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)

The role of the medullary H+-sensitive chemoreceptors on the drive of breathing was studied in 10 unanesthetized newborn animals (8 lambs and 2 kids). The experiment consisted of sequential measurements of ventilation (VE) during a progressive change in the arterial pH (pHa) and in the pH of the cisternal cerebrospinal fluid (pHCSF), induced by intravenous infusion of hydrochloric acid (HCl) followed after an 8-h steady state of acidosis by rapid bicarbonate [HCO3-] infusion. It is shown that a rapid change in [HCO3-]CSF occurs during the infusion of HCl or NaHCO3. As a consequence both CSF and arterial pH change in the the same direction and large changes in pHCSF (from 7.331 to 7.227) were observed. Such CSF acidosis did not contribute to further increase VE beyond the level by hyperventilation induced by the initial fall of pHa. The ventilatory response to the decrease in pHa was found to fall off with moderate to severe acidosis (pHa less than 7.20). In conclusion, this study demonstrates an instability of the pHCSF during neonatal metabolic acidosis and it suggests an immaturity of both the H+-sensitive medullary and peripheral chemoreceptors in the 8-day-old newborns.
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PMID:Central chemical regulation of respiration in term newborn. 4 60

In this study, the urinary H.V.A. of new borns and of older children was measured. The urinary H.V.A. titer of the new borns was found to be significantly greater than in older children. Moreover the increase is more pronounced when those infants are born prematurely. Former studies have shown that the metabolism of central nervous system catecholamine reflected by the urinary titers of H.V.A. is as accurate as titers measured in the CSF. Recently several authors have found increased titers of urinary H.V.A. in autistic children. It is therefore possible that the elevated urinary H.V.A. titers in the new born are due to an immaturity of the dopaminergic structures. Blocking these structures provokes an accelerated catecholamine turnover, thereby increasing the levels of catecholamines metabolites (most notably H.V.A.).
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PMID:[Measurement of homovanillic acid in urine of newborns and in older children]. 16 Aug 14

The commonly held belief that the fetal blood-brain and blood-CSF barriers are immature is reviewed. Results obtained from carefully conducted experiments with horseradish peroxidase and optimal freeze-fracturing suggest that the chick, rat and monkey brain barrier systems to proteins are tight from the earliest stages of development. Previous studies are reviewed in the light of new information on retrograde axonal transport, circumventricular organs, the proper use of horseradish peroxidase, freeze-fracturing, immunocytochemistry and plasma protein gene expression in the developing human brain. Original data on the development of human brain barrier systems are included. Tight junctions between cerebral endothelial and choroid plexus epithelial cells form the morphological basis for these systems. CSF in the fetus contains a remarkably high concentration of protein in contrast to adult CSF which is characterized by a very low protein concentration. This has previously been interpreted as due to immaturity of barriers in the fetal brain. Tight junctions between cerebral endothelial cells and between choroid plexus epithelial cells have been investigated in human embryos and fetuses by freeze fracture and thin section electron microscopy. As soon as the choroid plexus and the brain capillaries differentiated they exhibited well formed tight junctions. These junctions were very complex at early stages of development. A new barrier consisting of 'strap junctions' was found in the developing germinal matrix. The very high concentration of protein in early human fetal CSF cannot be accounted for by a lack of tight junctions in the developing brain barrier systems. Some transfer of proteins from blood to CSF, possibly via an intracellular route, has been demonstrated in immature experimental animals, but it seems that an important contribution to CSF proteins in the fetus may be synthesis by the developing brain and choroid plexuses with subsequent release into the CSF.
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PMID:The development of the human blood-brain and blood-CSF barriers. 353 22

Host defenses in the human neonate are limited by immaturity in phagocytic immunity. Such limitations seem to predispose infected newborns to neutropenia from an exhaustion of the neutrophil reserve. Among the critical defects thus far identified in neonatal phagocytic immunity is a specific reduction in the capacity of mononuclear cells to express granulocyte colony-stimulating factor (G-CSF) after stimulation. However, the safety, pharmacokinetics, and biological efficacy of administration of recombinant human (rh)G-CSF to infected human newborns to compensate for this deficiency is unknown. Forty-two newborn infants (26 to 40 weeks of age) with presumed bacterial sepsis within the first 3 days of life were randomized to receive either placebo or varying doses of rhG-CSF (1.0, 5.0 or 10.0 micrograms/kg every 24 hours [36 patients] or 5.0 or 10.0 micrograms/kg every 12 hours [6 patients]) on days 1, 2, and 3. Complete blood counts with differential and platelet counts were obtained at hours 0, 2, 6, 24, 48, 72, and 96. Circulating G-CSF concentrations were determined at hours 0, 2, 6, 12, 14, 16, 18, 24, and 36. Tibial bone marrow aspirates were obtained after 72 hours for quantification of the bone marrow neutrophil storage pool (NSP), neutrophil proliferative pool, granulocyte progenitors, and pluripotent progenitors. Functional activation of neutrophils (C3bi expression) was determined 24 hours after rhG-CSF or placebo administration. Intravenous rhG-CSF was not associated with any recognized acute toxicity. RhG-CSF induced a significant increase in the blood neutrophil concentration 24 hours after the 5 and 10 micrograms/kg doses every 12 and 24 hours and it was sustained as long as 96 hours. A dose-dependent increase in the NSP was seen following rhG-CSF. Neutrophil C3bi expression was significantly increased at 24 hours after 10 micrograms/kg every 24-hour dose of rhG-CSF. The half-life of rhG-CSF was 4.4 +/- 0.4 hours. The rhG-CSF was well tolerated at all gestational ages treated. The rhG-CSF induced a significant increase in the peripheral blood and bone marrow absolute neutrophil concentration and in C3bi expression. Future clinical trials aimed at improving the outcome of overwhelming bacterial sepsis and neutropenia in newborn infants might include the use of rhG-CSF.
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PMID:A randomized, placebo-controlled trial of recombinant human granulocyte colony-stimulating factor administration in newborn infants with presumed sepsis: significant induction of peripheral and bone marrow neutrophilia. 752 Jul 70

Human status epilepticus (SE) is consistently associated with cognitive problems, and with widespread neuronal necrosis in hippocampus and other brain regions. In animal models, convulsive SE causes extensive neuronal necrosis. Nonconvulsive SE in adult animals also leads to widespread neuronal necrosis in vulnerable regions, although lesions develop more slowly than they would in the presence of convulsions or anoxia. In very young rats, nonconvulsive normoxic SE spares hippocampal pyramidal cells, but other types of neurons may not show the same resistance, and inhibition of brain growth, DNA and protein synthesis, and of myelin formation and of synaptogenesis may lead to altered brain development. Lesions induced by SE may be epileptogenic by leading to misdirected regeneration. In SE, glutamate, aspartate, and acetylcholine play major roles as excitatory neurotransmitters, and GABA is the dominant inhibitory neurotransmitter. GABA metabolism in substantia nigra (SN) plays a key role in seizure arrest. When seizures stop, a major increase in GABA synthesis is seen in SN postictally. GABA synthesis in SN may fail in SE. Extrasynaptic factors may also play an important role in seizure spread and in maintaining SE. Glial immaturity, increased electronic coupling, and SN immaturity facilitate SE development in the immature brain. Major increases in cerebral blood flow (CBF) protect the brain in early SE, but CBF falls in late SE as blood pressure falters. At the same time, large increases in cerebral metabolic rate for glucose and oxygen continue throughout SE. Adenosine triphosphate (ATP) depletion and lactate accumulation are associated with hypermetabolic neuronal necrosis. Excitotoxic mechanisms mediated by both N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors open ionic channels permeable to calcium and play a major role in neuronal injury from SE. Hypoxia, systemic lactic acidosis, CO2 narcosis, hyperkalemia, hypoglycemia, shock, cardiac arrhythmias, pulmonary edema, acute renal tubular necrosis, high output failure, aspiration pneumonia, hyperpyrexia, blood leukocytosis and CSF pleocytosis are common and potentially serious complications of SE. Our improved understanding of the pathophysiology of brain damage in SE should lead to further improvement in treatment and outcome.
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PMID:Pathophysiological mechanisms of brain damage from status epilepticus. 838 2

Eighty six of 430 acute myeloblastic leukemia (AML) patients (20.0%) and forty of 173 acute lymphoblastic leukemia (ALL) patients (23.1%) had CD7 on their leukemia cells. CD7(+) AML occurred at a younger age than CD7(-) AML, and is more frequent in males. Hepatomegaly and central nervous system involvement were also more frequent in CD7(+) AML than in CD7(-) AML. The age of onset of CD7(+) ALL is also younger than that of CD7(-) ALL. Phenotypically, CD(+) AML expressed CD34, HLA-DR, and TdT more frequently than CD7(-) AML while CD7(+) ALL expressed CD13/33 more often than CD7(-) ALL cells responded most significantly to interleukin 3 (IL-3), whereas most CD7(-) AML cells responded more significantly to granulocyte macrophage-colony stimulating factor (GM-CSF) and/or granulocyte (G)-CSF than to IL-3. CD7(+)sCD3(-)CD4(-)CD8(-) ALL expressed G-CSF receptor and c-kit mRNA more frequently, which is not usual in other types of ALL. P-glycoprotein (P-gp)/multi-drug resistance gene (MDR1), thought to be expressed in hematopoietic stem cells, is expressed in CD7(+) AML and CD7(+)sCD3(-) CD4(-)CD8(-) ALL significantly more often than in CD7(-) acute leukemias and the CR rate and overall survival of CD7(+)AML was worse than CD7(-) AML. These data, collectively, suggest the close association of CD7(+) AML and CD7(+)sCD3(-)CD4(-)CD8(-) ALL, not only the common expression of CD7 itself but also because their phenotypical immaturity, cytokine receptor expression, P-gp/MDR1 expression and clinical manifestations including the frequent occurrence in males and the poor prognosis. We propose that CD7(+) acute leukemia is an hematopoietic stem cell leukemia which may be separate entity.
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PMID:Biological characteristics of CD7(+) acute leukemia. 872 5

The effects of rhG-CSF administration on fMLP-induced neutrophil CD11b and CD18 upregulation were studied in nine patients suffering from intermediate and high grade non-Hodgkin's lymphomas. Blood samples were obtained before recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration and 24 hrs after rhGSF interruption. The growth factor was administered subcutaneously for five days in a dosage of 5 microg/Kg/day. Nine normal subjects were studied as controls. Five patients showed an impaired baseline CD11b and CD18 upregulation, which was corrected by rhG-CSF therapy. Four patients showed a normal baseline CD11b and CD18 upregulation, but this function was reduced by rhG-CSF therapy. All patients showed a normal baseline fMLP-induced luminol-enhanced chemiluminiscence and significantly increased chemiluminescence values after rhG-CSF administration. We conclude that, while in some patients rhg-CSF is able to improve neutrophil CD11b and CD18 upregulation in response to chemotactic agents, in other patients a decrease of this function can occur, maybe due to a relative immaturity of the circulating neutrophils induced by rhG-CSF.
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PMID:fMLP-induced CD11b/CD18 upregulation on neutrophils from patients with non-Hodgkin's lymphomas treated with recombinant human granulocyte colony-stimulating factor. 938 5

Haematopoiesis and immune functions in cord blood (CB) are developmentally immature when compared with adult peripheral blood (APB). The defects in CB immune function and cytokine production may both contribute to the immaturity of CB immunity. We have studied the mechanisms associated with the dysregulation of myeloid lineage cytokines, GM-CSF and M-CSF, and lymphokines, IL-12, and IL-15 in activated CB when compared with APB MNC. Furthermore, we have studied the effects of IL-12 and IL-15 on induction of IFN-gamma and TNF-alpha production, NK, and LAK activities in CB and APB. GM-CSF, M-CSF, IL-12 and IL-15 protein and mRNA are decreased in activated CB MNC. These discrepancies are secondary, at least in part, to the altered post-transcriptional regulation. The impaired ability of CB to produce IL-12 and IL-15 in response to stimulation may contribute to the decrease in IFN-gamma, TNF-alpha production, NK and LAK activities. Furthermore, combination of low dose IL-12 and IL-15 may augment cytotoxic activities and minimize toxicity. These findings suggest that reduced cytokine expression from activated CB may contribute to the impaired CB cellular immunity and exogenous lymphokines may compensate for the immaturity in CB.
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PMID:Dysregulation of lymphokine production in the neonate and its impact on neonatal cell mediated immunity. 971 74

The developmental immaturity of neonatal phagocytic function is associated with decreased accumulation and half-life (t((1)/(2))) of granulocyte/macrophage colony-stimulating factor (GM-CSF) mRNA in mononuclear cells (MNC) from the neonatal umbilical cord compared with adult peripheral blood. The in vivo t((1)/(2)) of GM-CSF mRNA is 3-fold shorter in neonatal (30 min) than in adult (100 min) MNC. Turnover of mRNA containing a 3'-untranslated region (3'-UTR) A + U-rich element (ARE), which regulates GM-CSF mRNA stability, is accelerated in vitro by protein fractions enriched for AUF1, an ARE-specific binding factor. The data reported here demonstrate that the ARE significantly accelerates in vitro decay of the GM-CSF 3'-UTR in the presence of either neonatal or adult MNC protein. Decay intermediates of the GM-CSF 3'-UTR are generated that are truncated at either end of the ARE. Furthermore, the t((1)/(2)) of the ARE-containing 3'-UTR is 4-fold shorter in the presence of neonatal (19 min) than adult (79 min) MNC protein, reconstituting developmental regulation in a cell-free system. Finally, accelerated ARE-dependent decay of the GM-CSF 3'-UTR in vitro by neonatal MNC protein is significantly attenuated by immunodepletion of AUF1, providing new evidence that this accelerated turnover is ARE- and AUF1-dependent.
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PMID:Developmental regulation of RNA transcript destabilization by A + U-rich elements is AUF1-dependent. 1056 60

Aspirin is the most commonly used analgesic and antiinflammatory agent. In this study, at physiological concentrations, it profoundly inhibited CD40, CD80, CD86, and MHC class II expression on murine, GM-CSF + IL-4 stimulated, bone marrow-derived myeloid dendritic cells (DC). CD11c and MHC class I expression were unaffected. The inhibitory action was dose dependent and was evident at concentrations higher than those necessary to inhibit PG synthesis. Experiments with indomethacin revealed that the effects of aspirin on DC maturation were cyclooxygenase independent. Nuclear extracts of purified, aspirin-treated DC revealed a decreased NF-kappaB DNA-binding activity, whereas Ab supershift analysis indicated that aspirin targeted primarily NF-kappaB p50. Unexpectedly, aspirin promoted the generation of CD11c+ DC, due to apparent suppression of granulocyte development. The morphological and ultrastructural appearance of aspirin-treated cells was consistent with immaturity. Aspirin-treated DC were highly efficient at Ag capture, via both mannose receptor-mediated endocytosis and macropinocytosis. By contrast, they were poor stimulators of naive allogeneic T cell proliferation and induced lower levels of IL-2 in responding T cells. They also exhibited impaired IL-12 expression and did not produce IL-10 after LPS stimulation. Assessment of the in vivo function of aspirin-treated DC, pulsed with the hapten trinitrobenzenesulfonic acid, revealed an inability to induce normal cell-mediated contact hypersensitivity, despite the ability of the cells to migrate to T cell areas of draining lymphoid tissue. These data provide new insight into the immunopharmacology of aspirin and suggest a novel approach to the manipulation of DC for therapeutic application.
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PMID:Aspirin inhibits in vitro maturation and in vivo immunostimulatory function of murine myeloid dendritic cells. 1139 Apr 49


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