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P Piomboni

Publications and source records attributed to P Piomboni.

52 records · Page 3Linked to original sources
PubMed1991

HIV particles detected in spermatozoa of patients with AIDS.

In this paper the Authors describe the presence of HIV particles on and in mature spermatozoa either ejaculated by AIDS patients or incubated in vitro with HIV. Both kinds of spermatozoa have particles localized around the sperm organelles. In the first case, the nucleoid of the virus can be enveloped by a membrane-like coat or be devoid of it and form buddings in the plasma membrane. In the in vitro infected spermatozoa, only membrane enveloped nucleoids are present, and no process of budding can be found. The Authors conclude considering that the spermatozoa of the AIDS patients can be penetrated by the virus particles in different moments of their life, and show the HIV particles in different stages of their cycle: some of them have freshly penetrated the sperm, and are still contained in a membrane-like coat, others are replicated and are budding through the sperm plasma membrane. On the contrary, in vitro infected spermatozoa have only freshly penetrated virus particles, and lack buddings and membrane-free nucleoids. The presence of the HIV virus in spermatozoa is substantiated by labelling with monoclonal or polyclonal anti-HIV antibodies.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Crater defect in human spermatozoa.

This report describes the "crater defect" in human spermatozoa, a malformation that consists of a nuclear and acrosomal invagination present in 100% of the cells, whereas tail structure and motility are fairly normal. The defect occurs during spermiogenesis. A possible concomitance with abnormalities in the microtubular apparatus involved in the sperm molding is discussed.

Adult↗
PubMed1989

Morphogenesis of the decapitated and decaudated sperm defect in two brothers.

The "decapitated sperm" defect, found in both of two sterile brothers, may be assumed to have a genetic origin. The present material suggests that the term "decapitated spermatozoa" is not exact, because detached heads and tails were found in the brothers' ejaculate that could be regarded as "decapitated tails" and "decaudated heads." The present report describes frequent, more or less advanced stages of detachment. Both heads and tails showed a normal structure in which only the postnuclear region was deficient, lacking basal plate and implantation fossa. A break at a different level of the midpiece, and therefore three kinds of separation, were observed. The defect, according to the present research, must originate in the testicular region, whereas the detachment occurs in the epididymis.

Adult↗
PubMed1989

Localization of acrosomal enzymes in Arthropoda, Echinodermata and Vertebrata.

The presence and localization of acrosin and hyaluronidase have been detected by immunocytochemistry in animals belonging to different phyla and characterized by the different structure of the acrosomal complex. Acrosin is widely distributed from Insecta to Echinodermata and Vertebrata; hyaluronidase has a similar diffusion, but seems to be absent from an Insect and from Echinodermata. The presence of extraacrosomal layer and perforatorium seems not to be related to that of the two enzymes, that are absent from Teleost species devoid of acrosome or having only a pseudoacrosome.

Acrosin↗
PubMed1988

Immunocytochemistry and sperm pathology.

In this paper the Authors describe the localization of some significative proteins (acrosin, actin, tubulin, vimentin) detected by immunocytochemical methods in human infertile spermatozoa and correlate their distribution with the ultrastructural characteristics of the same spermatozoa, in order to clarify the structural bases of infertility.

Acrosome↗
PubMedDate not supplied

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↗
PubMedDate not supplied

Notulae seminologicae. 4. Mathematical evaluation of submicroscopical alterations in spermatozoa of sterile men with varicocele.

In this paper the mathematical formula recently proposed by Baccetti & Mirolli in this journal is used for the quantitative electron microscopical evaluation of six submicroscopical defects frequently present in the spermatozoa ejaculated by patients affected by various degrees of varicocele. All these characteristics are independent from each other and are in some way related to imperfect sperm maturation. They concern the shape and position of the acrosome, the status of the chromatin, of the mitochondria, of the axoneme, the individuality of the cell. The incidence in the sperm population of these submicroscopical characters is clearly related to the degree of the affection as estimated by usual clinical parameters. This demonstrates that the electron microscopical sperm analysis evaluated by the present formula is a very sensitive tool in revealing fine prognostical parameters.

Acrosome↗
PubMedDate not supplied

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

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

Acetylcholine synthesis and possible functions during sea urchin development.

Cholinergic neurotransmitter system molecules were found to play a role during fertilisation and early cell cycles of a large number of invertebrate and vertebrate organisms. In this study, we investigated the presence and possible function of choline acetyltransferase (ChAT, the biosynthetic enzyme of acetylcholine) in gametes of the sea urchin, Paracentrotus lividus, through localisation and functional studies. ChAT-like molecules were detected in oocytes, mature eggs and zygotes with indirect immunofluorescence methods. Positive immunoreactivity was found in the ovarian egg cytoplasm and surface as well as at the zygote surface. This suggests the eggs' capacity to autonomously synthesise acetylcholine (ACh), the signal molecule of the cholinergic system. Acetylcholinesterase (AChE, the lytic enzyme of acetylcholine) was also found in ovarian eggs, with a similar distribution; however, it disappeared after fertilisation. Ultrastructural ChAT localisation in sperms, which was carried out with the immuno-gold method, showed immunoreactivity in the acrosome of unreacted sperms and at the head surface of reacted sperms. In order to verify a functional role of ACh during fertilization and sea urchin development, in vivo experiments were performed. Exposure of the eggs before fertilisation to 1 mM ACh + 1 microM eserine caused an incomplete membrane depolarisation and consequently enhanced polyspermy, while lower concentrations of ACh caused developmental anomalies. The exposure of zygotes to 0,045 AChE Units/mL of sea water caused developmental anomalies as well, in 50% of the embryos. Altogether, these findings and other previously obtained results, suggest that the cholinergic system may subserve two different tasks during development, according to which particular type of ACh receptor is active during each temporal window. The first function, taking place in the course of fertilisation is a result of autonomously synthesised ACh in sperms, while the second function, taking place after fertilisation, is due to maternal ChAT molecules, assembled on the oolemma along with egg maturation and fertilisation processes.

Acetylcholine↗
PubMedDate not supplied

A "miniacrosome" sperm defect causing infertility in two brothers.

A sperm defect causing infertility in two brothers is described. The malformation, named the "miniacrosome sperm defect," occurs in the total sperm population. It involves both the nuclei, which have a roundish apex, and the acrosomes, which are small, located in an apical position on the top of the nucleus, and sometimes ring-shaped. The midpiece and tail segments are normal, and the sperm are perfectly motile but fail to fertilize zona-free hamster ova in vitro. In spermatids, the absence of a microtubular manchette and reduction of the Golgi complex are evident.

Acrosome↗
PubMedDate not supplied

Notulae seminologicae. 5. Mathematical evaluation of interdependent submicroscopic sperm alterations.

This paper concerns the mathematical evaluation of sperm quality as examined by electron microscopy. Proceeding with a Bayesian technique, we have developed a formula considering all statistical possibilities for defects of the examined sperm to be present in a sperm cell, the total number of affected spermatozoa, and, as consequence, that of sperm devoid of defects, also considering the probability of association characteristics of some of them. The formula has been studied in three applications. The first concerns the number of healthy spermatozoa present in ejaculates of fertile men. We have found an enormous variability, but we have observed that the minimal number of spermatozoa free of defects assuring a normal fertility seems to be a little higher than 2 x 10(6). The second and third examples concern varicocele and assisted fertilization. In both cases the formula allows a precise simultaneous evaluation of the totality of studied characters and a determination of the number of spermatozoa free from defects. This comparative analysis shows that the formula is sufficiently sensitive to distinguish the different degrees of the varicocele condition and the various possibilities of fertility power in cases of natural or artificial insemination. In this way we will easily control the level of improvement of sperm quality in cases of varicocele treated pharmacologically or surgically, or we will better predict the success of artificial insemination.

Bayes Theorem↗
PubMedDate not supplied

The effect of follicle-stimulating hormone therapy on sperm quality: an ultrastructural mathematical evaluation.

We investigated the effect of follicle-stimulating hormone (FSH) administration on the ultrastructure of spermatozoa in order to evaluate the potential of FSH therapy for improving sperm quality. Forty-six patients exhibiting idiopathic oligoasthenoterato-zoospermia who attended the intrauterine insemination (IU), in vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI) program at our clinic received FSH in daily dosages of 150 IU over a period of 12 weeks. Using transmission electron microscopy, the ultrastructural analysis of spermatozoa was performed prior to the start of FSH therapy, after the treatment had been finished, and 6 weeks posttherapy. Applying a mathematical formula based on submicroscopic characteristics, we calculated the number of morphologically normal spermatozoa. After the FSH treatment, the examined subcellular organelles achieved a higher percentage of integrity. Follicle-stimulating hormone treatment leads to a higher number of morphologically normal spermatozoa. The electron microscopic findings indicate that treatment with pure FSH may be an effective way to improve sperm quality in cases with oligoasthenoterato-zoospermia. Applying the mathematical analysis based on the whole complex of the selected sperm characteristics, we obtained a way to evaluate the success of therapy for the first time.

Follicle Stimulating Hormone↗