Biomedical subjects

Brissia Lazalde

Publications and source records attributed to Brissia Lazalde.

3 recordsLinked to original sources

PubMed2006

Estrogens are potentially the only steroids with an antioxidant role in pregnancy: in vitro evidence.

BACKGROUND: Pregnancy is a condition that favors oxidative stress by reactive oxygen species. Oxidative stress is involved in the etiopathogenesis of disorders of pregnancy such as pre-eclampsia. An antioxidant effect of estrogens has been described and a putative role of them as antioxidants has been proposed. The aim of this work was to evaluate in vitro the antioxidant properties of dehydroepiandrosterone sulfate, estradiol, estriol, progesterone, and testosterone, five steroid hormones present in the maternofetal circulation. METHODS: The antioxidant properties of the hormones were evaluated by two methods: 1. their antioxidant effect on the auto-oxidation of linoleic acid, a hydrogen atom transfer reaction; 2. diphenylpicrylhydrazyl-scavenging capacity, a single electron transfer reaction. RESULTS: Of the five hormones tested, only estradiol and estriol at 10 microM concentration exerted a strong antioxidant effect of 81.73 and 70.97% respectively on linoleic acid auto-oxidation, at the end-point of the reaction. Likewise, only these two hormones showed radical-scavenging activity on diphenylpicrylhydrazyl, noticeable only at supraphysiological concentrations of 1 mM. CONCLUSIONS: Estradiol and estriol could play a role as antioxidants for maternofetal autoprotection in addition to their hormonal activity, but this role could be preferentially exerted by estriol due to its higher concentrations exhibited during pregnancy. In vivo studies are necessary to shed light on this issue.

Adult↗

PubMedDate not supplied

del(X)(p22.1)/r(X)(p22.1q28) Dynamic mosaicism in a Turner syndrome patient.

We report on a 16-year-old patient with Turner syndrome who presented a mos 46,X,del(X)(p22.1)[35]/45,X [19]/46,X,r(X)(p22.1q28)[6]GTG-band karyotype. The R-banding showed that the abnormal X-chromosome was inactive in all 61 cells analyzed. Fluorescence in situ hybridization with a Xp/Yp subtelomeric probe revealed that both abnormal chromosomes lacked the complementary sequences, a fact consistent with a terminal deletion. Besides, the molecular analysis of the human androgen receptor gene showed that the rearranged chromosome was paternal in origin. Since the deleted and the ring chromosomes had the same size and banding pattern, and because the former was the predominant cell line, it was inferred that the Xp- formed a ring in some cells apparently without further loss of genetic material. However, the reverse sequence and even a simultaneous origin due to a complex intrachromosomal exchange are also conceivable. The mild Turner syndrome phenotype is explained by the mosaicism and by the size of the deleted segment.

Adolescent↗

PubMedDate not supplied

Cell growth in vitro directed by handmade patterns.

In this report, we show how the in vitro model of mechanically injured confluent monolayers of cultured mammalian cells, consisting in denudation by gentle scraping of areas in the monolayer, can be extended to obtain patterned cell cultures without using preadded attaching matrices. This work was done with a sinusoidal endothelial liver cell line. Patterns for cell growth were drawn in confluent monolayers by cell detaching with the aid of pipette tips followed by reincubation of the culture. In one or some d, acellular patterns were closed by cell migration and proliferation. For unveiling the pattern formed by migration and cell duplication, an enzymatic digestion with trypsin-collagenase solution was applied; after some min, only the migrating and younger cells filling the previous acellular pattern remained attached to the dish, and the now cellular pattern was clearly depicted. After stopping and recovering from the enzymatic treatment, the culture was ready for starting studies such as those related to migration, proliferation, cell-cell interactions. This method allows us to create simple and complex patterns, does not require preparation of the dishes with attaching matrices, and extracellular matrices in acellular areas are absent because of the enzymatic treatment, thus, potentially having many applications in cell culture techniques.

Animals↗