Effect of the ectomycorrhizal fungus Hebeloma cylindrosporum on in vitro rooting of micropropagated cuttings of arbuscular mycorrhiza-forming Prunus avium and Prunus cerasus

 The effect of different genotypes of the ectomycorrhizal fungus Hebeloma cylindrosporum on in vitro rooting of micropropagated cuttings of Prunus avium and P. cerasus was studied in an attempt to determine whether ectomycorrhizal fungi could enhance in vitro adventitious root formation in plants which form arbuscular endomycorrhizas. The rooting percentage of P. avium cuttings was approximately 16% in the absence of hormonal treatment; it increased up to 30% in the presence of 5.7 μM IAA which was the most favourable auxin concentration. The rooting percentage of cuttings cultivated in the absence of IAA was enhanced by all the studied strains of H. cylindrosporum. It ranged from 50 to 60% with the IAA-overproducing mutant D 111 or the wild-type dikaryon D1, to 100% in the presence of the mutants 331 or D 117. The cuttings of P. cerasus showed a higher rooting ability than those of P. avium since approximately 40% of them were able to root in the absence of hormonal treatment. Except for the mutant D117, their rooting percentage was not significantly improved by H. cylindrosporum. Fungal inoculation also affected the survival of cuttings at acclimatization: 50% of the uninoculated P. avium cuttings survived whereas the survival percentage of inoculated cuttings ranged from 30 to 100% depending on the fungal genotype. With P. cerasus, the percentage of survival of uninoculated cuttings ranged from 85 to 100% and fungi either did not significantly improve it or lowered it. At acclimatization fungal hyphae could be observed in close contact with adventitious roots, but they did not establish mycorrhizal association. The shoot height of P. avium plantlets obtained from inoculated cuttings was not significantly different from that of plantlets originating from uninoculated ones. By contrast, fungal inoculation generally depressed the growth of acclimatized P. cerasus plantlets. The possibility of using ectomycorrhizal fungi as a tool to enhance rooting of micropropagated cuttings of plants which do not form ectomycorrhizas is discussed. Received: 25 November 1996 / Accepted: 2 June 1997     

Effect of antineoplastic agents and X-irradiation on the adherence of Candida spp. to human buccal epithelial cells in vitro

The role of chemotherapy, X-irradiation and a combination of both on the phenomenon of adherence of yeast to buccal epithelial cells (BEC) was investigated in vitro. Growth of three Candida spp. in the presence of eight of eleven antineoplastic agents led to reduction of adherence of the isolates tested (reduction between 30% and 61% of the control value), and this effect was observed whether exponential or stationary phase Candida cells were used. Exposure of C. albicans to various doses of radiation also led to a reduction in adherence of this yeast to BEC between 31% and 53% of the control value. This reduction was shown to be dose related. Similar results were obtained when BEC were exposed to radiation, and the effect of radiation treatment was accentuated when both yeast and BEC were irradiated simultaneously. Furthermore, treating C albicans with a combination of chemotherapy and radiation led to the greatest reduction in adherence of yeast to BEC compared to when the yeast was treated with either chemotherapy or radiation alone (reduction between 63% to 74% as compared with control). The possible mechanism/s involved in reduction of adherence of yeast to BEC are discussed.     

Xylitol and Erythritol Decrease Adherence of Polysaccharide-Producing Oral Streptococci

Xylitol consumption decreases counts of mutans streptococci. However, the mechanism behind this decrease is not well understood. We studied not only type strains and clinical isolates of mutans streptococci, but also other polysaccharide-forming oral streptococci. Growth inhibition and adherence of cells to a smooth glass surface—reflecting synthesis of water-insoluble polysaccharides were studied in the presence of 2% (0.13 mol/l) and 4% (0.26 mol/l) xylitol. The effect of xylitol was compared to a novel polyol sweetener, erythritol. Except for Streptococcus mutans 10449 and S. sobrinus OMZ 176, the glass surface adhesion of most polysaccharide-forming streptococci was reduced by the presence of both 4% xylitol and erythritol. For the S. mutans and S. sobrinus type strains, the growth inhibition with 4% xylitol and erythritol was 36–77% and for the clinical S. mutans isolates 13–73%. Of the other oral streptococci, only S. sanguinis was inhibited with 4% xylitol (45–55%). For both polyols, the magnitude of the growth inhibition observed was not associated with the magnitude of the decrease in adherence (xylitol: r = −0.18; erythritol: r = 0.49). In conclusion, both xylitol and erythritol can decrease polysaccharide-mediated cell adherence contributing to plaque accumulation through a mechanism not dependent on growth inhibition.     

Adhesion and biofilm formation of <Emphasis Type="Italic">Mycoplasma pneumoniae</Emphasis> on an abiotic surface

We demonstrated that when M. pneumoniae was grown on an abiotic surface of either glass or polystyrene with a serum-containing medium, the bacteria adhered to the surface and formed highly differentiated volcano-like biofilm structures. As adherence to the surface and/or biofilm formation was totally inhibited by anti-P1 polyclonal monospecific antibodies, we suggest that the adherence of M. pneumoniae to the abiotic surface and/or biofilm formation is associated with P1, the major tip organelle protein of this organism. Furthermore, adherence and/or biofilm formation was markedly inhibited by treating the serum component of the growth medium with neuraminidase or by growing the bacteria in the presence of sialyllactose, suggesting that the initial step in the adherence to and/or biofilm formation by M. pneumoniae on an abiotic surface is the interaction of the bacterium through its tip organelle with sialic acid residues of serum glycoproteins.     

Role of the YehD fimbriae in the virulence-associated properties of enteroaggregative Escherichia coli

The interaction of enteroaggregative Escherichia coli (EAEC) strains with the colonic gut mucosa is characterized by the ability of the bacteria to form robust biofilms, to bind mucin, and induce a local inflammatory response. These events are mediated by a repertoire of five different aggregative adherence fimbriae variants (AAF/I-V) typically encoded on virulence plasmids. In this study, we report the production in EAEC strains of a new Y ehD f imbriae (YDF), which is encoded by the chromosomal gene cluster yehABCD, also present in most E. coli strains. Immuno-labelling of EAEC strain 042 with anti-AAF/II and anti-YDF antibodies demonstrated the presence of both AAF/II and YDF on the bacterial surface. We investigated the role of YDF in cell adherence, biofilm formation, colonization of spinach leaves, and induction of pro-inflammatory cytokines release. To this aim, we constructed yehD deletion mutants in different EAEC backgrounds (strains 17-2, 042, 55989, C1010, 278-1, J7) each harbouring one of the five AAFs. The effect of the YDF mutation was strain dependent and AAF independent as the lack of YDF had a different impact on the phenotypes manifested by the different EAECs tested. Expression of the yehABCD operon in a E. coli K12 ORN172 showed that YDF is important for biofilm formation but not for adherence to HeLa cells. Lastly, screening of pro-inflammatory cytokines in supernatants of Caco-2 cells infected with EAEC strains 042 and J7 and their isogenic ΔyehD mutants showed that these mutants were significantly defective in release of IL-8 and TNF-α. This study contributes to the understanding of the complex and diverse mechanisms of adherence of EAEC strains and identifies a new potential target for preventive measures of gastrointestinal illness caused by EAEC and other E. coli pathogroups.     

Mouse embryo fibroblast proliferation and prostaglandin production in medium supplemented with fetal bovine serum or serum substitutes (Ultroser SF and G): role of glucocorticoids

The growth of DBA/2 mouse embryo fibroblasts, as well as their prostaglandin (PG) production, was compared under 3 different culture conditions: RPMI 1640 supplemented with 10% fetal bovine serum (FBS), 2% Ultroser SF (steroid-free) or with 2% Ultroser G (containing steroids). The effect of the absence or presence of glucocorticoids on both parameters was more precisely investigated. In FBS-supplemented cultures, dexamethasone had a stimulatory effect on cells characterized by a slow growth rate, whereas it markedly inhibited proliferation in rapidly growing fibroblasts. The experiments carried out with serum substitutes (Ultroser SF and G) strongly corroborated the role of the absence or presence of glucocorticoids on fibroblast proliferation. Manipulations of glucocorticoid concentrations in Ultroser SF by adding 5 x 10(-8) M dexamethasone or in Ultroser G by adding 10(-6) M RU 486 reversed the effect of the absence of glucocorticoid in the first case, or in the latter case the effect of the presence of glucocorticoid on both cell growth and PG production. Progesterone had no effect by itself. Our results emphasize the importance of performing complete kinetic studies to investigate the effect of a given factor on cell proliferation in vitro, since glucocorticoids may have opposite effects on fibroblast proliferation according to their cell growth pattern in vitro.     

Anti-Giardia activity of Syzygium aromaticum essential oil and eugenol: effects on growth, viability, adherence and ultrastructure

The present work evaluates the anti-Giardia activity of Syzygium aromaticum and its major compound eugenol. The effects were evaluated on parasite growth, adherence, viability and ultrastructure. S. aromaticum essential oil (IC₅₀ = 134 μg/ml) and eugenol (IC₅₀ = 101 μg/ml) inhibited the growth of G. lamblia. The essential oil inhibited trophozoites adherence since the first hour of incubation and was able to kill almost 50% of the parasites population in a time dependent manner. The eugenol inhibited G. lamblia trophozoites adherence since the third hour and not induce cell lyses. The main morphological alterations were modifications on the cell shape, presence of precipitates in the cytoplasm, autophagic vesicles, internalization of flagella and ventral disc, membrane blebs, and intracellular and nuclear clearing. Taken together, our findings lead us to propose that eugenol was responsible for the anti-giardial activity of the S. aromaticum essential oil and both have potential for use as therapeutic agents against giardiasis.     

Inhibition of Adherence of Actinobacillus pleuropneumoniae to Porcine Respiratory Tract Cells by Monoclonal Antibodies Directed Against LPS and Partial Characterization of the LPS Receptors

Actinobacillus pleuropneumoniae is the causative agent of porcine fibrinohemorrhagic necrotizing pleuropneumonia. We have previously identified the lipopolysaccharides (LPS) as the major adhesin of A. pleuropneumoniae involved in adherence to porcine respiratory tract cells. In the present study, adherence of A. pleuropneumoniae to porcine tracheal frozen sections was inhibited by homologous monovalent Fab fragments produced from monoclonal antibodies 5.1 G8F10 and 102-G02 directed, respectively, against the A. pleuropneumoniae serotype 1 or serotype 2 O-antigens. These results confirm the important role played by LPS in adherence of A. pleuropneumoniae and suggest that these adhesins might represent good vaccine candidates. We also investigated the presence of A. pleuropneumoniae receptors in tracheal cell preparations from piglets of four different breeds. Using Far-Western binding assays, we identified proteins recognized by whole cells of A. pleuropneumoniae reference strains for serotype 1 and 2, and local isolates belonging to the same serotypes, and also recognized by extracted LPS from both reference strains. We confirmed the proteinaceous nature of these LPS-binding molecules by their staining with Coomassie brilliant blue, sensitivity to proteinase K digestion, resistance to sodium m-periodate oxidation, and their inability to stain with glycoprotein-specific reagents. Four low-molecular-mass bands (14–17 kDa) seemed to correspond to histones. We also identified proteins at Mr 38,500 that could represent putative receptors for A. pleuropneumoniae LPS in swine respiratory tract cells. Received: 16 April 1999 / Accepted: 1 July 1999     

Adhesion of Staphylococcus aureus to Bovine Mammary Epithelial Cells Induced by Growth in Milk Whey

Staphylococcus aureus strains isolated from bovine intramammary infection (mastitis) were tested for adhesion to bovine mammary epithelial cells after growth in milk whey or TSB. Bacteria grown in milk whey adhered more efficiently to mammary gland epithelial cells in vitro than the corresponding homologous bacteria grown in TSB. Trypsin treatment of milk whey-grown S. aureus had no effect on their adherence. Whereas, pretreatment with periodate significantly decreased bacterial adherence capacity. Periodate treatment of TSB-grown bacteria had no effect on adhesion to the mammary gland epithelial cells.     

Detection of glucocorticoid sensitive secretory proteins from human melanoma cells

Summary NEL-M1 human melanoma cells have been established to grow in Ham's F12 medium in the absence of serum, hormones, and exogenous growth factors. Conditioned medium from NEL-M1 cultures stimulates growth of these same cells whereas glucocorticoids retard growth in the presence and absence of conditioned medium. Because recent reports indicate that glucocorticoids inhibit the synthesis of growth factors from a variety of cell types, we hypothesized that glucocorticoids may be inhibiting growth of NEL-M1 cells by either suppressing the synthesis of the autocrine growth factor or regulating other secretory proteins that may inhibit the activity of the autocrine growth factor. Initial studies were done to clearly show that NEL-M1 cells were growth inhibited, both in vivo and in vitro, when exposed to the synthetic glucocorticoid, triamcinolone acetonide (TA). When NEL-M1 cells were injected into nude mice and treated with TA (100 μg per mouse per week) a 67% reduction in tumor mass was observed compared to the control group over a 5-wk growth period. Additional studies show that in a serum-free defined medium TA (100 nM) inhibited growth of MEL-M1 cells by 56% after 6 d in culture. At this same time TA was shown to affect the expression of several proteins secreted from these cells. TA treatment resulted in the appearance of a 125 000 molecular weight protein, suppression of the synthesis-secretion of three proteins (37 000, 57 000, and 76 000 molecular weight) and enhanced expression of a 60 000-molecular weight protein. However when NEL-M1 cells were cultured in conditioned medium from TA-treated cells, a stimulation in both [³H]thymidine incorporation into DNA and cell proliferation was observed. When the conditioned medium was fractionated by Amicon ultrafiltration, the growth stimulatory activity was found in the <10 000 molecular weight fraction. These results demonstrate that glucocorticoids, as a single agent, inhibit the growth of NEL-M1 human melanoma cells. However, this growth inhibition by glucocorticoids may not be through the regulation of the synthesis-secretion of the autocrine growth factor. Furthermore, the data suggest that the glucocorticoid-sensitive secretory proteins may not be directly involved in the in vitro regulation of NEL-M1 cellular growth.     

In vitro selection of Coffea arabica callus for resistance to partially purified phytotoxic culture filtrates from Colletotrichum kahawae

Calli derived from hypocotyl explants of a susceptible and resistant genotype of Coffea arabica were evaluated for their response to different concentrations of partially purified culture filtrates (PPCFs) produced by Colletotrichum kahawae which are phytotoxic. The size of calli was measured non-destructively by automated image analysis. Differential responses of calli ranged from complete necrosis or reduced growth in the susceptible genotype (N39) to an absence of necrosis and rapid growth in the resistant genotype (cv. Hybrido de Timor). Subsequently, one selection cycle in the presence of PPCF was devised and applied to calli of nine C. arabica genotypes. Normal plants were regenerated through somatic embryogenesis of callus lines that survived the phytotoxin treatment and in vitro and in vivo testing of these plants against the PPCF showed that increased resistance to the toxin had been obtained. These studies suggest that in vitro selection of calli may be a feasible approach to acquiring germplasm with improved resistance to coffee berry disease.     

Influence of hormones and growth factors on viability,DNA, and protein content of adult hepatocytes in primary culture

Summary The survival of adult rat hepatocytes in monolayer culture was studied in the presence of different hormones (neurotensin, oxytocin, thyrotropin releasing hormone, luteinizing hormone releasing hormone, cholecalciferol, bradykinin, substance P, aldosterone, melanocyte stimulating hormone, 3,3′,5-triiodo-1-thyronine, corticosterone, human growth hormone, glucagon, insulin, progesterone, testosterone, estradiol, and dexamethasone phosphate) or growth factors (fetal bovine serum). For this purpose trypan blue exclusion, lactate dehydrogenase, and DNA and protein content were measured at 24 and 72 h of culture. 10⁻⁷ M Dexamethasone, a mixture of eight hormones, 10% fetal bovine serum, and a combination of the latter two supplements caused a more than 64% higher DNA content at 72 h when compared to control cultures. A striking agreement of these results with changes of lactate dehydrogenase leakage was observed, whereas trypan blue exclusion gave erratic results. Considerable changes of cell arrangement apparently specific for each supplement were ovserved by low magnification microscopy. It is concluded that glucocorticoids and fetal bovine serum have an outstanding effect on cell viability and that DNA or protein content or both are reliable indicators of cell viability in amitotic cultures.     

Adherence Inhibition of <Emphasis Type="Italic">Cronobacter sakazakii</Emphasis> to Intestinal Epithelial Cells by Prebiotic Oligosaccharides

Cronobacter sakazakii is an opportunistic pathogen that has been implicated in meningitis, NEC, and sepsis in neonates. Colonization and subsequent infection and invasion of C. sakazakii require that the organism adheres to host cell surfaces. Agents that inhibit or block attachment of the pathogen to epithelial cells could be useful in reducing infections. The goal of this research was to assess the ability of prebiotic galactooligosaccharides (GOS) and polydextrose (PDX) to inhibit adherence of C. sakazakii 4603 to a HEp-2 human cell line. Adherence experiments were performed in the presence or absence of prebiotics using HEp-2 cells grown to confluency on glass coverslips. Prebiotics and bacteria were added and incubated for 3 h. Coverslips were washed, and adherence was determined by cultural and microscopic methods. When measured microscopically or by cultural methods, significant reductions in adherence (56 and 71%, respectively) of C. sakazakii were observed in the presence of GOS (16 mg/ml). Adherence inhibition also occurred (48%) when a GOS–PDX blend (8 mg/ml each) was tested, although PDX by itself had less effect. Similar results were also observed for Caco-2 cells and also for another strain of C. sakazakii (29004). These results suggest that GOS and PDX, alone and in combination, may have an anti-adhesive effect on C. sakazakii and directly inhibit the adherence to gastrointestinal epithelial cells.     

Valorisation of wastepaper using the fibrolytic/hydrogen producing bacterium Ruminococcus albus

The present study aimed to investigate the biotransformation of different kinds of wastepaper to hydrogen by the fibrotylic bacterium Ruminococcus albus. Five different types i.e. paper tissue, office paper, illustrated magazine paper, paperboard and newspaper, were selected as representatives of the most common types of wastepaper found in municipal solid wastes. The percentage of total carbohydrates measured as glucose equivalents, ranged from 50% to 100% (w/w), whereas the bioconversion by R. albus ranged from 18% to 100% of their initial weigh. The only metabolic products detected in all cases were acetate, ethanol, formate, hydrogen and carbon dioxide. The hydrogen yields ranged from 46 to 280 L H₂/kg paper, indicating that wastepaper could be a promising candidate for second generation biohydrogen production. Subsequently, hydrolysis was investigated for paper tissue and paperboard. It was shown that in both cases the degradation process could be satisfactory described by zero order kinetics and it was identified to be the rate limiting step for the whole process, controlling biomass growth and metabolites generation rate.     

In vitro and ex vitro growth of grapevine rootstock `5BB' as influenced by number of air exchanges and the presence or absence of sucrose in culture media

Single node cuttings of grapevine rootstock `5BB' were cultured for 5 weeks under different numbers of air exchange (0, 0.8, 1.5, 2.5 and 4.4 h ^–1) with or without sucrose in the medium. To determine the effect of number of air exchanges related to presence or absence of sucrose, in vitro growth, net photosynthetic rate, stomata characteristics and ex vitro growth were investigated. Increasing numbers of air exchanges accelerated plantlet growth regardless of the presence or absence of sucrose in the medium; under the same number of air exchanges, plantlet growth and net photosynthesis were greater in sucrose-containing medium compared with sucrose-free medium. However, a high number of air exchanges (4.4 h^–1) inhibited the growth and photosynthesis in sucrose-containing medium compared to sucrose-free medium. A higher number of stomata was observed in sucrose-containing medium, and larger size stomata was observed in sucrose-free medium. These results emphasize the importance of ventilation (increased number of air exchanges) during in vitro culture, for ex vitro plantlet survival was greatly affected by with or without air exchanges. Without air exchanges ex vitro plantlet survival was less than 70%, while air exchanges increased ex vitro survival by more than 90% with greater growth.     

The antimicrobial action of low-molar-mass chitosan,chitosan derivatives and chitooligosaccharides on bifidobacteria

The crude fractions of chitooligosaccharides (COS) and low-molar-mass chitosans (LMWC) were prepared by enzyme hydrolysis of chitosan (CS). Specific growth rate of B. adolescentis, B. bifidum, B. breve, B. catenulatum, B. infantis and B. longum ssp. longum was determined in the presence of 0.025 and 0.5 % COS (<5 kDa), LMWC (5–10 kDa), and 0.025, 0.1 and 0.5 % of CS, chitosan succinate and chitosan glutamate in vitro. Minimum inhibitory concentrations (MIC; assayed by colony counting on TPY agar plates) of COS-LMWC and CS ranged from 0.025 % to 0.75 % of CS-LMWC. The growth of all bifidobacterial strains in the presence of chitosan, its derivatives and LMWC decreased at a concentration of 0.025 %; the bacterial growth was completely inhibited at a concentration of 0.5 %. COS did not show any inhibitory effect, an increased growth rate was even observed in the case of B. bifidum, B. catenulatum and B. infantis.     

The role of DNA base excision repair in filamentation in Escherichia coli K-12 adhered to epithelial HEp-2 cells

Base excision repair (BER) is dedicated to the repair of oxidative DNA damage caused by reactive oxygen species generated by chemical and physical agents or by metabolism which can react with DNA and cause a variety of mutations. Epithelial cells are typically the first type of host cell to come into contact with potential microbial invaders. In this work, we have evaluated whether the adherence to human epithelial cells causes DNA damage and associated filamentation. Experiments concerning adherence to HEp-2 cells were carried out with mutants deficient in BER that were derived from Escherichia coli K-12. Since the removal of mannose during bacterial interaction with HEp-2 cells allows adhesion through mannose-sensitive adhesins, the experiments were also performed in the presence and the absence of mannose. Our results showed enhanced filamentation for the single xth (BW9091) and triple xth nfo nth (BW535) mutants in adherence assays with HEp-2 cells performed without d-mannose. The increased filamentation growth was inhibited by complementation of BER mutants with a wild type xth gene. Moreover, we measured SOS induction of bacteria adhered to HEp-2 cells in the presence and absence of d-mannose through of SOS-chromotest assay and we observed a higher β-galactosidase expression in the absence of mannose. In this context, data showed evidence that bacterial attachment to HEp-2 epithelial surfaces can generate DNA lesions and SOS induction.     

Glucocorticoids enhance the mitogenic action of insulin in serum-free cultures of chick embryo cells.

Addition of insulin to nonproliferating serum-free cultures of secondary chicken embryo (CE) cells caused a 30% to 50% increase in cell number. Addition of any one of several glucocorticoids (dexamethasone, cortisol, or corticosterone) to the cultures two days before insulin addition increased the mitogenic effect of insulin by about twofold at each insulin concentration tested. This glucocorticoid stimulation of cell proliferation was “permissive” because in the absence of insulin glucocorticoids caused little increase in cell number (usually less than 15%). Glucocorticoids were maximally active at low concentrations (e.g., 10^?10 M dexamethasone). Steroids without glucocorticoid activity were inactive over a wide range of concentrations. Glucocorticoids increased the mitogenic response to insulin largely by increasing the percentage of cells that insulin stimulated to synthesize DNA. The maximum mitogenic effect of insulin upon CE cells rapidly decreased after the cells were serially subcultured. After only nine population doublings (4 passages) in culture, the response to insulin was diminished by about 70%. The mitogenic effect of insulin plus dexamethasone declined similarly during serial subculture, and was always about twofold greater than the effect of insulin alone. The cells maintained their mitogenic responsiveness to serum as these responses decreased. In contrast to the growth promoting influence of glucocorticoids in the presence of insulin, glucocorticoids inhibited the mitogenic response of CE cells to serum. This result may resolve our above findings with reports that glucocorticoids inhibit the proliferation of CE cells.     

Interleukin 1 production by human lung tissue. II. Inhibition by anti-inflammatory steroids

Glucocorticoids block the localized accumulation of leukocytes as sites of inflammation by preventing their adherence to vascular endothelium. This implies that glucocorticoids are acting either on the leukocytes, endothelium, or cells which produce adherence-promoting factors (such as interleukin 1 (IL-1)). Previous studies have shown that dexamethasone (DEX) treatment of either polymorphonuclear leukocytes (PMN) or human umbilical vein vascular endothelial cells (VEC) or both in vitro does not prevent adherence induced by thrombin or formylmethionyl-leucyl-phenylalanine (f-met peptide). We now show that pretreatment of PMN and/or VEC for 24 hr with 0.1 microM DEX had no effect on adherence of PMN to VEC activated with IL-1 (2 U/ml), lipopolysaccharide (1 microgram/ml), or 12-O-tetradecanoylphorbol-13-acetate (30 ng/ml) suggesting that glucocorticoids may inhibit adherence in vivo by blocking formation of IL-1 and other adherence-inducing stimuli. We have recently established that cultured human lung fragments produce IL-1 in vitro. To investigate whether glucocorticoids could inhibit the production of adherence-inducing factors, we examined the effect of glucocorticoids on IL-1 production from human lung tissue. Treatment of human lung fragments in vitro for 18 hr with glucocorticoids such as DEX and hydrocortisone resulted in dose dependent inhibition of IL-1 production; these and other glucocorticoids, at concentrations ranging between 0.1 and 1 microM, produced greater than 50% inhibition of IL-1 release. Nonglucocorticoid steroids including testosterone and beta-estradiol (1 microM) had no effect. Inhibition of IL-1 production occurred after a lag period 5 of 16 hr, and the relative glucocorticoid potencies agreed with their known anti-inflammatory potencies in vivo (beta-methasone approximately triamcinolone acetonide greater than DEX greater than fludrocortisone greater than prednisolone greater than hydrocortisone). Inhibition of IL-1 production in vivo may, in part, explain the remarkable ability of glucocorticoids to prevent the adherence of leukocytes to endothelium and their accumulation at an inflammatory site.     

Composition of the essential oil from cell suspension cultures of Achillea millefolium ssp. millefolium

The composition of the essential oil isolated from Achillea millefolium L. ssp. millefolium cell suspension cultures was analysed by GC and GC-MS. The yield of the oil obtained by hydrodistillation or a simultaneous distillation -extraction of these cultures, harvested at days 8–10 (end of exponential phase), was 0.001 % (w/w). The analysis of the volatiles showed the presence of thirteen components; monoterpenes amounted to 5%, sesquiterpene hydrocarbons attained 40%, while eugenol, demethoxyencecalin and two unidentified compounds amounted to 45% of the total oil. Several methods were tested in an attempt to increase the essential oil production by the cultures: growth on solid medium, growth in light, use of a different culture medium, elicitation with cellulase or yeast extract, and growth in a two-phase system. Of the different methods tested, the growth in B5⁺ medium with Miglyol 812 led to the highest essential oil yield (0.002%, w/w), and resulted in a more diverse oil composition.