Secretory phospholipases A2 induce beta-glucuronidase release and IL-6 production from human lung macrophages.

Secretory phospholipases A2 (sPLA2s) are a group of extracellular enzymes that release fatty acids at the sn-2 position of phospholipids. Group IIA sPLA2 has been detected in inflammatory fluids, and its plasma level is increased in inflammatory diseases. To investigate a potential mechanism of sPLA2-induced inflammation we studied the effect of group IA (from cobra venom) and group IIA (human synovial) sPLA2s on human macrophages. Both sPLA2s induced a concentration- and Ca2+-dependent, noncytotoxic release of beta-glucuronidase (16.2 +/- 2.4% and 13.1 +/- 1.5% of the total content with groups IA and IIA, respectively). Both sPLA2s also increased the rate of secretion of IL-6 and enhanced the expression of IL-6 mRNA. Preincubation of macrophages with inhibitors of the hydrolytic activity of sPLA2 or cytosolic PLA2 did not influence the release of beta-glucuronidase. Incubation of macrophages with p-aminophenyl-mannopyranoside-BSA (mp-BSA), a ligand of the mannose receptor, also resulted in beta-glucuronidase release. However, while preincubation of macrophages with mp-BSA had no effect on beta-glucuronidase release induced by group IIA sPLA2, it enhanced that induced by group IA sPLA2. A blocking Ab anti-mannose receptor inhibited both mp-BSA- and group IIA-induced beta-glucuronidase release. Taken together, these data indicate that group IA and IIA sPLA2s activate macrophages with a mechanism independent from their enzymatic activities and probably related to the activation of the mannose receptor or sPLA2-specific receptors. The secretion of enzymes and cytokines induced by sPLA2s from human macrophages may play an important role in inflammation and tissue damage associated with the release of sPLA2s.

Phase I-II study of gemcitabine and paclitaxel in pretreated patients with stage IIIB-IV non-small cell lung cancer.

Gemcitabine and paclitaxel are among the most active new agents in non-small cell lung cancer (NSCLC) and are worth considering for second-line chemotherapy. In this phase I-II study, we combined gemcitabine and paclitaxel for second-line treatment of advanced NSCLC. Gemcitabine doses were kept fixed at 1000 mg/m2 on day 1 and 8, and paclitaxel doses were escalated from 90 mg/m2 on day 1 of the 21-day cycle. Thirty-seven patients were treated at six different dose levels. Grade 4 neutropenia was dose-limiting toxicity (DLT), since it occurred in two out of six patients treated at paclitaxel 240 mg/m2; the paclitaxel dose level just below (210 mg/m2) was selected for phase Il evaluation. Non-hematologic toxicity was mild. One complete response (CR) (3%) and 13 partial responses (PR) (36%) were observed in 36 evaluable patients for an overall response rate of 39% (95% C.I., 23-57%). Median duration of response was 35 weeks (range, 8-102). All of the observed objective responses occurred in the 19 patients who had previously responded to the first-line therapy. Median survival was 40 weeks (range, 8-108 weeks). The combination of gemcitabine and paclitaxel is a feasible, well-tolerated, and active scheme for second-line treatment of advanced NSCLC; further evaluation, at least in selected patients, such as those previously responding to first-line chemotherapy, is definitely warranted.

New triplet chemotherapy combination with carboplatin, paclitaxel and gemcitabine plus amifostine support in advanced non small cell lung cancer: a phase II study.

New triplet chemotherapy combinations are under investigation in advanced non small cell lung cancer (NSCLC). Carboplatin, plus paclitaxel, plus gemcitabine is among the most active and promising regimens. The use of more aggressive chemotherapy in order to improve results can increase toxicity. Amifostine (WR-2721) reduces toxicity of radiotherapy and chemotherapy and protects selectively a number of normal, but not neoplastic, tissue. Based on this background, we performed a phase II study on carboplatin, plus paclitaxel, plus gemcitabine with amifostine support in advanced NSCLC. Patients received chemotherapy at the following dosage: carboplatin AUC 5, i.v., at day 1; paclitaxel 175 mg/m2, i.v. by 3-hour infusion, at day 1; gemcitabine 1000 mg/m2, i.v. by 3-hour infusion, at days 1 and 8; every 3 weeks for a maximum of 6 cycles. Amifostine was administered at the dose of 740 mg/m2, i.v., at day 1 of each cycle. Seventeen patients entered the study. They were prevalently male, median age was 62 years, PS (ECOG) was 0 in 10 cases (58.8%), 1 in 6 (35.3%) and 2 in 1 (5.9%). Histology was epidermoid in 8 cases (47%) and adenocarcinoma in 9 (53%). We observed 8 (47.5%) objective responses with 2 (11.7%) complete responses. Median time to progression and median survival were 24 and 36 weeks, respectively. Treatment was well tolerated. The main toxicity was as follows: grade 3 neutropenia, grade 2 thrombocytopenia and grade 3 anemia in one (5.8%) case; grade 2 peripheral neurologic toxicity in 3 (17.6%) patients; grade 2 cardiac toxicity (atrial fibrillation) in one case; and grade 3 respiratory toxicity (dispnoea) in one patient. These data indicate that this combination has promising activity and tolerability. A randomized trial comparing carboplatin plus paclitaxel, plus gemcitabine versus carboplatin, plus paclitaxel, plus gemcitabine, plus amifostine in advanced NSCLC is warranted.

Phase I-II study of gemcitabine and carboplatin in stage IIIB-IV non-small-cell lung cancer.

PURPOSE: Platinum-based chemotherapy currently represents standard treatment for advanced non-small-cell lung cancer. Gemcitabine is one of the most interesting agents currently in use in advanced non-small-cell lung cancer, and high response rates have been reported when it is administered in combination with cisplatin. The aim of the present study was to evaluate the combination of gemcitabine and carboplatin in a phase I-II study. PATIENTS AND METHODS: Chemotherapy-naive patients with stage IIIB-IV non-small-cell lung cancer received carboplatin at area under the concentration-time curve (AUC) 5 mg/mL/min and gemcitabine at an initial dose of 800 mg/m2, subsequently escalated by 100 mg/m2 per step. Gemcitabine was administered on days 1 and 8 and carboplatin on day 8 of the 28-day cycle. Dose escalation proceeded up to dose-limiting toxicity (DLT), which was defined as grade 4 neutropenia or thrombocytopenia or grade 3 nonhematologic toxicity. RESULTS: Neutropenia was DLT, inasmuch as it occurred in three of five patients receiving gemcitabine 1,200 mg/m2. Nonhematologic toxicities were mild. Gemcitabine 1,100 mg/m2 plus carboplatin AUC 5 was recommended for phase II studies. An objective response was observed in 13 (50%) of 26 patients, including four complete responses (15%) and nine partial responses (35%). Median duration of response was 13 months (range, 3 to 23 months). Median overall survival was 16 months (range, 3 to 26 months). CONCLUSION: The combination of gemcitabine and carboplatin is well tolerated and active. Neutropenia was DLT. The observed activity matches that observable in cisplatin-gemcitabine studies, whereas duration of response and survival are even higher. A phase II trial is under way.

Polyclonal/monoclonal ratio in kidney and bone marrow transplanted patients treated with cyclosporine.

On 296 blood samples obtained from 22 bone marrow and 21 kidney transplanted patients, the concomitant measurements of polyclonal and monoclonal cyclosporine (CsA) were performed and the relative polyclonal/monoclonal (P/M) ratios were calculated. Biochemical profiles of kidney and liver functions were also determined in all patients. For each type of transplant, biochemical data were divided into two subgroups on the basis of P/M ratio: A) data obtained in patients with P/M ratio > 3.0; B) data obtained in patients with P/M ratio < or = 3.0. While in kidney transplanted patients no difference of biochemical profiles was found between two subgroups, in bone marrow transplant recipients the subgroup A showed a worsening of hepatic function parameters as compared to subgroup B. Therefore, it appears that P/M ratio could represent in bone marrow transplantation an index of hepatic CsA toxicity.

Lack of effect of gemfibrozil on cyclosporine blood concentrations in kidney-transplanted patients.

Forty kidney-transplanted patients with hypertriglyceridemia, under treatment with cyclosporine alone or associated with other immunosuppressive drugs, were treated with gemfibrozil. This drug, for a long-term treatment (ranging from 4 to 6 months), was able to decrease hypertriglyceridemia and did not modify either polyclonal (P) and monoclonal (M) cyclosporine blood levels or P/M ratio. These data seem to exclude an effect of gemfibrozil on cyclosporine blood concentrations. Therefore, the use of gemfibrozil in kidney-transplanted patients does not require modifications of cyclosporine dose.

Immunopharmacology of human mast cells and basophils.

Human mast cells and basophils play a key role in the pathogenesis of several immunological and inflammatory disorders, not only by producing inflammatory and fibrogenic mediators, but also by directly (CD40 ligand) and indirectly secreting various cytokines and chemokines. Studies carried out to evaluate the effects of drugs that modulate the release of mediators and cytokines from these cells have contributed to clarifying the biochemical mechanism by which immunological and non-immunological stimuli activate these cells. Significant differences have been documented between human mast cells and basophils as regard the pharmacological agents that modulate the release of mediators, between mast cells isolated from different anatomical sites, and between compounds of the same class of drugs. Efforts to gain insight into the biochemical events occurring during immunological activation of mast cells and basophils could lead to the identification of new biochemical targets for therapeutic interventions in several immunological disorders.

Characterization of platelet-activating factor acetylhydrolase in human bronchoalveolar lavage.

Platelet-activating factor (PAF) is a mediator produced in human airways during acute and chronic inflammatory lung diseases. The levels of PAF are regulated by acetylhydrolase (AH), the enzyme that converts PAF to lyso-PAF. To determine whether AH was present in human bronchoalveolar lavage (BAL) fluid, BAL was obtained from normal donors (n = 18) and from adult patients with mild bronchial asthma (n = 15) or with lung fibrosis (n = 15). AH activity was consistently found in the cell-free BAL fluid. BAL-AH is an enzyme different from secretory phospholipase A2 and from plasma AH and erythrocyte AH. Furthermore, BAL-AH is inhibited as much as 95% by exposure to an oxygen radical-generating system (xanthine/xanthine oxidase). BAL-AH is significantly correlated with the number of BAL macrophages (rs = 0.63; p < 0.02). In addition, BAL macrophages release AH both spontaneously and after stimulation with tumor necrosis factor-alpha (TNF-alpha) (100 ng/ml). BAL-AH activity in patients with bronchial asthma (1.32 +/- 0.18 pmol of PAF converted to lyso-PAF/min) is significantly lower than that in normal donors (2.25 +/- 0.26 pmol/min; p < 0.001). In contrast, BAL-AH activity in patients with lung fibrosis (6.13 +/- 0.81 pmol/min) is higher than that found in normal donors (p < 0.01). The variations in BAL-AH activity in patients with bronchial asthma or lung fibrosis are due to a reduction and to an increase, respectively, in the number of active molecules rather than to changes in enzyme affinity. These data demonstrate that human BAL fluid contains an extracellular AH activity that inactivates PAF released in the airways. BAL-AH is secreted by alveolar macrophages and is highly sensitive to oxygen radical-induced damage. The secretion and inactivation of BAL-AH may influence the levels of this enzyme in BAL fluid during acute and chronic inflammatory lung diseases and, ultimately, regulate the proinflammatory activities of PAF in these disorders.

Arachidonic acid remodeling in human inflammatory cells migrating to the lung in vivo.

Recent evidence suggests that arachidonic acid (AA), the precursor of eicosanoids, is stored in various glycerolipid pools with different biochemical specificities. Upon cell activation, AA is rapidly remodeled within these glycerolipid pools. We have explored the changes in AA content and distribution in human neutrophils as they are activated in vivo in the lungs of patients with adult respiratory distress syndrome (ARDS). Neutrophils from bronchoalveolar lavage fluid of ARDS patients contained an amount of total cellular AA four times larger than that of blood (resting) neutrophils and accumulated a larger proportion of AA into a pool associated with triglycerides (TG). These biochemical changes were associated with an increased number of cytoplasmic lipid bodies and with the acquisition of the hypodense phenotype. These data indicate that the accumulation of AA into TG is a marker of cell activation and suggest a central role of the TG pool in AA metabolism in inflammatory cells activated in vivo.

Effects of different routes of cyclosporin A administration on blood levels in patients undergoing bone marrow transplantation.

This follow-up study has been carried out on 15 bone marrow transplant recipients treated intravenously with cyclosporin A (CsA) as a bolus (1.25-2.5 mg/kg/12 h) or by continuous infusion (1-3 mg/kg/24 h) from -2 until the 21st day after transplantation. All patients were subsequently treated with CsA orally at a starting dose of 6.25 mg/kg/12 h; this starting dose was then adjusted on the basis of CsA blood levels until the 60th day after transplantation, followed by progressive reduction and withdrawal within 6-12 months. In whole blood, trough levels of polyclonal (P) and monoclonal (M) CsA were monitored by a FPIA method and the polyclonal/monoclonal ratio (P/M) was calculated. This ratio was lower during CsA administration as a bolus or by continuous infusion than during oral administration; the decrease was statistically significant. This difference was probably due to first-pass metabolism which occurs in the liver and gut after oral administration.

A new dry chemistry immunoassay: comparison with a fluorescence polarization system.

A new dry chemistry fluorescence immunoassay has been recently developed for therapeutic drug monitoring. In the present study we compared this new assay with a fluorescence polarization immunoassay. The drugs tested were carbamazepine, phenobarbital, phenytoin, theophylline and valproate. An high degree of correlation (coefficients ranging from 0.95 to 1.00) was obtained for all drugs tested.

Evaluation of monoclonal/polyclonal ratio in kidney-transplanted patients treated with cyclosporine.

Fifty-seven kidney-transplanted outpatients, treated with cyclosporine alone or associated with azathioprine, prednisone, or methylprednisolone, were submitted to a monthly follow-up in order to determine cyclosporine blood levels and the monoclonal/polyclonal (M/P) ratio. Only methylprednisolone was able to modify the M/P ratio. This drug increased the M/P ratio, suggesting a cyclosporine metabolic inhibition. This effect disappeared in a few months in spite of the continuation of methylprednisolone treatment.

Effects of nimodipine on psychological-stress situation in aged rats.

Female aged rats treated with nimodipine, a calcium-blocker dihydropyridine derivative, were submitted to a psychological-stress situation. Nimodipine at the doses of 3 and 6 mg/Kg antagonized the stress-related body-weight decrease and lethality. These findings seem to validate the role of Ca-mediated mechanisms in the physiopathology of stress and the protective effects of the Ca-blockers in the stress-related illnesses.

[Physiological bases and therapeutic uses of inodilator drugs]. / I presupposti fisiologici e gli impieghi terapeutici dei farmaci inodilatatori.

The pharmacodynamic and pharmacokinetic parameters of inodilators have been reviewed. The clinical usefulness of these compounds is underlined.

[Quinolones: confirmations and promises]. / Chinoloni: conferme e promesse.

The authors review new and old quinolones and their pharmacokinetics. The clinical usefulness of these compounds is discussed on the basis of their bactericidal properties and of the uncommon development of resistance.

Effects of betamethasone on theophylline disposition in man. Are saliva values predictive of serum theophylline levels?

The pharmacokinetic interaction between betamethasone (5 mg/day for 5 days) and theophylline (3.35 mg/kg orally before and after betamethasone treatment) was studied in 13 female patients evaluating saliva and serum theophylline concentrations by means of an enzyme multiplied immunoassay technique. Betamethasone treatment did not significantly change saliva and serum theophylline levels. As regards the potential usefulness of saliva theophylline levels in predicting the concomitant serum concentrations of the bronchodilator, in spite of the significant correlation found in our study (r = 0.758; P less than 0.001), we think that, using individual saliva values, there is a poor predictive value for serum theophylline concentrations.