Inhibitory effect of rhodamine B on the proliferation of human lip fibroblasts in culture

The effect of the cosmetic dye rhodamine B on the proliferation of human lip fibroblasts (KD cells) was investigated in a culture system. Rhodamine B at 25 micrograms/ml and above significantly decreased the number of the cells after a 72 h culture. A time course study revealed that 50 micrograms/ml of rhodamine B-induced decrease in the cell number occurred after 48 h and longer, suggesting that the dye inhibited cell proliferation without a decrease in cell attachment. The detachment of [3H]thymidine-labeled cells from the monolayer was unaffected by rhodamine B at 100 micrograms/ml and below. The incorporation of [3H]thymidine and [14C]leucine into the acid-insoluble fraction of the cell layer was significantly inhibited by 50 micrograms/ml rhodamine B treatment. Histologically, the damage of KD cells was not marked, however, a degenerative change of nuclei and an irregular shape of the cells as well as a decrease in the cell number were caused by 50 micrograms/ml rhodamine B. Rhodamine 6G caused a severe damage of the cells, and rhodamine B significantly decreased the cell number; rhodamine 123 had no significant effect; rhodamine 116 significantly increased the cell number. Furthermore, rhodamine B decreased the number of both vascular endothelial cells from bovine aorta and vascular smooth muscle cells from murine aorta after a 72 h culture. It is concluded that rhodamine B inhibits the proliferation of human lip fibroblasts. This rhodamine B effect may be a warning sign for the dye toxicity.     

A pertussis toxin-sensitive G protein is required to induce histamine release from rat peritoneal mast cells by bradykinin.

Bradykinin, kallidin (Lys-bradykinin) and [Thi 5,8, D-Phe7]-bradykinin, a functional B2 antagonist, induce histamine release from rat peritoneal mast cells. The histamine release is dependent upon added calcium when mast cells are placed in calcium-free medium 30 min before being triggered with the kinins. Histamine release was dose-dependently inhibited by pertussis toxin (1-100 ng/ml) and by benzalkonium chloride (0.1-3 micrograms/ml). The efficiency of ionophore A23187 on histamine release was affected neither by pertussis toxin nor by benzalkonium chloride. The parallel response of rat peritoneal mast cells to kinins and to substance P suggest that these peptides have the same mechanisms of action i.e. activation of a pertussis toxin-sensitive G protein and of phospholipase C defining a peptidergic triggering pathway of mast cells.     

Hydroxyurea-induced cell death in human T lymphoma cells as related to imbalance in DNA/protein cycle and deoxyribonucleotide pools and DNA strand breaks.

The aim of this study was to elucidate the mechanism(s) behind the cellular toxicity of therapeutic concentrations of hydroxyurea (HU). Treatment of human T lymphoma cells (CCRF-CEM) with 60-100 microM of HU for 24 h decreased the growth rate by 90% due to accumulation of cells in early S phase. It induced a marked imbalance in both the DNA/protein cycle (as measured by two-parameter flow cytometry) and the deoxyribonucleotide (dNTP) pools. HU treatment did not enhance the frequency of DNA single-strand breaks (SSBs), as measured by the alkaline unwinding technique. Cell viability was unaffected. However, removal of HU led to 10-15% cell loss during the following 12 h period in parallel with increasing SSBs, and a rapid progression of cells through S and G2 stages. The unbalanced DNA to protein content per cell and the dNTP pools were normalized 6-12 and 24 h after removal of HU, respectively. These results show that marked changes in the DNA to protein ratio and dNTP pools alone are not directly lethal, but when combined with a high replicative DNA synthesis rate, as found after removal of HU, apparently lead to elevated cell death.     

Experimental Combination Chemotherapy with Thymidylate Synthetase and Ribonucleotide Reductase Inhibitors

The synergistic cytotoxic effects on exponentially growing 9L rat brain tumor cells of several inhibitors of thymidylate synthetase (TS) and ribonucleotide reductase (RNR) used in combination were investigated using a colony forming efficiency assay as the experimental endpoint. A 24 h treatment with nontoxic (0.1 µg/ml) or low (1.0 µg/ml) doses of 5-fluorouracil (FUra), 5-fluorodeoxyuridine, 5,8-dideazaisofolic acid, or 2-deoxy-2-fluoro-ara-uracil markedly enhanced cell kill caused by subsequent administration of 100 µg/ml hydroxyurea (HU) for 6 h. When a similar dose of HU or 1-formylisoquinoline thiosemicarbazone was administered for 6 h immediately after a 24 h treatment with either a 0.1 µg/ml or 1.0 µg/ml of FUra, a cell kill of approximately 1 log in addition to that caused by each drug alone was obtained. Thus a synergistic cell kill was consistently obtained when a low dose of TS inhibitors was administered 24 h before a 6 h treatment with another low dose of agents that act as RNR inhibitors. This synergism was not observed when FUra-treated cells were treated with methotrexate, 6-mercaptopurine, vincristine, or l,3-bis(2-chloroethyl)-1-nitrosourea. Similarly, a 6 h treatment with 1 µg/ml of FUra of cells that had been treated for various periods with 100 µg/ml of HU did not increase cell kill more than that obtained with HU alone (30% cell kill).     

灵芝多糖对混合淋巴细胞培养反应中白细胞介素2生成和T细胞亚类的影响(英文)

利用混合淋巴细胞培养反应研究了灵芝多糖的免疫作用机理。结果表明培养12h,灵芝多糖(25,50,100,200μg/ml)可促进白细胞介素2的分泌,且具有剂量依赖关系。培养4d后,可增加总的细胞回收量以及Lyt 2⁺和L3T4⁺细胞的回收量。灵芝多糖还明显增强细胞毒T细胞的功能,在浓度为200μg/ml时,其杀伤活性增加100%。     

Effect of aminophylline on renal vasoconstriction produced by amphotericin B in the rat

Administration of the antifungal agent amphotericin B causes a pronounced reduction in renal blood flow (RBF). Since amphotericin B induced renal vasoconstriction may contribute to the clinical nephrotoxicity of this drug, the purpose of these studies was to investigate the mechanism of amphotericin B induced renal vasoconstriction. To determine if the vascular response to amphotericin B is linked to the intrarenal release of either adenosine or angiotensin II, the effects of aminophylline (5 mumol/kg/min for 10 min followed by 0.5 mumol/kg/min) and saralasin (6 micrograms/min) on the renal vascular response produced by two 10 min intravenous amphotericin B (0.35 mg/kg) infusions were examined. In the control group, amphotericin B decreased RBF 1.7 ml/min (22%, P less than 0.01) and 3.5 ml/min (44%, P less than 0.001) during the 1st and 2nd amphotericin B infusions, respectively. In animals pretreated with aminophylline the decrease in RBF produced by amphotericin B was only 0.4 ml/min (5.5%; N.S.) and 1.3 ml/min (15%, P less than 0.05) during the 1st and 2nd amphotericin B infusions, respectively. In contrast, neither saralasin nor the direct vasodilator sodium nitroprusside (0.4-2 micrograms/min) influenced the renal vascular response to amphotericin B. These data suggest that the renal vascular response to amphotericin B is not linked to the formation of angiotensin II, but rather might be mediated by increases in renal adenosine levels.     

Effect of antiarrhythmic drugs on the cycle length-dependent action potential duration in dog Purkinje and ventricular muscle fibers

We examined the steady-state action potential duration (APD) within a wide range of cycle lengths (CL) in cardiac dog Purkinje (P) and ventricular (V) muscle fibers in the presence of: lidocaine (L) 4 and 8 micrograms/ml, mexiletine (M) 4 and 8 micrograms/ml, flecainide (F) 1 and 4 micrograms/ml, disopyramide (D) 3.1 and 10 micrograms/ml, quinidine (Q) 2.5, 5, and 10 micrograms/ml, bretylium tosylate (B) 5 and 10 micrograms/ml, and sotalol (S) 5 micrograms/ml. In the P fibers, all drugs except for B and S shortened plateau duration, increased slope of phase 2 and decreased slope of phase 3 repolarization, and either shortened (L, M, Q, F) or prolonged (D) APD. B and S lengthened APD and did not change significantly the slopes of phase 2 and 3 of repolarization. Each drug altered the relation between APD and Cl according to one of the following three patterns: (a) L, M, Q, and F shortened APD more at long than at short CL; (b) D lengthened APD more at short than at long CL; (c) B and S lengthened APD more at long that at short CL. In the V fibers, APD was lengthened by F, Q, and B, and shortened by L and M. The drug-induced changes in the relation between APD and CL were as in the P fibers. The results suggest that the drug-induced changes in the relation between APD and CL can be predicted from the drug effects on the course of repolarization.     

Fundamental and clinical studies on aztreonam in the pediatric field

Fundamental and clinical studies on aztreonam (AZT), a new monobactam antibiotic, were performed in the pediatric field. The MICs of AZT were assessed against the clinically isolated strains in the pediatric infections. AZT showed an excellent antibacterial activity against Gram-negative bacteria, i.e., against E. coli (20 strains), K. pneumoniae (9), P. mirabilis (16), P. vulgaris (5), P. aeruginosa (10), S. typhimurium (4) and H. influenzae (11); the MICs of AZT against the above strains were less than 0.39 microgram/ml, 0.10 microgram/ml, 0.024 microgram/ml, 0.024 microgram/ml, 6.25 micrograms/ml, 0.10 microgram/ml and 0.10 microgram/ml, respectively. However, antibacterial activity of AZT against Gram-positive bacteria was inferior to that against Gram-negative bacteria, i.e., against the strains of S. aureus (16) and S. pyogenes (4), those MICs were more than 400 micrograms/ml and 3.13 micrograms/ml, respectively. Serum concentrations and urinary excretion of AZT were measured in 2 children aged 7 and 11 years after a single intravenous injection at the dose of 20 mg/kg. The mean serum concentration of AZT followed by the injection 62.5 micrograms/ml at 1/4 hour, 28.5 micrograms/ml at 1/2 hour, 16.5 micrograms/ml at 1 hour, 12.0 micrograms/ml at 2 hours, 3.6 micrograms/ml at 4 hours and 1.1 micrograms/ml at 6 hours, respectively. The mean half-life (beta-phase) was 1.24 hours. The mean urinary concentrations after the injection were 5,000 micrograms/ml in 0-2 hours, 1,650 micrograms/ml in 2-4 hours and 611 micrograms/ml in 4-6 hours and the mean urinary recovery rate up to 6 hours was 61.2%. These results in our studies were considered to be comparable with those reported in adults. In our clinical studies, AZT was administered to a total of 14 cases, i.e., acute pneumonia (4 cases), acute pyelonephritis (4), acute enteritis (5) and acute sppurative cholangitis (1). Clinical effect of AZT was excellent or good in 13 cases except fair in 1 case with acute enteritis and the efficacy rate (excellent and good) was 92.9%. With regard to bacteriological effect, all the strains of H. influenzae (3), E. coli (2), P. mirabilis (1) and P. vulgaris (1) were eradicated, but, S. typhimurium (4) was not eradicated. Neither side effect nor abnormal laboratory findings were observed during the study.     

Laboratory and clinical studies on 6059-S in children (author's transl)

Laboratory and clinical studies were performed on 6059-S in the field of pediatrics, a new semi-synthetic 1-oxacephem antibiotic, and results were as follows. 1. MICs of 6059-S were compared with those of cefazolin (CEZ) and cefmetazole (CMZ) on 31 strains of S. aureus, 29 strains of E. coli, 30 strains of K. pneumoniae and 16 strains of P. aeruginosa. With the inoculum size of 10(8) cells/ml an 10(6) cells/ml, the peak of distribution of MICs were S. aureus 6.25, 3.13 micrograms/ml, E. coli 0.2, 0.1 micrograms/ml, K. pneumoniae 0.2, 0.05 micrograms/ml and P. aeruginosa 12.5, 6.25 micrograms/ml, respectively. MICs 6059-S against S. aureus was more less 2 to 3 tubes than CEZ and CMZ, but against E. coli and K. pneunoniae were more higher than 3 to 4 tubes than CEZ and CMZ. 2. The serum concentrations and urinary recovery rate of 6059-S were measured in 5 pediatric patients. 6059-S was given 20 mg/kg by an intravenous injection to 2 cases or a 30 minutes intravenous drip infusion to 3 cases. The mean concentration of the former were 64.3, 44.3, 26.8, 11.7 and 5.0 micrograms/ml at 0.5, 1, 2, 4 and 6 hours, and T 1/2 was 1.51 hours. The urinary recovery rates was 75.0% within 6 hours after the injections. The mean concentration of the latter were 65.3, 86.3, 63.0, 40.3, 17.8 and 8.9 micrograms/ml at 0.25, 0.5, 1, 2, 4 and 6 hours, and T 1/2 was 1.63 hours. The urinary recovery rates was 52.1% within 6 hours after the injection. 3. Eleven cases with acute pneumonia, 1 case with acute bronchitis, 3 cases with acute purulent tonsillitis, 1 case with acute purulent parotitis and 1 case subcutaneous abscess were treated with 6059-S by intravenous injection. All cases were above effective clinically. Five strains of H. influenzae, 3 strains of S. pneumoniae, 2 strains of S. pyogenes and 1 strain of S. aureus were eradicated in all strains. No clinical adverse reaction and abnormal laboratory findings were noted.     

Endotoxin stimulates endothelin release from cultured epithelial cells of guinea-pig trachea.

We examined the release of endothelin from cultured epithelial cells of guinea-pig trachea in response to treatment with endotoxin, using a sandwich-enzyme immunoassay. Cultured epithelial cells released endothelin in a time-dependent fashion (3, 6, 12, 24 h), and endotoxin (4-40 micrograms/ml) significantly increased endothelin release. Endotoxin (4-10 micrograms/ml) showed no cytotoxicity against epithelial cells. These results suggest that guinea-pig airway epithelial cells are capable of producing endothelin and this peptide may be related to the pathophysiological effects of endotoxin.     

Rhodamine B inhibition of glycosaminoglycan production by cultured human lip fibroblasts

Rhodamine B (Rh B) is a dye which is used in cosmetics such as lipsticks. We investigated the effect of the dye on the metabolism of [3H]glucosamine-labeled glycosaminoglycans ([3H]-GAG) in confluent cultures of human lip fibroblast KD cells. It was found that Rh B at 10 micrograms/ml and above significantly decreased the accumulation of [3H]-GAG in both the cell layer and the medium after a 24-hr culture. This Rh B (50 micrograms/ml) effect was recognized in the cell layer and the medium after 8 and 24 hr, respectively, and longer. The Rh B at the 25 micrograms/ml-induced decrease in the [3H]-GAG accumulation was reversible in both the cell layer and the medium. On the other hand, the release of [3H]-GAG from the cell layer was unaffected by Rh B. A characterization of [3H]-GAG revealed that all components of the GAG including hyaluronic acid, heparan sulfate, chondroitin 4- and/or 6-sulfate, and dermatan sulfate were significantly decreased by 50 micrograms/ml Rh B in both the cell layer and the medium. Rh B significantly decreased the accumulation of [3H]-GAG in the presence of either 10 microM cycloheximide or 1 mM p-nitrophenyl-beta-D-xyloside, suggesting that Rh B inhibited the sugar chain formation rather than core protein synthesis. Although the number of confluent KD cells was significantly decreased by Rh B at 10 micrograms/ml and above, this Rh B effect was much weaker than that on the [3H]-GAG accumulation. The release of lactate dehydrogenase from the cell layer was significantly increased by 100 micrograms/ml Rh B but not by the dye at 75 micrograms/ml and below. From these results, it was suggested that Rh B decreases the GAG content of human lip fibroblasts through a functional suppression of polysaccharide chain formation in the process of the GAG production.     

Bleomycin control of transplasma membrane redox activity and proton movement in HeLa cells

Bleomycin, tallysomycin A, tallysomycin S10b and copper-bleomycin have been tested for their capacity to inhibit the transplasma membrane electron transport and associated proton release by HeLa cells. Transplasma membrane redox activity is measured using reduction of external ferricyanide by the cells. At 75 micrograms/ml bleomycin, tallysomycin A and tallysomycin S10b gave a maximum of 65% inhibition of the ferricyanide reduction rate; half-maximum inhibition was observed at 30 micrograms/ml. The copper-bleomycin complex was slightly more effective as an inhibitor with half-maximum inhibition at 20 micrograms/ml. Survival of cells after 1 hr of drug treatment was 50% at 25 micrograms/ml for bleomycin and copper-bleomycin and at 75 micrograms/ml for tallysomycin A. Tallysomycin A and tallysomycin S10b gave 75 to 83% inhibition of ferricyanide-induced proton extrusion, respectively at 50 micrograms/ml, whereas bleomycin and copper-bleomycin appeared to be slightly less effective with 50 to 60% inhibition, respectively, at 50 micrograms/ml. In all aspects studied, which included transplasma membrane ferricyanide reduction, ferricyanide-induced proton release, and cell survival, there were significant effects by these compounds on HeLa cells in the range of 25-50 micrograms/ml.     

A newly developed immunofluorescent assay for determining the Pichinde virus-inhibitory effects of selected nucleoside analogues

An immunofluorescent assay (IFA) for Pichinde virus (PCV), a member of the family Arenaviridae, was developed for antiviral drug assays against the virus. The assay was performed by adding fluorescein-labeled anti-PCV monoclonal antibody to virus-infected cells at 24 h after the initial infection and counting the infected cells with an epifluorescence microscope. The average 50% effective dose (ED50) for a series of nucleoside analogues tested against PCV using this IFA was: 2-beta-D-ribofuranosylselenazole-4-carboxamide (selenazofurin), less than 1.0 microgram/ml; 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin), 6.0 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide- 5'-phosphate hydrate (ribavirin-5'-monophosphate), 15.8 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide-5'-hemisuccinate (ribavirin-5'-hemisuccinate), 14.7 micrograms/ml; ammonium 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide-5'-(2,3- dimethyl)hemisuccinate [ribavirin-5'-(2,3-dimethyl)hemisuccinate], 213.5 micrograms/ml; 4-hydroxy-1-beta-D-ribofuranosyl-2-pyridone (3-deazauridine), 5.2 micrograms/ml; and (S)-9-(2,3-dihydroxypropyl)adenine, ([S]-DHPA), 471.0 micrograms/ml. In comparison, the ED50 of ribavirin using inhibition of marginal PCV-induced cytopathogenic effect after 12 days was 6.0 micrograms/ml and using plaque reduction after 5 days was 2.5 micrograms/ml, indicating that this IFA was of comparable sensitivity to these other tests.     

Laboratory and clinical studies of ceftazidime in the pediatric field

The authors have carried out the laboratory and clinical studies of ceftazidime ( CAZ ) and obtained the following results. The antibacterial activities of CAZ against the clinical isolates of S. aureus, E. coli, K. pneumoniae, E. cloacae, E. aerogenes, S. marcescens, C. freundii and P. aeruginosa were measured by the plate dilution method with inoculum size of 10(6) cells/ml. The susceptibility distribution of S. aureus to CAZ ranged from 3.13 to 100 micrograms/ml, and the peak of distribution was 12.5 micrograms/ml. The peak of susceptibility distribution of E. coli, K. pneumoniae and E. cloacae was 0.2 micrograms/ml, and the distribution of E. aerogenes ranged from 0.1 to 100 micrograms/ml and that of S. marcescens, from 0.05 to 3.13 micrograms /ml. The growth of 92% of P. aeruginosa was inhibited at the concentration of 3.13 micrograms/ml or lower. For pharmacokinetic study, CAZ was given in a single dose of 10 mg/kg by intravenous administration for 5 minutes in 1 child and by drip infusion for 30 minutes in 2 children. After intravenous administration of CAZ , the serum level got to the peak of 41.0 micrograms/ml at 15 minutes, and was 1.0 micrograms /ml at 6 hours. Half-life time was 1.30 hours. With drip infusion of CAZ , the mean peak serum level was 52.45 +/- 2.05 micrograms/ml on completion of the infusion, and 1.05 +/- 0.05 micrograms/ml at 6 hours. Half-life time was 1.30 hours. CAZ was effective in 9 cases out of 11 cases with bacterial infection. No side effect was observed except for elevation of serum GOT and GPT in 1 case and eosinophilia in 1 case.     

Valproic acid and phenytoin effects on serum proteins and immunoglobulins of epileptic patients

An evaluation of serum protein and immunoglobulins with regard to valproic acid (VPA) and phenytoin (phen) serum levels was performed in 28 epileptic patients. Serum antiepileptic levels were measured in fasting conditions. All patients were classified into the following groups: A (VPA below 50 micrograms/ml), B (VPA 50-89 micrograms/ml), C (VPA above 89 micrograms/ml), D (VPA 50-89 micrograms/ml and phen below 10 micrograms/ml). Patients of group C showed higher serum protein values than groups A (P less than 0.02), B and D (P less than 0.001). The alpha 2 and beta-globulin fractions were higher in group C than the remaining groups (P less than 0.05). Immunoglobulin A, G and M remained unaltered in all patients.     

Immunomodulatory activity of two new aza alkyl phospholipid antineoplastic drugs.

The present work reports the modulation of immunocompetent cell functions by two aza alkyl phospholipids (AAP), BN 52205 and BN 52211. Each compound was compared with 1-O-octadecyl-2-O-rac-glycero-3-phosphocholine (ET-18-OCH3) and/or three drugs used for cancer treatment, i.e. cisplatyl (CIS), 5-fluorouracil (5-FU) and cytosine arabinoside (ARA-C). Interleukin (IL)-1 release from P388D1 cells was increased 2-fold in the presence of 5 micrograms/ml BN 52205 or BN 52211. However, these stimulations were lower than those obtained with ARA-C, 5-FU and CIS. Compared with ET-18-OCH3, CIS and 5-FU, BN 52205 and BN 52211 were more efficient in increasing tumor necrosis factor production induced by lipopolysaccharide (LPS) from human monocytes. In vitro, all compounds exhibited similar activity in enhancing IL-6 production from human monocytes stimulated with LPS, with the exception of 5-FU and CIS that were inactive. At 20 mg/kg (i.v.), a peak of IL-6 production was reached 2 h after injection of ET-18-OCH3 [> 1280 U/ml (n = 4, p < 0.001) versus 3.5 +/- 0.2 U/ml (n = 7)], whereas BN 52211 induced a maximum of IL-6 production after 4 h (77 +/- 27 U/ml, n = 5, p < 0.001). BN 52205 induced peaks of IL-6 production after 3 and 6 h (90 +/- 62 and 68 +/- 35 U/ml, respectively, p < 0.001, n = 4). The proliferation of rat splenocytes was abolished in the presence of BN 52205 and BN 52211 at 10 micrograms/ml, corresponding to only a partial reduction of IL-2 production at the same concentration. The production of interferon-gamma was stimulated 6- to 10-fold in the presence of 1-5 micrograms/ml BN 52205, BN 52211 and ARA-C. BN 52211 and BN 52205 were also potent enhancers of IL-3 production, whereas 5-FU and ARA-C were inhibitory. These results indicate that in addition to a direct antitumoral effect, AAP may also exhibit immunomodulatory activity both in vitro and in vivo.     

Phyllanthus orbicularis aqueous extract: cytotoxic, genotoxic, and antimutagenic effects in the CHO cell line

The present work evaluates the cytotoxic, genotoxic, and antimutagenic effects of Phyllanthus orbicularis (plant of genus Phyllantus) aqueous extract in Chinese hamster ovary (CHO) cells. P. orbicularis aqueous extracts are used in Cuban traditional medicine for their antiviral activity against Hepatitis B virus and A and B flu virus. The cytotoxicity of the extract was tested by means of colony-forming ability and growth-inhibition assays as well as by measuring the mitotic index. Apoptosis induction and cell-cycle kinetics were analyzed by cytofluorimetric methods. Chromosome aberration assays were performed to study the genotoxic and antimutagenic activity of the extract. Results show that doses of up to 100 microg/ml of the extract did not induce any cytotoxic effects. Cell survival and mitotic index decreased significantly at doses higher than 100 microg/ml as a function of dose as well as of treatment time. Moreover, continuous treatments of up to 18 h induced the appearance of a significant number of apoptotic cells. Following a 3-h exposure to a dose of 750 microg/ml, cells accumulated significantly in G(2)-M phase and remained blocked in G(1-) and G(2)-M phases after several posttreatments in fresh growth medium. The aqueous extract alone did not induce chromosome aberrations but, in combined treatment with H(2)O(2), significantly reduced H(2)O(2)-induced chromosome aberrations. Flow cytometric analysis of DCFH intracellular oxidation showed that the extract decreased the oxidizing power of H(2)O(2.) This ability could possibly explain the extract's antigenotoxic activity. Absence of cytotoxicity at the lower tested doses and the antimutagenic properties of the extract stimulate the interest in studying possible new pharmaceutical uses of P. orbicularis.     

Enhancement of interleukin 1 and interleukin 2 releases by ubenimex

The effect of ubenimex on the release of interleukin 1 (IL-1) and interleukin 2 (IL-2) from immuno-competent cells was studied. Ubenimex enhanced release of IL-1 from mouse peritoneal macrophages at 1.0 and 100 micrograms/ml in vitro and the release at 1.0 microgram/ml was larger. When ubenimex was administered to mice IL-1-releasing activity of the peritoneal macrophages was enhanced 3 and 5 days after the administration but not enhanced 1 day after the administration. Ubenimex also enhanced IL-2 release from rat spleen cells at 0.1 and 10 micrograms/ml, when concanavalin A (Con A) was added in the IL-2-releasing system. The enhancement was still observed with mouse spleen cells, when serum was further added. Moreover, thymocyte-proliferating activity was attained in the broths which rat spleen cells were incubated with ubenimex from 0.1 to 10 micrograms/ml in the absence and presence of Con A.     

Activation and damage of cultured airway epithelial cells by human elastase and cathepsin G.

Accumulation of polymorphonuclear neutrophils (PMN) and epithelium damage have often been described during airway inflammation. We studied the effects of two PMN-derived proteinases, namely elastase and cathepsin G, on guinea-pig tracheal epithelial cells in culture. Both proteinases activated tracheal epithelial cells in terms of prostaglandin (PG) E2 production. A concentration- and time-dependent effect was observed with 10 micrograms/ml and 6 h as the optimal conditions for both enzymes. Optical microscopic studies confirmed an effect on tracheal epithelial cells as intercellular gaps were observed upon incubation of the monolayers with proteinases. A small cytotoxic effect was observed after 1 h incubation but remained stable up to 6 h. This cytotoxic effect, more pronounced with elastase than with cathepsin G, was dissociated from PGE2 formation.