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

Newborns are more susceptible than adults to infections, which suggests a relative immaturity of the immune system early after birth. Cord blood T cells differ significantly both in surface phenotype and function from adult T cells. We examined the proliferation and expression of activation molecules by lymphocytes isolated from umbilical cord blood or peripheral blood of adults. The lymphocytes were cultured for 5 days in the presence of phytohemagglutinin, concanavalin A, or anti-CD3 monoclonal antibody. Cord blood T cells expressed the CD45RA molecule, while a low proportion expressed the RO isoform, a marker of primed or activated lymphocytes. Furthermore, more than 95% of neonatal lymphocytes bear the CD38 molecule, but do not express the CD57 molecule. After stimulation by phytohemagglutinin or concanavalin A, the lymphocytes from newborns were activated and proliferated as efficiently as adult T cells. Anti-CD3 did not cause neonatal lymphocytes to proliferate, but these cells expressed activation molecules, such as HLA-DR antigens and the receptor for interleukin-2 and transferrin. The relevance of these findings to tolerance induction in immature cord blood T cells is discussed.
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PMID:Functional characteristics of cord blood T lymphocytes after lectin and anti-CD3 stimulation. Differences in the way T cells express activation molecules and proliferate. 900 17

It has been observed that immunological reactivity of neonatal leukocytes is diminished. It seems to result from lymphocytes immaturity. In the present study we have evaluated the phenotype of cord blood lymphocytes with the use of flow cytometry. In neonates we have observed the increase in the absolute number of CD1a and CD7 positive lymphocytes as well as CD2, CD3, CD4, CD8, CD16, CD19 and CD20 positive, while number of CD57 positive cells was significantly decreased. The ratios of CD4/CD8 and T/B lymphocytes were similar to the corresponding ratios observed in adults. Our results have shown the presence of immature lymphocyte population as well quantitative depletion of subpopulation of CD57 cells, what may pose an increased risk of infection in neonates. Nevertheless, increased number of T and B lymphocytes with mature phenotype along with normal ratio of lymphocyte subpopulations and increased number of CD16 positive cells (NK cells), may explain phenomenon of good health among majority of newborns.
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PMID:[Flow cytometric analysis of cord blood lymphocytes]. 964 Aug 62

We characterized the ontogeny of NK-1 receptor agonist affinity (Kd) and density (Bmax) in membranes from tracheal epithelium, smooth muscle, and lung of pigs aged 1-7 days, 8-21 days, and adult in comparison to contractile responses in vitro. Affinity of [125I] Bolton-Hunter substance P ([125I]BH-SP) in epithelium and smooth muscle was three- to fourfold lower in young piglets than in adults. The Bmax of NK-1 sites in epithelium was elevated by more than twofold at 8-21 days relative to 1-7 days piglets and adults. In the lung, NK-1 density as well as affinity was lower than in trachea, regardless of age. In all three groups, [125I]BH-SP binding was potently inhibited by Gpp(NH)p, in both trachea and lung, implying coupling to G-proteins. Inhibition by Gpp(NH)p was most potent in the adult relative to younger animals, in both tracheal epithelium and smooth muscle. Functional sensitivity to the NK-1 agonists substance P and septide was reduced in neonates, as shown by the higher concentration of agonist required to elicit contractile responses. We conclude that the reduced sensitivity of newborn piglet airways to substance P reflects immaturity of G-protein coupling to NK-1, independent of receptor density.
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PMID:Ontogeny of neurokinin-1 receptors in the porcine respiratory system. 1061 51