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Query: UMLS:C0392674 (exhaustion)
 13,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We evaluated membrane expression and function of complement receptors CR1 and CR3 on neutrophils from 27 HIV-positive (HIV+) subjects (14 in the CDC class III and 13 class IV) as well as their modulation in vitro by recombinant tumour necrosis factor-alpha (rTNF-alpha) and granulocyte-macrophage colony stimulating factor (rGM-CSF). While CR1 was expressed at similar levels on neutrophils from controls and HIV+ subjects, CR3 expression was significantly higher in CDC class IV subjects than in healthy controls. CR1 and CR3 expression was significantly increased after treatment of neutrophils with both cytokines, without differences between controls and HIV+ subjects. Similarly, the superoxide anion (O2-) production in response to C3-coated zymosan (C3zy) was significantly enhanced on neutrophils from CDC class IV subjects when compared with controls. rGM-CSF and rTNF-alpha treatment significantly enhanced the spontaneous as well as C3zy-stimulated O2- production by neutrophils from controls and CDC class III subjects, and induced an upward trend in the CDC class IV group. These results indicate that the neutrophils of HIV+ patients are preactivated in vivo but they also indicate that these cells may correctly respond to a subsequent particulate stimulus as well as to activating cytokines. Our findings suggest that desensitization or functional exhaustion of complement receptors are not implicated in the abnormalities observed on neutrophils from HIV+ patients.
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PMID:Membrane expression and function of complement receptors CR1 and CR3 on neutrophils from HIV-infected subjects: modulation by rTNF-alpha and rGM-CSF. 141

The experiment was carried out on 19 cats with changed intracranial volume-pressure relations by means of an epidural balloon which was inflated to 1.0 ml volume over 60 minutes. The intracranial pressure, the resistance to cerebrospinal fluid resorption, the volume-pressure responses and visual evoked potentials were determined at balloon volumes of 0.3 ml, 0.5 ml, 0.8 ml, 1.0 ml, 1.3 ml, 1.5 ml, 1.8 ml, 2.0 ml and 2.3 ml. It was demonstrated that intracranial pressure is of important informative value only after exhaustion of 63% of the intracranial volume reserve. This value of the volume-pressure responses and resistance to CSF resorption appeared after exhaustion of 28% of this reserve, and the visual evoked potentials were changed after exhaustion of 43% of the reserve. The correlation coefficient between these parameters was high during decompensation. At the time of compensation of the volume the correlation coefficient between the intracranial pressure and the remaining determined parameters was only 0.6.
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PMID:[Analysis of the correlations of volume-pressure parameters and visual evoked potentials during disturbances of intracranial volume compensation]. 180 15

To gain insight into the mechanisms involved in regulating murine interleukin-3 (mIL-3) receptor expression, we have examined the effects of mIL-3 and murine granulocyte-macrophage colony-stimulating factor (mGM-CSF) on mIL-3 receptor internalization and re-expression and studied the relationship between mIL-3 cell surface receptor density and growth factor sensitivity. As a source of cells for our studies, we used a B6SUtA clone, B6SUtA1, which grows equally well in mIL-3 or mGM-CSF when supplemented with 20% fetal calf serum (FCS) in RPMI 1640. Intracellular processing studies carried out in the presence and absence of methylamine suggested that mIL-3 is cleaved at two specific sites before its complete digestion within lysosomes. However, unlike its ligand, cycloheximide studies indicated that internalized mIL-3 receptors are recycled to the cell surface. When B6SUtA1 cells were continuously passaged in mIL-3, cell populations allowed to exhaust the mIL-3 in the medium (high density cells) expressed more than ten times (ie, approximately 100,000/cell) the mIL-3 receptor number of those growing exponentially at low cell concentrations (low density cells). Since the high density cells were no larger than the low density cells, the marked increase in mIL-3 receptor number per cell reflects a true up-regulation of receptor expression. A kinetic analysis of this up-regulation revealed that it begins within one hour of mIL-3 exhaustion. Moreover, proliferation assays with these two cell populations, using 3H-thymidine incorporation, suggested that the high density cells were 30-fold more responsive to mIL-3. However, when B6SUtA1 cells were passaged in mGM-CSF, there was no difference in mIL-3 receptor number between high density and low density cells (ie, approximately 100,000/cell). Identical studies carried out with another mIL-3 dependent cell line, 32D C3, demonstrated that this phenomenon was not unique to B6SUtA1 cells.
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PMID:Interleukin-3 down-regulates its own receptor. 264 69

ICP being a very significant parameter of intracranial pathology, it needs to be recorded continuously. ICP of 7 cases of normal pressure hydrocephalus (NPH) and 6 postoperative patients, for whom relationship between REM sleep and ICP was under discussion, was monitored at night and recorded by Brock's method. Polygraphic records also were obtained. Increased ICP was related to REM sleep in 3 of 6 postoperative cases. In the remaining 3 cases, REM sleep could not be observed the first postoperative night, and ICP was lower and stable all night. This fact may be an effect of anesthetic drugs. NPH patients were divided into 2 groups by pressure profile during night recording of ICP. One group of 2 cases demonstrated irregular ICP during REM sleep while the other group of 5 cases did not. The former 2 cases showed neurological improvement after shunt operations. In NPH cases, ICP has significance in deciding whether surgery is necessary. It appears reasonable to suggest that the augumentation of ICP during REM sleep in cases of hydrocephalus and postoperative condition is related to an increase in cerebral blood flow and an exhaustion of the absorptive mechanisms of CSF.
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PMID:[Intracranial pressure changes during sleep in man]. 668 71

The roles of colony-stimulating factors in long-term bone marrow cultures were studied and compared. After single additions of high concentrations of unpurified colony-stimulating activities to the cultures, rapid deterioration of the cultures was observed. This appears to result from contaminants in the stimulatory preparations. Cultures to which one purified colony-stimulating factor (csf) from endotoxin mouse lung-conditioned medium was added did not run down ten weeks after addition and were found to be the same as the controls. The deterioration of the cultures to which unpurified stimulators were added could not be accounted for by accelerated granulopoiesis leading to subsequent exhaustion of the cultures. The inability of purified CSF to affect the cellularity of the suspension cells did not result from instability or masking of the activity in the cultures, nor did CSF preferentially stimulate the cells within the adherent layer. The suspension cells responded to purified CSF after separation from the adherent cells. The data suggest that if CSFs are marrow stimulators, their effects in turn may be stringently regulated within the marrow.
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PMID:The effect of mouse lung granulocyte-macrophage colony-stimulating factor and other colony-stimulating activities on the proliferation and differentiation of murine bone marrow cells in long-term cultures. 696 69

For patients with advanced-stage or poor-prognosis malignant lymphoma, high-dose therapy with peripheral blood progenitor cell (PBPC) support may become a first-line treatment. The duration of severe cytopenia in this setting is inversely related to the number of PBPCs autografted. In a retrospective analysis, we therefore looked for factors influencing the yield of PBPCs in 61 patients (16 with high-grade and 29 with low-/intermediate-grade non-Hodgkin's lymphoma [NHL], and 16 with Hodgkin's disease) who received cytotoxic chemotherapy and filgrastim (R-metHuG-CSF, 300 micrograms/d; median, 4.2 micrograms/kg/d; range, 2.7 to 6.6 micrograms/kg/d; subcutaneously). Sixteen patients had active disease, while 45 were in partial remission (PR) or complete remission (CR) after conventional therapy. A median of three leukaphereses (range, one to 10) resulted in a median of 5.7 x 10(6) CD34+ cells/kg (range, 0.03 to 31.1 x 10(6)). Previous cytotoxic chemotherapy and irradiation adversely affected the yield of CD34+ cells. Each cycle of chemotherapy is associated with an average decrease of 0.2 x 10(6) CD34+ cells/kg per leukapheresis in nonirradiated patients, while large-field radiotherapy reduces the collection efficiency by an average of 1.8 x 10(6)/kg CD34+ cells. The collection efficiency was also significantly lower in patients with Hodgkin's disease. However, except for one, all had been previously irradiated. In contrast, age, sex, disease status, bone marrow involvement during mobilization, and the time since the last chemotherapy or radiotherapy were not significantly related to the collection efficiency. Following high-dose conditioning therapy, 42 patients were autografted with filgrastim-mobilized PBPCs. Hematological recovery (neutrophils > or = 0.5 x 10(9)/L and an unsupported platelet count > or = 20 x 10(9)/L) within 2 weeks was observed in patients autografted with > or = 2.5 x 10(6) CD34+ cells/kg. In seven patients, the quantity of CD34+ cells reinfused was below this threshold. They required a median of 17 days (range, 11 to 34) and 31 days (range, 13 to 141) for neutrophil and platelet recovery, respectively. If autografting with PBPCs in malignant lymphoma with poor prognosis is being considered, mobilization and harvesting should be planned early after initial diagnosis to avoid exhaustion of hematopoiesis by cumulative toxicity.
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PMID:Patient characteristics associated with successful mobilizing and autografting of peripheral blood progenitor cells in malignant lymphoma. 751 21

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

We have investigated the mechanism behind the hematopoietic stimulation mediated by AM5, a protein-associated polysaccharide that stimulates in vivo the murine hematopoietic system. A dose-dependent increase in hematopoietic progenitors was observed in long-term bone marrow cultures (LTBMCs) treated in vitro with AM5. The stimulatory effect was more marked in colony-forming units-granulocyte-macrophage (CFU-GM) than in CFU-spleen (CFU-S) progenitors and also more significant in the supernatant than in the adherent layer. This stimulatory effect was reversible, and continuous stimulation with high doses of AM5 was conductive to a progressive exhaustion of the culture. The analysis of the CFU-GM stimulating activity present in the supernatant of AM5-treated cultures revealed a dose-dependent induction of granulocyte-macrophage colony-stimulating activity (GM-CSA), in contrast with control cultures in which no CSA was detected. Northern blots of LTBMC-adherent layers obtained after in vitro treatment with AM5 revealed a significant mRNA expression for interleukin 1 alpha (IL-1 alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage CSF (M-CSF) and granulocyte CSF (G-CSF), in contrast with adherent layers from untreated cultures which only expressed, in detectable levels, M-CSF and stem cell factor (SCF). The SCF expression was down-modulated in AM5-treated cultures. Our results strongly suggest that the hematopoietic stimulation induced by AM5 is mediated by the modulated expression of endogenous hematopoietic growth factors.
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PMID:AM5, a protein-associated polysaccharide, stimulates hematopoiesis and modulates the expression of endogenous hematopoietic growth factors in murine long-term bone marrow cultures. 754 Apr 71

The small neutrophil reserve and exaggerated release of stored neutrophils are factors which predispose neonates to neutrophil reserve exhaustion during bacterial sepsis. Our objective is to try to improve in utero the myelopoietic function of the fetus before delivery. In the first series, recombinant human (rh) granulocyte colony-stimulating factor (G-CSF) (rhG-CSF; 100 microg/kg) was injected subcutaneously into rat fetuses at the indicated times to assess drug absorption and fetal response. In the second series, rhG-CSF (100 microg/kg) or saline (control) was injected into the fetuses once every other day to investigate the effect of repeated injections of rhG-CSF on enhancing fetal myelopoiesis preceding birth. Delivery was performed by cesarean section on embryonic day 21. The plasma concentration of G-CSF was determined by ELISA. The effect of rhG-CSF injection on granulopoiesis was assessed by measurement of the neutrophil count in the fetal peripheral blood and by histological examination of the fetal bone marrow, spleen, and liver. Fetally administered rhG-CSF enhanced fetal myelopoiesis preceding birth.
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PMID:Stimulation of fetal granulopoiesis by intrauterine injection of recombinant human granulocyte colony- stimulating factor into rat fetuses. 1032 40

The hematopoietic system in patients with aplastic anemia (AA) shows both quantitative and qualitative deficiencies, i.e., reduced numbers of hematopoietic progenitor cells (HPC) and impaired HPC proliferation in long-term marrow cultures (LTMC). Since recombinant human granulocyte macrophage-colony stimulating factor (rhGM-CSF) has been shown to be a potent stimulator of normal hematopoiesis, both in vivo and in vitro, in the present study we wanted to assess the possibility of stimulating hematopoiesis in LTMC from 17 patients with AA, by weekly addition of rhGM-CSF (10 ng/ml). In LTMC from 11 patients (group of responders), rhGM-CSF induced a significant increase (4.8-fold, compared with untreated cultures) in the levels of myeloid progenitor cells; in contrast, in six patients (group of nonresponders), myeloid progenitors were refractory to this cytokine. In the group of responders, rhGM-CSF also induced a pronounced increment in the levels of nonadherent and adherent cells (5.99- and 5.18-fold, respectively, compared with untreated cultures). Among the different myelopoietic lineages, rhGM-CSF preferentially stimulated the macrophagic lineage; this was evident both at the progenitor and mature cell levels. Interestingly, the effect of rhGM-CSF in LTMC from AA patients was only transient. Indeed, the effects mentioned above were observed only during the first three weeks of culture; afterwards, myeloid progenitor and nonadherent cell levels in treated cultures declined, practically reaching the levels observed in untreated cultures. At the moment, we do not know whether this transient stimulatory effect is due to the production of inhibitory cytokines, by macrophages generated in response to rhGM-CSF, or to the exhaustion of the HPC pool in AA cultures. In all 17 patients, rhGM-CSF had no effect on the kinetics of erythroid or multipotent progenitor cells. These results are in keeping with clinical studies in which it has been observed that most AA patients treated with rhGM-CSF show increments in circulating monocytes and granulocytes, as well as in bone marrow cellularity. However, little or no effect is observed on erythropoiesis. The actual mechanisms involved in the in vitro effects of rhGM-CSF on myeloid progenitor cells from AA bone marrow are still not completely understood. Future studies on this issue should be encouraged, since they may help to understand the in vivo (clinical) effects of this cytokine.
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PMID:Effect of recombinant human granulocyte macrophage-colony stimulating factor in long-term marrow cultures from patients with aplastic anemia. 1036 89


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