UMLS:C0029713 - FACTA Search

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)

We have developed an animal model for congenital syphilis. Treponema pallidum is injected intravenously into pregnant rabbits and fetuses are infected in utero. As a prelude to characterizing the immunologic consequences of fetal infection, it was necessary to expand on the baseline information about newborn rabbit immune capabilities. Studies were undertaken to determine splenic macrophage and T lymphocyte functions with emphasis on newer immunologic parameters. Newborns aged 2 weeks were compared to adults. Macrophage capabilities in newborn rabbits differed from those of their adult counterparts. These cells produced similar basal levels of interleukin 1 (IL-1) but failed to respond to the IL-1 stimulants of lipopolysaccharide (LPS) or T. pallidum. Macrophages also exhibited diminished levels of la expression and increased levels of prostaglandin E2 (PGE2) secretion. T lymphocyte functions were altered in newborn spleen preparations. Following concanavalin A (Con A) stimulation, interferon gamma production was half that of adults; in direct contrast, IL-2 production was twice that of adults. Con A-induced lymphocyte proliferation was markedly decreased in newborn preparations. This diminished response resulted from down-regulation rather than immaturity. When newborn splenic cells were stimulated with Con A in the presence of indomethacin, anti-transforming growth factor (anti-TGF), or exogenous IL-1/IL-2, better proliferation resulted. PGE2, which is well established as a down-regulator of newborn immune functions in human and mouse systems, also appears to play a role in suppressing newborn rabbit functions. TGF is a potent suppressor of a number of adult immunologic reactions. This is the first documentation of the potential role of this factor in down-regulating newborn immune capabilities. These findings provide a framework for future investigations of our congenital syphilis model.
...
PMID:Macrophage and lymphocyte functions are down-regulated in newborn rabbits. 143 51

The mortality of septic shock remains high in newborns. Although the effectiveness of adrenergic drug therapy continues to be controversial, adrenergic drugs have been used for the treatment of newborn endotoxic shock. To elucidate the effects of beta-adrenergic drugs on the fulminant hemodynamic deterioration of newborn endotoxic shock, newborn dogs (2-10-day-old, 264-800 g) were given Escherichia coli lipopolysaccharide (LPS; 10 mg/kg iv) and treated with isoproterenol (0.1 micrograms/kg/min) or dopamine (5 micrograms/kg/min) infusion from 5 to 120 min after LPS injection. Isoproterenol attenuated the effects of LPS by increasing the mean arterial pressure (32 +/- 2 vs. 13 +/- 1 mmHg at 120 min), cardiac output (183 +/- 29 vs. 118 +/- 23 ml/min/kg at 120 min), and the survival time (5.3 vs 2.9 hr). However, dopamine did not improve the hemodynamic deterioration. As dopamine-beta-hydroxylase activity in the blood was significantly lower in newborn dogs than in adult dogs, inadequate response of newborn dogs to dopamine was thought to be in part due to enzymatic immaturity.
...
PMID:Beta-adrenergic drug therapy in newborn canine endotoxic shock. 197 57

Spleen cells from newborn mice do not respond by proliferation to concanavalin A (Con A) or bacterial lipopolysaccharide (LPS) stimulation. This non-reactivity cannot be reversed to a positive response by exogenous interleukin-2 (IL-2). The stimulation with Con A of spleen cells from newborn mice, in contrast to cells from adult animals, does not result in synthesis of mRNA for inducible 55,000 molecular weight (MW) IL-2 receptors (IL-2R). The failure of neonatal spleen cells to synthesize IL-2R mRNA is an intrinsic property of the cells themselves, and it is not due to activity of natural suppressor cells present in newborn animals. Since the expression of functional IL-2R represents one of the early and pivotal events in immune cell activation, we propose that the inability to synthesize IL-2R may be one of the primary reasons for the immunological immaturity of newborns.
...
PMID:Inability of mitogen-stimulated spleen cells from newborn mice to synthesize interleukin-2 receptors. 227 35

Interleukin-12 (IL-12) is a critical cytokine regulating natural killer (NK) and T-cell function. We hypothesized that the impaired ability of cord blood (CB) to produce normal adult levels of IL-12 in response to stimulation may contribute to the immaturity of CB immunity. Furthermore, exogenous IL-12 may compensate for the immaturity in CB cellular immunity and have the potential for immunotherapy post cord blood transplantation. We compared the expression and production of IL-12 from activated cord versus adult mononuclear cells (MNC), regulatory mechanisms associated with IL-12 expression in CB MNC, and the effects of IL-12 on induction of CB interferon (IFN)-gamma production, NK, and lymphokine-activated killer (LAK) cytotoxicity. Northern analysis and enzyme-linked immunosorbent assay were performed in lipopolysaccharide (LPS)-stimulated CB and adult peripheral blood (APB) MNC. IL-12 mRNA expression was induced within 6 hours with LPS (10 micrograms/ml) and reached peak levels at 12 hours in both CB and APB MNC. However, IL-12 mRNA expression and protein accumulation in CB MNC were 35.8% +/- 4.84% (12 hours, n = 11, P < .05), and 17.6% +/- 1.7% (24, 72, 96 hours, n = 9, P < .05) respectively, when compared with APB MNC. Nuclear run-on assays showed no differences between CB and APB MNC in both the basal levels of transcription and the degree of transcriptional activation. However, the half-life of IL-12 p40 mRNA was approximately threefold lower in activated CB MNC than in activated APB MNC (CB: 114 +/- 3.0 minutes v APB: 353 +/- 7.8 minutes, n = 3, P < .05). Exogenous IL-12 (10 U/mL) induced a significant increase of IFN-gamma from both CB and APB MNC (24 hours, 72 hours, P < .05, n = 3). The stimulated CB IFN-gamma level reached comparable levels produced by unstimulated APB. IL-12 treatment also significantly enhanced CB NK cytotoxicity against K562 and NB-100 cell lines to the comparable levels of APB (P < .05, n = 4). CB MNC was more responsive to IL-12 stimulation with respect to IFN-gamma production, NK, and LAK cytotoxicity when compared with APB. The present study suggests that IL-12 mRNA and protein expression is decreased in activated CB. This discrepancy in IL-12 production is secondary, at least in part, to the altered posttranscriptional regulation. The impaired, ability of CB MNC to produce IL-12 in response to stimulation may contribute to the decrease in IFN-gamma production and NK cytotoxicity. However, IL-12 enhanced IFN-gamma and NK activity in CB MNC up to the comparable levels of APB MNC. These findings suggest that reduced expression and production of IL-12 from activated CB may contribute to the immaturity in CB cellular immunity and contribute, in part, to decreased graft-versus-host disease following CB stem cell transplantation.
...
PMID:Decreased interleukin-12 (IL-12) from activated cord versus adult peripheral blood mononuclear cells and upregulation of interferon-gamma, natural killer, and lymphokine-activated killer activity by IL-12 in cord blood mononuclear cells. 870 53

The inability of neonates to fully evoke the acute-phase reaction to infection is thought to be due in part to central nervous system immaturity. We used the expression of Fos protein to evaluate whether acute-phase reaction deficits in neonates may indeed be linked to unresponsiveness of brain regions that mediate the responses to infection in adult animals. In this study, we used lipopolysaccharide (LPS) as the infectious agent. Rats aged 0-1, 3, 6, 9, 12 and 15 days were divided into groups treated with low- or high-dose LPS (Escherichia coli; 50 and 500 micrograms/kg, respectively, i.p.) or pyrogen-free saline (PFS) i.p. Two hours after injection, the animals were deeply anesthetized, sacrificed, and their brains removed for Fos immunocytochemistry. Fos-like immunoreactive (FLI) neurons in the preoptic area (POA), paraventricular nucleus of the hypothalamus (PVN), and organum vasculosum laminae terminalis (OVLT) were compared between the treatment and the age groups. The forebrain was devoid of FLI neurons in 1-day-old rats, but FLI neurons were present at 3 days of age and continued to increase with age until 9 days after birth. There were no significant differences between the LPS- and PFS-treated groups until day 12 of age. At 12 and 15 days of age, FLI neurons in the PVN, medial preoptic and lateral preoptic nuclei, and the area surrounding the OVLT were greater in the LPS-treated animals. The expression appeared to be both age- and dose-dependent. These observations show that the rat brain structures that participate in the mediation of the acute-phase reaction do not become responsive to systemic pyrogens until 12 days of age, thus suggesting that insensitivity of the brain to pyrogenic agents may be partly responsible for the poor response of neonates to infectious agents.
...
PMID:Lipopolysaccharide-induced Fos expression in hypothalamic nuclei of neonatal rats. 873 1

The release of cytokines and prostaglandins (PG) by peritoneal macrophages (PM luminal diameter of) may influence the cytokine network controlling peritoneal inflammation and in the long-term the function of the peritoneum as a dialysis membrane. In the present study, an evaluation of the long-term effects of peritoneal dialysis on the release of cytokines and prostaglandins, and the expression of surface markers of cellular maturation on blood and mononuclear cells has been performed in patients during their first year on CAPD. Spontaneous release of tumour necrosis factor alpha (TNF alpha) and interleukins 6 (IL-6) by PM luminal diameter of, after 4 or 24 hours in culture, increased significantly with time on CAPD, while there was a small but significant decrease in release of prostaglandin E2 (PGE2). Production of TNF alpha and IL-6 was enhanced following incubation of the cells with lipopolysaccharide (LPS), but the effect of LPS was proportionally greater on blood monocytes than on PM luminal diameter of. There was a significant increase in the concentrations of PGE2 and 6-keto-prostaglandin F1 alpha in overnight dwell peritoneal dialysis effluent with time on CAPD. The levels of TNF alpha and IL-6 in uninfected PDE were below the detection limit of the immunoassay over the whole time period studied. Expression of CD15, which correlates with immaturity, by PM luminal diameter of and blood monocytes increased with time on CAPD, while expression of CD11c, a marker of maturation, decreased on blood monocytes, but did not change significantly on PM luminal diameter of. There was also a slight increase in expression of transferrin receptor in both PM luminal diameter of and monocytes, but this did not reach statistical significance. These findings suggest that peritoneal macrophages and blood monocytes isolated from CAPD patients over a one year period become increasingly immature with time, and this is accompanied by a significant modulation of their ability to secrete inflammatory cytokines. Dysregulation of macrophage function may have important consequences with respect to inflammatory processes and the long-term function of the peritoneal membrane in CAPD patients.
...
PMID:Longitudinal evaluation of peritoneal macrophage function and activation during CAPD: maturity, cytokine synthesis and arachidonic acid metabolism. 882 40

Previous studies have demonstrated enhanced intestinal trypsin uptake and decreased liver clearance of trypsin in newborn rats compared to adults. In order to examine the effectiveness of the reticuloendothelial system (RES) in clearing trypsin, bovine trypsin (1.25 mg/100 g body weight) plus trace 125I-trypsin were injected into the portal vein of 2-week-old (n = 57) and adult (n = 44) control rats or following RES stimulation using intraperitoneally injected lipopolysaccharide or RES suppression with intraperitoneally injected oleic acid emulsion. Plasma, liver and spleen 125I activities were assessed at 1, 5 or 15 min following infusion in control, stimulated and suppressed animals. Newborn control rats had significantly increased 125I plasma levels with decreased liver and spleen 125I activity compared to control adults. RES stimulation in the newborns did not lead to any change in liver or plasma levels although splenic values increased while adults had a decrease in liver 125I activity. RES suppression in the newborns led to increased plasma and decreased spleen 125I-trypsin values while adult rat levels were unchanged. The immature reticuloendothelial system in newborns is poorly responsive to RES stimulation although it can be made even further inefficient by RES suppression. The combination of RES immaturity and lack of response to stimulation may make newborns susceptible to proteolytic damage, especially during times of increased systemic levels of proteolytic enzymes.
...
PMID:Reticuloendothelial system uptake of infused 125I-trypsin in newborn and adult rats. 905 94

Very little is known about alveolar macrophage (AM) immunological function in early childhood. Using nonbronchoscopic bronchoalveolar lavage (BAL), this study sought to compare the proportion, number, and function of AM between very young and older children. BAL fluid (BALF) leukocyte parameters were determined in 63 children, and data divided into 3 age groups: group 1 (<2 yrs), group 2 (> or =2-< or =5 yrs) and group 3 (> or =6-< or =17 years). In a further subgroup of children, AM function and immune receptor expression were assessed, and data categorized into two age groups: <2 yrs and > or =2 yrs of age. Compared to groups 2 and 3, the AM percentage in the BAL in group 1 was significantly increased (median: 98% versus 92% and 91%), as was the albumin-adjusted AM concentration. AM from children <2 yrs expressed less human leukocyte antigen (HLA)-DR (versus > or =2 yrs of age), were less effective in reducing nitro blue tetrazolium, and released less interleukin (IL)-1 and tumour necrosis factor on lipopolysaccharide stimulation. There was no difference in release of IL-6, expression of intercellular adhesion molecule-1 (CD54), and AM stimulation of allogeneic T-cells, between children <2 yrs and > or =2 yrs of age. It was concluded that the capacity of alveolar macrophage to stimulate T-cells is not enhanced in early childhood, and that immaturity of alveolar macrophage function may contribute to an increased susceptibility to respiratory infections in this age group.
...
PMID:Alveolar macrophage immaturity in infants and young children. 1059 13

The in vitro effect of indomethacin (IM) and ibuprofen (IB) on the production of the interleukin-1 receptor antagonist (IL-1ra) by cord blood mononuclear cells (CBMC) from preterm newborns was compared to that of peripheral blood mononuclear cells (PBMC) from adults. Mononuclear cells (MC) were incubated with lipopolysaccharide (LPS) in the absence or presence of various concentrations of IM and IB. The level of IL-1ra in the supernatants was tested by ELISA. The results showed a lower ability of MC from preterm newborns to produce IL-1ra as compared with adult cells, supporting the assumption of neonatal immune cell immaturity. IM at pharmacological concentrations caused inhibition of IL-1ra secretion by PBMC from adults whereas IB suppressed the secretion of IL-1ra at higher concentrations only. At the same concentrations neither drug had an in vitro effect on the production of IL-1ra by CBMC of preterm newborns. In conclusion, the lower ability of CBMC of preterm newborns to produce IL-1ra in response to LPS and the absence of an IM and IB effect on the secretion of this cytokine by these cells as compared with PBMC of adults, suggest an underdevelopment of the immune response in preterm newborns.
...
PMID:Indomethacin and ibuprofen effect on IL-1ra production by mononuclear cells of preterm newborns and adults. 1216 27

Dendritic cells (DCs) play a pivotal role in the activation of T cells, which are effector cells in graft-versus-host disease (GVHD). A low incidence of GVHD following cord blood (CB) transplantation has long been reported; despite this, little information is currently available on the characteristics of CB DCs. The goal of the present study was to investigate the immunophenotypic characteristics and distribution of CB DCs and their subsets. For that purpose we have analyzed 15 CB samples as compared to normal peripheral blood (PB) (n = 7) and blood from patients submitted to an allogeneic PB stem cell transplantation (allo-PBSCT) (n = 6). Our results show an overall decreased frequency of DCs in CB due to the presence of significantly lower numbers of CD123inter./CD33inter./CD16+ DCs. Phenotypically, CB DCs displayed a tendency to express lower levels of the gamma-chain interleukin-2 (IL-2) receptor (CD132) and of the CD86 co-stimulatory molecule, supporting a higher degree of immaturity for CB as compared to PB DCs. After activation of CB DCs with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) higher frequencies of cytokine-producing cells were found among CD123inter./CD33inter./CD16+ and CD123dim/CD33bright/CD16- DCs; however, when only the cytokine-producing DCs were considered, a significant decrease in the amount of different cytokine (e.g., IL-1beta and IL-6) produced per cell was observed especially for CD16+ CB DCs. These findings support a higher degree of immaturity for CB as compared to PB DCs that might contribute to explain, at least in part, the low incidence and severity of GVHD observed after CB transplantation.
...
PMID:Immunophenotypic and functional characterization of cord blood dendritic cells. 1506 94

1 2 3 Next >>