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At least 19 recordsLinked to original sources
PubMed2002

Potential impact of global warming on deciduous oak dieback caused by ambrosia fungus Raffaelea sp. carried by ambrosia beetle Platypus quercivorus (Coleoptera: Platypodidae) in Japan.

Deciduous oak dieback in Japan has been known since the 1930s, but in the last ten years epidemics have intensified and spread to the island's western coastal areas. The symbiotic ambrosia fungus Raffaelea sp. is the causal agent of oak dieback, and is vectored by Platypus quercivorus (Murayama). This is the first example of an ambrosia beetle fungus that kills vigorous trees. Mortality of Quercus crispula was approximately 40% but much lower for associated species of Fagaceae, even though each species had a similar number of beetle attacks. It is likely that other oaks resistant to the fungus evolved under a stable relationship between the tree, fungus and beetle during a long evolutionary process. Quercus crispula was probably not part of this coevolution. This hypothesis was supported by the fact that P. quercivorus showed the least preference for Q. crispula yet exhibited highest reproductive success in this species. Therefore, P. quercivorus could spread more rapidly in stands with a high composition of Q. crispula. The present oak dieback epidemic in Japan probably resulted from the warmer climate that occurred from the late 1980s which made possible the fateful encounter of P. quercivorus with Q. cripsula by allowing the beetle to extend its distribution to more northerly latitudes and higher altitudes. Future global warming will possibly accelerate the overlapping of the distributions of P. quercivorus and Q. crispula with the result that oak dieback in Q. crispula will become more prevalent in Japan.

Animals↗
PubMed1992

Studies of the HLA class II alleles involved in human responses to ragweed allergens Ambrosia artemisiifolia V (Ra5S) and Ambrosia trifida V (Ra5G)

Previous studies have associated skin test sensitivity and specific IgE response to Ambrosia artemisiifolia V (Amb a V) with HLA-DR2, and to Ambrosia trifida V (Amb t V) with HLA-DRw52 haplotypes in atopic individuals. Using HLA class II typing by restriction fragment length polymorphism (RFLP) analysis with DRB, DQB and DQA DNA probes to define the HLA-D alleles, we have demonstrated the association of the DQw6 in 16 out of 16 (100%) Amb a V-responsive individuals, compared to 3 out of 18 (17%) ragweed-sensitive but Amb a V-nonresponsive individuals (p = 5.7 x 10(-6), RR greater than 75). We suggest that the DQw6 association with Amb a V sensitivity may be a reflection of an association with the DQA*0102 allele. This suggests an association of a particular HLA class II allele with an immune response to a well-characterized antigen (Amb a V). The HLA-DRw52 haplotypes in the Amb t V-sensitive individuals are not of one particular subtype. The HLA-DRw52 association with Amb t V sensitivity may reside in homologous DRB1 alleles linked on HLA-DRw52-bearing haplotypes.

Alleles↗
PubMed1995

T cell epitope mapping of ragweed pollen allergen Ambrosia artemisiifolia (Amb a 5) and Ambrosia trifida (Amb t 5) and the role of free sulfhydryl groups in T cell recognition.

Ambrosia artemisiifolia (Amb a 5; Ra5S) and Ambrosia trifida (Amb t 5; Ra5G) are homologous allergens purified from short and giant ragweed pollen, respectively. Allergic human sera and hyperimmunized animal antisera directed against Amb a 5 or Amb t 5 show a high degree of species specificity, with little or no cross-reactivity between these two allergens, suggesting that the major Ab binding epitopes of Amb a 5 and Amb t 5 are distinct. Overlapping synthetic peptides derived from the allergen sequences were used to investigate the specificity of T cell responses in four strains of mice, BALB/c (H-2d), CBA (H-2k), C57BL/6 (H-2b), and A/J (H-2a). All four strains of mice responded to purified Amb a 5 and Amb t 5. Cross-reactivity was found at the T cell level between Amb a 5 and Amb t 5 in T cells from BALB/c, A/J, and CBA mice, but not in T cells from C57BL/6 mice. A T cell epitope from Amb a 5, residues 27-36 (PWQVVCYESS), was mapped using T cell hybridomas from BALB/c mice. A T cell epitope in Amb t 5 was mapped in the same strain to residues 24-34 (KYCVCYDSKAI). Disulfide bonds in Amb a 5 and Amb t 5 were found to be involved in T cell reactivity. Conversion of disulfide bridges into free sulfhydryl (SH) forms was required for the response of T cell hybridomas to peptide t5 (residues 27-40) from Amb t 5. Reduction of peptide a4 (residues 21-37) from Amb a 5 was essential for inducing the cross-reactivity observed with Amb t 5-specific T cell hybridomas. It is concluded that free sulfhydryl groups play a major role in the T cell recognition of cross-reactivity T cell epitopes within these related allergens.

Allergens↗
PubMed2006

Examining Ambrosia pollen episodes at Poznań (Poland) using back-trajectory analysis.

The pollen grains of Ambrosia spp. are considered to be important aeroallergens in parts of southern and central Europe. Back-trajectories have been analysed with the aim of finding the likely sources of Ambrosia pollen grains that arrived at Poznań (Poland). Temporal variations in Ambrosia pollen at Poznań from 1995-2005 were examined in order to identify Ambrosia pollen episodes suitable for further investigation using back-trajectory analysis. The trajectories were calculated using the transport model within the Lagrangian air pollution model, ACDEP (Atmospheric Chemistry and Deposition). Analysis identified two separate populations in Ambrosia pollen episodes, those that peaked in the early morning between 4 a.m. and 8 a.m., and those that peaked in the afternoon between 2 p.m. and 6 p.m.. Six Ambrosia pollen episodes between 2001 and 2005 were examined using back-trajectory analysis. The results showed that Ambrosia pollen episodes that peaked in the early morning usually arrived at Poznań from a southerly direction after passing over southern Poland, the Czech Republic, Slovakia and Hungary, whereas air masses that brought Ambrosia pollen to Poznań during the afternoon arrived from a more easterly direction and predominantly stayed within the borders of Poland. Back-trajectory analysis has shown that there is a possibility that long-range transport brings Ambrosia pollen to Poznań from southern Poland, the Czech Republic, Slovakia and Hungary. There is also a likelihood that Ambrosia is present in Poland, as shown by the arrival of pollen during the afternoon that originated primarily from within the country.

Air↗
PubMed2003

[Ambrosia, Franseria, Xanthium from the Bonaparte Herbarium].

Recently, French Association for Ragweed Study (AFEDA) founders published, in French, a book "Ambrosia, ragweed, biological pollutants". This association was founded in 1982. The authors referred to Bonaparte Herbarium set up in the Université Claude-Bernard Lyon 1. This herbarium is ranking second in France and seventh in the world. There were three aims for this work: to set up, for this herbarium, a complete list of different species of Ambrosia, Franseria and their pollen grains and to study with them Xanthium whose pollen grains look like Ambrosia, to establish a chronological order for Ambrosia that were collected in Europe and in some countries of the New World, to compare some pollen grains of Ambrosia and Xanthium (scanning electronic microscope). Good state plants in spite of about a century of conservation could be selected. They were photographied and some pollens so. The consultation of this herbarium brought a better morphological knowledge of different species of Ambrosia, Franseria and Xanthium, (plants and pollen grains). The authors were able to broadcast this knowledge to scientists and interested public through their book.

Ambrosia↗
PubMed2004

Efficacy and safety of subcutaneous immunotherapy with a biologically standardized extract of Ambrosia artemisiifolia pollen: a double-blind, placebo-controlled study.

BACKGROUND: The allergological relevance of Ambrosia in Europe is growing but the efficacy of the injective immunotherapy for this allergen has been documented only in Northern America. OBJECTIVE: We sought to study the safety and efficacy of injective immunotherapy in European patients sensitized to Ambrosia artemisiifolia. METHODS: Thirty-two patients (18 M/14 F, mean age 36.78, range 23-60 years) suffering from rhinoconjunctivitis and/or asthma and sensitized to Ambrosia were enrolled and randomized in a double-blind, placebo-controlled (DBPC) study lasting 1 year. A maintenance dose corresponding to 7.2 microg of Amb a 1 was administered at 4-week intervals after the build-up. During the second and the third year, all patients were under active therapy in an open fashion. Symptom and medication scores, skin reactivity to Ambrosia (parallel line biological assay), and pollen counts were assessed throughout the trial. RESULTS: Twenty-three patients completed the trial. No severe adverse event was observed. During the DBPC phase, actively treated patients showed an improvement in asthmatic symptoms (P=0.02) and drug (P=0.0068) scores days with asthmatic symptoms (P=0.003), days with rhinitis symptoms (P=0.05), and days with intake of drugs (P=0.0058), as compared to before therapy. No improvement for any of these parameters was detected in the placebo group. Moreover, the number of days with rhinitis and asthma was significantly higher in the placebo as compared to the active group (P=0.048 and P<0.0001, respectively). Patients who switched from placebo to active therapy improved in rhinoconjunctivitis, asthma, and drug intake. The skin reactivity decreased significantly (12.2-fold, P=0.0001) in the active group whereas a slight increase (1.07-fold, P=0.87) was observed in the placebo group after the DBPC phase. After switching to active therapy, patients previously under placebo showed a significant decrease of this parameter (4.78-fold, P=0.002). CONCLUSION: Injective immunotherapy is safe and clinically effective in European patients sensitized to Ambrosia.

Adult↗
PubMedDate not supplied

Effects of sublingual immunotherapy in patients sensitised to Ambrosia. An open controlled study.

BACKGROUND: Allergy to Ambrosia is a disease of growing importance in Europe. Injective and non-injective immunotherapy have been recognised as safe and effective but no evidence is currently available for sublingual immunotherapy (SLIT) in patients sensitised to Ambrosia. This study was planned to assess the effects and the safety of SLIT in patients clinically sensitised to Ambrosia. METHODS: 19 patients clinically sensitised to Ambrosia and treated with SLIT were compared to 14 patients treated only with drugs. Diary cards with symptoms and drug consumption were filled-in by patients during the pollen season whereas specific nasal challenge and skin prick test were run two months before and after the pollen season. Patients and doctors were also asked to express their subjective assessment about symptoms and drug consumption during the season. RESULTS: SLIT-treated patients had less symptoms and a significantly minor drug intake (p = 0.04) as compared to untreated patients. Nasal challenge test improved significantly in the SLIT group (p = 0.0001) but not in the control group (p = 0.6875) with a significant difference between groups at the end (p = 0.0413) but not at the beginning of the trial (p = 0.213). The decrease in skin reactivity was significant in the control group (p = 0.0186) and highly significant in the SLIT group (p < 0.0001), with no difference between groups (p = 0.2987). Subjective assessment from both patients and doctors was favorable to SLIT (p = 0.0005 for symptoms; p = 0.0019 for drug consumption). Only one minor local side effect was registered during SLIT. CONCLUSIONS: According to our data, SLIT in patients allergic to Ambrosia is safe and able to improve both subjective and objective parameters.

Administration, Sublingual↗
PubMed2002

[Ambrosia pollen in Switzerland--produced locally or transported?].

The ambrosia (Ambrosia artemisiifolia L.) has been announced in Switzerland for more than 100 years. During the last decade, signs of an increased presence of the ambrosia and its pollen appear in the south-west of Switzerland, in particular in Geneva. Aerobiologic measurements make it possible to highlight the importance of the transport of pollen by the winds since the area of Lyon, where the ambrosia is abundant. It also bring elements making it possible to detect a local production of pollen in the Geneva area, where several invaded fields were discovered with the autumn 2001. A multidisciplinary group was created in Geneva and it attempts to prevent as far as possible probable invasion of the ambrosia.

Asteraceae↗
PubMed2006

Relationship between climate, pollen concentrations of Ambrosia and medical consultations for allergic rhinitis in Montreal, 1994-2002.

The aim of this study is to evaluate the influence of meteorological factors on Ambrosia pollen concentrations and its impact on medical consultations for allergic rhinitis of residents from various socio-economic levels in Montréal (Québec, Canada) between 1994 and 2002. The study was conducted to recognize the sensitivity of pollen productivity to daily climate variability in order to estimate the consequences on human health vulnerability in the context of global climate change. Information related to medical consultations for allergic rhinitis due to pollen comes from the Quebec Health Insurance Board (Régie de l'assurance-maladie du Québec). Ambrosia pollen concentration was measured by the Aerobiology Research Laboratories (Nepean, Ontario). Daily temperature (maximum, minimum, and mean) and precipitation data were obtained from the Meteorological Service of Canada. Socio-economic data come from the 1996 and 2001 census data of Statistics Canada. Between 1994 and 2002, during the Ambrosia pollen season, 7667 consultations for allergic rhinitis due to pollen were recorded. We found a significant association between the number of medical consultations and pollen levels. Significant associations were detected for over-consultation the day of exposure, 1, 2, 3 and 5 days after exposure to high levels of pollen. The consultation rate is higher from low-income residents (3.10 consultations per 10,000 inhabitants) than for high-income (1.65 consultations per 10,000 inhabitants). Considering the demonstrated impact of pollen levels on health, it has become critical to ensure adequate monitoring of Ambrosia and its meteorological sensivity in the context of the anticipated climate change and its potential consequences on human health.

Air Pollutants↗
PubMed2004

[Ambrosia pollen under high surveillance].

The pollinic season of ambrosia in 2003 present strong disturbances due to the meteorology of the end of this summer. The areas with the allergenic risk are concentrated on the area of Rhône-Alpes (more than 40 days with a risk equal to or higher than 3) and on the peripheral areas: the area Centre Auvergne with Saint Etienne, Clermont-Ferrand and Montlucon with approximately 10 days with a the allergenic risk equal to or higher than 3; the Saône-Savoie area with the towns of Macon and Grenoble with about twenty days with a allergenic risk equal to or higher than 3 and Dijon, Châlon-sur-Saône with 6 days with a allergic risk equal to or higher than 3; the Mediterranean area with the towns of Avignon and Aix-in-Provence presenting ten days with allergenic risk equal to or higher than 3, Marseille and Toulon with 7 days with a allergenic risk equal to or higher than 3. The allergic risk related to the ambrosia in 2003 had peaks overall less high, but the season is spread out and had during until September 20. The daily peaks for the Rhône-Dauphiné-Drôme area were noted between 6 h and 8 h or 8 h and 10 h, for 2003. On the peripheral areas, we remark a diversity of the daily peaks (Châlon-sur-Saône between 18 h and 20 h). Are these pollens local grains or immigrants grains? On Lyon I (Gerland), the follow-up of the data of the ambrosia since 1987 permit to remark a stagnation of the number of days with an allergic risk, despite a reduction of the number of pollens.

Air↗
PubMed2006

Ambrosia fungi in the insect-fungi symbiosis in relation to cork oak decline.

Ambrosia fungi live associated with beetles (Scolytidae and Platypodidae) in host trees and act as a food source for the insects. The symbiotic relation is important to the colonizing strategies of host trees by beetles. Ambrosia fungi are dimorphic: they grow as ambrosial form and as mycelium. The fungi are highly specialized, adapted to a specific beetle and to the biotope where they both live. In addition other fungi have been found such as tree pathogenic fungi that may play a role in insects host colonization success. Saprophytic fungi are also present in insects galleries. These may decompose cellulose and/or be antagonistic to other less beneficial fungi. This paper summarizes the importance of ambrosia fungi and the interaction with insects and hosts. The possibility of the transport of pathogenic fungi by Platypus cylindrus to cork oak thus contributing for its decline is discussed.

Animal Structures↗
PubMed1989

Health implications of radionuclide levels in cattle raised near U mining and milling facilities in Ambrosia Lake, New Mexico.

This study was conducted to determine radionuclide tissue levels in cattle raised near U mining and milling facilities. Ambrosia Lake, New Mexico, has been the site of extensive U mining for 30 y and contains several underground U mines, a processing mill, and two large U tailings piles. Ten cows were purchased from two grazing areas in Ambrosia Lake and ten control animals were purchased from Crownpoint, New Mexico. Muscle, liver, kidney, and bone tissue taken from these animals, and environmental samples, including water, grasses and soil collected from the animals' grazing areas, were analyzed for 238U, 234U, 230Th, 226Ra, 210Pb, and 210Po. Mean radionuclide levels in cattle tissue and environmental samples from Ambrosia Lake were higher in almost every comparison than those found in respective controls. Liver and kidney tissues were particularly elevated in 226Ra and 210Po. Radiation dose commitments from eating cattle tissue with these radionuclide concentrations were calculated. We concluded that the health risk to the public from eating exposed cattle is minimal, unless large amounts of this tissue, especially liver and kidney, are ingested.

Animals↗
PubMed1992

[Problems and eradication of Ambrosia artemisiifolia L. in Quebec in the urban and suburban environments].

Ambrosia artemisiifolia is a common weed in Canada and it is one of the most important source of aero-allergenic pollen in the north-eastern part of North America. It is a problem mostly along roads in urban or suburban areas. It is easily controlled by herbicides but their use is increasingly restricted because of environmental considerations. Therefore, new methods must be developed to control this weed. Three types of controls were evaluated against Ambrosia artemisiifolia along an expressway in the summer of 1990. The control methods were hand weeding, mowing at 2 cm, 5 cm, or 8 cm, and crushing by a roadroller. These treatments were done at different dates in the course of the summer. Hand weeding was the most effective in reducing pollen and seed production although it was also the most expensive. Mowing was very effective when it was done at a height of 2 cm from the soil. It is the only height at which seed production was significantly reduced. Mowing efficacy in reducing pollen production tended to decrease with the raising of the mowing blade. The efficiency of weed pulling or moving improved when they were performed later in the growing season. Crushing was not an effective method of control. Mowing or hand weeding cannot eradicate Ambrosia artemisiifolia but if they are consistently used, they could reduce its population level over several years by decreasing seed production. The treatments either eliminated pollen production or reduced it at least by 88%, thereby insuring a relative relief for people allergic to the pollen of this plant.

Agriculture↗
PubMed2005

Dryadomyces amasae: a nutritional fungus associated with ambrosia beetles of the genus Amasa (Coleoptera: Curculionidae, Scolytinae).

During surveys of woodlands in Taiwan a previously undescribed fungus Dryadomyces amasae gen. sp. nov., was found in the sapwood of dead angiosperm timbers in the gallery systems of the scolytine ambrosia beetle Amasa concitatus. The fungus grows predominantly in the immediate vicinity of the feeding beetle larvae and serves as a nutritional ambrosia fungus. The transmission of D. amasae to new breeding substrates is ensured by an oral mycetangium, a paired organ which was found in A. concitatus and A. aff. glaber near the mandibles and contained multiple cells of the fungus. Morphologically D. amasae resembles species of Ambrosiella. However, phylogenetic analysis based on partial nucSSU rDNA placed the fungus with certain species of the genus Ambrosiella within the Ophiostomatales, whereas the type species of Ambrosiella, A. xylebori, was assigned to the Microascales. A. xylebori, as well as A. ferruginea and A. hartigii, demonstrated phialidic conidial development, leading to an emendation of the description of the genus Ambrosiella. In contrast, Dryadomyces exhibited conidial development by apical, sympodial wall formation with prominent denticles bearing conidia. Other, previously described Ambrosiella species exhibited non-phialidic conidiogenesis, but lacked denticles on the conidiophores. Consequently, their classification needs further revision.

Ambrosia↗