Biomedical subjects

María L Alvarez

Publications and source records attributed to María L Alvarez.

5 recordsLinked to original sources

PubMed2006

Rhodamine-pink as a genetic marker for yeast populations in wine fermentation.

Winemaking with selected yeasts requires simple techniques to monitor the inoculated yeast. New high-concentration rhodamine-resistant mutants and low-concentration rhodamine-pink mutants, easy to detect by replica-plate assay, were obtained from selected wine yeasts. The rhodamine-pink mutations were dominant and were located at the pdr5 locus that encodes for the Pdr5 ATP-binding cassette multidrug resistance transporter. The mutants were genetically stable but had lost the killer phenotype of the parent yeast strain. They were genetically improved by elimination of recessive growth-retarding alleles followed by crossing with selected killer wine yeasts. Several spore-clones were selected according to their must fermentation kinetics and the organoleptic quality of the wine. Some spore-clones were tested in industrial winemaking, and they were easily monitored during must fermentation using a simple color-plate assay. They accounted for >96% of the total yeasts in the must, and the resulting wine had as good a quality as those made with standard commercial wine yeasts. The rhodamine-pink yeasts may also be detected by direct seeding onto rhodamine agar or by observation under fluorescence microscopy. These possibilities greatly reduce the time of analysis and make the monitoring procedure for rhodamine-pink yeasts faster, easier, and cheaper than for the genetically marked wine yeasts obtained previously.

ATP-Binding Cassette Transporters↗

PubMed2003

Stable wheat transformation obtained without selectable markers.

Transgenic wheat plants without the selectable marker gene were obtained either in the presence or in the absence of selective pressure during the transformation protocol. When using hygromycin as selective agent in a co-transformation experiment involving a mixture of plasmids pGL2, containing the hpt gene, and pAI1Gus, containing the uidA gene, 3 out of 19 transgenic wheat plants had the uidA gene alone as shown by Southern blots. The gene was transmitted to the progeny following Mendelian rules. Segregation and loss of the selectable marker gene was also found in three out of six events from other experiments where high-molecular-weight glutenin genes were expressed or over-expressed. On the other hand, in 7 experiments where no selective pressure was applied and that involved 1016 bombarded explants, 23 transgenic wheat plants were obtained. The uidA gene was stably integrated as suggested by its transmission to the progeny.

Blotting, Southern↗

PubMedDate not supplied

[Tobacco advertising and printed mass media in Spain: a fatal attraction].

OBJECTIVE: Tobacco advertising is a powerful factor in encouraging smoking initiation. We analyzed tobacco advertising in written mass media in Spain between 2002 and 2005. METHODS: We performed an annual cross-sectional study of advertisements in the 41 most widely disseminated written mass media (nearly 10 million readers). RESULTS: In the period studied, 37% of the media included tobacco advertising (an average of 4.35 million readers). Only 4% of the media included anti-drug campaigns (an average of 0.27 million readers). Tobacco advertising increased from 2.0 to 4.7% (overall) and from 4.3 to 8.0% (in media allowing tobacco advertising). Four out of every 10 readers and one out of eight Spaniards aged 15 years or older were exposed to tobacco advertising. Fifty-six percent of advertisements included young people. CONCLUSIONS: Tobacco advertising remains prominent in written mass media in Spain and was mainly directed at young people.

Adolescent↗

PubMedDate not supplied

Apolipoprotein D expression in retinoblastoma.

The presence of apolipoprotein D (apoD) synthesis in brain suggests that this protein could play a major role in mediating neuronal degeneration and regeneration in the central nervous system (CNS). For instance, apoD is overexpressed in neural tissues in Niemann-Pick's type C disease, after acute CNS injury and cerebral ischemia, Alzheimer's disease and by a number of different tumors such as breast, prostate, ovarian and endometrial carcinomas. Recent data have raised the possibility that apoD expression could be a marker of cellular differentiation and growth arrest. By immunohistochemistry, we evaluated the tumoral expression of apoD in retinoblastoma, a tumor that results from malignant transformation of primitive retinal cells before final differentiation, and analyzed the possible relationship with clinicopathological parameters such as: age, sex, histological type, staging, local invasion, metastasis, preoperative or postoperative treatment and bilateral tumors. A total of eleven retinoblastomas (55%) showed apoD-positive immunostaining, but no significant correlation was found between apoD expression and patient or tumor characteristics.

Apolipoproteins↗

PubMedDate not supplied

Expression of two androgen-induced proteins (pepsinogen C and apolipoprotein d) in epithelial skin cancers of the eyelids.

By immunohistochemistry, we investigated pepsinogen C (pepC) and apolipoprotein D (apoD) expressions in 23 basal cell (BCC) and 25 squamous cell carcinomas (SCC) of the eyelids and analyzed the possible relationship to clinicopathological parameters. A total of 3 (13%) BCC and 7 (28%) SCC stained positively for pepC, whereas 11 (47.8%) BCC and 6 (24%) SCC stained positively for apoD. No significant correlation was found between pepC and apoD expressions and patients or tumor characteristics (p > 0.05). pepC and apoD, two androgen-inducible proteins, may be expressed by BCC and SCC of the eyelids. Further studies will be necessary to determine their clinical significance.

Aged↗