Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cellular immune system of the newborn infant is immature and hypo-responsive when compared with adults. The extent to which immaturity of the leucocyte function underlies hyporesponsiveness in the newborn is incompletely understood. In this study flow cytometric techniques were applied to investigate the concurrent expression of a range of surface and intracellular leucocyte functional molecules and cytokines in resting and stimulated cord and adult blood. Production of interleukin (IL)-2 and expression of the components of its receptor, IL-2R alpha/beta/gamma, were investigated. No differences in the proportion of leucocytes producing IL-2R alpha and IL-2R gamma were observed for newborns and adults. A lower proportion of T cells and natural killer (NK) cells from newborns expressed IL-2R beta and upregulation of expression was slower. We hypothesize that reduced IL-2R beta may curtail early autocrine IL-2 activation of immune responses in the newborn. This hypothesis was supported by the observation that an increased proportion of stimulated T cells from newborns produced IL-2 at 4 h poststimulation, but at 24 h the proportion was lower than for adult T cells. The very low levels of interferon (IFN)-gamma produced by neonatal T cells and NK cells may also be partly explained by a curtailment of early autocrine activation of T cells. Expression and kinetics of upregulation for other functional molecules were studied. CD71, HLA-DR, tissue factor and CD152 levels were not significantly different for adults and newborns, suggesting that cord blood leucocytes, in some respects, may demonstrate functional maturity. IL-6 secretion by stimulated monocytes was also comparable in cord and adult blood. However, IL-1 alpha and IL-1 beta were produced by a lower proportion of monocytes from newborns than adults. Similarly, tumour necrosis factor (TNF)-alpha production for monocytes and T cells was lower in cord blood. The mean fluorescence intensity for IL-1 alpha, IL-1 beta and TNF-alpha was also lower for leucocytes from cord blood. These findings are significant in relation to the inability of newborn infants to mount a febrile response to infection. The findings of lower expression of IL-2R beta and lower production of inflammatory cytokines IL-1 alpha, IL-1 beta and TNF-alpha is a basis for improved understanding of the immunological immaturity of leucocytes in the newborn.
 ...
PMID:Cord blood leucocyte expression of functionally significant molecules involved in the regulation of cellular immunity. 1116 9

Haematopoietic stem cell transplantation is indicated in several haematologic and genetic diseases, the most notable being aplastic anemia and leukemias. Bone marrow has been the traditional source of these cells. Human umbilical cord blood (UCB) has recently become an alternative source of haematopoietic stem cells for transplants. The advantages of cord blood include noninvasive collection without risk to mother and neonate, low risk of viral infection, and immunologic immaturity of cord cells. Single umbilical cord blood donation is usually sufficient for transplantation to adult recipients. Additionally, banking of HLA-typed UCB appears valuable in patients lacking a family donor. This study has focused on basic "perinatological" parameters of umbilical cord blood: average volume of single donation UCB and initial storage conditions before isolation of haematopoietic stem cells. Additionally, the mean content of CD34+ haematopoietic stem cells in leukocyte, lymphocyte and mononuclear cell fractions was established. Correlations between levels of so-called pro-inflammatory cytokines (present in cord blood serum) and number, viability and clonogenicity of cord blood mononuclear cells were checked. UCB samples were obtained by "open" collection during vaginal deliveries and cesarean sections. The collected blood was stored in solutions of anticoagulants (ACD, CPDA-1, heparin) and culture media (PBS, Iscove medium, RPMI), during several time intervals (0-1 h, 1-6 h, 6-12 h, 12-24 h) and at two temperatures (+4 degrees C, ambient). UCB volumes, as well as MNC counts, correlated with delivery type, placental weight, neonatal body weight and duration of pregnancy. The concentration, viability and clonogenicity of MNCs were assessed after collection and storage. The subpopulation of CD34+ haematopoietic stem cells was isolated from MNCs using monoclonal antibodies and magnetic-based separation. The number, viability and clonogenicity of CD34+ cells were evaluated. Subsequently in some samples, the concentration of proinflammatory cytokines (IL-1 alpha, IL-1 beta, IL-6, IL-8, and TNF-alpha), number of mononuclear cells and in vitro clonogenicity of myeloid progenitors (CFU-GM) were determined. It was found that the collected blood volume depended on neonatal body weight (Fig. 1). Umbilical blood could be stored either at ambient temperature (Fig. 4) or +4 degrees C (recommended because of reduced risk of infection) for up to 24 hours in RPMI solution (Fig. 5) with heparin (Fig. 2, 3). CD34+ cell count correlated with mononuclear cell count only (Fig. 6). A negative correlation between the number of mononuclear cells and concentration of TNF-alpha was revealed (Fig. 7), as well as between the number of detectable CFU-GM and concentration of IL-1 beta (Fig. 8). In conclusion, UCB collection and short-term storage is a safe and simple method for graftable haematopoietic stem cell recovery. Save for IL-1 beta and TNF-alpha, cytokine levels did not correlate with the studied parameters of umbilical cord blood.
 ...
PMID:[Improved method for delivery room collection and storage of human cord blood cells for grafting]. 1251 5