Allergic reaction following fish consumption can trigger life-threatening reactions in predisposed individuals. Parvalbumins from different species have been identified as the major fish allergens. There are two distinct phylogenetic lineages of parvalbumins, alpha and beta. Most allergic reactions are caused by beta-parvalbumins. We cloned and expressed cDNAs encoding cod (Gadus morhua) and carp (Cyprinus carpio) beta-parvalbumins and purified natural cod beta-parvalbumin. CD spectra of the purified proteins showed that their overall secondary structure contents were very similar. No differences in thermal stability were monitored in the calcium-bound or calcium-depleted form of natural cod parvalbumin. IgE reactivity was assessed using 26 sera of fish allergic patients from Spain, The Netherlands, and Greece in immunoblot and ELISA experiments. Twenty-five of the 26 patients with IgE reactivity to native and recombinant cod parvalbumin also reacted to the recombinant carp parvalbumin. IgE inhibition assays were performed using cod and carp extracts and purified recombinant parvalbumin of cod and carp. High crossreactivity among cod and carp parvalbumins was observed in immunoblots as well as in fluid phase assays. Natural and recombinant parvalbumins gave comparable results when performing various in vitro diagnostic assays.
The nose-to-brain pathway has been proven to be a shortcut for direct drug delivery to the brain. However, whether and to what extent nanoparticles can be delivered through this passage is still awaiting validation with evidence. In this study, nose-to-brain transportation of nanoparticles is tracked via fluorescence bioimaging strategies using nanoemulsions (NEs) as model carriers. Identification of NEs in biological tissues is based on the on → off signal switching of a new type of environment-responsive embedded dyes, P2 and P4, and two conventional probes, DiR and coumarin-6 (C6), are embedded to represent the cargoes. Evidence for the translocation of NEs was collected either via live imaging or ex vivo histological examination in rats after nasal administration. Results suggest that NEs with a particle size of about 100 nm, either naked or coated with chitosan, have longer retention duration in nostrils and slower mucociliary clearance than larger ones. P2 signals, representing integral NEs, can be found in mucosa and trigeminal nerves for all size groups, whereas only weak P2 signals are detected in the olfactory bulb for chitosan-coated NEs of 100 nm. Confocal microscopy further confirms the translocation of integral 100 nm NEs in nasal mucosa and along the trigeminal nerve in decremental intensity. Weak signals of the P4 probe, also representing integral NEs, can be detected in the olfactory bulb but few in the brain. NEs as large as 900 nm cannot be transported to the olfactory bulb. However, the DiR or C6 signals that represent the cargoes can be found in significant amounts along the nose-to-brain pathway and finally reach the brain. Evidence shows that integral NEs can be delivered to the olfactory bulb, but few to the brain, whereas the cargoes can be released and permeated into the brain in greater amounts.
Background: Individual amino acid residues of the major birch pollen allergen, Bet v 1, have been identified to be crucial for IgE recognition. The objective of the present study was to evaluate whether this concept was applicable for the Bet v 1-homologous apple allergen, Mal d 1. Methods: A Mal d 1 five-point mutant was produced by PCR techniques, cloned into pMW 172 and expressed in Escherichia coli BL21(DE3) cells. To evaluate the allergenic properties of the engineered protein compared to Mal d 1 wild-type IgE immunoblotting, ELISA, peripheral blood monocytes proliferation assays, and skin prick tests were performed. Results: The Mal d 1 mutant showed reduced capacity to bind specific IgE as compared to wild-ype Mal d 1 in in vitro assays in the majority of the sera tested. In ELISA, 10 out of 14 serum samples displayed an 88–30% decrease in IgE binding to Mal d 1 mutant compared to wild-type Mal d 1. Skin prick tests in apple-allergic patients (n = 2) confirmed the markedly decreased ability of the Mal d 1 mutant to induce allergic reactions in vivo. However, the relevant T cell epitopes were present in the mutated molecule according to peripheral blood mononuclear cell proliferation assays. Conclusions: Our findings suggest that it is possible to modulate the IgE-binding properties of allergens by single amino acid substitutions at crucial positions which might be useful for future immunotherapy of birch-pollen-associated food allergies which are not ameliorated by birch pollen immunotherapy.
The parvalbumins of cod, whiff and swordfish are highly cross-reactive. The high amino acid sequence identity among cod, whiff and swordfish parvalbumins results in the observed IgE cross-reactivity. The low allergenicity of swordfish is due to the low expression levels of its parvalbumin.
Within the last 10 years, the percentage of low back pain (LBP) prevalence increased by 18%. The management and high cost of LBP put a tremendous burden on the healthcare system. Many risk factors have been identified, such as lifestyle, trauma, degeneration, postural impairment, and occupational related factors; however, as high as 95% of the cases of LBP are non-specific. Currently, LBP is treated pharmacologically. Approximately 25 to 30% of the patients develop serious side effects, such as drowsiness and drug addiction. Spinal surgery often does not result in a massive improvement of pain relief. Therefore, complementary approaches are being integrated into the rehabilitation programs. These include chiropractic therapy, physiotherapy, massage, exercise, herbal medicine and acupuncture. Acupuncture for LBP is one of the most commonly used non-pharmacological pain-relieving techniques. This is due to its low adverse effects and cost-effectiveness. Currently, many randomized controlled trials and clinical research studies have produced promising results. In this article, the causes and incidence of LBP on global health care are reviewed. The importance of treatment by acupuncture is considered. The efforts to reveal the link between acupuncture points and anatomical features and the neurological mechanisms that lead to acupuncture-induced analgesic effect are reviewed.
The optical properties of type-II GaAsSb/GaAs multiple quantum wells were investigated by photoluminescence. It was found that the peak position of photoluminescence (PL) spectra shows a giant blueshift under a moderate optical excitation level. As the pumping intensity increases further, the saturation of the peak position was observed. The giant blueshift can be interpreted in terms of the band-bending effect due to the spatially photoexcited carriers in a type-II alignment. The saturation effect was attributed to the creation of an energy barrier induced by photocarriers, which prevents the charge transfer. The change of integrated photoluminescence intensity with increasing excitation intensity is also consistent with the band-bending model. In addition, the temperature dependence of the PL spectra reveals that the thermal escape of electrons from the GaAs well into the GaAsSb barrier is responsible for the PL quenching.
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