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J L Prieto

Publications and source records attributed to J L Prieto.

6 recordsLinked to original sources
PubMed2005

Development of crop-specific transposable element (SINE) markers for studying gene flow from oilseed rape to wild radish.

The screening of wild populations for evidence of gene flow from a crop to a wild related species requires the unambiguous detection of crop genes within the genome of the wild species, taking into account the intraspecific variability of each species. If the crop and wild relatives share a common ancestor, as is the case for the Brassica crops and their wild relatives (subtribe Brassiceae), the species-specific markers needed to make this unambiguous detection are difficult to identify. In the model oilseed rape (Brassica napus, AACC, 2n = 38)-wild radish (Raphanus raphanistrum, RrRr, 2n = 18) system, we utilized the presence or absence of a short-interspersed element (SINE) at a given locus to develop oilseed rape-specific markers, as SINE insertions are irreversible. By means of sequence-specific amplified polymorphism (SINE-SSAP) reactions, we identified and cloned 67 bands specific to the oilseed rape genome and absent from that of wild radish. Forty-seven PCR-specific markers were developed from three combinations of primers anchored either in (1) the 5'- and 3'-genomic sequences flanking the SINE, (2) the 5'-flanking and SINE internal sequences or (3) the SINE internal and flanking 3'-sequences. Seventeen markers were monomorphic whatever the oilseed rape varieties tested, whereas 30 revealed polymorphism and behaved either as dominant (17) or co-dominant (13) markers. Polymorphic markers were mapped on 19 genomic regions assigned to ten linkage groups. The markers developed will be efficient tools to trace the occurrence and frequency of introgressions of oilseed rape genomic region within wild radish populations.

Brassica napus↗
PubMed2001

The evolutionary origin and genomic organization of SINEs in Arabidopsis thaliana.

We have characterized the two families of SINE retroposons present in Arabidopsis thaliana. The origin, distribution, organization, and evolutionary history of RAthE1 and RAthE2 elements were studied and compared to the well-characterized SINE S1 element from Brassica. Our studies show that RAthE1, RAthE2, and S1 retroposons were generated independently from three different tRNAs. The RAthE1 and RAthE2 families are older than the S1 family and are present in all tested Cruciferae species. The evolutionary history of the RAthE1 family is unusual for SINEs. The 144 RAthE1 elements of the Arabidopsis genome cannot be classified in distinct subfamilies of different evolutionary ages as is the case for S1, RAthE2, and mammalian SINEs. Instead, most RAthE1 elements were probably derived steadily from a single source gene that was maintained intact and active for at least 12-20 Myr, a result suggesting that the RAthE1 source gene was under selection. The distribution of RAthE1 and RAthE2 elements on the Arabidopsis physical map was studied. We observed that, in contrast to other Arabidopsis transposable elements, SINEs are not concentrated in the heterochromatic regions. Instead, SINEs are grouped in the euchromatic chromosome territories several hundred kilobase pairs long. In these territories, SINE elements are closely associated with genes. A retroposition partnership between Arabidopsis SINEs and LINEs is proposed.

Arabidopsis↗
PubMed1996

Sensitivity and maximal response to methacholine in perennial and seasonal allergic rhinitis.

BACKGROUND: Airway hyperresponsiveness to pharmacological agonists is a common feature in subjects with allergic rhinitis. OBJECTIVE: The aim of this study was to investigate differences in threshold value and shape of the concentration-response curves to methacholine between subjects with perennial allergic rhinitis and subjects with seasonal rhinitis. METHODS: We studied a sample of 72 non-asthmatic patients with allergic rhinitis. They were subdivided into two groups: subjects with only seasonal symptoms and skin sensitization to grass and/or Parietaria pollen allergens (seasonal group, n = 38), and subjects with perennial symptoms and skin sensitization to house dust mite, alone or with other allergens (perennial group, n = 34). They were challenged with methacholine (up to 200 mg/mliter), and concentration-response curves were characterized by the threshold value (PC20 = provocative concentration of methacholine required to produce a 20% fall in FEV1) and maximal response plateau, if possible. The measurements in the seasonal group were done within the pollen season. RESULTS: The geometric mean methacholine PC20 for subjects of the perennial group was 6.9 mg/mliter, compared with 23.4 mg/mliter in subjects of the seasonal group (P < 0.01). A plateau response was detected in 16 subjects of the perennial group and in 28 subjects of the seasonal group (P < 0.05). Moreover, the level of plateau was higher in subjects of the perennial group when compared with subjects of the seasonal group (23.8 +/- 2.0% vs 19.2 +/- 1.6%, P < 0.05). CONCLUSION: In subjects with allergic rhinitis, sensitization to perennial allergens is associated not only with lower methacholine threshold values, but also with lower prevalence and higher level of plateau than sensitization to pollen allergens.

Adolescent↗
PubMed1979

[Primary hyperparathyroidism (author's transl)].

Experience gained from 100 patients with surgically and histologically proven primary hyperparathyroidism over a period of 14 years led to simplification of diagnostic procedures and development of a surgical scheme. Over the years patients with discrete disease symptoms or with asymptomatic disease were observed more frequently. This can be seen as the result of earlier diagnosis due to increasing spread of laboratory autoanalysers and the resulting routine calcium determination. Development of surgical intervention is characterised by omitting preoperative diagnostic procedures to determine localisation, a schematised operation, and more reliance on macroscopic criteria rather than on quick sections during surgery.

Adolescent↗
PubMedDate not supplied

Determinations of Par j 1 by a competitive enzyme immunoassay using human specific IgE and IgG. Validation by skin prick testing.

Par j 1 is the major allergen of Parietaria judaica. The objectives of this study were the following: 1) to purify Par j 1; 2) to develop an enzyme immunoassay based on the bivalent properties of specific IgE and IgG to determine the Par j 1 content in several batches of P. judaica extracts; and, 3) to study the contribution of Par j 1 to the total allergenicity and antigenicity of P. judaica extracts. P. judaica pollen was extracted and subjected to hydrophobic interaction and gel filtration chromatography for the purification of Par j 1. Inhibition enzyme immunoassays, SDS-PAGE and immunoblotting were used to characterize the allergen content. The in vivo biological potency of the extracts was estimated by skin prick testing 26 P. judaica clinically sensitive patients. The new enzyme immunoassay showed a high degree of specificity and sensitivity, detecting from 2 to 100 ng Par j 1/ml. The range of Par j 1 content in nine batches ranged from 23% to 78% of the total protein in the extracts. The Par j 1 content showed a significant correlation with the allergenic potency of these extracts evaluated by specific IgE inhibition and skin prick testing; the correlation with the specific IgG inhibition capacity was not significant. Purified Par j 1 shows great specific IgE and IgG binding capacity; its content can be determined using this newly developed enzyme immunoassay. Par j 1 levels exhibit a significant correlation with the biological potency of the extracts. This method allows the detection of Par j 1 isoforms.

Allergens↗