Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
J Fungi (Basel) ; 9(1)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36675908

RESUMO

Many wild edible polypore mushrooms have medicinal value. In this study, we investigate the potential medicinal properties of the wild polypore mushroom Royoporus badius collected from north-central British Columbia, Canada. Water extract from R. badius was found to exhibit potent immunomodulatory activity. The extract was purified using DEAE-Sephadex anion-exchange chromatography as well as Sephacryl S-500 and HPLC BioSEC5 size-exclusion chromatography, to yield a novel polysaccharide-protein complex (IMPP-Rb).IMPP-Rb has a peak maxima molecular weight (Mp) of 950 kDa. GC-MS analyses showed that IMPP-Rb is composed predominantly of glucose (49.2%), galactose (11.3%), mannose (10.8%), rhamnose (9.6%), and galacturonic acid (8.2%), with smaller amounts of xylose (5.2%), fucose (2.8%), N-acetyl glucosamine (1.8%), and arabinose (1.2%). IMPP-Rb has multiple linkages, with 4-Glcp, 4-Manp, 6-Manp, 3,4-Manp, 4-Xylp, and 2-Rhap being the most prominent. IMPP-Rb is capable of inducing many cytokines in vitro and the protein component is indispensable for its immunomodulatory activity. IMPP-Rb has potential application as an immuno-stimulatory agent with pharmaceutical value.

2.
Sci Rep ; 12(1): 17298, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241661

RESUMO

A novel polysaccharide EtGIPL1a was purified from fruiting bodies of Echinodontium tinctorium, a fungus unique to western North America. EtGIPL1a has an estimated weight average molecular weight of 275 kDa and is composed of glucose (54.3%), galactose (19.6%), mannose (11.1%), fucose (10.3%), glucuronic acid (4%), and rhamnose (0.6%). It has multiple glycosidic linkages, with 3-Glcp (28.9%), 6-Glcp (18.3%), 3,6-Glcp (13%), 4-GlcpA (9.2%), 6-Galp (3.9%), 2,6-Galp (2.6%), 3-Fucp (2.5%), 6-Manp (2.4%) being the most prominent, and unsubstituted glucose (15.3%), mannose (1.3%) and fucose (0.9%) as major terminal sugars. EtGIPL1a has a backbone containing mostly 3-substituted ß-glucopyranose with 4-substituted glucopyranosyluronic acid. EtGIPL1a showed anti-proliferative activity against multiple cancer cell lines, with IC50 ranging from 50.6 to 1446 nM. Flow cytometry analyses confirmed that apoptosis induction is one mechanism for its anti-proliferative activity. EtGIPL1a should be further investigated for its potential anti-cancer activity in animal models, and for its possible utility in differentiation cancer therapy.


Assuntos
Basidiomycota , Galactose , Animais , Fucose , Glucose/análise , Ácido Glucurônico , Manose , Peso Molecular , Polissacarídeos/farmacologia , Ramnose
3.
Carbohydr Polym ; 258: 117700, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33593571

RESUMO

An immuno-stimulatory polysaccharide (EtISPFa) was purified from water extract of the fungus Echinodontium tinctorium. EtISPFa has an estimated weight average molecular weight (Mw) of 1354 kDa and is composed of glucose (66.2 %), glucuronic acid (10.1 %), mannose (6.7 %), galactose (6.4 %), xylose (5.6 %), rhamnose (3.1 %), fucose (1.8 %), and arabinose (0.2 %). It has multiple glycosidic linkages, with 3-Glcp (19.8 %), 4-GlcpA (10.8 %), 6-Glcp (10.7 %), and 3,6-Glcp (8.7 %) being the most prominent. NMR analysis showed that EtISPFa has a backbone containing mostly of 3-substituted ß-glucopyranose with 4-substituted glucopyranosyluronic acid. Short side chains consisting of an average of two ß-glycopyranose residues, connected through 1→6 linkages, are attached to the 6-position of about every 4th or 5th backbone glucose residue. EtISPFa is a novel glucuronic acid-containing ß-glucan capable of significantly inducing the production of cytokines IL-17, IL-16, MIP-2, G-CSF,GM-CSF, LIF, MIP-1α, MIP-1ß, and RANTES in vitro. EtISPFa should be further explored for its immuno-stimulatory activity in vivo.


Assuntos
Basidiomycota/metabolismo , Citocinas/metabolismo , Ácido Glucurônico/química , Polissacarídeos/química , Animais , Arabinose/química , Quimiocinas/metabolismo , Fucose/química , Galactose/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Glucose/análise , Macrófagos/metabolismo , Espectroscopia de Ressonância Magnética , Manose/química , Metilação , Camundongos , Monossacarídeos/química , Células RAW 264.7 , Ramnose/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Xilose/química
4.
PLoS One ; 15(5): e0231948, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32369483

RESUMO

In our search for bioactive mushrooms native to British Columbia, we determined that the ethanol extracts from fruiting bodies of the terrestrial polypore Albatrellus flettii had potent anti-cell viability activity. Using bioassay-guided fractionation, mass spectrometry and nuclear magnetic resonance, we successfully isolated three known compounds (grifolin, neogrifolin and confluentin). These compounds represent the major anti-cell viability components from the ethanol extracts of A. flettii. We also identified a novel biological activity for these compounds, specifically in down-regulating KRAS expression in two human colon cancer cell lines. Relatively little is known about the anti-cell viability activity and mechanism of action of confluentin. For the first time, we show the ability of confluentin to induce apoptosis and arrest the cell cycle at the G2/M phase in SW480 human colon cancer cells. The oncogenic insulin-like growth factor 2 mRNA-binding protein 1 (IMP1) has been previously shown to regulate KRAS mRNA expression in colon cancer cells, possibly through its ability to bind to the KRAS transcript. Using a fluorescence polarization assay, we show that confluentin dose-dependently inhibits the physical interaction between KRAS RNA and full-length IMP1. The inhibition also occurs with truncated IMP1 containing the KH1 to KH4 domain (KH1to4 IMP1), but not with the di-domain KH3 and KH4 (KH3&4 IMP1). In addition, unlike the control antibiotic neomycin, grifolin, neogrifolin and confluentin do not bind to KRAS RNA. These results suggest that confluentin inhibits IMP1-KRAS RNA interaction by binding to the KH1&2 di-domains of IMP1. Since the molecular interaction between IMP1 and its target RNAs is a pre-requisite for the oncogenic function of IMP1, confluentin should be further explored as a potential inhibitor of IMP1 in vivo.


Assuntos
Basidiomycota/química , Neoplasias do Colo/genética , Fenóis/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Resorcinóis/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Terpenos/farmacologia
5.
Int J Med Mushrooms ; 21(7): 629-643, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679298

RESUMO

Wild mushrooms, while largely explored for their ecological significance, have not been systematically studied for their medicinal properties. This is the first report of biological activities of mushrooms from Haida Gwaii, British Columbia, Canada. The 17 mushroom species in this study were collected from multiple locations on Haida Gwaii and were screened for antiproliferative, immunostimulatory, and anti-inflammatory activities. Prior to screening, mushrooms were genetically identified and then sequentially fractionated into four crude extracts using 80% ethanol, 50% methanol, water, and 5% sodium hydroxide. We report here the strong antiproliferative and antiinflammatory activities of Amanita augusta, Phellodon atratus, Guepinia helvelloides, Chroogomphus tomentosus, Laetiporus conifericola, and Inocybe sp. In addition, A. augusta, G. helvelloides, and Inocybe sp. showed potent immunostimulatory activity. Two other species (Ganoderma tsugae and Pleurotus ostreatus) displayed strong immunostimulatory activity consistent with previous reports by others, suggesting that similar constituents are present in the same species from Haida Gwaii. For nine species (Russula paludosa, Hygrophoropsis aurantiaca, Tricholomopsis rutilans, Tyromyces chioneus, Hydnum repandum, Hypholoma fasciculare, Clavulina cinerea, P. ostreatus and Ramaria cystidiophora), we describe antiproliferative, immunostimulatory, and/or anti-inflammatory activities that have never been reported before. The new findings serve as a platform for future investigations into the potentially novel bioactive constituents of these mushrooms, as well as an incentive to further study a wider array of wild mushrooms for medicinal properties.


Assuntos
Adjuvantes Imunológicos/farmacologia , Agaricales/química , Anti-Inflamatórios/farmacologia , Misturas Complexas/farmacologia , Animais , Colúmbia Britânica , Proliferação de Células/efeitos dos fármacos , Misturas Complexas/isolamento & purificação , Células HeLa , Humanos , Camundongos , Células RAW 264.7
6.
Molecules ; 24(19)2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31569655

RESUMO

The aim of this study was to investigate the anti-inflammatory activity of a previously un-studied wild mushroom, Echinodontium tinctorium, collected from the forests of north-central British Columbia. The lipopolysaccharide (LPS)-induced RAW264.7 macrophage model was used to study the in vitro anti-inflammatory activity. The crude alkaline extract demonstrated potent anti-inflammatory activity, and was further purified using a "bio-activity-guided-purification" approach. The size-exclusion and ion-exchange chromatography yielded a water-soluble anti-inflammatory polysaccharide (AIPetinc). AIPetinc has an average molecular weight of 5 kDa, and is a heteroglucan composed of mainly glucose (88.6%) with a small amount of galactose (4.0%), mannose (4.4%), fucose (0.7%), and xylose (2.3%). In in vivo settings, AIPetinc restored the histamine-induced inflammatory event in mouse gluteus maximus muscle, thus confirming its anti-inflammatory activity in an animal model. This study constitutes the first report on the bioactivity of Echinodontium tinctorium, and highlights the potential medicinal benefits of fungi from the wild forests of northern British Columbia. Furthermore, it also reiterates the need to explore natural resources for alternative treatment to modern world diseases.


Assuntos
Agaricales/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Macrófagos/efeitos dos fármacos , Animais , Anti-Inflamatórios/isolamento & purificação , Histamina/farmacologia , Macrófagos/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Células RAW 264.7 , Fator de Necrose Tumoral alfa/biossíntese
7.
PLoS One ; 14(8): e0220776, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31437163

RESUMO

Cell-to-cell communication is a key element of microvascular blood flow control, including rapidly carrying signals through the vascular endothelium in response to local stimuli. This cell-to-cell communication is negatively impacted during inflammation through the disruption of junctional integrity. Such disruption is associated with promoting the onset of cardiovascular diseases as a result of altered microvascular blood flow regulation. Therefore, understanding the mechanisms how inflammation drives microvascular dysfunction and compounds that mitigate such inflammation and dysfunction are of great interest for development. As such we aimed to investigate extracts of mushrooms as potential novel compounds. Using intravital microscopy, the medicinal mushroom, Inonotus obliquus was observed, to attenuate histamine-induced inflammation conducted vasodilation in second-order arterioles in the gluteus maximus muscle of C57BL/6 mice. Mast cell activation by C48/80 similarly disrupted endothelial junctions and conducted vasodilation but only histamine was blocked by the histamine antagonist, pyrilamine not C48/80 suggesting the importance of mast cell activation. Data presented here supports that histamine induced inflammation is a major disruptor of junctional integrity, and highlights the important anti-inflammatory properties of Inonotus obliquus focusing future assessment of mast cells as putative target for Inonotus obliquus.


Assuntos
Basidiomycota/isolamento & purificação , Microvasos/efeitos dos fármacos , Microvasos/imunologia , Agaricales/isolamento & purificação , Agaricales/metabolismo , Animais , Arteríolas/efeitos dos fármacos , Basidiomycota/metabolismo , Endotélio Vascular/efeitos dos fármacos , Histamina/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Junções Intercelulares/efeitos dos fármacos , Junções Intercelulares/metabolismo , Masculino , Mastócitos/efeitos dos fármacos , Mastócitos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Pirilamina/farmacologia , Vasodilatação/efeitos dos fármacos
8.
Carbohydr Polym ; 181: 923-930, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29254055

RESUMO

A growth-inhibitory polysaccharide (GIPinv) was purified using size-exclusion and ion-exchange chromatography from the fourth sodium hydroxide extraction step of a fungus found in British Columbia. The fungus was genetically identified as a member of the Paxillus involutus complex. GIPinv has an average molecular weight of 229kDa and is a heteroglycan composed of glucose (65.9%), galactose (20.8%), mannose (7.8%), fucose (3.2%) and xylose (2.3%). GC-MS methylation analysis suggests that GIPinv has mixed linkages in the backbone containing (1→6)-Gal (25.5%), (1→4)-Glc (18.3%), (1→6)-Glc (8.3%), (1→3)-Glc (5.3%) and (1→2)-Xyl (4.5%). GIPinv has branching points at (1→2, 6)-Man (8.6%) and (1→3, 6)-Man (4.9%) having unsubstituted fucose (8.3%) and glucose (16.3%) as terminal sugars. GIPinv had growth-inhibitory activity against several cancer cell lines and triggered apoptosis. GIPinv should be further explored as a potential anti-cancer agent and a unique polysaccharide.


Assuntos
Basidiomycota/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fracionamento Químico , Misturas Complexas , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Monossacarídeos/análise , Filogenia
9.
Int J Med Mushrooms ; 19(6): 485-497, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29199559

RESUMO

Wild mushrooms, especially from North America, have not been systematically explored for their medicinal properties. Here we report screening for the growth-inhibitory and immunomodulatory activities of 12 species collected from multiple locations in north-central British Columbia, Canada. Mushrooms were characterized using morphology and DNA sequencing, followed by chemical extraction into 4 fractions using 80% ethanol, 50% methanol, water, and 5% sodium hydroxide. Growth-inhibitory, immunostimulatory, and anti-inflammatory activities of 5 mushrooms (Leucocybe connata, Trichaptum abietinum, Hydnellum sp., Gyromitra esculenta, and Hericium coralloides) are reported here, to our knowledge for the first time. Growth-inhibitory effects were assessed using the cytotoxic MTT assay. Immunostimulatory activity was assessed by tumor necrosis factor-α production in Raw 264.7 macrophages, whereas anti-inflammatory activity was assessed based on the inhibition of lipopolysaccharide-induced tumor necrosis factor-α production. The ethanol and aqueous extracts of Hydnellum sp. were potent growth inhibitors, with a half-maximal inhibitory concentration of 0.6 mg/mL. All 5 fungi displayed strong immunostimulatory activity, whereas only L. connata and T. abietinum showed strong anti-inflammatory activity. For the 7 other fungi investigated, which included well-known medicinal species such as Inonotus obliquus, Phellinus igniarius, and Ganoderma applanatum, the remarkable similarities in the biological activities reported here, and by others for specimens collected elsewhere, suggest that mushrooms can produce similar metabolites regardless of their habitat or ecosystem. This is to our knowledge the first study to explore wild mushrooms from British Columbia for biological activities that are relevant to cancer, and the results provide an initial framework for the selection of mushroom species with the potential for discovery of novel anticancer compounds.


Assuntos
Anti-Inflamatórios/farmacologia , Ascomicetos/química , Basidiomycota/química , Fatores Imunológicos/farmacologia , Lipopolissacarídeos/farmacologia , Animais , Ascomicetos/classificação , Ascomicetos/genética , Basidiomycota/classificação , Basidiomycota/genética , Colúmbia Britânica , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Imunomodulação/efeitos dos fármacos , Camundongos , Células RAW 264.7
10.
Mycorrhiza ; 25(7): 517-31, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25694036

RESUMO

Climatic and land use changes have significant consequences for the distribution of tree species, both through natural dispersal processes and following management prescriptions. Responses to these changes will be expressed most strongly in seedlings near current species range boundaries. In northern temperate forest ecosystems, where changes are already being observed, ectomycorrhizal fungi contribute significantly to successful tree establishment. We hypothesised that communities of fungal symbionts might therefore play a role in facilitating, or limiting, host seedling range expansion. To test this hypothesis, ectomycorrhizal communities of interior Douglas-fir and interior lodgepole pine seedlings were analysed in a common greenhouse environment following growth in five soils collected along an ecosystem gradient. Currently, Douglas-fir's natural distribution encompasses three of the five soils, whereas lodgepole pine's extends much further north. Host filtering was evident amongst the 29 fungal species encountered: 7 were shared, 9 exclusive to Douglas-fir and 13 exclusive to lodgepole pine. Seedlings of both host species formed symbioses with each soil fungal community, thus Douglas-fir did so even where those soils came from outside its current distribution. However, these latter communities displayed significant taxonomic and functional differences to those found within the host distribution, indicative of habitat filtering. In contrast, lodgepole pine fungal communities displayed high functional similarity across the soil gradient. Taxonomic and/or functional shifts in Douglas-fir fungal communities may prove ecologically significant during the predicted northward migration of this species; especially in combination with changes in climate and management operations, such as seed transfer across geographical regions for forestry purposes.


Assuntos
Mudança Climática , Micorrizas/fisiologia , Dispersão Vegetal , Pseudotsuga/microbiologia , Pseudotsuga/fisiologia , Colúmbia Britânica , Ecossistema , Microbiota , Pinus/microbiologia , Pinus/fisiologia , Microbiologia do Solo
11.
Folia Microbiol (Praha) ; 60(5): 399-410, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25540132

RESUMO

Following a pine beetle epidemic in British Columbia, Canada, we investigated the effect of fire severity on rhizosphere soil chemistry and ectomycorrhizal fungi (ECM) and associated denitrifying and nitrogen (N)-fixing bacteria in the root systems of regenerating lodgepole pine seedlings at two site types (wet and dry) and three fire severities (low, moderate, and high). The site type was found to have a much larger impact on all measurements than fire severity. Wet and dry sites differed significantly for almost all soil properties measured, with higher values identified from wet types, except for pH and percent sand that were greater on dry sites. Fire severity caused few changes in soil chemical status. Generally, bacterial communities differed little, whereas ECM morphotype analysis revealed ectomycorrhizal diversity was lower on dry sites, with a corresponding division in community structure between wet and dry sites. Molecular profiling of the fungal ITS region confirmed these results, with a clear difference in community structure seen between wet and dry sites. The ability of ECM fungi to colonize seedlings growing in both wet and dry soils may positively contribute to subsequent regeneration. We conclude that despite consecutive landscape disturbances (mountain pine beetle infestation followed by wildfire), the "signature" of moisture on chemistry and ECM community structure remained pronounced.


Assuntos
Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Micorrizas/isolamento & purificação , Pinus/microbiologia , Solo/química , Árvores/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Besouros/fisiologia , Ecossistema , Incêndios , Fungos/classificação , Fungos/genética , Micorrizas/classificação , Micorrizas/genética , Micorrizas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Pinus/crescimento & desenvolvimento , Pinus/parasitologia , Doenças das Plantas/parasitologia , Rizosfera , Árvores/crescimento & desenvolvimento , Árvores/parasitologia , Água/análise
12.
J Exp Bot ; 65(20): 5823-34, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25104762

RESUMO

Periodic drought events present a significant and, with climate change, increasing constraint on temperate forage plants' production. Consequently, improving plants' adaptive response to abiotic stress is a key goal to ensure agricultural productivity in these regions. In this study we developed a new methodology, using both area-based comparison and soil water content measurements of individual non-irrigated and irrigated clones, to assess performance of perennial ryegrass (Lolium perenne L.) genotypes subjected to moisture stress in a simulated competitive environment. We applied this method to the evaluation of a full-sibling population from a pair cross between genotypes from a New Zealand cultivar and a Moroccan ecotype. Our hypothesis was that: (i) both leaf lamina regrowth after defoliation (LR) and plant vigour affect plant performance during drought and rehydration; and (ii) quantitative trait loci (QTLs) associated with plant performance under moisture stress could be identified. Differences amongst genotypes in dry matter (DM) production, early vigour at establishment, leaf elongation rate and LR were measured. LR explained most of the variation in DM production during exposure to moisture deficit and rehydration followed by plant vigour, indicated by initial DM production in both treatments and subsequent measures of DM production of irrigated clones. We identified two main QTL regions associated with DM production and LR, both during drought exposure and rehydration. Further research focused on these regions should improve our understanding of the genetic control of drought response in this forage crop and potentially other grass species with significant synteny, and support improvement in performance through molecular breeding approaches.


Assuntos
Cruzamento/métodos , Ligação Genética , Lolium/fisiologia , Locos de Características Quantitativas/genética , Irrigação Agrícola , Mapeamento Cromossômico , Secas , Meio Ambiente , Genótipo , Lolium/genética , Lolium/crescimento & desenvolvimento , Nova Zelândia , Fenótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Solo , Sintenia , Água/fisiologia
13.
Int J Cancer ; 134(4): 988-96, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23934954

RESUMO

Imatinib is the standard of care in chronic meloid leukemia (CML) therapy. However, imatinib is not curative since most patients who discontinue therapy relapse indicating that leukemia initiating cells (LIC) are resistant. Interferon alpha (IFN) induces hematologic and cytogenetic remissions and interestingly, improved outcome was reported with the combination of interferon and imatinib. Arsenic trioxide was suggested to decrease CML LIC. We investigated the effects of arsenic and IFN on human CML cell lines or primary cells and the bone marrow retroviral transduction/transplantation murine CML model. In vitro, the combination of arsenic and IFN inhibited proliferation and activated apoptosis. Importantly, arsenic and IFN synergistically reduced the clonogenic activity of primary bone marrow cells derived from CML patients. Finally, in vivo, combined interferon and arsenic treatment, but not single agents, prolonged the survival of primary CML mice. Importantly, the combination severely impaired engraftment into untreated secondary recipients, with some recipients never developing the disease, demonstrating a dramatic decrease in CML LIC activity. Arsenic/IFN effect on CML LIC activity was significantly superior to that of imatinib. These results support further exploration of this combination, alone or with imatinib aiming at achieving CML eradication rather than long-term disease control.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose , Transformação Celular Neoplásica/efeitos dos fármacos , Interferon-alfa/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Animais , Antivirais/farmacologia , Trióxido de Arsênio , Arsenicais/administração & dosagem , Benzamidas/administração & dosagem , Transplante de Medula Óssea , Transformação Celular Neoplásica/patologia , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Camundongos Endogâmicos BALB C , Óxidos/administração & dosagem , Piperazinas/administração & dosagem , Prognóstico , Pirimidinas/administração & dosagem , Reação em Cadeia da Polimerase em Tempo Real , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaio Tumoral de Célula-Tronco
14.
Rev Mal Respir ; 30(10): 868-78, 2013 Dec.
Artigo em Francês | MEDLINE | ID: mdl-24314710

RESUMO

Cypress belongs to the Cupressaceae family, which includes 140 species with non-deciduous foliage. The most important genera in allergic diseases are Cupressus sempervirens or Green cypress, Cupressus arizonica or Blue cypress, Juniperus oxycedrus, Juniperus communis and Thuya. Because J. oxycedrus pollinates in October, C. sempervirens in January and February, C. arizonica in February and March, J. communis in April, the symptomatic period is long-lasting. Because of global warming, the pollination period is tending to last longer and Cupressaceae species are becoming established further the north. In Mediterranean countries, cypress is by far the most important pollinating species, accounting for half of the total pollination. The major allergens belong to group 1. The other allergens from cypress and Juniper share 75 to 97 % structural homology with group 1 major allergens. The prevalence of cypress allergy in the general population ranges from 5 % to 13 %, according to exposure to the pollen. Among outpatients consulting an allergist, between 9 and 35 %, according to different studies, are sensitized to cypress pollen. Repeated cross-sectional studies performed at different time intervals have demonstrated a threefold increase in the percentage of cypress allergy. Risk factors include a genetic predisposition and/or a strong exposure to pollen, but air pollutants could play a synergistic role. The study of the natural history of cypress allergy allows the identification of a subgroup of patients who have no personal or family history of atopy, whose disease began later in life, with low total IgE and often monosensitization to cypress pollen. In these patients, the disease is allergic than rather atopic. In the clinical picture, rhinitis is the most prevalent symptom but conjunctivitis the most disabling. A cross-reactivity between cypress and peach allergy has been demonstrated. The pharmacological treatment of cypress allergy is not different from that for other allergies. Hyposensitization has been used, at first by injection, but nowadays mostly through the sublingual route, but clinical trials have included few patients. Avoidance can be implemented at the individual level but also at the community levels using alternative plants, low-pollinating cypresses or by trimming hedges prior to pollination.


Assuntos
Cupressus/imunologia , Rinite Alérgica Sazonal , Alérgenos/imunologia , Cupressus/classificação , Dessensibilização Imunológica , Humanos , Rinite Alérgica Sazonal/diagnóstico , Rinite Alérgica Sazonal/epidemiologia , Rinite Alérgica Sazonal/terapia
15.
PLoS One ; 8(6): e67850, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23826347

RESUMO

Black pigmented leaves are common among horticultural cultivars, yet are extremely rare across natural plant populations. We hypothesised that black pigmentation would disadvantage a plant by reducing photosynthesis and therefore shoot productivity, but that this trait might also confer protective benefits by shielding chloroplasts against photo-oxidative stress. CO2 assimilation, chlorophyll a fluorescence, shoot biomass, and pigment concentrations were compared for near isogenic green- and black-leafed Ophiopogonplaniscapus 'Nigrescens'. The black leaves had lower maximum CO2 assimilation rates, higher light saturation points and higher quantum efficiencies of photosystem II (PSII) than green leaves. Under saturating light, PSII photochemistry was inactivated less and recovered more completely in the black leaves. In full sunlight, green plants branched more abundantly and accumulated shoot biomass quicker than the black plants; in the shade, productivities of the two morphs were comparable. The data indicate a light-screening, photoprotective role of foliar anthocyanins. However, limitations to photosynthetic carbon assimilation are relatively small, insufficient to explain the natural scarcity of black-leafed plants.


Assuntos
Ophiopogon/fisiologia , Ophiopogon/efeitos da radiação , Fotossíntese/efeitos da radiação , Pigmentação/efeitos da radiação , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Luz Solar , Dióxido de Carbono/metabolismo , Clorofila/metabolismo , Clorofila A , Ritmo Circadiano/efeitos da radiação , Fluorescência , Ophiopogon/crescimento & desenvolvimento , Complexo de Proteína do Fotossistema II/metabolismo , Temperatura
16.
Mycorrhiza ; 20(6): 391-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20054589

RESUMO

All members of the Monotropoideae (Ericaceae), including the species, Allotropa virgata and Pleuricospora fimbriolata, are mycoheterotrophs dependent on associated symbiotic fungi and autotrophic plants for their carbon needs. Although the fungal symbionts have been identified for A. virgata and P. fimbriolata, structural details of the fungal-root interactions are lacking. The objective of this study was, therefore, to determine the structural features of these plant root-fungus associations. Root systems of these two species did not develop dense clusters of mycorrhizal roots typical of some monotropoid species, but rather, the underground system was composed of elongated rhizomes with first- and second-order mycorrhizal adventitious roots. Both species developed mantle features typical of monotropoid mycorrhizas, although for A. virgata, mantle development was intermittent along the length of each root. Hartig net hyphae were restricted to the host epidermal cell layer, and fungal pegs formed either along the tangential walls (P. fimbriolata) or radial walls (A. virgata) of epidermal cells. Plant-derived wall ingrowths were associated with each fungal peg, and these resembled transfer cells found in other systems. Although the diffuse nature of the roots of these two plants differs from some members in the Monotropoideae, the structural features place them along with other members of the Monotropoideae in the "monotropoid" category of mycorrhizas.


Assuntos
Ericaceae/microbiologia , Micorrizas/citologia , Ericaceae/ultraestrutura , Micorrizas/isolamento & purificação , Micorrizas/ultraestrutura , Oregon , Raízes de Plantas/microbiologia , Raízes de Plantas/ultraestrutura , Especificidade da Espécie
17.
Environ Microbiol Rep ; 2(4): 587-93, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23766229

RESUMO

Petroleum hydrocarbon (PHC) contamination is becoming more common in boreal forest soils. However, linkages between PHC biodegradation and microbial community dynamics in the mycorrhizosphere of boreal forest soils are poorly understood. Seedlings (lodgepole pine, paper birch, lingonberry) were established in reconstructed soil systems, consisting of an organic layer (mor humus, coarse woody debris, or previously oil-contaminated mor humus) overlying mineral (Ae, Bf) horizons. Light crude oil was applied to the soil surface after 4 months; systems were destructively sampled at 1 and 16 weeks following treatment. Soil concentrations of four PHC fractions were determined using acetone-hexane extraction followed by gas chromatography - flame ionization detection analysis. Genotypic profiles of root-associated bacterial communities were generated using length heterogeneity-PCR of 16S rDNA. Most plant-soil treatments showed significant loss in the smaller fraction PHCs indicating an inherent capacity for biodegradation. Concentrations of total PHCs declined significantly only in planted (pine-woody debris and birch-humus) systems (averaging 59% and 82% loss between 1 and 16 weeks respectively), reinforcing the importance of the mycorrhizosphere for enhancing microbial catabolism. Bacterial community structure was correlated more with mycorrhizosphere type and complexity than with PHC contamination. However, results suggest that communities in PHC-contaminated and pristine soils may become distinct over time.

18.
Rev Mal Respir ; 25(7): 821-7, 2008 Sep.
Artigo em Francês | MEDLINE | ID: mdl-18946407

RESUMO

INTRODUCTION: Input from Housing and health counselling services is advisable when a patient's health seems to be impaired by their housing conditions. METHODS: 650 home visits have been performed by our organisation since 2002. Each visit includes a questionnaire to assess respiratory as well as non-respiratory indoor risk factors, Acarex test to assess mite-allergen content in mattress dust, mould sampling and, when appropriate, air sampling for measurement of volatile organic compounds and aldehydes. RESULTS: The dwellings studied were mostly flats located in the downtown and occupied by a tenant. In most instances, several health hazards were identified. These hazards, in decreasing occurrence included: mold (74.4%), mite infestation in mattress dust (56.3%), cleaning products accessible to children's'hands (47.8%), dangerous electrical circuits (21.1%), exposure to chemical air pollutants (9.0%), exposure to an electromagnetic field (2.8%). Numerous fungal species were identified often occurring in association. CONCLUSION: This service allowed the identification of numerous and various health hazards. Its efficacy and effectiveness remains to be evaluated.


Assuntos
Poluição do Ar em Ambientes Fechados , Alérgenos , Asma , Monitoramento Ambiental/métodos , Substâncias Perigosas , Habitação , Adolescente , Adulto , Asma/diagnóstico , Asma/etiologia , Conjuntivite Alérgica/diagnóstico , Conjuntivite Alérgica/etiologia , Feminino , Habitação/normas , Humanos , Masculino , Pessoa de Meia-Idade , Infestações por Ácaros/diagnóstico , Rinite Alérgica Perene/diagnóstico , Rinite Alérgica Perene/etiologia , Fatores de Risco , Inquéritos e Questionários
20.
Mycorrhiza ; 18(2): 103-10, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18157555

RESUMO

Although roots of species in the Pinaceae are usually colonized by ectomycorrhizal (EM) fungi, there are increasing reports of the presence of arbuscular mycorrhizal (AM) and dark septate endophytic (DSE) fungi in these species. The objective of this study was to determine the colonization patterns in seedlings of three Pinus (pine) species (Pinus banksiana, Pinus strobus, Pinus contorta) and Picea glauca x Picea engelmannii (hybrid spruce) grown in soil collected from a disturbed forest site. Seedlings of all three pine species and hybrid spruce became colonized by EM, AM, and DSE fungi. The dominant EM morphotype belonged to the E-strain category; limited colonization by a Tuber sp. was found on roots of Pinus strobus and an unknown morphotype (cf. Suillus-Rhizopogon group) with thick, cottony white mycelium was present on short roots of all species. The three fungal categories tended to occupy different niches in a single root system. No correlation was found between the percent root colonized by EM and percent colonization by either AM or DSE, although there was a positive correlation between percent root length colonized by AM and DSE. Hyphae and vesicles were the only AM intracellular structures found in roots of all species; arbuscules were not observed in any roots.


Assuntos
Fungos/isolamento & purificação , Micorrizas/crescimento & desenvolvimento , Picea/microbiologia , Pinus/microbiologia , Plântula/microbiologia , Raízes de Plantas/microbiologia , Árvores
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...