Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined potential mechanisms responsible for the parenchymal lung injury seen in an animal model of smoke inhalation with concurrent inflammation. Rats injected with sterile glycogen and exposed to smoke generated by the nonflaming pyrolysis of combined Douglas fir wood and polyvinylchloride showed a 74% increase in 125I-albumin lung permeability and a fivefold increase in lung myeloperoxidase (MPO) compared with control rats. There was also a significant increase in plasma indices of oxidative injury in these animals. Compared with control animals, plasma concentrations of thiobarbituric acid reactive substances (TBARS) were elevated by 62%, the concentrations of reduced sulfhydryl groups declined by 37%, and the levels of dinitrophenylhydrazine-reactive proteins (DNPH-RP) were doubled. In addition, the plasma concentrations of nitrate (NO3-) in rats exposed to glycogen plus smoke were increased three times that of control animals. Injection of the nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), immediately after smoke exposure or induction of neutropenia using either nitrogen mustard or antineutrophil antiserum, abolished the increase in concentrations of circulating NO3-, and prevented changes in plasma concentrations of TBARS, DNPH-RP, lung MPO activity, and tissue permeability index. These data suggest that neutrophil activation and the production of nitric oxide-derived oxidants contribute to the lung and plasma indices of oxidative injury in this smoke inhalation model.
 ...
PMID:Role of neutrophils and nitric oxide in lung alveolar injury from smoke inhalation. 804 12

Macrophage colony-stimulating factor (M-CSF) is a homodimeric glycoprotein which stimulates differentiation of progenitor cells to mature monocytes and enhances production of hemopoietic growth factors from mature monocytes such as granulocyte-macrophage CSF, granulocyte CSF and megakaryocyte potentiator, suggesting that M-CSF administration enhances production of monocytes, neutrophils and platelets. Since the commercial availability of M-CSF in 1991, serial M-CSF infusions at a daily dose of 8 million units have been performed in patients with acute myeloid leukemia in complete remission after combination chemotherapy. Although M-CSF infusion reduced the duration of neutropenia in 3 of 5 patients, it reduced the duration of pyrexia over 37 degrees C in all patients, and that over 38 degrees C in 4 of 5 patients. Average durations of pyrexia and parenteral antibiotic injections were significantly shorter in M-CSF than in control courses. Although M-CSF infusion reduced the duration of thrombopenia in 2 of 5 patients, it reduced total platelet units transfused in 4 of 5 patients. The average number of platelet units transfused after combination chemotherapy was significantly lower in M-CSF than in control courses. In mice, M-CSF injection increased the serum concentration of reactive nitrogen intermediates which inhibited the growth of L1210 cells, and increased the survival rate of mice previously injected with them. These results indicate that M-CSF may be a promising agent not for improving patients' quality of life after cancer chemotherapy, but also in cancer immunotherapy.
 ...
PMID:Macrophage colony-stimulating factor for cancer therapy. 819 2

Aortic aneurysm repair produces inflammatory mediators, neutrophil activation, and remote organ injury. Reperfusion plasma from these patients produces microvascular injury in an ex vivo chemotactic model. This study investigates the mechanism of this injury. Vena caval blood was obtained before and 15 minutes after aortic clamp removal (n = 16) or at laparotomy (n = 10). Plasma or saline solution was introduced into unit dose chambers fixed atop dermabrasions on the back of depilated anesthetized rabbits. Animals were treated with intravenous saline solution (n = 4); made neutropenic with nitrogen mustard (n = 4); pretreated with the xanthine oxidase inhibitor allopurinol (n = 4); or cotreated intravenously with the free radical scavengers superoxide dismutase (SOD) and catalase (n = 4). Three hours later neutrophil counts (polymorphonuclear cells [PMN]/mm3) and activity (free radical production by flow cytometry), protein leakage, and inflammatory mediators (thromboxane [TX] and leukotriene B4 [LTB4]) were measured. In contrast to control plasma in untreated rabbits, reperfusion plasma produced TX and LTB4 generation (1090 +/- 105 and 794 +/- 91 pg/ml, respectively, p < 0.01), PMN accumulation (1636 +/- 210/mm3, p < 0.01) and activation (276 +/- 31 mean fluorescent units), and microvascular permeability (554 +/- 90 micrograms/ml, p < 0.01). Neutropenia (3 +/- 1 PMN/mm3) and cotreatment with SOD and catalase abolished these responses, whereas pretreatment with allopurinol did not. Human reperfusion plasma contains a soluble factor that stimulates free radical generation by rabbit neutrophils to produce a microvascular injury characterized by de novo TX production, neutrophil accumulation and activation, and increased microvascular permeability to protein.
 ...
PMID:Reperfusion plasma contains a neutrophil activator. 839 Aug 48

Macrophage colony-stimulating factor (M-CSF) was found to be a glycoprotein with a molecular weight of 85 kDa which stimulated macrophage colony formation of mouse bone marrow cells in a semisolid agar culture system in 1978. M-CSF stimulates differentiation of progenitor cells to mature monocytes, and prolongs the survival of monocytes. It enhances expression of differentiation antigens and stimulates chemotactic, phagocytic and the killing activities of monocytes. Macrophage CSF also stimulates production of several cytokines such as granulocyte-macrophage CSF, granulocyte CSF and interleukin (IL)-6 by priming monocytes, and directly stimulates production and secretion of IL-8 and reactive nitrogen intermediates. In addition to the stimulation of hematopoiesis, M-CSF also stimulates differentiation and proliferation of osteoclast progenitor cells and cytotrophoblasts. Proteoglycan type M-CSF, which contains chondroitin sulfate chains, was found in 1992. In a large-scale double-blind controlled study on acute myeloid leukemia (AML), it has been shown that the administration of M-CSF to patients after consolidation chemotherapies shortens the periods of neutropenia and thrombopenia after chemotherapy and reduces the incidence and shortens the duration of febrile neutropenia, as well as shortening the period required to finish three courses of intensive consolidation therapy.
 ...
PMID:Biological activities and clinical application of M-CSF. 963 77

Clozapine, an atypical antipsychotic used in the treatment of refractory schizophrenia, causes neutropenia and agranulocytosis in 3 and 0.8% of patients, respectively. Clozapine undergoes bioactivation to a chemically reactive nitrenium ion, which has been shown to cause neutrophil cytotoxicity. To define further the mechanism of cell death, we have investigated the toxicity of clozapine, its stable metabolites, and its chemically reactive nitrenium ion to neutrophils and lymphocytes. Clozapine was able to induce neutrophil apoptosis at therapeutic concentrations (1-3 microM) only when it was bioactivated to the nitrenium ion. The parent drug caused apoptosis at supratherapeutic concentrations (100-300 microM) only. Neutrophil apoptosis induced by the nitrenium ion, but not by the parent drug itself, was inhibited by antioxidants and genistein and was accompanied by cell surface haptenation (assessed by flow cytometry) and glutathione depletion. Dual-color flow cytometry showed that neutrophils that were haptenated were the same cells that underwent apoptosis. No apoptosis of lymphocytes was evident with the nitrenium ion or the parent drug, despite the fact that the former caused cell surface haptenation, glutathione depletion, and loss of membrane integrity. Demethylclozapine, the major stable metabolite in vivo, showed a profile that was similar to, although less marked than that observed with clozapine. N-oxidation of clozapine or replacement of the nitrogen (at position 5) by sulfur produced compounds that were entirely nontoxic to neutrophils. In conclusion, the findings of the study expand on potential mechanisms of clozapine-induced cytotoxicity, which may be of relevance to the major forms of toxicity encountered in patients taking this drug.
 ...
PMID:Induction of metabolism-dependent and -independent neutrophil apoptosis by clozapine. 1086 Sep 43

Substantial losses of total body protein (TBP) can occur in chronic diseases and in aging. Such losses impact negatively on immunity and quality of life, and on growth rates in children. Direct measurements of total body nitrogen (TBN) monitor the integrated changes in TBP over time and allow comparison with normal subjects. TBN assessment via neutron capture analysis is therefore the gold-standard method of TBP estimation, so that risk factors for protein deficit can be identified and patient management optimized. The nitrogen index (NI) can be used to predict prognostic outcome: an NI < 0.9 is associated with substantial wasting in HIV disease, an NI < 0.8 predicts significant pathophysiology in chronic renal failure, and a low NI is predictive of neutropenia in breast-cancer patients. These findings emphasize the central importance of adequate protein stores in recovery from disease or in maintaining quality of life. Aging appears to involve a gradual loss of TBP throughout adulthood. Cross-sectional data suggest that TBP declines curvilinearly with age, such that there is an accelerated decline after 65 years of age. However, longitudinal data are scarce, and little is known about the relative loss of visceral protein, as opposed to skeletal muscle protein. More clearly-defined data are essential if the effects of aging per se are to be separated from the effects of chronic disease. A further complication is the knowledge that physical activity also declines with age. Thus sarcopenia, the loss of skeletal muscle mass, could primarily result from disuse rather than aging. The economic impact of unsuccessful aging places a pressing need for multicompartment data in longitudinal study designs.
 ...
PMID:Total body protein in chronic diseases and in aging. 1086 69

We investigated the roles of neutrophil and neutrophil elastase in acute lung injury (ALI) to elucidate the mechanism of ALI. We designed two protocols. Protocol I: Experimental ALI was induced by endotoxin (0.02 mg/kg) and platelet-activating factor (8 microg/kg/4 h) in untreated rabbits (control group I), in neutropenic rabbits pretreated with nitrogen-N-oxide hydrochloride, and in untreated rabbits infused with a neutrophil elastase inhibitor (ONO-5046; 20 mg/kg/4 h). Protocol II: ALI was induced by smaller doses of endotoxin (0.015 mg/kg) and platelet-activating factor (7 microg/kg/4 h) than those used in protocol I in untreated rabbits (control group II), in neutrophilic rabbits pretreated with human recombinant granulocyte colony-stimulating factor, and in neutrophilic rabbits infused with ONO-5046 (as in protocol I). The severity of ALI was assessed by the protein concentration, the elastase activity in the bronchoalveolar lavage fluid, and the histologic pulmonary edema ratio. The degree of pulmonary neutrophil accumulation was assessed by pulmonary myeloperoxidase activity and histological findings. Both ALI and pulmonary neutrophil accumulation were suppressed by neutropenia (protocol I), while they were exacerbated by neutrophilia (protocol II). The neutrophil elastase inhibitor could suppress ALI, but it could not suppress pulmonary neutrophil accumulation in both untreated and neutrophilic rabbits (protocols I and II). These findings indicate that neutrophils play an important role in the pathogenesis of ALI via neutrophil elastase.
 ...
PMID:Neutrophils mediate acute lung injury in rabbits: role of neutrophil elastase. 1118 17

Oxygen free radicals (OFR) and neutrophils are potent sources of reperfusion injury. We compared the effect of EPC-K1, a new OFR scavenger, and neutrophil depletion on the reperfusion injury in skeletal muscle, using an ischemic revascularized hindlimb model in rats. Warm ischemia, produced by vascular pedicle clamping, was sustained for 4 h. After 24 h of reperfusion, muscle function and damage were evaluated in 4 groups: a sham operation group, a control study group, a group treated by EPC-K1 (EPC group), and a group that received nitrogen mustard to induce neutropenia (NM group). Both the EPC and NM groups had limited muscle damage compared to the control group. The EPC group preserved muscle function significantly better than the control group and the mean isometric tetanic tension in the EPC group appeared to be higher than that in the NM group. Furthermore, levels of lipid peroxides in muscle and serum, and muscle edema in the EPC group, were significantly lower than in the NM group. Histological examinations supported these results. These findings suggest that limiting OFR generation by EPC-K1 in the early phase of reoxygenation is more potent than depletion of neutrophils in reducing reperfusion injury.
 ...
PMID:Effects of a hydroxyl radical scavenger, EPC-K1, and neutrophil depletion on reperfusion injury in rat skeletal muscle. 1158 Jan 30

Analogues of the potent, conformationally biased, decapeptide agonist of human C5a anaphylatoxin, C5a(65-74)Y65,F67,P69,P71,D-Ala73 (YSFKPMPLaR, peptide 54), were synthesized with methyl groups occupying specific amide nitrogen atoms along the peptide backbone. This N-methylation induced crucial extended backbone conformations in a manner similar to the two Pro residues, but without eliminating the contributions made by the side-chain of the residue for which Pro was substituted. The presence of backbone N-methyl groups on peptide 54 analogues had pronounced detrimental effects on the ability to bind and activate C5aRs expressed on human PMNs, but not on the ability to contract smooth muscle of human umbilical artery. Several N-methylated analogues of peptide 54 (peptides 56, 67, 124, 125, and 137) were significantly more selective for smooth muscle contraction, which is mediated by tissue resident macrophages, than for enzyme release from PMNs. Indeed, peptide 67, YSFKDMP(MeL)aR was almost 3000-fold more selective for smooth muscle contraction than for PMN enzyme release. Consistent with these differential activities was the observation that peptide 67 expressed a significantly greater binding affinity to C5aRs expressed on rat macrophages than on rat PMNs. This differential activity was also observed in vivo in the rat where peptide 67 induced a hypotensive response similar to peptide 54 and rhuC5a, but without accompanying neutropenia.
 ...
PMID:Differential activities of decapeptide agonists of human C5a: the conformational effects of backbone N-methylation. 1171 May 44

Initial evaluation of patients with febrile neutropenia includes a thorough history and physical examination; a complete blood cell count; measurement of serum creatinine, blood urea nitrogen, transaminases, and C-reactive protein; and culture of blood (samples from a peripheral vein and/or catheter). Chest radiography is indicated for patients with respiratory signs or symptoms. Signs and symptoms of inflammation may be minimal or absent. However, a search should be undertaken in the sites most commonly infected, including the periodontium, pharynx, lower esophagus, lung, perineum, eyes, and skin. Blood samples, including samples from catheter lumen(s), if present, and a peripheral vein, should be obtained for cultures for bacteria and fungi. Urine culture is indicated in the presence of signs or symptoms of urinary tract infection, a urinary catheter in place, or abnormal results of urinalysis. Fever is defined as a single axillary temperature measurement of > or =37.5 degrees C (oral temperature of > or =38.0 degrees C). Neutropenia is defined as a neutrophil count of <1000 cells/mm3.
 ...
PMID:Clinical features of the neutropenic host: definitions and initial evaluation. 1525 22


<< Previous 1 2 3 4 5 Next >>