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Biomedical subjects

G Collodel

Publications and source records attributed to G Collodel.

48 records · Page 3Linked to original sources
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

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

Effect of hydrostatic pressure on morphological and ultrastructural aspects of normal and osteoarthritic human articular chondrocytes.

In this work we studied the morphological and ultrastructural aspects of normal and osteoarthritic (OA) human articular chondrocytes cultivated in alginate gel for 48 hours. After this period the chondrocytes in Petri dishes were exposed to cyclic pressurization (minimum pressure 1 MPa and maximum pressure 5 MPa) at 0.25 Hz frequency for three hours. In other loading procedures the cells were exposed to continuous pressure (24 MPa) for three hours. Some dishes were not pressurised and these served as controls. The cells were then fixed for transmission electron microscopy (T.E.M.) and for scanning electron microscopy (S.E.M.). No ultrastructural changes were observed in normal chondrocytes exposed at physiological pressure. OA cells placed under physiological pressure showed a partial recovery on morphological and ultrastructural aspects. Normal and OA samples exposed to continuous pressure (24 MPa) showed a morphological worsening in both T.E.M. and S.E.M. studies.

Adult↗
PubMedDate not supplied

Morphological and cytoskeletal aspects of cultivated normal and osteoarthritic human articular chondrocytes after cyclical pressure: a pilot study.

OBJECTIVE: This study investigated the effect of hydrostatic cyclical pressure on the cell ultrastructure and cytoskeleton of normal and osteoarthritis (OA) human cultivated chondrocytes in vitro. METHODS: The different effects of pressurization with sinusoidal waves at a minimum pressure of 1 MPa, a maximum pressure of 5 MPa and a frequency of 0.25 Hz for 3 hrs on normal and OA chondrocytes were assessed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and immunoflurescence microscopy (IF). RESULTS: Structural differences exist between normal and OA chondrocytes at the nuclear, cytoplasmic and cytoskeletal level. Pressurization did not alter the normal chondrocytes, but had a beneficial effect on OA chondrocytes, by increasing the number of cell organelles responsible for synthesis activities. IF examination has shown that the distribution of actin protein in normal chondrocytes is polarized on the apical sides of the cellular cytoplasm. However, in OA chondrocytes the signal of the actin protein is not as well defined. Similarly, the localization of the tubulin protein in normal and OA cells also appears to be different. Hydrostatic pressure did not cause any modification in the cytoskeletal organization of the OA chondrocytes. CONCLUSION: This study confirms the different morphology, structure and cytoskeletal aspect of normal and OA chondrocytes and the important role played by pressure on cell morphology. The recovery of OA chondrocytes observed by an increase of cytoplasmic organelles does not seem to involve the cytoskeleton.

Adult↗
PubMedDate not supplied

Effect of continuous high hydrostatic pressure on the morphology and cytoskeleton of normal and osteoarthritic human chondrocytes cultivated in alginate gels.

OBJECTIVE: To investigate the effect of continuous high hydrostatic pressure on the cell ultrastructure and cytoskeleton of cultivated normal and osteoarthritic (OA) human chondrocytes. METHODS: The effects of continuous hydrostatic pressure (24 MPa) for 3 hrs on normal and OA chondrocytes were assessed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and immunofluorescence microscopy (IF). RESULTS: Structural differences at the nuclear, cytoplasmic and cytoskeletal levels were observed between normal and OA chondrocytes. Continuous high hydrostatic pressure severely altered normal chondrocytes that became similar in structural organization to OA chondrocytes and further reduced the number of cell organelles involved in the synthesis of collagen and proteoglycans. IF showed major changes in the distribution of actin and tubulin after pressurization in normal and OA chondrocytes. CONCLUSIONS: The results confirm the major role of pressure on chondrocyte ultrastructure. Continuous high hydrostatic pressure caused structural alterations in normal chondrocytes, which obtained similar, if not identical, characteristics to those typical of osteoarthritic chondrocytes.

Aged↗
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↗