder layer without recombinant cytokines (culture condition C). Identified expansion kinetics in all kinds of committed HPCs showed plateaus at 7 culture days, suggesting some consumable components were required for the expansion. Physiological importance and different roles for different committed HPCs of UCB-derived MSCs as a cell feeder layer were revealed by a distinguished expansion capacity for colony forming unit-megakaryocyte. The preferred maintenance of CD33(-)CD34(+) in culture condition C was also identified. The presence of cobblestone-like areas as hematopoietic microenvironment and various cell feeder layer-originated hematopoietic cytokines including interleukin-1beta and granulocyte, macrophage-colony stimulating factor were suggested as underlying mechanisms for the identified expansion capacity. The present numeric and biological information about intrinsic expansion capacity for UCB-derived committed HPCs will increase further biological and clinical applications of UCB-derived MSCs.

An effective metal-free C–H amination of N-Ts-2-alkenylanilines by using DDQ as an oxidant has been developed to afford a diverse range of substituted indoles. This protocol is operationally simple and robust, obviates the need of expensive transition-metal catalysts, and offers a broad substrate scope. A mechanism involving a radical cation generated by SET and a migratorial process via a phenonium ion intermediate is proposed.

Owing to an error by the publisher, an incorrect version of Fig. 1 appeared. The correct figure is given here.The online version of the original article can be found at: http://dx.

SummaryWe investigated the cross-sectional area of the femoral vein and its relationship to the femoral artery at two anatomical levels, in infants and children. Sixty-six subjects were allocated to one of two groups: infants (< 1 year, n = 31) or children (1-6 years, n = 35). After induction of general anaesthesia, the femoral vein was evaluated by ultrasound with the patients' legs at 30°and 60°of abduction and their hips externally rotated. In each position, measurements were taken at the level of the inguinal crease and 1 cm below the crease. Hip rotation with 60°leg abduction decreased femoral artery overlap at the level of the inguinal crease in both infants (p = 0.013) and children (p = 0.003). Thus, the optimal place for femoral vein cannulation in paediatric patients seems to be at the level of the inguinal crease with 60°leg abduction and external hip rotation.

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