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M Pineiro

Publications and source records attributed to M Pineiro.

4 recordsLinked to original sources
PubMed2001

Tritolylporphyrin dimer as a new potent hydrophobic sensitizer for photodynamic therapy of melanoma.

We report the synthesis, photochemical and photophysical properties and preliminary studies on biological effect of a new tritolylporphyrin dimer (T-D). Absorption and emission properties of T-D suggest its possible use in photodynamic therapy. T-D is capable of singlet oxygen production with 0.8 quantum yield. It also has a high photostability. The photodynamic properties of the dimer were examined following the growth of SKMEL 188 (human melanoma) cells irradiated with red light (cut off < 630 nm). The surviving fraction of the cells decreased about 3-fold (vs. non-irradiated cells) for an 81 J/cm dose. Our results suggest that tritolylporphyrine dimer T-D may be an interesting hydrophobic sensitizer for photodynamic therapy.

Dimerization↗
PubMed2000

ACAULIS5, an Arabidopsis gene required for stem elongation, encodes a spermine synthase.

Polyamines have been implicated in a wide range of biological processes, including growth and development in bacteria and animals, but their function in higher plants is unclear. Here we show that the Arabidopsis: ACAULIS5 (ACL5) gene, whose inactivation causes a defect in the elongation of stem internodes by reducing cell expansion, encodes a protein that shares sequence similarity with the polyamine biosynthetic enzymes spermidine synthase and spermine synthase. Expression of the recombinant ACL5 protein in Escherichia coli showed that ACL5 possesses spermine synthase activity. Restoration of the acl5 mutant phenotype by somatic reversion of a transposon-induced allele suggests a non-cell-autonomous function for the ACL5 gene product. We also found that expression of the ACL5 cDNA under the control of a heat shock gene promoter in acl5 mutant plants restores the phenotype in a heat shock-dependent manner. The results of the experiments showed that polyamines play an essential role in promotion of internode elongation through cell expansion in Arabidopsis: We discuss the relationships to plant growth regulators such as auxin and gibberellins that have related functions.

Alleles↗