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Biomedical subjects

E Moretti

Publications and source records attributed to E Moretti.

At least 73 records · Page 4Linked to original sources
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Ultrastructural and DNA fragmentation analyses in swim-up selected human sperm.

Seventeen sperm samples were evaluated by transmission electron microscopy (TEM) before and after swim-up separation. DNA-fragmentation was tested by terminal d-UTP nick end labeling (TUNEL) in unselected and selected semen samples, and the results were analyzed in relation to sperm ultrastructural characteristics detected by TEM. A significant improvement in mean numbers and percentages of structurally normal sperm was observed after swim-up selection, corresponding to a significant decrease in the percentage of necrotic and apoptotic sperm, while the percentage of sperm with immature nuclei did not change significantly. TUNEL indicated a significant decrease in chromatin-fragmented sperm after swim-up. Swim up selection based on sperm motility excludes many sperm with ultrastructural evidence of necrosis (absent or reacted acrosome, disrupted chromatin, broken plasma membrane) and apoptosis (misshapen nuclei with marginated chromatin), as confirmed by TUNEL analysis. Nevertheless, immature sperm with elliptical or roundish nuclei, misshapen acrosomes and uncondensed chromatin remain part of fertilizing pool.

Adult↗
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Notulae seminologicae. 8. Ultrastructural sperm defects in two men, carriers of autosomal inversion.

The electron microscopical analysis of spermatozoa in two infertile male carriers of a pericentric inversion in one of the chromosomes 9 revealed the presence of a peculiar defect affecting the tails' fibrous sheath in both patients. This structure appeared completely disorganized and hyperplasic; sometimes the defect was associated with other usual malformations concerning the nuclear and acrosomal shape and texture and the axonemal assembly. Most spermatozoa (90-100%) of these patients were immotile. Our findings point to a definite ultrastructural sperm defect found in cases of autosomal inversion.

Acrosome↗
PubMedDate not supplied

[Experimental Chagas' disease: I. Study of different immunization conditions in the infection course].

In previous works it has been demonstrated that Balb/c albino mice immunized with Trypanosoma rangeli developed cellular and humoral immune response to Tripanosoma cruzi. Moreover, the immunized animals were protected against lethal infection by virulent T. cruzi trypomastigotes. In fact, immunized mice had significantly lower parasitemias and longer survival than controls. To go further in this experimental model, the aim of the present work was to analyze the effect of the number of antigenic stimuli and the conservation of the antigen on the effectiveness of protective effect. For that purpose, three different immunization schedules injecting T. rangeli epimastigotes fixed with glutaraldehide and emulsified with Saponin (SAP) as adjuvant were assayed. Different lots of mice which received only phosphate buffer saline or SAP were used as controls. In another set of experiments the conservation of the antigen during 90 days at 4 degrees C was studied. In all the experiments mice were infected with 100 trypomastigotes of T. cruzi, Tulahuén strain. The parasitemias were analyzed on 13th, 16th and 21st post infection days, and the survival until the 60th day. The results revealed that one dose of antigen was inadequate to give an effective protection. On the other hand, mice immunized with 2 and 3 dose showed a significant decrease of parasitemia with regard to controls (p < 0.001 - p < 0.0001) and the survival were markedly increased. Likewise, the antigen kept during 90th days at 4 degrees C showed similar protective efficacy than fresh antigen. Both of these experimental groups showed significant differences with respect to control animals in parasitemia (p < 0.05 - p > 0.01) and survival (p < 0.01). In conclusion, the results of this work showed that in the experimental conditions assayed, the immunization with T. rangeli trigger and adequate immune response when mice received at least two antigenic stimuli. Likewise, it is interesting to point out the stability of the antigenic preparation during at least 90th days.

Animals↗
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Functional and ultrastructural features of DNA-fragmented human sperm.

The functional significance of deoxyribonucleic acid (DNA) fragmentation in ejaculated human sperm is unclear. In this study the extent of DNA strand breakage in swim-up selected spermatozoa was evaluated by terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end labeling (TUNEL)-coupled flow cytometry and correlated with several functional and morphological sperm parameters. The extent of DNA fragmentation (mean = 11.07%+/-8.00%, range = 0.79%-42.64%, n = 140) was positively related to abnormal morphology and associated with defects of the sperm tail. A negative correlation was found between DNA breakage and progressive motility. When a stepwise multiple linear regression model was used to analyze the relationship between DNA fragmentation and the aforementioned parameters, only motility results were included in the model. The presence of spermatozoa showing submicroscopic characteristics resembling those of somatic apoptosis has been reported in human ejaculate. To verify whether sperm DNA fragmentation was associated with the presence of such apoptotic-like cells, we performed electron microscopy and TUNEL-coupled flow cytometry in a limited number of sperm samples (n = 24). Although we did not observe any significant relationship between DNA breakage and the characteristics that are suggestive of apoptosis, an association was found with several ultrastructural features, indicating an impaired motility. Hence, we conclude that in ejaculated sperm, DNA fragmentation does not correspond to the apoptosis-like phenomenon and that it is associated with defects of motility.

Cell Size↗
PubMedDate not supplied

Localization of molecules related to cholinergic signaling in eggs and zygotes of the sea urchin, Paracentrotus lividus.

In recent years, the finding of a complete set of molecules related to the cholinergic neurotransmitter system in male gametes of different invertebrate and vertebrate species has opened the question of the possible involvement of this signaling system in the regulation of intracellular ion change, functional to sperm motility and probably also to interaction with the egg. In this work, we localized molecules immunologically related to muscarinic acetylcholine receptors (mAChRs) in sea urchin (Paracentrotus lividus) eggs and zygotes, by use of the monoclonal antibody M35. The ultrastructural analysis of immunoreactivity revealed that the localization of M35-positive molecules is different between unfertilized and fertilized egg. In the unfertilized eggs, immunoreactive molecules were localized inside and associated to the membrane of vesicles, scattered in a thick zone of the cortical cytoplasm. Following fertilization, the oolemma was decored along the surface, and positive vesicles were seldom seen in the cytoplasm. At the surface of fertilized eggs, evident pinocytotic vesicles, recognized by the surrounding coat, indicate that the positive sites correspond to receptorial activity, able to rescue ligand portions. The presence of a cholinergic signaling pattern was also suggested by the presence of molecules immunologically related to acetylcholinesterase (AChE), performing AChE enzyme activity, detected by both immunofluorescent and histochemical methods in membranous organelles belonging to the cortical region of unfertilized eggs.

Acetylcholinesterase↗
PubMedDate not supplied

[Audiologic evaluation of patients with thalassemic syndromes treated with desferrioxamine B].

Following various articles in literature which have appeared in the last 3 years regarding the neurotoxicity of desferrioxamine B we studied, from the auditory functionality point of view, 95 patients affected with transfusion-dependent thalassemic syndromes, under regular chelation treatment with desferrioxamine B. Our results lead us to conclude that at standard doses, between 40 and 60 mg/Kg/day, desferrioxamine B does not demonstrate a neurotoxicity enough to cause an organic deficit in the auditory sphere, while maintaining therapeutic efficacy.

Acoustic Impedance Tests↗