Involvement of lipid transfer proteins in saffron hypersensitivity: molecular cloning of the potential allergens

BACKGROUND

Lipid transfer proteins (LTPs) are relevant allergens, and have recently been proposed as model plant allergens from fruit, vegetables, seeds, and pollens. However, no LTP spice allergen has been characterized to date.

OBJECTIVES

To identify and isolate saffron LTPs and to explore their relevance in saffron allergy.

METHODS

Six patients with rhinitis and positive skin prick test (SPT) results to saffron extract were selected. Two recombinant LTPs from saffron were isolated, cloned into pPIC9 plasmid, and produced in Pichia pastoris. Immunoglobulin (Ig) E immunodetection and enzyme-linked immunosorbent assays were performed with the 2 purified allergens and with the major peach allergen Pru p 3.

RESULTS

Full cDNA corresponding to 2 saffron LTP variants was isolated and expressed in P pastoris. The molecular weight of rCro s 3.01 and rCro s 3.02 was 9.15 kDa and 9.55 kDa, respectively. The sequences obtained had a 47% identity with each other and 51% and 43% with Pru p 3. Both proteins were recognized by anti-Pru p 3 antibodies. Specific IgE to the purified allergens was found in 50% of patients for rCro s 3.01 and 33% for rCro s 3.02 and Pru p 3 in the saffron-allergic patients.

CONCLUSIONS

Our results indicated that rCro s 3.01 and rCro s 3.02 are minor allergens of saffron, at least in the study patients. To our knowledge, this is the first report on the implication of LTPs in spice allergy.

Missense mutation Thr309Lys in the coagulation factor XII gene in a Spanish family with hereditary angioedema type III

BACKGROUND

A new type of hereditary angioedema (type III) affecting mainly women with normal C1-inhibitor level and function has been described. Exposition to estrogens is an important precipitating factor. Recently, a missense mutation in the gene of the blood coagulation factor XII (Hageman factor) has been reported in a few families with this type of hereditary angioedema.

AIM

To study a patient and her family with recurrent swelling attacks during pregnancy.

METHODS

Complement factors C3 and C4 as well as C1-inhibitor level and function were determined. Genomic DNA was isolated from venous blood samples and screened for mutations in the coagulation factor XII gene.

RESULTS

C3 and C4 levels as well as C1-inhibitor level and function were normal. A missense mutation Thr309Lys was identified in factor XII gene with a heterozygotic pattern. This mutation was also identified in the mother of the patient, her daughter and her son.

CONCLUSION

These results support that the mentioned mutation in factor XII gene causes hereditary angioedema type III.

Development of a stir bar sorptive extraction and thermal desorption-gas chromatography-mass spectrometry method for the simultaneous determination of several persistent organic pollutants in water samples

Stir bar sorptive extraction (SBSE) and thermal desorption followed by capillary gas chromatography coupled to mass spectrometry (SBSE-TD-GC-MS) was applied to the simultaneous determination of ultra-traces of 16 polycyclic aromatic hydrocarbons (PAHs), 12 polychlorinated biphenyls (PCBs), 6 phthalate esters (PEs) and 3 nonylphenols (NPs) in water samples. The parameters that could affect the sorption-desorption efficiency were studied. A Plackett-Burman design was used for the screening of the main effects of the experimental parameters related to the desorption step (desorption time, desorption temperature, desorption flow, cryo-focusing temperature and vent pressure). Afterwards, two central composite designs were used to find the optimal process settings for the extraction and desorption steps. The best analytical compromise conditions for the simultaneous determination of analytes from spiked water samples were found to be: sample volume (20 mL), sodium chloride addition (30%), methanol addition (20%), desorption time (10 min), desorption temperature (300 degrees C), desorption flow (23 mL min(-1)), cryo-focusing temperature (-50 degrees C) and vent pressure (7 psi). Remarkable recovery, repeatability and reproducibility were attained. Furthermore, excellent linearities (r(2) = 0.959-0.999) and low detection limits (0.1-10 ng L(-1)) were also achieved for the congeners studied. The proposed methodology was applied for the simultaneous determination of PAHs, PCBs, PEs and NPs in sea and estuarine waters. The influence of humic acids on the recovery was also studied.

Production of artifact methylmercury during the analysis of certified reference sediments: Use of ionic exchange in the sample treatment step to minimise the problem

Production of artifact methylmercury (MeHg(+)) during the analysis of two certified reference sediments, CRM-580 and IAEA-405, was investigated. Leaching of the analyte from the solid sample was achieved by ultrasound assisted acidic extraction. The aqueous leachate was either ethylated (NaBEt(4)) or phenylated (NaBPh(4)) using acetic/acetate or citric/citrate to buffer the solution. Preconcentration of the volatile compounds was carried out by extraction with an organic solvent (n-hexane) or solid phase microextraction (SPME). MeHg(+) was finally separated and detected by gas chromatography with atomic emission or mass spectrometry detection (GC-MIP-AED or GC-MS). In all the cases the concentrations obtained for MeHg(+) in the CRM-580 were significantly higher than the certified value. For the IAEA-405, however, the MeHg(+) concentration found was always statistically indistinguishable from the certified value. Experiments were also conducted with synthetic samples, such as aqueous mixtures of MeHg(+) and inorganic mercury (Hg(2+)) or silica-gel spiked with both compounds. The methylation rates found (defined as the percentage of Hg(2+) present in the sample which methylates to give artifact MeHg(+)) ranged from not observable (in certain synthetic aqueous mixtures) to 0.57% (analysis of CRM-580 under certain conditions). As the amount of Hg(2+) available in the sample seems to be the main factor controlling the magnitude of the artifact, several experiments were conducted using an ionic exchange resin (Dowex M-41) in order to minimise the concentration of this chemical in the reaction medium. First, a hydrochloric leachate of the sample was passed through a microcolumn packed with the exchanger. Second, the resin was mixed with the sample prior to extraction with HCl. In both cases, the predominant Hg(2+) species, HgCl(4)(2-), was adsorbed on the resin, whereas MeHg(+), mainly as MeHgCl, remained in solution. Following the second option, a new method to analyse MeHg(+) in conflictive matrices like certain sediments was proposed. This approach produced better results for the CRM-580, but a MeHg(+) concentration slightly, but statistically significant, higher than the reference value was still obtained.

[Cervical infection epidemiology of human papillomavirus in Ushuaia, Argentina]

Genital infection with human papillomavirus (HPV) is decisive in the causation of cervical cancer. In order to evaluate the epidemiology of HPV infection in Ushuaia, Province of Tierra del Fuego, Argentina, 132 endocervical cytobrushes from preneoplastic and neoplastic cases and controls were studied. Detection and typing of the viral genome was performed by polymerase chain reaction, combined with a restriction fragment length polymorphism assay or hybridization. The overall prevalence of HPV infection was 41% in the population examined, with a frequency of 26% in the controls and 71% in the cases under study. The 14-24 age group showed the highest HPV prevalence. The most common viral types in the infected population were HPV 16 (23%), HPV 18 (11%), HPV 33 (8%) and HPV 35 (8%), while high risk viral types were detected in 30% of the samples, 16% of the controls and 60% of the cases. This study provides the first data on the predominant viral types in Ushuaia. Our results show lower levels of infection than in regions with a high incidence of cervical cancer, HPV 16 being the most prevalent viral type. This research may be useful for selecting a specific vaccine targeting the population examined.