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Biomedical subjects

A Grasso

Publications and source records attributed to A Grasso.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Characterization of the epitope for 4C4.1 mAb on alpha-latrotoxin using phage display-peptide libraries: prevention of toxin-dependent 45Ca(2+) uptake in non-neuronal human embryonic cells transiently expressing latrophilin.

alpha-Latrotoxin, a protein toxin present in the venom of black widow spider, interacts with membrane receptors of neurons and other secretory cells to stimulate exocytosis. Two types of receptors have been identified and cloned. Our attention has been focused on the calcium independent receptor, a G-protein coupled receptor, named latrophilin to see whether alpha-latrotoxin interaction was capable to produce an ionotropic effect, in alternative to the metabotropic hypothesis. Expression of latrophilin receptor is sufficient for the alpha-latrotoxin effect to become manifest. By inducing the transient expression of latrophilin receptor in non-neuronal human embryonic cells, we made them susceptible to toxin action as demonstrated by the increase in 45Ca(2+) accumulation detected after toxin treatment. Since the presence of a monoclonal antibody against alpha-latrotoxin (4C4.1 mAb) was able to obliterate toxin-dependent effects, we further investigated the nature of toxin-antibody interaction by characterization of the binding epitope using phage display-peptide libraries. A conformational epitope was recognized and partially localized on a region of the peptide toxin whereby a tetrameric structure is formed and inserted into the membrane of target cells where it functions as a pore.

Animals↗
PubMedDate not supplied

Does amniotic fluid alpha-fetoprotein have diagnostic or prognostic value at the time of second midtrimester genetic amniocentesis?

In order to assess the usefulness of amniotic fluid alpha-fetoprotein (AFP) levels at the time of midtrimester genetic amniocentesis, 4,430 cases were retrospectively studied to compare the high, normal or low AFP values with the karyotype characteristics and fetal anatomy using ultrasound (US) scanning and confirmed by postnatal evaluation or necroscopy in the case of termination of pregnancy. All the cases presenting malformations were correctly diagnosed by US examinations. AFP levels over the 2nd standard deviation (SD) were found in 112 cases (2.52%) and below the 2nd SD in 11 cases (0.24%). The characteristics of these cases are presented and discussed. According to our results, it is concluded that routine assessment of AFP at the time of midtrimester genetic amniocentesis, if coupled with optimal US scanning, is no longer justified.

Abortion, Spontaneous↗