Leukotriene B4 release by human lung macrophages via receptor- not voltage-operated Ca2+ channels.

Increased numbers of macrophages and neutrophils in the lung is a key feature of chronic obstructive pulmonary disease (COPD). The major neutrophil chemotactic agent in the airways of COPD patients is leukotriene (LT)B(4) and is released by macrophages. The present study examines the role and mechanism of Ca(2+) in platelet-activating factor (PAF)-stimulated LTB(4) release from human lung macrophages. Macrophages were isolated from lung tissue of subjects undergoing lung resection surgery and monocyte-derived macrophages (MDM) were obtained from nonsmokers, smokers without obstruction and COPD patients. Cells were stimulated with PAF and LTB(4) release and [Ca(2+)](i) was measured. Lung macrophages and MDM released LTB(4) following stimulation with PAF (mean effective concentration: 0.08+/-0.06 microM (n = 5) versus 0.17+/-0.12 microM (n = 17), respectively). Compared with MDM, lung macrophages released approximately eight-fold more LTB(4). Neither smoking nor COPD altered MDM responses. PAF-stimulated LTB(4) release was abrogated by ethylene glycol tetraacetic acid suggesting a role for extracellular Ca(2+). This was substantiated by using store-operated channel blockers econazole, SK&F96365 and Gd(3+). However, econazole and SK&F96365 were more effective in MDM than lung macrophages. Neither LOE908 nor nifedipine could attenuate this response. These data suggest that platelet-activating factor-stimulated leukotriene B(4) release from human lung macrophages is mediated, in part, by Ca(2+) influx through receptor- but not voltage-operated Ca(2+) channels.

Successful autologous bone marrow transplant without the use of blood product support.

We describe a successful autologous bone marrow transplant without the use of any blood products. The patient had relapsed large cell lymphoma. He was a Jehovah's Witness and would not accept transfusions of red blood cells or platelets. He enrolled in our Bloodless Medicine and Surgery Program and was maintained on a regimen of erythropoietin, iron, Amicar, and G-CSF throughout the transplant. He tolerated the transplant well and is alive with no evidence of disease 10 months after autografting.

Renal toxicities of antineoplastic drugs and bone marrow transplantation.

A number of antineoplastic chemotherapeutic drugs may produce fluid and electrolyte disturbances or nephrotoxic reactions extending across the clinical spectrum, from subclinical renal dysfunction to progressive chronic renal insufficiency to severe acute failure. Although some of the drugs that are highly nephrotoxic are now seldom used, others are tremendously useful in modern clinical oncology. Some newer antineoplastic therapies such as interleukin-2 and bone marrow transplantation are commonly associated with nephrotoxicity. Although our understanding of the pathophysiological mechanisms underlying these toxic reactions is still rather rudimentary, information derived from animal models, coupled with clinical experience, has in many circumstances generated clinical interventions that can successfully limit treatment-related renal injury.

Phase I trial of etoposide, doxorubicin and cisplatin (EAP) in combination with GM-CSF.

The aim of this study was to ameliorate the toxicity of the etoposide, doxorubicin and cisplatin (EAP) regimen and to investigate the feasibility of dose escalation, using the molgramostim form of granulocyte macrophage-colony stimulating factor (GM-CSF) 10 micrograms/kg/day s.c. into the regimen. The design of the trial allowed for amended scheduling of the agents in the event of suboptimal results. Initially the regimen comprised etoposide 120 mg/m2, days 1-3, doxorubicin 40 mg/m2, day 1, and cisplatin 40 mg/m2, days 2 and 8. GM-CSF was begun on day 4 and continued until recovery of granulocyte counts. Courses were repeated every 21 days. 3 patients were treated at these doses. 5 patients received escalated doses (etoposide 180 mg/m2; doxorubicin 60 mg/m2; cisplatin 60 mg/m2) on this schedule; 4 out of 5 had intolerable myelosuppression (grade IV neutropenia or thrombocytopenia lasting > or = 7 days). These results prompted the administration of the day 8 cisplatin dose on day 3, with GM-CSF beginning on day 4. At the lowest doses of each agent (etoposide 120-doxorubicin 40-cisplatin 40), 3 of 6 patients had intolerable myelosuppression, and 3 patients had febrile neutropenia. Dose escalation of all of the drugs to etoposide 180 mg/m2, doxorubicin 60 mg/m2, cisplatin 60 mg/m2 resulted in documented infections in 4 out of 4 patients. GM-CSF toxicity included rash, dyspnoea, arrhythmias and pericardial effusions. The conclusion was that the use of GM-CSF does not permit escalation of drug doses on either schedule of EAP administration, and that these results do not support the combined use of GM-CSF and EAP.

Interference in an electrochemical detection system for peroxidase-linked reactions based on a fluoride ion-selective electrode.

Use of the fluoride ion-selective electrode as a detector in a linked glucose oxidase (EC 1.1.3.4)/peroxidase (EC 1.11.1.7) method for glucose was investigated for possible interference from sugars, metabolites, drugs, and anticoagulants. The CV for the method was 1.5% (SD 0.37 mmol/L) at a glucose concentration of 25.0 mmol/L. Interference was studied with glucose at this concentration, interference being defined as any result differing by more than +/- 3 SD. When present in concentrations of clinical relevance, interference from urea, uric acid, or acetaminophen would preclude the use of this detection system for routine analysis.

A reversed-phase high-performance liquid chromatographic assay for the determination of N-acetylcysteine in aqueous formulations.

A stability-indicating assay is described for the determination of N-acetylcysteine in aqueous pharmaceutical formulations. The sample is diluted to an appropriate concentration with dilute aqueous orthophosphoric acid. An aliquot of the solution, containing added l-tyrosine as an internal standard, is chromatographed using a 10-mum C(18) stationary phase with dilute orthophosphoric acid (pH 2.0) containing 0.5% w/v of sodium perchlorate as the mobile phase. The assay, which has a relative standard deviation of about 0.8%, can also be used as a test for related impurities in N-acetylcysteine. It is also suitable for determining the N-acetylcysteine content of the drug substance.