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)

The pathophysiology of anaphylaxis is very complex, and the sequelae of events are not fully explained in terms of the effects of histamine and peptide leukotrienes alone. Platelet-activating factor (1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, PAF-acether) has been detected in animals undergoing anaphylaxis. Injection of synthetic PAF-acether induces similar effects, including bronchoconstriction, respiratory arrest, systemic hypotension, neutropenia, and thrombocytopenia. The results reported here demonstrate that the histamine- and leukotriene-independent component of guinea pig anaphylaxis in vivo and in isolated lung parenchymal strips in vitro is mediated by PAF-acether. However, PAF-acether is not responsible for the anaphylaxis-induced thrombocytopenia.
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PMID:Role of platelet-activating factor-acether in mediating guinea pig anaphylaxis. 308 8

Neonatal and young animals fail to develop antigen-induced, lethal, systemic anaphylactic reactions. Recent evidence has documented that, in the adult rabbit, an unusual phospholipid autacoid, platelet-activating factor, induces almost all of the physiologic events associated with IgE-induced anaphylaxis. Thus, in the present study, the intravascular alterations after intravenous infusion of synthetic platelet-activating factor (1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine; AGEPC) into young rabbits were examined. In comparison to 13-week-old, adult rabbits, the intravascular infusion of greater than 1.0 micrograms/kg AGEPC was not lethal in rabbits of 8 weeks of age or less. In dose-response studies, the amount of AGEPC required to induce a lethal response in 50% of the animals tested (LD50) was found to inversely correlate with age. In contrast, AGEPC-induced platelet aggregation in vitro was not affected by the age of the donor animal. Consistent with age-independent platelet responsiveness in vitro, AGEPC-induced thrombocytopenia and intravascular accumulation of platelet factor 4 and thromboxane B2 were also unaffected by animal age. Neutropenia and basopenia, as well as platelet and neutrophil sequestration in the pulmonary microvasculature after intravenous AGEPC infusion also were similarly unaffected by animal age. Although the mechanisms which modulate the profound and lethal physiologic responses following AGEPC infusion in the adult rabbit remain to be established, the current study clearly documents an age-dependent acquisition of systemic physiologic sensitivity to AGEPC and/or other mediators released as a result of intravascular AGEPC administration.
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PMID:Ontogeny of the responsiveness to intravenous platelet-activating factor. 362 21

Calves were sensitized to horse serum in Freund's complete adjuvant and were subjected to acute systemic anaphylactic shock. Increased packed cell volume and potassium ion concentration together with severe neutropenia were observed to accompany the systemic hypotension. The hemoconcentration and hyperkalemia were not inhibited by antihistaminic or antiserotonin drugs, but were strongly inhibited by pretreatment of the calves with sodium meclofenamate and by disodium cromoglycate (DSCG) given simultaneously with diethylcarbamazine (DECC). In contrast there was no measurable diminution of the leukopenia by any inhibitor drug tested. Pulmonary edema and congestion of the liver, intestine, spleen, and kidney accompanied anaphylaxis. Atelectasis and edema with thickening of alveolar septa, together with polymorphonuclear cell infiltration were recorded histologically in the lungs of calves subjected to anaphylaxis. Calves premedicated with sodium meclofenamate sustained slight pulmonary edema only, with no other obvious pathological changes. Pretreatment with DSGG and DECC reduced the edema, congestion, and histopathological damage, but offered less protection than sodium meclofenamate. Antihistaminic or antiserotonin drugs were ineffective in protecting against anaphylactic changes in calves.
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PMID:Hematological and pathological changes in acute systemic anaphylaxis in calves: effects of pharmacological agents. 426 91

Arachidonic acid is metabolized to prostaglandins and thromboxane via the cyclooxygenase pathway and to leukotrienes B4, C4, D4, and E4 via the lipooxygenase pathway. A possible role played by leukotrienes in cardiogenic shock resulting from anaphylaxis prompted us to investigate the action of these compounds on coronary vessels and myocardial contractility. In this study leukotriene B4 (LTB4) and C4 (LTC4) were injected directly into the left circumflex (LCx) coronary artery of nine anesthetized Suffolk sheep. LTB4 had no effect on coronary artery blood flow or myocardial contractility, but 3 X 10(-9) mole induced profound transient circulating neutropenia, reflecting the potent chemotactic and chemokinetic properties of this compound. Injecting as little as 1.6 X 10(-11) mole of LTC4 caused a 14.5 +/- 4.3% (mean +/- SE) reduction of LCx coronary artery flow while 1.6 X 10(-10) mole caused a 26.5 +/- 3.7% decrease of LCx coronary artery flow and an 18.1 +/- 3.2% decrease in systolic shortening of the myocardial region supplied by the LCx coronary artery. Since the decrease in systolic shortening was far greater than that expected on the basis of the reduction in coronary artery flow, we postulate that LTC4 has a direct negative inotropic effect. FPL 55712, a receptor antagonist of leukotrienes C4, D4, and E4, blocked the vasoconstriction induced by LTC4 but only partially blocked the negative inotropic effects of LTC4. LTC4 is a potent vasoconstrictor and negative inotropic agent and may play an important role in anaphylactic shock.
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PMID:Effects of leukotrienes B4 and C4 on coronary circulation and myocardial contractility. 630 44

Platelet activating factor is a multifaceted mediator of inflammation capable of stimulating platelet aggregation as well as anaphylaxis, neutropenia and numerous other in vitro and in vivo cellular changes. This lipid mediator, or autocoid, is released by a wide variety of inflammatory cells following an equally diverse group of cellular stimuli including phagocytosis or antigenic stimulation. The synthesized form of PAF is acetyl glyceryl ether phosphorylcholine (AGEPC). In this study AGEPC aggregated bovine platelets in a dose dependent manner. Maximal, irreversible aggregation occurred at 3.6 X 10(-11) M AGEPC with unwashed platelets and at 8.8 X 10(-12) M AGEPC with washed platelets. Aggregation failed to occur when platelets were tested with the biologically inactive structural analog of AGEPC. The possible contribution by platelet cyclooxygenase products was eliminated by showing lack of platelet aggregation to arachidonic acid and also by pretreating platelets with aspirin.
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PMID:Aggregation of bovine platelets by acetyl glyceryl ether phosphorylcholine (platelet activating factor). 643 5

We tested paclitaxel (Taxol) and low dose hydroxyurea as second line therapy in 30 patients with non-small cell lung cancer since both drugs are active against non-small cell lung cancer in other settings, and since hydroxyurea may reverse chemotherapy resistance by disrupting double minute chromosomes. Hydroxyurea 500 mg was given orally each Monday, Wednesday, Friday starting 1 week before paclitaxel, and continuing until removal from study. Paclitaxel 135 mg/m2 was given i.v. over > or = 1 h every 3 weeks with dexamethasone, diphenhydramine, and ranitidine. Patients could have paclitaxel doses escalated to 175 mg/m2 in course 2 and to 200 mg/m2 in course 3, where tolerated. Sixteen males and 14 females were treated. All patients had previously received a single cisplatin-based chemotherapy regimen and 23 had previously received radiotherapy. Twelve patients had adenocarcinomas, six had squamous cell carcinomas, and 12 had large cell carcinomas. Eight patients had Stage IIIb cancers and 22 had Stage IV. Paclitaxel doses were 135 mg/m2 in 56 courses, 175 mg/m2 in 24, and 200 mg/m2 in 15. Treatment was well tolerated. Median granulocyte nadirs were 2.5 (x 10(9)/l) for paclitaxel 135 mg/m2, 1.8 for 175 mg/m2, and 1.3 for 200 mg/m2. No patient developed febrile neutropenia, and none required a dose reduction. Two patients had reversible anaphylaxis. Other toxicities were quite tolerable. They included fatigue, myalgias, dizziness, paresthesias, diarrhea, alopecia, mucositis, flushing, headache, swollen red hands, and anxiety. One patient had a partial remission and 15 had stable disease (including six with minor responses). Median survival was 20 (95% CI, 12-34) weeks, with 19% of patients remaining alive at 1 year from initiation of treatment. This is a well-tolerated regimen with modest activity as second line chemotherapy for patients with non-small cell lung cancer previously treated with cisplatin regimens. Higher doses would be feasible and other strategies are now being explored.
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PMID:Paclitaxel plus hydroxyurea as second line therapy for non-small cell lung cancer. 886 29

Platelet-activating factor (PAF) is a potent proinflammatory phospholipid mediator that causes hypotension, increases vascular permeability, and has been implicated in anaphylaxis, septic shock and several other inflammatory responses. PAF is hydrolyzed and inactivated by the enzyme PAF-acetylhydrolase. In the intact rat, a mesenteric vein infusion of lipopolysaccharide (LPS) served as an acute, liver-focused model of endotoxemia. Plasma PAF-acetylhydrolase activity increased 2-fold by 24 h following LPS administration. Ribonuclease protection experiments demonstrated very low levels of plasma-type PAF-acetylhydrolase mRNA transcripts in the livers of saline-infused rats; however, 24 h following LPS exposure, a 20-fold induction of PAF-acetylhydrolase mRNA was detected. In cells isolated from endotoxin-exposed rat livers, Northern blot analyses demonstrated that Kupffer cells but not hepatocytes or endothelial cells were responsible for the increased PAF-acetylhydrolase mRNA levels. In Kupffer cells, plasma-type PAF-acetylhydrolase mRNA was induced by 12 h, peaked at 24 h, and remained substantially elevated at 48 h. Induction of neutropenia prior to LPS administration had no effect on the increase in PAF-acetylhydrolase mRNA seen at 24 h. Although freshly isolated Kupffer cells contain barely detectable levels of plasma-type PAF-acetylhydrolase mRNA, when Kupffer cells were established in culture, PAF-acetylhydrolase expression became constitutively activated concomitant with cell adherence to the culture plates. Alterations in plasma-type PAF-acetylhydrolase expression may constitute an important mechanism for elevating plasma PAF-acetylhydrolase levels and an important component in minimizing PAF-mediated pathophysiology in livers exposed to endotoxemia.
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PMID:Cell-specific regulation of expression of plasma-type platelet-activating factor acetylhydrolase in the liver. 934 88

This study was aimed to determine the activity and toxicity of combination paclitaxel and carboplatin in stage III B and IV NSCLC. Eligibililty required performance status. Paclitaxel was administered at a dose of 200 mg/m2, 3-hour infusion, followed by carboplatin at a tartgeted area under the concentration-time curve (AUC) of 6. Treatment was repeated at 3-week intervals for 6 courses. G-CSF 5 micrograms/kg was subcutaneously injected during subsequent courses if there was grade 3-4 leukopenia or granulocytopenia in the previous course. From August 1996 through June 1997, 15 patients were enrolled. The median age was 47 years (range 20-68 years), 60 per cent were female. 73.3 per cent had adenocarcinoma, and 66.7 per cent had stage III B disease. Eighty three courses were administered; 13 patients (86.7%) completed all six cycles. The objective response rate was 53.3 per cent, with 1 (6.7%) complete response and 7 (46.7%) partial responses. Pleural effusion, lung lesion and lymph node were the three most common sites that responded to chemotherapy. The major toxicity was myelosuppression. Grade 3 or 4 granulocytopenia, anemia and thrombocytopenia were observed in 18 per cent, 7.2 per cent and 1.2 per cent, respectively, of 83 courses administered. Four episodes of febrile neutropenia (4.8%) occurred in 3 patients. There was one episode of anaphylaxis during Paclitaxel infusion. Other common toxicities were mild myalgia, paresthesias, alopecia and fatigue. Most of the toxicities showed cumulative effect. Paclitaxel plus carboplatin is a moderately active regimen in advanced NSCLC. Toxicities of this regimen are well tolerated.
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PMID:Paclitaxel and carboplatin in combination in the treatment of advanced non-small-cell lung cancer (NSCLC): a preliminary study. 980 67

A prospective phase II study was conducted to determine the response, toxicity and survival rate of lung cancer patients treated with combination paclitaxel and carboplatin in stage IIIB and IV NSCLC. Eligible patients required measurable and/or evaluable diseases; performance status (ECOG) 0-2; no previous chemotherapy; adequate hepatic, renal and bone marrow function. Paclitaxel was administered at a dose of 200 mg/m2, 3 h infusion, followed by carboplatin at an AUC of 6. Treatment was repeated every 3 weeks for six courses. G-CSF 5 microgram/kg was subcutaneously injected during subsequent courses if there was grade 3-4 leucopenia or granulocytopenia in the previous course. From April 1996 through July 1997, 53 patients were enrolled; all are assessable for toxicity and response. The median age was 56 years (range, 20-77 years). Sixty four percent were male, 64% had adenocarcinoma and 62% had stage IV disease. Two hundred and seventy two courses were administered; 36 patients (68%) completed all six cycles. Two patients achieved a complete response (4%) and 27 patients achieved a partial response (51%), for an overall response rate of 55%. Sixteen patients had stable disease (30%) and 8 patients had progressive disease (15%). The median progression free survival time for all patients, stage IIIB and stage IV patients was 28 weeks (range, 18-37 weeks), 31 weeks (range 21-41 weeks) and 22 weeks (range 16-29 weeks), respectively. The median survival time and 1 year survival rate for all patients was 55 weeks (range, 51-59 weeks) and 55%, respectively. Stage IIIB patients had better median survival time and 1-year survival rate than stage IV patients (75 vs. 46 weeks, P = 0.007; 80% vs. 42%, P = 0.003). Grade 3 and 4 granulocytopenia, anemia and thrombocytopenia were observed in 25, 3, and 1%, respectively, of the 272 courses administered. G-CSF was required in 28% of the 272 courses. There were four episodes of febrile neutropenia (1.5%), three episodes of angina pectoris (1%) and one episode of anaphylaxis (0.4%). Other common toxicities, generally mild, included myalgia, arthralgia, peripheral neuropathy and asthenia. Most toxicities showed cumulative effect. Paclitaxel plus carboplatin is a moderately active regimen in advanced NSCLC. Toxicities of this regimen are well tolerated.
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PMID:Phase II study of paclitaxel and carboplatin for advanced non-small-cell lung cancer. 1059 28

A phase II trial was performed to determine the antitumour efficacy and tolerance of combined paclitaxel and cisplatin with or without hematopoetic growth factor support in patients with advanced gastric cancer. Forty-five patients with histologically confirmed metastatic gastric cancer were entered in this trial. Treatment consisted of 2-weekly courses of paclitaxel 160 mg per m2 and cisplatin 60 mg per m2 both given on day 1. Depending on absolute neutrophil counts on the days of scheduled chemotherapeutic drug administration (1000-2000 per microl), a 5-day course of human granulocyte colony-stimulating factor 5 microg x kg(-1) per day was given subcutaneously; in addition, if haemoglobin was <12.0 mg dl(-1), erythropoietin 10 000 IU was administered subcutaneously three times per week. The confirmed overall response rate (intent-to-treat) was 44%, including five complete (11%) and 15 partial remissions (33%). Twelve patients had stable disease (27%), 11 (24%) progressed while on chemotherapy, and two patients were not evaluable. The median time to response was 3 months, the median time to progression 7.0 months, and the median survival time was 11.2 months with 12 patients currently alive. Haematologic toxicity was common, though WHO grade 4 neutropenia occurred in only five patients (11%). Apart from total alopecia in 16 patients (36%), severe non-haematologic adverse reactions included grade 3 peripheral neuropathy in six (13%) and anaphylaxis in two patients. In addition, there was one patient each who experienced grade 3 emesis, diarrhea, and infection, respectively. Our data suggest that the combination of paclitaxel and cisplatin with or without G-CSF and/or erythropoietin has promising therapeutic activity in patients with advanced gastric cancer.
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PMID:Effective combination chemotherapy with paclitaxel and cisplatin with or without human granulocyte colony-stimulating factor and/or erythropoietin in patients with advanced gastric cancer. 1208 76


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