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Iranian Journal of Allergy, Asthma, and... Apr 2024Allergen-specific immunotherapy is the only disease-modifying treatment for IgE-mediated allergic disorders. Intra lymphatic immunotherapy (ILIT) is an efficacious and... (Clinical Trial)
Clinical Trial
Allergen-specific immunotherapy is the only disease-modifying treatment for IgE-mediated allergic disorders. Intra lymphatic immunotherapy (ILIT) is an efficacious and time-saving alternative to subcutaneous immunotherapy (SCIT). This study aimed to evaluate the effects and safety of ILIT in patients with moderate to severe allergic rhinitis. In this clinical trial, patients between 18 and 65 years old with moderate to severe allergic rhinitis were enrolled. They received monthly intra-lymphatic inguinal injections of an active allergen (1000 SQ-U Salsola kali pollen). Their clinical symptoms were assessed before and four weeks after treatments. The clinical signs were also evaluated during two consecutive pollination seasons and the following non-pollination season in April. No moderate or severe reactions were recorded following ILIT treatment. Lymph node enlargement, angioedema/urticaria, and local itching were seen instantly after injection. Patients who received ILIT experienced a significant clinical improvement in self-recorded seasonal allergic symptoms after the treatments, compared to themselves before ILIT. Furthermore, their quality of life significantly improved. This study suggests ILIT with Salsola-pollen extract may decrease symptoms of allergic rhinitis. It was safe and did not cause any crucial complications.
Topics: Humans; Rhinitis, Allergic, Seasonal; Adult; Male; Female; Desensitization, Immunologic; Quality of Life; Middle Aged; Injections, Intralymphatic; Young Adult; Allergens; Severity of Illness Index; Adolescent; Treatment Outcome; Aged; Pollen
PubMed: 38822510
DOI: 10.18502/ijaai.v23i2.15321 -
Conservation Physiology 2024Bumblebee populations across the globe are experiencing substantial declines due to climate change, with major consequences for pollination services in both natural and...
Bumblebee populations across the globe are experiencing substantial declines due to climate change, with major consequences for pollination services in both natural and agricultural settings. Using an economically important species, , we explored the physiological mechanisms that may cause susceptibility to extreme heat events. We tested the hypothesis that heat exposure limits the activity of the pentose phosphate pathway (PPP)-a parallel pathway to glycolysis that can use nectar sugar to generate antioxidant potential and combat oxidative stress. Using isotopically labelled glucose, we tracked PPP activity in at rest, during exercise and during a post-exercise recovery period under two different temperature regimes (22°C and 32°C). We found that the PPP is routinely used by at moderate temperatures, but that its activity is markedly reduced when ATP demands are high, such as during periods of exercise and heat exposure. We also exposed to either 22°C or 32°C for 5 hours and assessed levels of oxidative damage (lipid peroxidation, protein carbonyls) and antioxidant potential [reduced (GSH) and oxidized (GSSG) glutathione concentrations]. Interestingly, bees exhibited little oxidative damage after the thermal exposure, but we found a lower GSH:GSSG ratio in 32°C-exposed bees, reflecting lower antioxidant potential. Overall, our study demonstrates that acute heat stress severely limits PPP activity and may constrain antioxidant potential in . The repeated attenuation of this pathway in a warming climate may have more severe physiological consequences for this species, with potential implications for pollination services across North America.
PubMed: 38812726
DOI: 10.1093/conphys/coae031 -
PloS One 2024The sweat bee Halictus rubicundus is an important pollinator with a large latitudinal range and many potential barriers to gene flow. Alongside typical physical...
The sweat bee Halictus rubicundus is an important pollinator with a large latitudinal range and many potential barriers to gene flow. Alongside typical physical barriers, including mountain ranges and oceans, the climate may also impose restrictions on gene flow in this species. The climate influences voltinism and sociality in H. rubicundus, which is bivoltine and can nest socially at warmer lower latitudes but tends to be univoltine and solitary in the cooler north. Variation in voltinism could result in phenological differences, potentially limiting gene flow, but a previous study found no evidence for this in H. rubicundus populations in mainland Britain. Here we extend the previous study to consider populations of H. rubicundus at extreme northern and southern latitudes in the UK. We found that bees from a population in the far north of Scotland were genetically differentiated from bees collected in Cornwall in the south-west of England. In contrast, bees collected across the Irish Sea in Northern Ireland showed slight genetic overlap with both the Scottish and Cornish bees. Our results suggest that when populations at extreme latitudes are considered, phenology and the climate may act alongside physical barriers such as the Scottish Highlands and the Irish Sea to restrict gene flow in H. rubicundus. We discuss the implications of our results for local adaptation in the face of rapidly changing selection pressures which are likely under climate change.
Topics: Animals; Bees; Gene Flow; Genetic Variation; Microsatellite Repeats; Scotland; Genetics, Population
PubMed: 38809856
DOI: 10.1371/journal.pone.0302688 -
Plant Diversity Mar 2024Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is...
Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic, 13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants. Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.
PubMed: 38807913
DOI: 10.1016/j.pld.2023.07.010 -
Plant Diversity Mar 2024Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of...
Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of hybridization, particularly at ecological margins where parental species may exhibit reduced fitnesses. Moreover, it is unknown whether future ecosystem change will increase the prevalence of hybridization. and are closely related species co-distributed from southern Thailand to southwest China where hybridization, yielding viable seeds, has been documented. As a robust test of ecological factors driving hybridization, we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range. Both species showed high population differentiation and strong patterns of isolation by distance. Admixture estimates exposed asymmetric interspecific gene flow. Signatures of hybridization increase significantly towards higher latitude zones, peaking at the northern climatic margins. Geographic variation in reproductive phenology combined with ecologically challenging marginal habitats may promote this phenomenon. Our work is a first systematic evaluation of such patterns in a comprehensive, latitudinally-based clinal context, and indicates that tendency to hybridize appears strongly influenced by environmental conditions. Moreover, that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.
PubMed: 38807912
DOI: 10.1016/j.pld.2023.08.003 -
Open Biology May 2024Both leaves and petals are covered in a cuticle, which itself contains and is covered by cuticular waxes. The waxes perform various roles in plants' lives, and the...
Both leaves and petals are covered in a cuticle, which itself contains and is covered by cuticular waxes. The waxes perform various roles in plants' lives, and the cuticular composition of leaves has received much attention. To date, the cuticular composition of petals has been largely ignored. Being the outermost boundary between the plant and the environment, the cuticle is the first point of contact between a flower and a pollinator, yet we know little about how plant-pollinator interactions shape its chemical composition. Here, we investigate the general structure and composition of floral cuticular waxes by analysing the cuticular composition of leaves and petals of 49 plant species, representing 19 orders and 27 families. We show that the flowers of plants from across the phylogenetic range are nearly devoid of wax crystals and that the total wax load of leaves in 90% of the species is higher than that of petals. The proportion of alkanes is higher, and the chain lengths of the aliphatic compounds are shorter in petals than in leaves. We argue these differences are a result of adaptation to the different roles leaves and petals play in plant biology.
Topics: Plant Leaves; Waxes; Flowers; Phylogeny; Plant Epidermis; Plants; Species Specificity
PubMed: 38806146
DOI: 10.1098/rsob.230430 -
Journal of Insect Science (Online) May 2024Honey bees exhibit age polyethism and thus have a predictable sequence of behaviors they express through developmental time. Numerous laboratory studies show exposure to...
Honey bees exhibit age polyethism and thus have a predictable sequence of behaviors they express through developmental time. Numerous laboratory studies show exposure to pesticides may impair critical honey bee behaviors (brood care, foraging, egg-laying, etc.) that adversely affect colony productivity and survival. There are fewer studies that examine the impacts of pesticides in natural field settings, especially given the challenges of implementing treatment groups and controlling variables. This study helps address the need for impact studies on pollinators under field conditions to assess the consequences of chemical overuse and dependency in agricultural and urban landscapes. To assess the impact of systemic pesticides in a natural field setting on worker bee behavioral development, observation hives were established to monitor changes in behaviors of similarly aged workers and sister queens within 2 experimental groups: (i) colonies located near point-source systemic pesticide pollution (pesticide contaminated treatment), and (ii) colonies embedded within a typical Midwestern US agricultural environment (control). In this study, worker bees in the contaminated environment exhibited important and biologically significant behavioral differences and accelerated onset of hive tasks (i.e., precocious behavioral development) compared to similarly aged bees at the control site. Queen locomotion was largely unaffected; however, the egg-laying rate was reduced in queens at the contaminated (treated) site. These results show that environmental pesticide exposure can disrupt colony function and adversely affect worker bee behavioral maturation, leading to reduced worker longevity and decreased colony efficiency.
Topics: Animals; Bees; Behavior, Animal; Pesticides; Female
PubMed: 38805655
DOI: 10.1093/jisesa/ieae034 -
Journal of Insect Science (Online) May 2024Managed honey bee (Apis mellifera L.) colonies in North America and Europe have experienced high losses in recent years, which have been linked to weather conditions,...
Managed honey bee (Apis mellifera L.) colonies in North America and Europe have experienced high losses in recent years, which have been linked to weather conditions, lack of quality forage, and high parasite loads, particularly the obligate brood parasite, Varroa destructor. These factors may interact at various scales to have compounding effects on honey bee health, but few studies have been able to simultaneously investigate the effects of weather conditions, landscape factors, and management of parasites. We analyzed a dataset of 3,210 survey responses from beekeepers in Pennsylvania from 2017 to 2022 and combined these with remotely sensed weather variables and novel datasets about seasonal forage availability into a Random Forest model to investigate drivers of winter loss. We found that beekeepers who used treatment against Varroa had higher colony survival than those who did not treat. Moreover, beekeepers who used multiple types of Varroa treatment had higher colony survival rates than those who used 1 type of treatment. Our models found weather conditions are strongly associated with survival, but multiple-treatment type colonies had higher survival across a broader range of climate conditions. These findings suggest that the integrated pest management approach of combining treatment types can potentially buffer managed honey bee colonies from adverse weather conditions.
Topics: Animals; Bees; Varroidae; Beekeeping; Weather; Seasons; Pennsylvania; Pest Control; Colony Collapse
PubMed: 38805654
DOI: 10.1093/jisesa/ieae043 -
Journal of Insect Science (Online) May 2024Agrochemical exposure is a major contributor to ecological declines worldwide, including the loss of crucial pollinator species. In addition to direct toxicity,...
Neonicotinoid exposure increases Varroa destructor (Mesostigmata: Varroidae) mite parasitism severity in honey bee colonies and is not mitigated by increased colony genetic diversity.
Agrochemical exposure is a major contributor to ecological declines worldwide, including the loss of crucial pollinator species. In addition to direct toxicity, field-relevant doses of pesticides can increase species' vulnerabilities to other stressors, including parasites. Experimental field demonstrations of potential interactive effects of pesticides and additional stressors are rare, as are tests of mechanisms via which pollinators tolerate pesticides. Here, we controlled honey bee colony exposure to field-relevant concentrations of 2 neonicotinoid insecticides (clothianidin and thiamethoxam) in pollen and simultaneously manipulated intracolony genetic heterogeneity. We showed that exposure increased rates of Varroa destructor (Anderson and Trueman) parasitism and that while increased genetic heterogeneity overall improved survivability, it did not reduce the negative effect size of neonicotinoid exposure. This study is, to our knowledge, the first experimental field demonstration of how neonicotinoid exposure can increase V. destructor populations in honey bees and also demonstrates that colony genetic diversity cannot mitigate the effects of neonicotinoid pesticides.
Topics: Animals; Bees; Varroidae; Genetic Variation; Neonicotinoids; Insecticides; Thiazoles; Thiamethoxam; Guanidines; Host-Parasite Interactions; Nitro Compounds
PubMed: 38805648
DOI: 10.1093/jisesa/ieae056 -
Journal of Insect Science (Online) May 2024Honey bees are the most important managed insect pollinators in the US and Canadian crop systems. However, the annual mortality of colonies in the past 15 years has been...
Honey bees are the most important managed insect pollinators in the US and Canadian crop systems. However, the annual mortality of colonies in the past 15 years has been consistently higher than historical records. Because they are eusocial generalist pollinators and amenable to management, honey bees provide a unique opportunity to investigate a wide range of questions at molecular, organismal, and ecological scales. Here, the American Association of Professional Apiculturists (AAPA) and the Canadian Association of Professional Apiculturists (CAPA) created 2 collections of articles featuring investigations on micro and macro aspects of honey bee health, sociobiology, and management showcasing new applied research from diverse groups studying honey bees (Apis mellifera) in the United States and Canada. Research presented in this special issue includes examinations of abiotic and biotic stressors of honey bees, and evaluations and introductions of various stress mitigation measures that may be valuable to both scientists and the beekeeping community. These investigations from throughout the United States and Canada showcase the wide breadth of current work done and point out areas that need further research.
Topics: Bees; Animals; Canada; United States; Beekeeping; Stress, Physiological; Pollination
PubMed: 38805646
DOI: 10.1093/jisesa/ieae055