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

An animal model of leukotriene B4- (LTB4) induced neutropenia has been developed to evaluate LTB4 receptor antagonists in vivo. LTB4, a potent chemotactic inflammatory mediator, when administered intravenously, induces a profound, rapid, and transient redistribution of blood neutrophils from the circulating pool to the marginated pool. This phenomenon is applied in the neutropenia model whereby circulating blood neutrophil counts prior to and after intravenous infusion of LTB4 are compared. Kinetics of LTB4-induced neutrophil responses are determined through the use of a Technicon H*1 automated blood cell analyzer. LTB4 receptor antagonists are identified by inhibition of LTB4-induced neutropenia. Standard antiinflammatory compounds including BW-755C, Abbott A-64077 (zileuton), dexamethasone-21-acetate, indomethacin, and naproxen did not affect LTB4-induced neutropenia. A potent LTB4 receptor antagonist, designated "RPR," inhibited LTB4-induced neutropenia following oral administration in a dose-dependent fashion.
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PMID:LTB4-induced transient neutropenia in the rat: a model for evaluating efficacy and bioavailability of LTB4 receptor antagonists. 830 13

The widespread use of intensive therapies and the need to haematologically monitor patients on a frequent basis means that the proportion of blood samples with moderate to severe leucopenia is significant and increasing. From a laboratory perspective, particularly because of the need to spend significant amounts of time in obtaining manual differentials from stained smears with low leucocyte numbers, these clinical trends have created additional pressures on what is often a limited manpower resource. Moreover in such situations, differentials obtained from examination of only 20 or 50 cells are not uncommon and the statistical consequences of this will be clearly apparent. Currently, there is general user confidence for automated leucocyte differentials for blood samples with normal WBC parameters, but there has been some reluctance to extend this to samples with leucopenia. In order to explore this further, we examined the efficiency of a modern automated five-part differential analyser (Abbott CELL-DYN 3500) in an unselected series of 292 samples with leucopenia (WBC count range range; 0.28-2.48 x 10(9)/l). Of these, 49 were from leucopenic sero-positive HIV patients with the remaining 243 samples originating from haematological oncology clinics, patients receiving radiotherapy for non-haemopoietic malignancies, and from patients with various chronic diseases. Morphologically, 204 of these samples did not show any blast cells or NRBC, 48 had blast cells but no NRBC, 29 had NRBC but no blasts, and the remaining 11 showed both blasts and NRBC. For 277 cases with less than 5% blasts, there was an excellent correlation between the manual and CD3500 automated differential, with no obvious bias between manual and automated subpopulation estimates at any percentage level. Linear regression analyses comparing absolute neutrophil, eosinophil, lymphocyte and monocyte counts for these same samples further revealed impressive correlations (r > 0.92) for all leucocyte populations and the absolute neutrophil count in particular (r = 0.986). Manual and CD3500 leucocyte differential comparisons for 11 cases with > 5% blasts showed good correlations for absolute neutrophil and eosinophil counts although, when the blast cell percentage was high, correlations for lymphocyte and monocyte counts were less consistent (an operator alert in the form of a 'Blast Flag' was, however, given in 10/11 of these particular cases). Four additional cases where manual differentiation between lymphoid cells and monocytes was recorded as difficult also showed consistently good correlations for manual vs automated neutrophil and eosinophil estimates. Not surprisingly, and essentially as a result of the low confidence noted for the manual differential itself, correlations for lymphoid and monocytic cells were relatively poor. In conclusion, this study has demonstrated that the CD3500 provides reliable and accurate absolute neutrophil and eosinophil counts in leucopenic samples irrespective of the presence of blasts or NRBC. These observations are particularly important in terms of monitoring patients who are liable to develop neutropenia as a result of chemotherapy and radiotherapy, and provide evidence that the routine use of automated leucocyte differentials may be confidently extended to the analysis of leucopenic samples.
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PMID:Automated leucocyte differentials in 292 patients with leucopenia: an evaluation of the Abbott CELL-DYN 3500 (CD3500) haematology analyser. 905 98

Reports at the 5th Conference on Retroviruses and Opportunistic Infections addressed new anti-HIV agents in primary phases of development that offer treatment alternatives to people with little or no treatment history and individuals with few treatment choices. FTC, a new nucleoside analog produced by Triangle Pharmaceuticals, is an alternative to 3TC. F-ddA (lodenosine), a nucleoside analog licensed by US Bioscience, is structurally similar to ddI and is reported to have good bioavailability, once-a-day dosing, and no bone marrow suppression. F-ddA has also shown in vitro activity against multidrug-resistant strains of HIV. Adult and pediatric studies are currently being conducted by the National Cancer Institute (NCI) and US Bioscience. Oral versus IV PMPA shows promising results as a possible alternative for 3TC- and AZT-experienced patients. Further testing is being done by Gilead Sciences and HIV Network for Prevention Trials (HIVNET). Abbott Laboratories is developing a second-generation protease inhibitor, ABT-378, which has a ten-fold greater antiviral activity in vitro than the original, ritonavir. It is administered with ritonavir to increase ABT-378 levels in the blood, but has no food requirements, and less severe side effects. Two trials are being conducted: one for patients who are treatment-naive and the second for patients who are failing other protease inhibitors. Immune-based therapies, such as Leukine (GM-CSF), are used to handle neutropenia and offset bone marrow toxicities from drugs. Concerns that GM-CSF may increase viral replication may be balanced by using highly active antiretroviral therapy. FP-21399, developed by Lexigen Pharmaceuticals, is being tested as an HIV fusion inhibitor.
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PMID:Looking down the drug pipeline. 1136 93

The Abbott Cell Dyn 3500 haematology analyzer was employed to study haematological parameters in 41 adult and young Friesian cattle naturally infected with Theileria annulata in the Qassim region of Saudi Arabia. Comparison was made with clinically healthy adult and young Friesian cattle. Changes in blood parameters in T. annulata-infected cattle indicated severe macrocytic hypochromic anaemia, panleukopenia, lymphocytopenia, eosinopenia, neutropenia and thrombocytopenia but no reticulocytosis.
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PMID:Haematological profiles in pure bred cattle naturally infected with Theileria annulata in Saudi Arabia. 1207 22