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Anisakis Simplex (Anisaki + simplex)
Selected AbstractsPhenotypic tradeoffs between egg number and egg size in three parasitic anisakid nematodesOIKOS, Issue 10 2007M. Victoria Herreras Phenotypic tradeoffs between number and size of eggs were tested in three component populations of three marine anisakid nematodes: Anisakis simplex, Pseudoterranova decipiens and Contracaecum osculatum. Body and uterine volumes (as proxies of female size), and egg number, mean egg volume and clutch volume (as descriptors of reproductive output) were measured in 50 females of each species. Evidence of a phenotypic tradeoff was detected only in A. simplex; the first time that has been found in a parasite population. Comparison of feasible values inferred from the van Noordwijk and de Jong's model and current data showed that interindividual variation in egg size was narrower than expected in the three populations. Structural constrictions in response to optimal allocation rules might account for this pattern. In P. decipiens and C. osculatum variation in egg size was the lowest and independent of female size, suggesting that the tradeoff is absent, rather than being present but masked by unaccounted variables. Spatial constrictions imposed by uterine size seemed to play an important role determining the emergence of the tradeoffs. So factors accounting for the tradeoff in A. simplex are probably constructional rather than physiological. Individual variability in investment in clutch volume was similar to previous studies but variation in allocation between number and size of eggs was much smaller than that reported previously. Perhaps differences in life-history strategies might explain this because the nematodes studied are either semelparous or short-lived iteroparus organisms whereas previous data derive from long-lived iteroparous ones. Despite the perception that parasites live in resource-rich habitats, the present study indicates that patterns relating number and size of eggs might not differ much from those observed in free-living populations and thus the same range of factors would operate in both types of organisms. [source] ORIGINAL ARTICLE: Chronic urticaria is associated with a differential helminth,arthropod-related atopy phenotypeTHE JOURNAL OF DERMATOLOGY, Issue 9 2010Alvaro DASCHNER Abstract The relationship between atopic sensitization and chronic urticaria is still controversial. In this study, we aimed to compare the prevalence of aeroallergen sensitization in chronic urticaria patients with (CU/As+) and without (CU/As,) sensitization against Anisakis simplex. Forty-nine CU/As+ and 80 CU/As, patients were studied and skin prick tests (SPT) were performed against aeroallergens. We assessed sensitization in a subgroup of patients with allergic rhinoconjunctivitis and/or bronchial asthma (RCBA) and compared the prevalence with a control group of 522 non-urticaria patients with RCBA. Forty-five percent of CU/As, and 60.4% of CU/As+ patients displayed positive SPT to at least one aeroallergen. CU/As+ patients had a higher prevalence of sensitization against pollen, mould or dander (PMD) (52.2% vs 29.1%, P < 0.01), whereas the prevalence of house dust mite (HDM) sensitization was not statistically different (26.3% in CU/As, and 36.7% in CU/As+). However, in chronic urticaria patients with RCBA, 53.8% of CU/As, and 57.9% of CU/As+ patients differed in the prevalence of HDM sensitization compared to the control group (33.5%, P = 0.03), whereas no difference could be stated for PMD sensitization. Compared to RCBA patients, both CU/As+ and CU/As, patients have a higher clinically relevant sensitization rate against HDM, thus displaying a differential atopy phenotype. [source] Characterization of allergens secreted by Anisakis simplex parasite: clinical relevance in comparison with somatic allergensCLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2004M. L. Baeza Summary Background Diagnostic methods for the study of allergic reactions to Anisakis simplex (A.s.) based on whole-body extracts of the larva are clearly insufficient. Objectives To study the allergenicity of the proteins secreted by the parasite. Comparison with somatic antigens and determination of their clinical importance in allergic patients were also addressed. Methods An excretory/secretory (E/S) extract was produced by culturing third-stage A.s. larvae. It was used to perform immediate skin tests and to determine specific IgE in 10 patients diagnosed with allergy to A.s. Both tests were compared with the results obtained with the whole-body extract (somatic (S)). The molecular weight (MW) of their allergens was determined by immunoblotting, and a single-blind placebo-controlled oral challenge with E/S proteins was performed. Finally, allergens' resistance to gastric pepsin and acid pH was explored. Results A.s. larvae secreted allergens more potent than those present in the S extract. The skin prick test wheal area produced by E/S molecules and the absorbance obtained in the determination of specific IgE with these allergens (ELISA) were 5.8 times bigger than those obtained with S extract. MW allergens of 72 and 56 kDa in E/S extracts and those of 56, 48 and 43 kDa in S extract were recognized by more than 50% of the patients. Partial cross-reactivity between them was revealed by immunoblotting inhibition studies. Oral challenge with E/S extract (up to 479 ,g) was negative in all the patients. Treatment of E/S proteins with gastric pepsin inhibited the binding of the E/S allergens for specific IgE. The acid pH did not affect the overall binding of IgE to E/S extract. It decreased by 15.23% and 19.96% at pH 4 and 2, but the difference was not statistically significant. Conclusion A.s. secretes allergens more potent than somatic antigens and should be used in the diagnostic procedures. These allergens are inactivated by the pepsin, which supports the theory that live larva is necessary to induce an allergic reaction in most of the patients. [source] Seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients with Helicobacter pylori infection: histological and laboratory findings and clinical significanceCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2006C. Toro Abstract Previous studies have demonstrated a high prevalence of seropositivity to the Ani s 1 protein in dyspeptic patients with Helicobacter pylori infection, but it is not known whether this represents episodes of anisakiasis misdiagnosis or previous exposure to the parasite without clinical relevance. To investigate the clinical significance of seropositivity to the Ani s 1 protein, a cohort study was performed with 87 consecutive dyspeptic patients who were treated for H. pylori infection. Fourteen (16.5%) patients were seropositive for the Ani s 1 protein, which was associated with the consumption of uncooked fish (p 0.0002). There were no differences in histological findings between subjects seropositive or seronegative for Ani s 1, but seropositive patients had increased eosinophil and basophil leukocyte counts (p < 0.05). Anti-Ani s 1 IgE was associated with a lack of improvement in the group of patients with non-ulcer dyspepsia after successful eradication of H. pylori (p 0.016). Thus, in at least a subset of patients with H. pylori infection, seropositivity to Ani s 1 could have clinical relevance. In addition, these data highlight that only anisakiasis associated with severe allergic or gastric symptoms is currently being diagnosed. [source] | ||||||||||