Biomedical subjects

Vicente Díaz

Publications and source records attributed to Vicente Díaz.

4 recordsLinked to original sources

PubMed2006

Prevalence and determinants of human papillomavirus infection in men attending vasectomy clinics in Mexico.

Large studies of genital human papillomavirus (HPV) infection in men are few and mainly include high-risk groups. We interviewed 779 men who requested a vasectomy in 27 public clinics in 14 states of Mexico. Exfoliated cells were obtained from the scrotum, the shaft of the penis, the top of the penis including the coronal sulcus, the glans and the opening of the meatus. HPV testing was performed using biotinylated L1 consensus primers and reverse line blot. Unconditional logistic regression was used to estimate odds ratios (ORs) of being HPV-positive and corresponding 95% confidence intervals (CIs). The prevalence of any type of HPV was 8.7%. HPV positivity was highest among men below age 25 (13.6%), and lowest among men aged 40 years or older (6.0%). The most commonly found HPV types were, in decreasing order, HPV59, 51, 6, 16 and 58. Lifetime number of sexual partners was associated with HPV positivity (OR for > or = 4 vs. 1 partner = 3.7, 95% CI: 2.0-6.8), mainly on account of the strong association with number of occasional and sex-worker partners. Condom use with both regular (OR = 0.4, 95% CI: 0.1-1.0) and sex-worker (OR = 0.1, 95% CI: 0.0-0.3) partners and circumcision (OR = 0.2, 95% CI: 0.1-0.4) were inversely associated with HPV positivity. HPV prevalence in Mexican men was similar to the prevalence found in Mexican women of the same age groups. The association between HPV positivity and lifetime number of sexual partners in the present low-risk male population is one of the strongest ever reported in studies in men. Condom use and circumcision were associated with a strong reduction in HPV prevalence.

Adult↗

PubMed2006

Inducible model for beta-six-mediated site-specific recombination in mammalian cells.

The prokaryotic beta recombinase catalyzes site-specific recombination between two directly oriented minimal six sites in chromatin-integrated substrates. Here, we demonstrate that an enhanced green fluorescent protein (EGFP)-fused version of beta recombinase (beta-EGFP) is fully active, retaining most specific activity. It is used to develop a recombination-dependent activatable gene expression (RAGE) system based on the androgen receptor (AR) ligand-binding domain (LBD). Two hybrid molecules, a direct fusion of the LBD-AR to the C-terminus of beta recombinase (beta-AR) and a triple fusion of beta-EGFP to the same ligand-binding domain (beta-EGFP-AR), were engineered and their subcellular behavior, stability and catalytic activity were evaluated. Both chimeric beta recombinase proteins showed in vivo inducible recombinogenic activity dependent on addition of an androgen receptor agonist, although the beta-AR fusion protein demonstrated more accurate ligand-dependent translocation from cytoplasm to nucleus.

Androgens↗

PubMed2004

Gold glyconanoparticles as new tools in antiadhesive therapy.

Gold glyconanoparticles (GNPs) have been prepared as new multivalent tools that mimic glycosphingolipids on the cell surface. GNPs are highly soluble under physiological conditions, stable against enzymatic degradation and nontoxic. Thereby GNPs open up a novel promising multivalent platform for biological applications. It has recently been demonstrated that specific tumor-associated carbohydrate antigens (glycosphingolipids and glycoproteins) are involved in the initial step of tumor spreading. A mouse melanoma model was selected to test glyconanoparticles as possible inhibitors of experimental lung metastasis. A carbohydrate-carbohydrate interaction is proposed as the first recognition step for this process. Glyconanoparticles presenting lactose (lacto-GNPs) have been used successfully to significantly reduce the progression of experimental metastasis. This result shows for the first time a clear biological effect of lacto-GNPs, demonstrating the potential application of this glyconanotechnology in biological processes.

Animals↗

PubMedDate not supplied

Glycodendritic structures based on Boltorn hyperbranched polymers and their interactions with Lens culinaris lectin.

Multivalent scaffolds bearing carbohydrates have been prepared to mediate biological processes where carbohydrates are involved. These systems consist of dendritic structures based on Boltorn H20 and H30 hyperbranched polymers to which carbohydrates are linked through a convenient spacer. Mannose has been chosen as a sugar unit to test the viability of this strategy. These glycodendritic compounds have been prepared in a few steps with good yields, showing a high solubility in physiological media and low toxicity. The binding of these dendritic polymers to the mannose-binding lectin Lens culinaris (LCA) was studied using STD-NMR experiments and quantitative precipitation assays. The results demonstrate the existence of a clear interaction between the mannose derivative systems and the Lens lectin where the dendritic scaffold does not have an important role in mannose binding but supplies the necessary multivalence for lectin cluster formation. These glycodendritic structures are able to interact with a receptor, and therefore they can be considered as promising tools for biological studies.

Animals↗