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Environmental Epidemiology... Dec 2023We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass)...
OBJECTIVE
We aimed to assess whether the influence of urban vegetation on asthma development in children (<13 years) varies by type (e.g., total vegetation, tree type, and grass) and season.
METHODS
We used a cohort of all children born in Montreal, Canada, between 2000 and 2015. Children and cases were identified from linked medico-administrative databases. Exposure to residential vegetation was estimated using the Normalized Difference Vegetation Index (NDVI) for total vegetation and using the total area covered by deciduous and evergreen crowns for trees in 250 m buffers centered on residential postal codes. Seasonal variations in vegetation were modeled by setting values to zero on days outside of pollen and leaf-on seasons. Cox models with vegetation exposures, age as a time axis, and adjusted for sex, material deprivation, and health region were used to estimate hazard ratios (HR) for asthma development.
RESULTS
We followed 352,946 children for a total of 1,732,064 person-years and identified 30,816 incident cases of asthma. While annual vegetation (total and trees) measures did not appear to be associated with asthma development, models for pollen and leaf-on seasons yielded significant nonlinear associations. The risk of developing asthma was lower in children exposed to high levels (>33,300 m) of deciduous crown area for the leaf-on season (HR = 0.69; 95% confidence interval [CI] = 0.67, 0.72) and increased for the pollen season (HR = 1.07; 95% CI =1.02, 1.12), compared with unexposed children. Similar results were found with the Normalized Difference Vegetation Index.
CONCLUSION
The relationship between urban vegetation and childhood asthma development is nonlinear and influenced by vegetation characteristics, from protective during the leaf-on season to harmful during the pollen season.
PubMed: 38912389
DOI: 10.1097/EE9.0000000000000280 -
Applications in Plant Sciences 2024In this study, we use simulations to determine how pollen flow and sampling constraints can influence the genetic conservation found in seed collections.
PREMISE
In this study, we use simulations to determine how pollen flow and sampling constraints can influence the genetic conservation found in seed collections.
METHODS
We simulated genotypes of parental individuals and crossed the parentals based on three different ranges of pollen flow (panmictic, limited, and highly limited) to create new seed sets for sampling. We tested a variety of sampling scenarios modeled on those occurring in nature and calculated the proportion of alleles conserved in each scenario.
RESULTS
We found that pollen flow greatly influences collection outcomes, with panmictic pollen flow resulting in seed sets containing 21.6% more alleles than limited pollen flow and 48.6% more alleles than highly limited pollen flow, although this impact diminishes when large numbers of maternal plants are sampled. Simulations of realistic seed sampling (sampling more seed from some plants and fewer from others) showed a relatively minor impact (<2.5%) on genetic diversity conserved compared to ideal sampling (uniform sampling across all maternal plants).
DISCUSSION
We conclude that future work must consider limited pollen flow, but collectors can be flexible with their sampling in the field as long as many unique maternal plants are sampled. Simulations remain a fruitful method to advance ex situ sampling guidelines.
PubMed: 38912130
DOI: 10.1002/aps3.11561 -
Frontiers in Immunology 2024Pollen from , i.e., saltwort, Russian thistle, is a major allergen source in the coastal regions of southern Europe, in Turkey, Central Asia, and Iran. allergic patients...
Pollen from , i.e., saltwort, Russian thistle, is a major allergen source in the coastal regions of southern Europe, in Turkey, Central Asia, and Iran. allergic patients mainly suffer from hay-fever (i.e., rhinitis and conjunctivitis), asthma, and allergic skin symptoms. The aim of this study was to investigate the importance of individual allergen molecules. Sal k 1, Sal k 2, Sal k 3, Sal k 4, Sal k 5, and Sal k 6 were expressed in as recombinant proteins containing a C-terminal hexahistidine tag and purified by nickel affinity chromatography. The purity of the recombinant allergens was analyzed by SDS-PAGE. Their molecular weight was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and their fold and secondary structure were studied by circular dichroism (CD) spectroscopy. Sera from clinically well-characterized -allergic patients were used for IgE reactivity and basophil activation experiments. allergen-specific IgE levels and IgE levels specific for the highly IgE cross-reactive profilin and the calcium-binding allergen from timothy grass pollen, Phl p 12 and Phl p 7, respectively, were measured by ImmunoCAP. The allergenic activity of natural pollen allergens was studied in basophil activation experiments. Recombinant allergens were folded when studied by CD analysis. The sum of recombinant allergen-specific IgE levels and allergen-extract-specific IgE levels was highly correlated. Sal k 1 and profilin, reactive with IgE from 64% and 49% of patients, respectively, were the most important allergens, whereas the other allergens were less frequently recognized. Specific IgE levels were highest for profilin. Of note, 37% of patients who were negative for Sal k 1 showed IgE reactivity to Phl p 12, emphasizing the importance of the ubiquitous cytoskeletal actin-binding protein, profilin, for the diagnosis of IgE sensitization in -allergic patients. rPhl p 12 and rSal k 4 showed equivalent IgE reactivity, and the clinical importance of profilin was underlined by the fact that profilin-monosensitized patients suffered from symptoms of respiratory allergy to saltwort. Accordingly, profilin should be included in the panel of allergen molecules for diagnosis and in molecular allergy vaccines for the treatment and prevention of allergy.
Topics: Humans; Profilins; Immunoglobulin E; Allergens; Salsola; Female; Pollen; Male; Cross Reactions; Adult; Recombinant Proteins; Rhinitis, Allergic, Seasonal; Middle Aged; Basophils; Antigens, Plant; Young Adult; Adolescent; Plant Proteins
PubMed: 38911871
DOI: 10.3389/fimmu.2024.1379833 -
Allergy, Asthma & Immunology Research May 2024This study investigated the impact of aeroallergens on the development and progression of chronic rhinosinusitis (CRS), with a focus on the specific associations between...
PURPOSE
This study investigated the impact of aeroallergens on the development and progression of chronic rhinosinusitis (CRS), with a focus on the specific associations between aeroallergens and CRS according to allergen type, number, and extent of sensitization.
METHODS
The medical records of 256 CRS patients were retrospectively analyzed. All were divided into nonallergic, house dust mite (HDM)-allergic, pollen-allergic, and double allergic groups via specific immunoglobulin E (IgE) testing. Clinical characteristics, computed tomography (CT) scores, olfactory functions, and demographic data were compared. Correlation analysis was performed to explore the relationships between the extent of allergen sensitization and CRS severity. Binary logistic regression analysis was used to identify risk factors for hyposmia and anosmia.
RESULTS
The allergic group exhibited higher total CT scores than the nonallergic group ( = 0.001). Sensitivity to HDM or pollen allergens alone was not significantly associated with increased CRS severity. No significant differences were observed between the effects of HDM and pollen allergens on CRS severity. However, the double allergic group exhibited significantly higher CT scores ( < 0.001, < 0.001, and 0.003) than the other groups. Although the prevalence rates of anosmia and hyposmia were notably higher in the double allergic group, the difference was not statistically significant. The maximum specific IgE levels to HDM and pollen allergens positively correlated with the CT scores ( = 0.001 and 0.001, respectively).
CONCLUSIONS
Allergen sensitization, particularly to multiple common allergens, contributed to CRS severity. CRS patients sensitized to both HDM and pollen allergens tended to experience the diminished olfactory function. These findings underscore the importance of considering the allergen sensitization pattern when assessing CRS severity and its potential progression.
PubMed: 38910285
DOI: 10.4168/aair.2024.16.3.279 -
STAR Protocols Jun 2024Molecular identification of pollen carried by insects informs about their history of visited plants. For migratory butterflies, it can be used to trace long-range...
Molecular identification of pollen carried by insects informs about their history of visited plants. For migratory butterflies, it can be used to trace long-range movements enduring days of flight over thousands of kilometers. Here, we present a protocol to (1) isolate pollen grains from butterfly bodies and (2) prepare metabarcoding libraries for their identification using the internal transcribed spacer 2 fragment, a common barcode used to identify plants. This protocol would be applicable to other insect groups and metabarcoding markers. For complete details on the use and execution of this protocol, please refer to Suchan et al. and Gorki et al..
PubMed: 38907998
DOI: 10.1016/j.xpro.2024.103012 -
Frontiers in Allergy 2024Birch pollen-related food allergy (BPFA) is the most common type of food allergy in birch-endemic areas such as Western and Central Europe. Currently, there is no... (Review)
Review
BACKGROUND
Birch pollen-related food allergy (BPFA) is the most common type of food allergy in birch-endemic areas such as Western and Central Europe. Currently, there is no treatment available for BPFA. Due to the cross-reactivity between birch pollen and a range of implicated plant foods, birch pollen allergen immunotherapy (AIT) may be effective in the treatment of BPFA. In this study, we systematically evaluate the effectiveness of birch pollen-specific subcutaneous or sublingual immunotherapy in treating BPFA.
METHODS
A search was performed in the PubMed, Embase, and Cochrane libraries. Studies were independently screened by two reviewers against predefined eligibility criteria. The outcomes of interest were changes in (1) severity of symptoms during food challenge, (2) eliciting dose (ED), and (3) food allergy quality of life (FA-QoL). The validity of the selected articles was assessed using the revised Cochrane risk of bias tool. We focused on studies with the lowest risk of bias and considered studies with a high risk of bias as supportive. Data were descriptively summarized.
RESULTS
Ten studies were selected that included 475 patients in total. Seven studies were categorized into "high risk of bias" and three into "moderate risk of bias." The three moderate risk of bias studies, with a total of 98 patients, reported on severity of symptoms during challenge and on the ED. All three studies had a control group. Compared to the control group, improvement in severity of symptoms was observed during challenge in two out of the three studies and on the eliciting dose in one out of three. Only one study investigated the effect of birch pollen AIT on FA-QoL, showing that there was no significant difference between patients receiving subcutaneous immunotherapy or a placebo. Of the seven supportive studies, four had a control group and of those, three showed improvement on both severity of symptoms and ED. None of the supportive studies investigated the effect of the therapy on FA-QoL.
CONCLUSION
This systematic review shows that there is not enough evidence to draw firm conclusions about the effect of AIT on BPFA. Future research is warranted that uses robust clinical studies that include long-term effects, QoL, and multiple BPFA-related foods.
PubMed: 38903704
DOI: 10.3389/falgy.2024.1360073 -
Plant Direct Jun 2024Chloroplasts play a vital role in plant growth and development, which are the main sites of photosynthesis and the production of hormones and metabolites. Despite their...
Chloroplasts play a vital role in plant growth and development, which are the main sites of photosynthesis and the production of hormones and metabolites. Despite their significance, the regulatory mechanisms governing chloroplast development remain unclear. In our investigation, we identified a rice mutant with defective chloroplasts in rice ( L.), named albino lethal 13 (), which displayed a distinct albino phenotype in leaves, ultimately resulting in seedling lethality. Molecular cloning revealed that encodes a novel rice protein with no homologous gene or known conserved domain. This gene was located in the chloroplast and exhibited constitutive expression in various tissues, particularly in green tissues and regions of active cell growth. Our study's findings reveal that RNAi-mediated knockdown of led to a pronounced albino phenotype, reduced chlorophyll and carotenoid contents, a vesicle chloroplast structure, and a decrease in the expression of chloroplast-associated genes. Consequently, the pollen fertility and seed setting rate were lower compared with the wild type. In contrast, the overexpression of resulted in an increased photosynthetic rate, a higher total grain number per panicle, and enhanced levels of indole-3-acetic acid (IAA) in the roots and gibberellin A3 (GA3) in the shoot. These outcomes provide new insights on the role of in regulating chloroplast development in rice.
PubMed: 38903415
DOI: 10.1002/pld3.610 -
Evolutionary Applications Jun 2024Land-use change and habitat fragmentation are threats to biodiversity. The decrease in available habitat, increase in isolation, and mating within populations can lead...
Land-use change and habitat fragmentation are threats to biodiversity. The decrease in available habitat, increase in isolation, and mating within populations can lead to elevated inbreeding, lower genetic diversity, and poor fitness. Here we investigate the genetics of two rare and threatened plant species, and , and we compare them to a widespread congener . We also report the first phylogenetic study of the genus (Apocynaceae), including 10 of the 17 taxa and multiple sampling locations, to understand species relationships. We used a double digest restriction-site associated DNA sequencing (ddRADseq) approach to investigate the genetic diversity and gene flow of each species and to create a maximum likelihood phylogeny. The ddRADseq data was mapped to a reference genome to separate out the chloroplast and nuclear markers for population genetic analysis. Our results show that genetic diversity and inbreeding were low across all three species. The chloroplast and nuclear dataset in were highly structured, whereas they showed no structure for , while lacked structure for nuclear data but not chloroplast. Phylogenetic results revealed that is distinct and sister to , and together they are distantly related to . Our results demonstrated that evolutionary history and contemporary ecological processes largely influences genetic diversity within . Interestingly, we show that in there was significant structure despite being pollinated by large, bodied hawkmoths that are known to be able to carry pollen long distances, suggesting that other factors are contributing to the structure observed among populations. Conservation efforts should focus on protecting all of the populations, as they contain unique genetic diversity, and a protection plan for needs to be established due to its limited distribution.
PubMed: 38903246
DOI: 10.1111/eva.13736 -
Molecular Plant Jun 2024Xenia, the phenomenon in which the pollen genotype directly affects the phenotypic characteristics of the maternal tissues (i.e., fruit ripening), has applications in...
Xenia, the phenomenon in which the pollen genotype directly affects the phenotypic characteristics of the maternal tissues (i.e., fruit ripening), has applications in crop production and breeding. However, the underlying molecular mechanism has yet to be elucidated. Here, we investigated whether mobile mRNAs from the pollen affect the ripening and quality-related characteristics of the fruit using cross-pollination between distinct Malus domestica (apple) cultivars. We demonstrated that hundreds of mobile mRNAs originating from the seeds are delivered to the fruit. We also found that the movement of one of these mRNAs, ACC oxidase 3 (MdACO3), is coordinated with fruit ripening. Salicylic acid treatment, which can cause plasmodesmal closure, blocks MdACO3 movement, indicating that MdACO3 transcripts may move through plasmodesmata. To assess the role of mobile MdACO3 transcripts in apple fruit, we created MdACO3-GFP-expressing apple seeds using MdACO3-GFP-overexpressing pollen for pollination and showed that MdACO3 transcripts in the transgenic seeds move to the flesh where they regulate fruit ripening. Furthermore, we demonstrated that MdACO3 can be transported from the seeds to fruit in the fleshy-fruited species tomato and strawberry. These results underscore the potential of mobile mRNAs from seeds to influence fruit characteristics, providing an explanation for the xenia phenomenon. Notably, our findings highlight the feasibility of leveraging diverse pollen genomic resources, without resorting to genome editing, to improve fruit quality.
PubMed: 38902921
DOI: 10.1016/j.molp.2024.06.008 -
Frontiers in Nutrition 2024Pollen grains are the male reproductive part of the flowering plants. It is collected by forager honey bees and mixed with their salivary secretions, enzymes, and... (Review)
Review
Pollen grains are the male reproductive part of the flowering plants. It is collected by forager honey bees and mixed with their salivary secretions, enzymes, and nectar, which form fermented pollen or "bee bread" which is stored in cells of wax honeycombs. Bee pollen (BP) is a valuable apitherapeutic product and is considered a nutritional healthy food appreciated by natural medicine from ancient times. Recently, BP has been considered a beneficial food supplement and a value-added product that contains approximately 250 different bioactive components. It contains numerous beneficial elements such as Mg, Ca, Mn, K, and phenolic compounds. BP possesses strong antioxidant, anti-inflammatory, antimicrobial, antiviral, analgesic, immunostimulant, neuroprotective, anti-cancer, and hepatoprotective properties. It is used for different purposes for the welfare of mankind. Additionally, there is a growing interest in honey bee products harvesting and utilizing for many purposes as a natural remedy and nutritive function. In this review, the impacts of BP on different organisms in different ways by highlighting its apitherapeutic efficacy are described.
PubMed: 38899322
DOI: 10.3389/fnut.2024.1371672