Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Mistletoe”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed2004

Knowledge of and attitudes toward complementary and alternative therapies; a national multicentre study of oncology professionals in Norway.

This study reports on oncology professionals' knowledge and attitude toward complementary and alternative medicines (CAM), classified according to their primary application as complementary or alternative methods. In June 2002, we conducted a national, multicentre survey of 828 Norwegian oncologists, nurses, clerks and therapeutic radiographers. A response rate of 61% was achieved. Only a few physicians (4%) described their reactions to alternative medicine as positive compared with nurses (33%), therapeutic radiographers (32%) and clerks (55%) (P<0.0001). Females showed a more positive view than males (33% versus 14%, P<0.0001). More participants expressed a positive attitude to complementary versus alternative medicines. Most respondents regarded healing by hand or prayer, homeopathy, and Iscador (mistletoe) as alternative therapies. In contrast, most respondents classified acupuncture, meditation, reflexology, music/art-therapy, aromatherapy and massage as complementary therapies. This survey demonstrates major differences, by gender as well as oncology health profession in views about and the classification of various CAM methods.

Adult↗
PubMed2005

Weekly 24 h infusion of aviscumine (rViscumin): a phase I study in patients with solid tumours.

Aviscumine is a ribosome-inactivating protein with potent antitumour activity in vitro and in vivo and is an Escherichia coli-derived recombinant counterpart of natural mistletoe lectin-I. The current study was performed to determine the safety profile, dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) of a prolonged infusion of aviscumine in cancer patients. Aviscumine was given once weekly as a 24 h central intravenous infusion in patients with advanced, refractory progressive solid malignant tumours. Fourteen fully eligible patients (11 male, 3 female) with a median age 58 yrs (range 41-77) were enrolled. They had histologically verified disease, were 18 yrs old, had an ECOG PS 2 and adequate bone marrow, liver and renal function. DLT was defined as any non-haematological grade 3-4 toxicity (Common Toxicity Criteria [CTC] version 2.0), neutrophil count <500/ microl for 7 days, febrile neutropenia or thrombocytopenia grade 4. The MTD was defined as the dose level below the dose at which 2 patients per dose level experienced a DLT during the first treatment cycle. Colorectal cancer, soft tissue sarcoma and pancreatic cancer were the most common tumour types. Dose levels of aviscumine ranged from 4 to 6 microg/kg. The median number of cycles was 2.8 (range, 2-8). Common side effects in cycle 1 were fatigue, fever, nocturia, urticaria, erythema and pruritus. DLTs occurred in 2/3 patients on the 6 microg/kg dose level and consisted of increases in ASAT grade 3, ALAT grade 3, gammaGT grade 3/4, hypokalemia grade 3 and fatigue grade 3. No DLTs were observed on dose levels 4 and 5 microg/kg. The best response (RECIST) was stable disease in 4 pts, lasting for 4-8 cycles. Pharmacokinetics indicated that potentially active plasma levels of the compound were maintained during the entire infusion. We conclude that the recommended dose for weekly 24 h infusions of Aviscumine should be 5 microg/kg.

Adult↗
PubMed2006

Viscolin, a new chalcone from Viscum coloratum, inhibits human neutrophil superoxide anion and elastase release via a cAMP-dependent pathway.

The mistletoe Viscum coloratum is used in traditional Chinese medicine to treat inflammatory diseases. In this study, a cellular model in isolated human neutrophils, which are important in the pathogenesis of rheumatoid arthritis, chronic obstructive pulmonary disease, and other inflammatory diseases, was established to elucidate the anti-inflammatory functions of V. coloratum. The partially purified extract of V. coloratum (PPE-SVC) potently inhibited formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-induced superoxide anion generation and elastase release in a concentration-dependent manner with IC(50) values of 0.58+/-0.03 and 4.93+/-0.54 microg/ml, respectively. Furthermore, a new chalcone derivative, viscolin (4',4''-dihydroxy-2',3',6',3''-tetramethoxy-1,3-diphenylpropane), was isolated from PPE-SVC. Viscolin was demonstrated to inhibit superoxide anion generation and elastase release, as well as to accelerate resequestration of cytosolic calcium in FMLP-activated human neutrophils. Furthermore, the inhibitory effects of viscolin were reversed by protein kinase A (PKA) inhibitor, suggesting that PKA mediates the viscolin-caused inhibitions. Viscolin induced a substantial increase in cAMP levels, and that occurred through the inhibition of phosphodiesterase (PDE) activity but not an increase in adenylate cyclase function. Consistent with this, viscolin potentiated the PGE(1)-caused inhibition of superoxide anion release and calcium mobilization, as well as elevation of cAMP formation. These results demonstrate that inhibition of inflammatory responses in human neutrophils by viscolin is associated with an elevation of cellular cAMP through inhibition of PDE. Comparable results were also observed by PPE-SVC, indicating that the effect of PPE-SVC is at least partly mediated by viscolin. In summary, viscolin is a novel inhibitor of PDE and might be useful for treatment of neutrophilic inflammation.

Biphenyl Compounds↗
PubMed2004

Phoradendron liga (Gill. ex H. et A.) Eichl. (Viscaceae) used in folk medicine: anatomical, phytochemical, and immunochemical studies.

Phoradendron liga (Gill. ex H. et A.) Eichl. is a Viscaceae widely distributed in Argentina. It has been commonly used in folk medicine as a substitute of the European mistletoe (Viscum album L.) to decrease high blood pressure due to their external similarity. In this study, the anatomical features as well as micromolecular and macromolecular analysis of this species are reported. Anatomical study has shown that Phoradendron liga presents as anatomic features: papillous cuticle, clusters in leaves and stems, and isodiametric stone cells only in stems. The analysis of flavonoids showed that this species produces C-glycosylflavones and 3-desoxyproanthocyanidins. Protein study showed a protein pattern with components ranging from 14 to 90 kDa and the presence of related epitopes between the species was demonstrated by cross recognition using anti-Phoradendron and anti-Viscum antisera of both species by Western blot assay. In addition, a galactose specific lectin (L-Phl) was isolated form Phoradendron liga extracts. These results are part of a comprehensive project on Argentine hemiparasite species destinated to be applied to quality control of commercial samples and disclosed their potential use as a potential source for immunomodulatory compounds.

Argentina↗
PubMed2003

Detection of ligand- and solvent-induced shape alterations of cell-growth-regulatory human lectin galectin-1 in solution by small angle neutron and x-ray scattering.

The bioactivity of galectin-1 in cell growth regulation and adhesion prompted us to answer the questions whether ligand presence and a shift to an aprotic solvent typical for bioaffinity chromatography might alter the shape of the homodimeric human lectin in solution. We used small angle neutron and synchrotron x-ray scattering studies for this purpose. Upon ligand accommodation, the radius of gyration of human galectin-1 decreased from 19.1 +/- 0.1 A in the absence of ligand to 18.2 +/- 0.1 A. In the aprotic solvent dimethyl sulfoxide, which did not impair binding capacity, galectin-1 formed dimers of a dimer, yielding tetramers with a cylindrical shape. Intriguingly, no dissociation into subunits occurred. In parallel, NMR monitoring was performed. The spectral resolution was in accord with these data. In contrast to the properties of the human protein, a nonhomologous agglutinin from mistletoe sharing galactose specificity was subject to a reduction in the radius of gyration from approximately 62 A in water to 48.7 A in dimethyl sulfoxide. Evidently, the solvent caused opposite responses in the two tested galactoside-binding lectins with different folding patterns. We have hereby proven that ligand presence and an aprotic solvent significantly affect the shape of galectin-1 in solution.

Computer Simulation↗
PubMed1988

A method for demonstration of lectin-binding sites using a blood group substance A/ferritin conjugate.

A new technique for demonstration of lectin-binding sites is proposed. At the 1st step of the method, the lectin binds the respective monosaccharide constituent of the glycoconjugate and at the 2nd step, the blood-group substance A-ferritin conjugate is used as a marker. The following lectins were tested: wheat germ agglutinin, soybean agglutinin, mistletoe lectin I, and concanavalin A. Human red blood cells were used as material. By means of control experiments, the specificity of the proposed technique was proved.

ABO Blood-Group System↗
PubMed1999

Ligands for Viscum album agglutinin and galectin-1 in human lung cancer: is there any prognostic relevance?

Viscum album agglutinin (VAA) is an extract component of mistletoe. It belongs to the plant lectin family and exerts various biological effects such as cytotoxic properties for tumor cells in culture. VAA as well as galectin-1, an endogenous lectin, possess galactose-specific surface-binding sites. We therefore investigated 159 cases of lung cancer for their capacity to bind VAA and galectin-1 and for Lewis antigen reactivity. Three different methods were used for detection of VAA: a two-step method with biotinylated VAA; an immune complex three-step method, and a four-step method. The most sensitive results were obtained with the four-step method utilising VAA, a goat-anti-VAA antibody and a biotinylated rabbit-anti-goat antibody. Intensity and distribution of staining were assessed using an immunoreactive score index (0-12). Approximately 70% of all tumors exhibited moderate to strong binding capacity for VAA. Adenocarcinomas and bronchiolo-alveolar carcinomas were more frequently labeled than squamous carcinomas. No relationship between expression of binding sites for VAA and galectin-1 as well as of Lewis antigens was found. Moreover, there was no correlation between VAA-binding capacity and survival, whereas expression of galectin-1-binding sites was of prognostic significance. Patients showing expression of galectin-1-binding sites revealed a better prognosis than those lacking binding sites or showing a weak reactivity (P = 0.0257 log rank test of Kaplan-Meier statistics).

Binding Sites↗
PubMed1998

Fusion of macrophages on an implant surface is associated with down-regulated expression of ligands for galectin-1 and -3 in the rat.

Galectins have a wide range of biological activities which are elicited by binding to appropriate glycoligands. Besides regulation of the expression of the galectins the extent of the presence of suitable binding sites will be relevant to infer the cellular responsiveness to this class of sugar receptors. Thus ligand presentation requires monitoring by the tissue lectin. We demonstrate the expression of galectin-3 by macrophages and foreign-body giant multinucleate cells colonizing a cellophane implant in the rat by the A1D6 monoclonal antibody. The extents of ligand presence are visualized in the same cells by biotinylated galectin-3 and also by galectin-1 which is produced by diverse mammalian cell types and widely distributed. Labeled mistletoe (VAA) and tomato (LEA) lectins are used as tools to assess the degree of similarity of the binding profile between endogenous and exogenous proteins. The presentation of alpha-galactosides is monitored with a natural immunoglobulin G subfraction obtained by two consecutive affinity chromatography steps. The binding of labeled galectins and plant lectins was significantly lower to foreign-body giant multinucleate cells than to mononuclear macrophages. The application of the alpha-galactoside-specific probe yielded no significant staining. The potential problem of epitope accessibility could be excluded by the concomitant positivity obtained with an IgG subfraction with selectivity to beta-galactosides also obtained by affinity chromatography. These results provide no evidence for a role of alpha-galactosides for the binding of galectins in the rat macrophages colonizing the implant. The reduced level of expression of glycoligands for galectin-1 and -3 in foreign-body giant multinucleate cells in contrast with the mononuclear macrophages suggests an inhibitory influence of macrophage fusion on the expression of galectin-reactive molecules.

Animals↗
PubMed2002

Synergism between rViscumin and cisplatin is not dependent on ERCC-1 expression.

Interactions between recombinant mistletoe lectin (rViscumin) and anticancer drugs were investigated in vitro. rViscumin enhanced the cytotoxic effects of vincristine, mafosfamide, idarubicin and cisplatin in the human leukemia cell lines K562 and KG1a. In human marrow progenitor cells, rViscumin inhibited colony formation and did not exert any protective activity against cisplatin-induced inhibition of clonogenicity. Quantitative real-time reverse transcription polymerase chain reaction analysis revealed that cisplatin treatment of K562 cells resulted in a 1.9-fold increase in mRNA expression of the nucleotide excision repair gene ERCC-1. This upregulation was not prevented when cells were post-incubated with rViscumin. Our study provides evidence that rViscumin is capable of enhancing cytotoxicity of anticancer agents in vitro. This synergism appears to be independent of transcriptional activity of DNA repair relevant genes.

Adjuvants, Immunologic↗
PubMed1998

Induction of apoptosis by the N-acetyl-galactosamine-specific toxic lectin from Viscum album L. is associated with a decrease of nuclear p53 and Bcl-2 proteins and induction of telomeric associations.

The ribosome-inhibiting proteins from Viscum album L., i.e. the mistletoe lectins (ML), were recognized to induce apoptosis in various tumour cell lines and human lymphocytes. However, several aspects of ML-induced cell death are unclear. We report that the galNAc-binding ML III incubated with human lymphocytes mediates a very effective death signal resulting in the binding of Annexin-V and expression of mitochondrial membrane proteins Apo2.7, but also in an influx of the DNA intercalating dye propidium iodide. The addition of the ribosome-inhibiting protein Volkensin also induced Apo2.7 molecules, while Momordin, lacking a carbohydrate-binding chain, did not enter the cell membrane and thus did not affect the cells. However, we observed ML III to preferentially affect CD8+ cells with a memory phenotype (CD62L(lo)) as compared to their CD8+ CD62L(hi) counterparts, CD4+ T cells and CD19+ B cells. Furthermore, ML III did not induce sister chromatid exchange-inducing DNA lesions but reduced the intensity of telomeric signals, increased the frequencies of telomeric associations and C-anaphases and reduced nuclear Bcl-2 and p53 proteins. Whatever the exact mechanisms are, our results provide strong evidence that the ML III-mediated cytotoxicity involves distinct killing pathways, i.e. (1) primary cell death via an induction of apoptosis which may not be dependent on protein and/or RNA synthesis and may not involve p53 and Bcl-2 proteins and (2) a loss of telomeres resulting in chromosomal instability in the surviving cells which is incompatible with life. However, we cannot exclude the possibility that this effect is due to a decrease in nuclear p53 proteins.

Apoptosis↗
PubMed1996

Demonstration of amoeboid and ramified microglial cells in pre- and postnatal bovine brains by lectin histochemistry.

In embryonic, fetal and postnatal bovine brains the development and distribution of microglial cells was examined by lectin histochemistry, using the isolectin B4 from Griffonia simplicifolia (GSA I-B4), the lectin from Ricinus communis (RCA-I), and mistletoe lectin (ML I). With GSA I-B4 and ML I, different types of microglial cells, i.e., amoeboid, intermediate and ramified cells, were specifically stained. On sections fixed in Bouin's fluid significantly higher numbers of microglial cells were labelled than on sections fixed in formalin. On the latter, proteolytic pretreatment was required. With RCA-I, no staining of microglial cells was achieved. This finding may indicate the presence of very low concentrations of beta-D-galactose residues on bovine microglial cells in comparison with other species studied so far. In the fetal telencephalon, the highest numbers of amoeboid microglial cells were found in transitory structures (subependymal regions of the lateral ventricles, cavum septi pellucidi, intermediate zone) and in areas of developing axon tracts (corpus callosum, internal and external capsules) between three and five months of gestational age. From 3-4 months of gestational age onward, the appearance of ramified microglial cells was noted. In 7-8 month-old fetuses, a complete change of the microglial cell picture occurred. Ramified cells clearly predominated, whereas amoeboid cells had markedly decreased. In 8-9 month-old fetuses, amoeboid microglial cells had almost disappeared from fetal brains. In brains from subadult and adult cattle, lectin-positive ramified microglial cells with up to five cellular processes were seen in all brain areas, located adjacent to vessels or surrounding neuronal perikarya.

Aging↗
PubMed1995

Audit of currently available endometrial ablative techniques.

Techniques for the treatment of menorrhagia have changed rapidly over the last few years. The enthusiastic introduction by a small number of protagonists of a variety of ablation/resection techniques has been followed by an exponential uptake in their use. At the same time there has been a period of critical appraisal by the Royal College of Obstetricians and Gynaecologists and the British Society for Gynaecological Endoscopy. The MISTLETOE Survey was the culmination of this association and has provided useful large data sets of the various techniques under evaluation. It is expected that recommendations concerning; the training of potential operators; various practical aspects of the surgical, medical and anaesthetic techniques required to undertake the procedures safely; types and frequencies of complications of the procedures, and success rates following the widespread use of these procedures will be made available following analysis of the data sets.

Catheter Ablation↗
PubMed1999

How useful are unconventional cancer treatments?

Unconventional cancer treatments are used frequently. Therefore, oncologists need to know about them. This article gives an overview of current knowledge on the most prevalent complementary or alternative cancer therapies. A distinction is made between alleged cures, preventive and adjunctive measures. Shark cartilage, mistletoe, thymus therapy, essiac, hydrazine sulphate, 714-X, dietary regimens, green tea and Panax ginseng are all covered specifically. None of these treatments offer reasonable hope for a cure. Some strategies are promising in terms of cancer prevention. The true potential of unconventional therapies might lie in adjunctive and palliative care. It is concluded that good evidence in this area is scarce. Vis-à-vis the high prevalence of unconventional cancer treatments, rigorous investigations are mandatory, not least for increasing the safety of future patients.

Complementary Therapies↗
PubMed1998

Laryngeal aspergillosis in an acquired immunodeficiency syndrome patient.

Aspergillosis is a rare infection. It varies considerably in its virulence depending on whether or not the patient affected is immunodepressed. The serious form is characterized by vascular invasion with haematogenic dissemination, tissue infarction and necrosis. The most often affected site is the lung. A laryngeal localization is exceptional and usually results from dissemination from a lower airways portal of entry. Diagnosis is difficult: cultures are only positive in 50 per cent of cases, while in 60 per cent of cases the characteristic histological features reminiscent of sprigs of mistletoe are only found on postmortem examination. In view of the high morbidity and mortality in acquired immunodeficiency syndrome (AIDS) sufferers, this condition must be treated early and aggressively. Treatment is based essentially on amphotericin B and itraconazole.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Persubstituted cyclodextrin-based glycoclusters as inhibitors of protein-carbohydrate recognition using purified plant and mammalian lectins and wild-type and lectin-gene-transfected tumor cells as targets.

Multivalent glycoclusters have the potential to become pharmaceuticals by virtue of their target specificity toward clinically relevant sugar receptors. Their application can also provide fundamental insights into the impact of two spatial factors on binding, i.e., topologies of ligand (branching mode, cluster presentation) and carbohydrate recognition domains in lectins. Persubstituted macrocycles derived from nucleophilic substitution of iodide from heptakis 6-deoxy-6-iodo-beta-cyclodextrin by the unprotected sodium thiolate of 3-(3-thioacetyl propionamido)propyl glycosides (galactose, lactose and N-acetyllactosamine) were prepared. The produced glycoclusters were first tested as competitive inhibitors in solid-phase assays. A plant toxin from mistletoe and an immunoglobulin G fraction from human serum were markedly susceptible. A nearly 400-fold increase in inhibitory potency of each galactose moiety in the heptavalent form relative to free lactose (217-fold relative to free galactose) was detected. Thus, these glycoclusters can efficiently interfere, for example, with xenoantigen-dependent hyperacute rejection. Among the tested galectins selected from this family of adhesion- and growth-regulatory endogenous lectins, the substituted beta-cyclodextrins acted as sensors to delineate topological differences between the two dimeric prototype proteins. The relatively strong reactivity with chimera-type galectin-3, a mediator of tumor metastasis, disclosed selectivity for glycocluster binding among galectins. Equally important, the geometry of ligand display (maxiclusters, bi- or triantennary N-glycans) made its mark on the inhibitory potency. To further determine the sensitivity of a distinct galectin presented on the cell surface and not in solution, we established a stably transfected tumor cell clone. We detected a significant response to presence of the multivalent inhibitor. This type of chemical scaffold with favorable pharmacologic properties might thus be exploited for the design of galectin- and ligand-type-selective glycoclusters.

Animals↗
PubMedDate not supplied

Neoglycoproteins with the synthetic complex biantennary nonasaccharide or its alpha 2,3/alpha 2,6-sialylated derivatives: their preparation, assessment of their ligand properties for purified lectins, for tumor cells in vitro, and in tissue sections, and their biodistribution in tumor-bearing mice.

Neoglycoproteins were prepared with chemoenzymatically synthesized complex biantennary N-glycan derivatives the nonreducing ends of which bear typical sequences found in glycoproteins. A chemically obtained biantennary heptasaccharide-azide was reduced and acylated with a 6-aminohexanoyl spacer. Elongation of the deprotected heptasaccharide using glycosyltransferases yielded a biantennary nonasaccharide with terminal galactose residues and two undecasaccharides terminating with alpha 2,6- or alpha 2,3-linked sialic acid. The free amino group of the spacer of these oligosaccharides was converted into an isothiocyanate. Its subsequent coupling to bovine serum albumin gave neoglycoproteins with a yield of 2.4-3.6 glycan chains per carrier molecule. This versatile synthetic pathway allows employment of a wide variety of complex-type glycans, which can be introduced to various test systems in vitro and in vivo to evaluate potential biomedical applications. Solid-phase assays with biotinylated sugar receptors revealed discriminatory binding properties of the three neoglycoproteins, especially for the mistletoe lectin. This direct assay system is preferable to the measurement of inhibitory capacities with respect to model ligands. Ligand type- and cell type-dependent quantitative differences in the binding properties of the probes were detected by FACScan analyses with a panel of tumor cell lines and by monitoring of staining in tissue sections for small cell and non-small-cell lung cancer and mesotheliomas. Biodistribution of iodinated neoglycoproteins in mice gave a prolonged presence of the sialylated probes in serum. Relative to the nonasaccharide, the uptake, especially of the iodinated neoglycoprotein with alpha 2,3-sialylated ligand chains, was clearly elevated in mice for kidneys and Ehrlich tumors. On the basis of the documented feasibility of these applications, it is concluded that the further elaboration of glycan chain variants by the described synthetic approach in combination with the given test panel is warranted to evaluate the potential of complex glycan chain-carrying neoglycoproteins for diagnostic and therapeutic purposes.

Animals↗
PubMed2000

Cell-type dependence of stability modulation of lectin-initiated contacts by impairment of multivalent carbohydrate binding and intracellular signaling.

Initial ligand selection and the intermolecular spatial arrangement of glycan-lectin complexes are assumed to be essential to induce formation of stable cell aggregates by a lectin. To distinguish effects of these two processes, the tetrameric mistletoe lectin and its isolated B-chain were used. A reduced impact of multivalency for Ehrlich ascites tumor cells in contrast to rat thymocytes was revealed. Signaling is thus initiated in a cell-type-dependent manner. Using selective metabolic inhibitors to reduce signal transfer for aggregate stability, decrease in cellular SH-group level was shown to be a common effect accompanying suppression of lectin-dependent aggregate stability. The results underscore an intrinsic variability in the relative importance of lectin-dependent glycan aggregation on the cell surface for triggering post-binding lectin effects.

Animals↗
PubMed1999

Dissection of the impact of various intracellular signaling pathways on stable cell aggregate formation of rat thymocytes after initial lectin-dependent cell association of using a plant lectin as model and target-selective inhibitors.

Bivalent lectins as bridging molecules between cells or cell surface lectins as docking points are involved in mediation of cell adhesion by specific recognition of suitable glycoconjugates on an opposing surface. The initial contact formation by a lectin can lead to intracellular post-binding events which effect stable cell association even in the presence of the haptenic sugar. To delineate the participation of intracellular signaling pathways in the cascade of reactions to establish firm association, reagents with proven inhibitory capacity on certain biochemical targets provide suitable tools. Using this approach with rat thymocytes and the galactoside-binding lectin from mistletoe (Viscum album L. agglutinin, VAA) as a model, a panel of 27 inhibitors with impact on e.g. several types of kinases, tyrosine phosphatases, NO synthases, G proteins, enzymes of arachidonate and cyclic nucleotide metabolism and calmodulin was systematically tested with respect to their capacity to impair the formation of lactose-resistant cell aggregates. In addition to the recently reported effectiveness of N-ethylmaleimide, nordihydroguaiaretic acid, and trifluoperazine the agents diacylglycerol kinase inhibitor II, emodin, D609, DPI, KT5720, KT5926, MK-886, bisindolylmaleimide I, and (+/-)methoxyverapamil were able to reduce aggregate stability in the presence of the haptenic sugar. Thus, various types of kinases including p561lck tyrosine kinase, lipoxygenases, phosphatidylcholine-specific phospholipase C as well as calmodulin and Ca(2+)-currents, but not modulators of the metabolism of cyclic nucleotides, NO synthases, MAP kinases, tyrosine phosphatases and phospholipase A (preferentially group II) and C can play a role in eliciting contact stability. More than one principal signaling pathway appears to be linked to the measurable parameter, since inhibitory substances show additive properties in co-incubation assays and differentially affect two lectin-elicited cellular activities, i.e. intracellular movement of Ca(2+)-ions and H2O2-generation, which can accompany cell adhesion and aggregation. Pronounced differences in the extent of modulation of H2O2-generation in human neutrophils by the same set of substances emphasizes that general conclusions on the post-binding effects for a certain lectin in different cell types are definitely precluded. In aggregate, the approach to employ inhibitors with target selectivity intimates an involvement of protein kinases A, C, Ca2+/calmodulin-dependent protein kinase II, p56lck tyrosine kinase, leukotrienes and/or hydroxyeicosatetraenoic acids, phosphatidylcholine-specific phospholipase C and Ca(2+)-fluxes in events following initial binding of a galactoside-specific plant lectin to rat thymocytes which establish firm cell contacts.

Animals↗