Allergy and the gastrointestinal system Vighi, G; Marcucci, F; Sensi, L ...
Clinical and experimental immunology,
September 2008, Volume:
153, Issue:
Supplement_1
Journal Article
Peer reviewed
Open access
The gastrointestinal system plays a central role in immune system homeostasis. It is the main route of contact with the external environment and is overloaded every day with external stimuli, ...sometimes dangerous as pathogens (bacteria, protozoa, fungi, viruses) or toxic substances, in other cases very useful as food or commensal flora. The crucial position of the gastrointestinal system is testified by the huge amount of immune cells that reside within it. Indeed, gut-associated lymphoid tissue (GALT) is the prominent part of mucosal-associated lymphoid tissue (MALT) and represents almost 70% of the entire immune system; moreover, about 80% of plasma cells mainly immunoglobulin A (IgA)-bearing cells reside in GALT. GALT interacts strictly with gastrointestinal functions in a dynamic manner; for instance, by increasing intestinal permeability in replay to particular stimulations, or orientating the immune response towards luminal content, allowing either tolerance or elimination/degradation of luminal antigens, or sometimes provoking damage to the intestinal mucosa, such as in coeliac disease or food allergy. The immune mechanisms implicated in these actions are very complex and belong to both innate and adaptive immunity; innate immunity supplies an immediate non-specific response that is indispensable before specific adaptive immunity, which needs 7-10 days to be efficacious, takes place. The results of their interactions depend upon different contexts in which contact with external agents occurs and may change according to different genetic settings of the hosts.
Plant lipid transfer proteins (LTPs) are widespread plant food allergens, highly resistant to food processing and to the gastrointestinal environment, which have been described as the most common ...food allergens in the Mediterranean area. LTP allergy is widely described in adults, but it represents an emerging allergen also in the pediatric population. Little is known about the real prevalence and the clinical features of this allergy in children and it still often remains underdiagnosed in these patients.
An early identification and a deeper knowledge of this allergy in childhood can avoid severe systemic reactions and improve the child's quality of life. Pediatricians should always consider the possibility of LTP involvement in cases of plant-derived food allergy.
Sublingual immunotherapy has been shown in some clinical studies to modulate allergen‐specific antibody responses with a decrease in the immunoglobulin E/immunoglobulin G4 (IgE/IgG4) ratio and to ...reduce the recruitment and activation of proinflammatory cells in target mucosa. Whereas a central paradigm for successful immunotherapy has been to reorient the pattern of allergen‐specific T‐cell responses in atopic patients from a T helper (Th)2 to Th1 profile, there is currently a growing interest in eliciting regulatory T cells, capable of downregulating both Th1 and Th2 responses through the production of interleukin (IL)‐10 and/or transforming growth factor (TGF)‐β. We discuss herein immune mechanisms involved during allergen‐specific sublingual immunotherapy (SLIT), in comparison with subcutaneous immunotherapy. During SLIT, the allergen is captured within the oral mucosa by Langerhans‐like dendritic cells expressing high‐affinity IgE receptors, producing IL‐10 and TGF‐β, and upregulating indoleamine dioxygenase (IDO), suggesting that such cells are prone to induce tolerance. The oral mucosa contains limited number of proinflammatory cells, such as mast cells, thereby explaining the well‐established safety profile of SLIT. In this context, second‐generation vaccines based on recombinant allergens in a native conformation formulated with adjuvants are designed to target Langerhans‐like cells in the sublingual mucosa, with the aim to induce allergen‐specific regulatory T cells. Importantly, such recombinant vaccines should facilitate the identification of biological markers of SLIT efficacy in humans.
The North-Western Mediterranean basin is well known for its high number of relictual endemic taxa, and has been indicated as one of the world's major biodiversity hotspots at the species level. A ...possible contributing factor may be long-term persistence of populations and their prolonged stability. This study was designed to investigate the phylogeographic structure of three common species of the genus Lepidocyrtus (Hexapoda: Collembola), soil-dwelling arthropods characterized by limited dispersal capabilities and generally associated with forest habitats. We observed a remarkable geographic structure, with numerous deeply divergent genetic lineages occupying islands as well as mainland sites with no apparent gene flow among most sites, even across distances of only tens of kilometres. The reconstructed time frame for the evolution of these lineages suggests divergence between 5 and 15 Ma. This indicates a remarkably ancient origin and long-term persistence of individual lineages over a fine geographic scale despite the occurrence of abrupt sea level and climatic fluctuations in the area. This further suggests that currently recognized morphological species might be a serious underestimation of the true springtail biodiversity within this region.
•A shorter BTD is associated with a higher incidence of unplanned obstetrical intervention due to labor dystocia.•There is an inverse correlation between the BTD and the length of the second stage of ...labor.•Antenatal identification of women at risk for labor dystocia might trigger some specific interventions during the second stage of labor.•Antenatal identification of women at higher risk for labor dystocia might prompt a referral of the patient to a district hospital.
The aim our study was to evaluate the association between the antepartum clinical measurement of the Bituberous Diameter (BTD) and the occurrence of unplanned obstetrical intervention (UOI) due to labor dystocia, including either operative vaginal delivery or caesarean section in a cohort of low-risk, nulliparous at term.
Retrospective analysis of prospectively collected data.
Tertiary maternity care.
With the women lying in lithotomic the distance between two ischial tuberosities was assessed using a tape measure during the routine antenatal booking between 37 and 38 weeks of gestation.
Overall, 116 patient were included, and of these 23(19.8%) were submitted to an UOI due to labor dystocia. Compared to women that had a spontaneous vaginal delivery, women submitted to an UOI had a shorter BTD (8.25 + 0.843 vs 9.60 + 1.12, p < 0.001), a higher frequency of epidural analgesia (21/23 or 91.3% vs 50/93 or 53.8%; p = 0.002) and of augmentation of labor (14/23 or 60.9% vs 19/93 or 20.4%; p < 0.001) as well as a longer first 455 (IQR 142–455 min vs 293 (IQR 142–455) min and second stages of labor 129 (IQR 85–155) min vs 51 (IQR 27–78) min. Multivariable logistic regression showed that the BTD (aOR 0.16, 95% CI 0.04–0.60; p = 0.007) and the length of the second stage of labor (aOR 6.83, 95% CI 2.10–22.23; p = 0.001) were independently associated with UOI. When evaluating the diagnostic accuracy of the BTD for the prediction of UOI due to labor dystocia, the BTD showed an AUC of 0.82 (95 %CI 0.73–0.91; p < 0.001) with an optimal cut-off value of 8.6 cm (78.3% (95 %CI 56.3–92.5) sensitivity, 77.4% (95 %CI 67.6–85.4) specificity, 46.2% (95% CI 30.1–62.8) PPV, 93.5% (95% CI 85.5–97.9) NPV, 3.5 (95% CI 2.3–5.4) positive LR, and 0.28 (95% CI 0.13–0.61) negative LR. A significant inverse correlation between the length of the second stage of labour and the BTD in patients that had a vaginal delivery was also demonstrated (Spearman’s rho = -0.24, p = 0.01).
Our study suggests that antepartum clinical assessment of the BTD might be used as a reliable predictor of UOI due to labor dystocia in low-risk, nulliparous women at term gestation.
Antenatal identification of women at higher risk for labor dystocia might trigger some interventions during the second stage of labor, such as maternal position shifting, to increase the pelvic capacity and potentially improve outcomes or might prompt a referral of the patient to a district hospital prior to the onset of labor.
Oviposition-induced plant synomones are semiochemical cues used by egg parasitoids during host selection, and are therefore considered important elements of plant defence. In this paper we show that, ...in the tritrophic system Brassica oleracea-Murgantia histrionica-Trissolcus brochymenae, the latter responded in a closed arena and in a static olfactometer to induced chemicals that are perceived from a very short range and after parasitoid contact with the leaf surface opposite the treated surface. An additive or synergistic effect due to (1) egg deposition, (2) feeding punctures and (3) chemical footprints of M. histrionica was observed. When all three phases were present, the parasitoid reacted to the induced synomone locally on the treated leaf area, at a close distance to the treated area, and on the leaf above the treated one, showing that there is also a systemic effect. When plants with host footprints combined with feeding punctures or with oviposition were tested, responses were obtained both locally and at a close distance, whereas in the remaining assays only local responses were observed. Induction time was less than 24 h, whereas signal duration was apparently related to the suitability of the host eggs, as parasitoids did not respond to plants carrying old or hatched eggs. These oviposition-induced short-range plant synomones might have an important role in the host location process after parasitoid landing on the plant, in different combinations with the host kairomones involved in the system studied here.
Relationships among Olive fly genomes, colour coded according to the genetic groups identified, overlaid on a map describing ancient (pre-domestication) wild Olive tree diversity. Display omitted
► ...Co-history indicates Quaternary association between olive fly and olive tree. ► Geographic structure of olive fly matches wild olive post-glacial recolonization. ► A recent multi-regional host shift from wild to cultivate olive is suggested. ► Middle Eastern origin of Californian invasive olive flies is supported.
The evolutionary history of the olive fly, Bactrocera oleae, was reconstructed in a phylogenetic and coalescent framework using full mitochondrial genome data from 21 individuals covering the entire worldwide distribution of the species. Special attention was given to reconstructing the timing of the processes under study. The early subdivision of the olive fly reflects the Quaternary differentiation between Olea europea subsp. europea in the Mediterranean area and the two lineages of Olea europea subsp. cuspidata in Africa and Asia, pointing to an early and close association between the olive fly and its host. The geographic structure and timing of olive fly differentiation in the Mediterranean indicates a clear connection with the post-glacial recolonization of wild olives in the area, and is irreconcilable with the early historical process of domestication and spread of the cultivated olive from its Levantine origin. Therefore, we suggest an early co-history of the olive fly with its wild host during the Quaternary and post-glacial periods and a multi-regional shift of olive flies to cultivated olives as these cultivars gradually replaced wild olives in historical times.
In massive biometric identification systems, response times mainly depends on the database searching algorithms. Thus, in large databases, an increment in the simultaneous queries traffic becomes a ...critical factor. This paper proposes an algorithm based on the use of a graphic processing unit to solve the exhaustive similarity search for the mass identification of finger veins, using the binary pattern descriptor of the local vertical line and the Hamming distance. The proposed approach reduces the computation time of the searching process over high query traffic by solving each query with a different processing block. The proposed method allows the identification of individuals in a database of 1 million elements, which is the largest database used for finger-vein identification. Experimental results show that our proposed method resolves up to 28 queries simultaneously (over a database of one million individuals) within a time lower than 3 seconds and achieving a speed-up of 283x. To our knowledge, our work is the first implementation of finger-vein recognition on a general-purpose graphics processing unit, which is the main contribution of this document.
Allergy and the skin Incorvaia, C.; Frati, F.; Verna, N. ...
Clinical and experimental immunology,
September 2008, Volume:
153, Issue:
Supplement_1
Journal Article
Peer reviewed
Open access
Summary
Allergic skin disorders include urticaria, angioedema, contact dermatitis and atopic dermatitis, but the model fitting most closely the systemic concept of allergy is atopic dermatitis (AD), ...the pathogenesis of which is linked to a complex interaction between skin barrier dysfunction and environmental factors such as allergens and microbes. In particular, an important advance was the demonstration that the mutation of the skin barrier protein filaggrin is related strictly to allergen sensitization and to the development of asthma in subjects with AD. The altered skin barrier function, caused by several factors, results in the passage of allergens through the skin and to systemic responses. A pivotal role in such a response is exerted by Langerhans cells which, via their immunoglobulin E (IgE) receptor, capture the allergens and present them to T cells. When T helper type 2 (Th2) cells are activated, the production of a proinflammatory cytokines and chemokines pattern sustains the persistence of inflammation. Known AD‐related cytokines are interleukin (IL)‐5, IL‐13 and tumour necrosis factor (TNF)‐α, with emerging importance for IL‐17, which seems to drive airway inflammation following cutaneous exposure to antigens, and IL‐31, which is expressed primarily in skin‐homing Th2 cells. Skin‐homing is another crucial event in AD, mediated by the cutaneous lymphocyte‐associated antigens (CLA) receptor, which characterizes T cell subpopulations with different roles in AD and asthma.
Summary
Background
As the main target of sublingual immunotherapy (SLIT) is to reduce at most the occurrence of adverse events (AE), safety represents a critical issue. This aspect deserves ...particular mention when a higher dose of allergen extract than traditional subcutaneous immunotherapy (SCIT) is required to be effective: that may be up to 500 times that employed for SCIT.
Objective
All published controlled studies concerning SLIT‐swallow were analysed to evaluate AE rates.
Methods
Studies were subdivided in two groups: (i) studies using low allergen dose (LAD), i.e. ranging from 1 to 50 times the dose commonly administered with SCIT, and (ii) studies with high allergen dose (HAD), i.e. ranging from 50 to 500 times the dose administered with SCIT.
Results
Twenty‐five studies were altogether analysed: 13 studies belonged to the low‐dose group, 12 belonged to the high‐dose group. We considered all patients with at least one AE. Local reactions were significantly more frequent in the LAD group than in the HAD group (P<0.0001), while there was no difference in the rate of systemic reactions. Severe systemic reactions were never reported.
Conclusion
This study represents the first analysis of the safety of SLIT concerning the allergen dose employed in the treatment. There is evidence that AE occurrence is substantially not dose‐dependent. This fact highlights two main clinical aspects: the elevated tolerability of SLIT in general and the safety of HAD regimen.
PDF
