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At least 145 records · Page 8Linked to original sources

PubMed1992

Effects of bracken fern (Pteridium aquilinum L Kuhn) feeding during the development of female rats and their offspring.

Bracken fern (Pteridium aquilinum L Kuhn), is widely food in many parts of the world; the toxic effects have been demonstrated on many species of animals, and both carcinogenicity and enzootic hematuria has been studied. We investigated the effects of feeding bracken fern on the development of female rats and their offspring. The plant was fed as 30% of the normal diet on an ad libitum basis. Bracken fern did not modify the weight gain of the female rats during development, nor affect estrus cycle duration or milk production, the plant did reduce female fertility and weight gain during pregnancy. It also adversely affected physical and neurobehavioral development in the offspring.

Animal Feed↗

PubMed1987

Ferning in conjunctival-cytologic preparations. Crystallisation in stained semiquantitative pipette samples of conjunctival fluid.

Two quantitative pipette samples and 3 smears from each of 305 eyes were re-evaluated. Two types of ferning (F) were detected i.e. rectangular (FR) and acute-angled (FA) ramifications, respectively. One FR corresponds in area to 0.11 FA. Ferning was present in 29% of pipette samples, averaging 0.41 mm2 in the form of FR in the total series. Ferning was most frequent in samples with fairly large amounts of mucus, more frequent in neutrophilia than in lymphocytosis, and the rarest in normal cytology. F was seen in several cases of acute infections conjunctivitis (55%), neonatal and follicular conjunctivitis, and keratitis, whereas it was rare in normal eyes (7%). This distribution is presumably due to the amount of mucus in the samples preserving the F-pattern during the preparation procedure. F was rarely seen in smears (0.7%).

Conjunctiva↗

PubMed1982

Bracken fern, phenacetin, and cancer of the urinary tract.

Bracken fern, a forage contaminant, is causally related to urinary bladder cancer in animals. In this review of experimental studies on carcinogenesis of bracken fern, little evidence of an association between cancer and bracken fern in humans was observed. Clinicoepidemiological studies have shown a high frequency of phenacetin abusers in certain cases of lower urinary tract cancers that indicate case-control studies of phenacetin and related compounds are needed.

Aged↗

PubMed1994

Ostrich fern poisoning--New York and Western Canada, 1994.

Fiddleheads (crosiers) of the ostrich fern (Matteuccia struthiopteris) are a seasonal delicacy harvested commercially in the northeastern United States and in coastal provinces of Canada. Although some common ferns may be poisonous or carcinogenic, this species has been considered to be nontoxic. However, in May 1994, outbreaks of food poisoning were associated with eating raw or lightly cooked fiddlehead ferns in New York and western Canada. This report summarizes the investigations of these outbreaks.

Canada↗

PubMed2004

Induction of callus from a metal hypertolerant fern, Athyrium yokoscense, and evaluation of its cadmium tolerance and accumulation capacity.

The callus of a metal hypertolerant fern, Athyrium yokoscense, was induced from the spores generated on a small sectioned frond in vitro. The callus grew vigorously with the periodical medium change, especially in a liquid culture. When the callus and regenerated tissues were exposed to Cd, every tissue tolerated at least 1 mM Cd for >1 month. These tissues accumulated high levels of Cd (maximum 3.3 mg g(-1) dry weight in roots) in accordance with the Cd concentration of the medium, and the Cd concentrations of all parts, except roots, were at a similar level. The data suggest that the Cd tolerance of this fern is basically independent of the plant parts and the developmental stages, although the accumulation ability is higher in roots than in the other plant parts.

Cadmium↗

PubMed2005

Lead tolerance and accumulation in the gametophytes of the fern Athyrium yokoscense.

The fern Athyrium yokoscense is known to be highly tolerant to lead toxicity, and is a lead hyperaccumulator that can accumulate over 1,000 microg g(-1) of lead in its dry matter. In this work, we examined whether the gametophytic generation of A. yokoscense also resists lead toxicity like the sporophytic generation. Spore germination in A. yokoscense was more tolerant to Pb2+, compared to that in other fern species, such as Pteridium aquilinum, Lygodium japonicum and Pteris vittata. In addition, the early gametophyte development of A. yokoscense was not much affected by 10 microM Pb2+, as evaluated from the prothallial growth and rhizoid development. We also showed that Athyrium gametophytes could accumulate more than 10,000 microg g(-1) of lead, and that the lead was localized in the cytosol and vacuole of rhizoidal cells, as determined by a transmission electron micrograph. These results indicate that Athyrium gametophytes have the ability to accumulate lead in the rhizoids. Furthermore, the gametophytes were found to include a large amount of proanthocyanidins (condensed tannins). Because proanthocyanidins have a latent ability to complex with lead ions, the possible roles of proanthocyanidins in the lead tolerance and accumulation of Athyrium gametophytes are discussed.

Biological Transport↗

PubMed2005

Effect of pH on lead removal from water using tree fern as the sorbent.

The sorption of lead from water onto an agricultural by-product, tree fern, was examined as a function of pH. The sorption processes were carried out using an agitated and baffled system. Pseudo-second-order kinetic analyses were performed to determine the rate constant of sorption, the equilibrium sorption capacity, and the initial sorption rate. Application of the pseudo-second-order kinetics model produced very high coefficients of determination. Results showed the efficiency of tree fern as a sorbent for lead. The optimum pH for lead removal was between 4 and 7, with pH 4.9 resulting in better lead removal. Ion exchange occurred in the initial reaction period. In addition, a relation between the change in the solution hydrogen ion concentration and equilibrium capacity was developed and is presented.

Absorption↗

PubMed2001

Rare earth elements in naturally grown fern Dicranopteris linearis in relation to their variation in soils in south-Jiangxi region (southern China).

Ferns (Dicranopteris linearis) and soils, sampled from four rare earth mining areas and one non-mining area locating in South-Jiangxi region, were chosen for analysis of 15 rare earth elements (REEs) by inductively coupled plasma-mass spectrometry (ICP-MS). The fern samples were divided into 4 parts: root, stem, petiole, and lamina. The soils of the same sites were also sampled, and 4 soil layers were observed at the profile: A (0-20 cm depth), B (20-150 cm depth), C (150-400 cm depth), and D (rock). The distribution patterns and transportation characteristics of REEs of different soil layers and of different parts of D. linearis were studied. The results showed that in the soil layers, the sigma REE (the sum of the concentrations of 15 REEs) of A layer, as well as B layer were lower than that of C layer, but Ce was relatively concentrated in A layer. The sigma REE of different parts of D. linearis were lamina, root > stem > petiole. The REE distribution patterns of D. linearis root were similar to the total REE distribution patterns of the A layer of their host soils, especially to the soluble REE distribution patterns of the A layer of their host soils. The REEs were fractionated in their transportation in D. linearis. The abundances of heavy rare earth elements (HREEs, Gd to Lu and Y) in the stem, petiole, lamina are lower than those in the root.

Environmental Monitoring↗

PubMed2003

XAS speciation of arsenic in a hyper-accumulating fern.

The coordination environment and the redox speciation of arsenic in a newly discovered arsenic hyper-accumulating fern (Pteris vittata L) were investigated by X-ray absorption spectroscopy. This method allowed us to probe arsenic directly, i.e., with minimal sample preparation. The results indicate that arsenic is predominantly accumulated as As(III) in the leaves. XANES and EXAFS results show that As(III) in the leaves is primarily present as aqueous arsenite species. The plant actively maintains arsenic in this reduced oxidation state, because after sample collection and subsequent aging and drying of the plant material, As(III) is gradually oxidized to As(V). We think that these arsenite species are sequestered in vacuoles. At extremely high As concentrations (ca. 1% As per dry weight) arsenic in the fern leaves is coordinated to a significant degree by sulfur in addition to oxygen. This spectral signature indicates that thiol-rich compounds are implicated in the biochemical transformations of arsenic within the plant.

Arsenic↗

PubMed2001

A preliminary study on the carcinogenicity of the common fern Onychium contiguum.

Onychium contiguum (Family Cryptogrammaceae) is a common terrestrial fern in the Himalayas and in many other parts of the world. It is also present on the pastures in areas where grazing animals suffer from bovine urinary bladder cancer. This fern is occasionally grazed by animals and in some areas it is present as a contaminant in grasses stored for winter feeding. Certain species of the genus Onychium are used in folk medicine. Long-term exposure of experimental animals to O. contiguum appeared to cause tumours of the ileum. urinary bladder and mammary glands.

Animals↗

PubMed2005

Origin of the endemic fern genus Diellia coincides with the renewal of Hawaiian terrestrial life in the Miocene.

The enigmatic fern genus Diellia, endemic to the Hawaiian archipelago, consists of five extant and one recently extinct species. Diellia is morphologically highly variable, and a unique combination of characters has led to several contrasting hypotheses regarding the relationship of Diellia to other ferns. A phylogenetic analysis of four chloroplast loci places Diellia within 'black-stemmed' rock spleenworts of the species-rich genus Asplenium, as previously suggested by W. H. Wagner. Using an external calibration point, we estimate the divergence of the Diellia lineage from its nearest relatives to have occurred at ca. 24.3 Myr ago matching an independent estimate for the renewal of Hawaiian terrestrial life (ca. 23 Myr ago). We therefore suggest that the ancestor of the Diellia lineage may have been among the first successful colonists of the newly emerging islands in the archipelago. Disparity between morphological and nucleotide sequence variation within Diellia is consistent with a recent rapid radiation. Our estimated time of the Diellia radiation (ca. 2 Myr ago) is younger than the oldest island of Kaua'i (ca. 5.1 Myr ago) but older than the younger major islands of Maui (ca. 1.3 Myr ago), Lana'i (ca. 1.3 Myr ago) and Hawaii (ca. 0.43 Myr ago).

Base Sequence↗

PubMed2005

Leaf hydraulic capacity in ferns, conifers and angiosperms: impacts on photosynthetic maxima.

* The hydraulic plumbing of vascular plant leaves varies considerably between major plant groups both in the spatial organization of veins, as well as their anatomical structure. * Five conifers, three ferns and 12 angiosperm trees were selected from tropical and temperate forests to investigate whether the profound differences in foliar morphology of these groups lead to correspondingly profound differences in leaf hydraulic efficiency. * We found that angiosperm leaves spanned a range of leaf hydraulic conductance from 3.9 to 36 mmol m2 s-1 MPa-1, whereas ferns (5.9-11.4 mmol m-2 s-1 MPa-1) and conifers (1.6-9.0 mmol m-2 s-1 MPa-1) were uniformly less conductive to liquid water. Leaf hydraulic conductance (Kleaf) correlated strongly with stomatal conductance indicating an internal leaf-level regulation of liquid and vapour conductances. Photosynthetic capacity also increased with Kleaf, however, it became saturated at values of Kleaf over 20 mmol m-2 s-1 MPa-1. * The data suggest that vessels in the leaves of the angiosperms studied provide them with the flexibility to produce highly conductive leaves with correspondingly high photosynthetic capacities relative to tracheid-bearing species.

Ecosystem↗

PubMed2001

Isolation and identification of antheridiogens in the ferns, Lygodium microphyllum and Lygodium reticulatum.

Antheridiogens in culture media of 6-week-old prothallia of two species of Schizaeaceous ferns, Lygodium microphyllum and Lygodium reticulatum, were analyzed by gas chromatography-mass spectrometry. In both species, the gibberellin A73 methyl ester (GA73-Me) was identified as the most abundant antheridiogen, and the methyl esters of GA9 and of several monohydroxy-GA73 derivatives were also detected. Since both species produced antheridiogens at a high level, they were classified into high-antheridiogen-producing ferns. The response to GA73-Me of gametophytes of both species is also discussed.

Ferns↗

PubMed2001

Characterization of toxin from cheilanthes fern and its effect on lymphocyte proliferation and DNA fragmentation.

Thin layer chromatography of aqueous extract of whole Cheilanthesfarinosa fern indicated the presence of ptaquiloside or ptaquiloside like compound, coinciding Rf values with that of Pterosin B standard. HPLC analysis revealed the presence of 26.3 mg/kg ptaquiloside. In vitro studies of the aqueous extract on lymphocyte culture revealed a correlation between stimulative indices and concentration of aqueous extract. Stimulation in lymphocyte proliferation was in order of bracken > cheilanthes > ConA> ptaquiloside standard. On incubation of lymphocyte with aqueous extract of ferns, no DNA damage was observed in isolated DNA.

Animals↗

PubMed1995

Absence of promoting potential of bracken fern (Pteridium aquilinum) in rat urinary bladder carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine and uracil.

Conventional studies on bracken fern (Pteridium aquilinum; PA) carcinogenicity have used high dietary concentrations (around 30%) and long-term exposure (up to 52-70 weeks) without consideration of the multistep character of the chemical carcinogenesis process. The present study evaluated specifically the promoting potential of 3-5% dietary crude PA in the rat urinary bladder mucosa in a 32-week-long initiation-promotion assay for chemical carcinogenesis. Initiation of urothelial carcinogenesis was accomplished with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Uracil (U) was provided through the diet in order to expand the population of initiated cells. Seven groups (G) of male Wistar rats were submitted to the following treatments: G1 = BBN (n = 8); G2 = U (n = 10); G3 = BBN-U (n = 9); G4 = BBN-PA-U-PA (n = 16); G5 = PA (n = 8); G6 = BBN-PA (n = 10); G7 = PA-U-PA (n = 12). At the end of the experiment rats presenting epithelial papillary or nodular hyperplasia (PNH), papillomas (PAP), or simultaneous PNH plus PAP numbered, respectively G1: 2-0-1; G2: 0-0-0; G3: 3-0-2; G4: 4-3-2; G5: 1-0-1; G6: 8-0-0; and G7: 0-0-0, with no significant differences in the incidence of lesions among the groups. More frequent and more severe lesions occurred in BBN-initiated animals, predominantly in those also exposed to uracil (G3 and G4). Low-dose crude bracken fern in the diet does not promote rat urinary bladder carcinogenesis after a 32-week period of exposure, even when the initiated urothelial cell population has been expanded through a mechanical stimulus.

Animals↗

PubMed1997

rbcL sequences: a promising tool for the molecular systematics of the fern genus Trichomanes (Hymenophyllaceae)?

A phylogenetic study using rbcL sequences was performed on 18 species of the fern genus Trichomanes (Hymenophyllaceae) in order to (i) test the ability of this gene for resolving relationships within this taxon and (ii) reveal major phylogenetic tendencies. Molecular divergence values suggest that subtaxa of this genus more closely conform to generic concepts as applied to other ferns and angiosperms. Although the gene rbcL appears to be a promising tool, the deepest relationships remain ambiguous, probably in relation with saturation, especially for transition events. Despite the taxonomic undersampling, some major systematic tendencies are evidenced. Morton's subgenus Didymoglossum appears to be strongly supported. The monotypic section Davalliopsis and subgenus Achomanes cluster together into an unexpected geographic group. The monophyly of each of Morton's subgenera Trichomanes and Pachychaetum is not retrieved. Molecular data seem in fact to be more in agreement with comparative cytology rather than with morphology. Additional taxa are suggested for confirming these tendencies.

Cloning, Molecular↗

PubMed1995

Polar distribution of annexin-like proteins during phytochrome-mediated initiation and growth of rhizoids in the ferns Dryopteris and Anemia.

Although the calcium requirement of phytochrome-mediated fern spore germination and early rhizoid growth is well established, the calcium-binding proteins that serve as transducers for these responses are not known. Here we report the presence of annexin-like proteins in germinating spores of Dryopteris filix-mas (L.) Schott and Anemia phyllitidis (L.) Sw. and evidence that they may be important participants in early photomorphogenic changes in gametophytes. Immunolocalization and immunoblot assays of these proteins were carried out using polyclonal antibodies raised either against a 35-kDa annexin-like protein from pea or against anchorin CII from chicken. Western-blot analysis showed that crude protein extracts obtained from both species after red-light treatment contained two cross-reactive protein bands with molecular weights around 70 kDa. These proteins were annexin-like in that they bound to a phosphatidylserine affinity column in a calcium-dependent fashion. Using this column, two protein bands around 70 kDa, i.e. 67 and 73 kDa, were partially purified together with proteins at 36 kDa and a doublet at 54 kDa. Proteins of these latter molecular weights are suggested to be members of the annexin family, but no cross-reactivity could be found between these and the two antibodies used in our investigations. Immunodetectable levels of these proteins were observed only after light-mediated induction of spore germination. Imaging of the immuno-localization patterns observed with both antibodies showed that the annexin-like proteins are concentrated at the extreme tips of the rhizoids in D. filix-mas and A. phyllitidis during rhizoid initiation and all stages of elongation. We suggest that these proteins may play a major role in the tip-oriented exocytosis events that are critical for the initiation and growth of fern rhizoids.

Annexins↗

PubMed1978

Examination and evaluation of germination and protonemal development for Onoclea sensibilis fern spores treated with aflatoxin B1.

Experiments were designed to test the effects of aflatoxin B1 (AFB1) on germination and subsequent development of the gametophytes of the sensitive fern Onoclea sensibilis. AFB1 concentrations used were 0, 2.5, 5.0, 7.5, 10.0 and 12.5 muM. Preliminary studies indicated that, under all AFB1 concentrations tested, germination was maximum after 144 hrs. Additional studies revealed that during this time period protonemal growth was in the log phase. Percent germination was inhibited by increasing concentrations of AFB1; A 50% inhibition was noted at 12.5 muM. In addition, increasing concentrations of AFB1 caused a reduction in the total number of cells per protonema. Preliminary analysis indicated that this was caused by a reduction of the rate of cell production rather than total inhibition of cell division. A comparison of the dose-response curves for both of the above effects demonstrated that sensitivity to AFB1 starts at 2.5 muM. This may indicate that AFB1 is acting on a process common to both phenomena. The fern spore germination system could be a "simple" model system in which to study the site and mode of action of AFB1.

Aflatoxins↗