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Biomedical subjects

F Cortés

Publications and source records attributed to F Cortés.

83 records · Page 5Linked to original sources
PubMed1984

Chromosomal aberrations and SCEs in Allium cepa root-tip cells treated with caffeine and pyronin Y.

The effectiveness of caffeine and pyronin Y in the induction of both chromosomal aberrations and sister-chromatid exchanges (SCEs) in root meristematic cells of A. cepa was studied. The rate of SCEs proved to be increased when 5-bromo-2'-deoxyuridine- (BrdU) substituted chromosomes were allowed to replicate in thymidine (dT) for a second S period simultaneously with caffeine or pyronin Y. In contrast, only caffeine was able to induce aberrations in BrdU-substituted chromosomes, while pyronin Y seemed to be ineffective at the doses employed.

Bromodeoxyuridine↗
PubMed1983

Cytological demonstration of DNA synthesis inhibition at late S by 5-amino-uracil.

Meristematic cells of Allium cepa were treated with 5-amino-uracil (5-AU) while incorporating 5-bromodeoxyuridine (BrdU) into DNA until complete inhibition of mitosis was obtained. The pattern of BrdU substitution in interphase nuclei detected by FPG technique in the cells so treated was that known as corresponding to BrdU incorporation in only early and middle replicating DNA. In addition, when the cells were allowed to reach mitosis in the absence of BrdU after the synchronization induced by 5-AU all the metaphase chromosomes showed, likewise, the typical late-replicating pattern. These results are a cytological demonstration of a preferential inhibition of late-replicating DNA synthesis by 5-AU proposed by several authors.

Bromodeoxyuridine↗
PubMed1983

High-resolution analysis of Allium cepa chromosome replication by an FPG technique.

In Allium cepa meristematic cells, BrdU incorporation into late-replicating DNA and its detection by FPG technique has shown to allow the visualization of characteristic late replicated segments (LRS) in metaphase chromosomes not detected till now. Since these LRS have very similar characteristics with the 'dot-like' exchanges reported previously in this system, they seem to represent a new support for the idea of a regular organization of chromatin in metaphase.

Azure Stains↗
PubMed1982

Effects of the fungicide tridemorph on mitosis in Allium cepa.

A mitodepressive effect of Tridemorph on the meristematic cells of Allium cepa has been observed. This effect increases with the concentration of the fungicide and the length of treatment, until complete inhibition of cell division occurs under certain conditions. Furthermore, this chemical has been revealed as a strong c-mitotic agent, although there are clear differences between its action and that of colchicine and other c-mitotic drugs. Other important features are the alterations observed in the development of the different mitotic phases depending on the dose employed. A high degree of chromosome contraction has been observed since the cells are in prophase until they reach telophase. Multipolar anaphases and micronuclei, and anomalous chromosome separation and anaphase emigration are other important modifications induced by the treatment on the development of mitosis.

Chromosomes↗
PubMedDate not supplied

Cytotoxic activity of flavonoids and extracts from Retama sphaerocarpa Boissier.

Seven flavonoids isolated from chloroform, ethyl acetate and butanol extracts, obtained from the aerial parts of Retama sphaerocarpa, have been assessed for cytotoxic activity against three human cancer cell lines: TK-10 (renal adenocarcinoma), MCF-7 (breast adenocarcinoma) and UACC-62 (melanoma), using the SRB assay. All of them, extracts and flavonoids, were actives in, at least, one of the three cell lines at the recommended National Cancer Institute doses. They produce a dose-dependent inhibition of cell growth at concentrations in the 10(-6)-10(-4) M and 25-250 microg/ml range for the flavonoids and extracts respectively, being the flavonol rhamnazin the most cytotoxic.

Adenocarcinoma↗
PubMedDate not supplied

[Incidence of influenza and influenza vaccine effectiveness in the 2004-2005 season].

BACKGROUND: To quantify the incidence of flu in different groups of the population of Navarra in the 2004-2005 season, and to evaluate the effectiveness of anti-flu vaccination. METHODS: The analysis of influenza cases in the system of compulsory notificable diseases was complemented by the individualised notifications in the network of sentinel doctors that covers a population of 22,339 inhabitants. The coverage and effectiveness of the vaccine was studied. RESULTS: Vaccine coverage in (3)65 year olds reached 62%. The incidence of influenza was 42.6 cases per 1,000 inhabitants. It reached a maximum in mid-January, exceeding 750 weekly cases per 100,000 inhabitants and 1,900 cases per 100,000 children. The highest rate of influenza was observed in under-15 year olds (49.4 cases per 1,000 inhabitants) and the lowest in non-institutionalised (3)65 year olds (2.6 per 1,000 inhabitants), although it was higher in geriatric residences (62.1 per 1,000; p<0.0001). Seventy-nine percent of the cases from 5 to 64 years resulted in absenteeism from school or work. The flu virus was identified in 42/65 (65%) nasopharyngeal smears, 90% being influenza virus A(H3). The incidence of influenza was 3.08% in the unvaccinated and 0.45% in the vaccinated (p<0.001). The global effectiveness of the anti-flu vaccine was 65%, and in (3)65 years old it was 73%. CONCLUSION: Although its effectiveness is not total, the vaccine is the main measure for preventing influenza. The network of sentinel doctors provide useful information for the coordination of care and public health activities against flu.

Adolescent↗
PubMedDate not supplied

[Cytogenetic findings in patients with Down's syndrome].

In order to describe the frequency of non classical forms of 21 trisomy in patients with Down's syndrome at the cytogenetic's laboratory of our institution (Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile) 201 chromosomal studies from peripheral blood lymphocytes of patients referred with a clinical diagnosis of Down's syndrome were analyzed. Among them 22 (11%) cases showed no chromosomal abnormalities, 161 (80%) had classic 21 trisomy, 7 (3.5%), showed 21 trisomy by translocation, 5 (2.5%) had 21 trisomy mosaicism, 6 (3%) showed 21 trisomy plus an autosomic balanced translocation. Male to female rate was 1.18:1 and diagnosis was done at the neonatal period in 26.8% of cases. Early recognition of the different kinds of chromosomal abnormalities in Down's syndrome is important if appropriate genetic council is the goal.

Child, Preschool↗