Search results for "Spermatozoon"
showing 8 items of 8 documents
Correlation between the DNA fragmentation index (DFI) and sperm morphology of infertile patients
2020
Abstract Purpose To evaluate the correlation between the DNA Fragmentation Index (DFI) and sperm morphology in patients undergoing ICSI, as a predictive parameter in reproductive outcomes. Methods A retrospective study was conducted on 125 infertile patients enrolled in a fertility clinic. Seminal characteristics were measured following the WHO guidelines (2010) for the examination of the seminal fluid. After collecting motile sperm population by pellet swim up, DFI was calculated and simultaneously associated with sperm morphology using in situ TUNEL assay and an image analyzer software in at least 250 spermatozoa for each patient. Results All subjects were divided into two groups accordin…
Effects of tributyltin(IV) chloride on fertilization of Styela plicata (Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy stud…
2003
The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm-egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.
First spermatological data on the digenean genus Ityogonimus derived from the description of sperm characters of Ityogonimus ocreatus (Brachylaimidae…
2021
Abstract The present study describes the ultrastructural organization of the spermatozoa of the brachylaimid digenean Ityogonimus ocreatus (Ityogoniminae) by means of transmission electron microscopy (TEM). Live digeneans were collected from the digestive tract of an Iberian mole Talpa occidentalis (Eulipotyphla, Talpidae) captured accidentally during a vole pest control campaign in Priesca (Asturias, Spain). The TEM study reveals that the I. ocreatus sperm are filiform, tapered at both extremities, and have two 9+'1' trepaxonematan axonemes, external ornamentation of the plasma membrane associated with cortical microtubules, spine-like bodies, two bundles of parallel cortical microtubules …
Effects of tributyltin(IV) chloride on the gametes and fertilization ofAscidia malaca (Ascidiacea: Tunicata)
2003
Ascidia malaca gametes before fertilization incubated in 10-5 or 10-7 M solutions of tributyltin(IV) chloride, TBTCl, for 3 h appear highly damaged under transmission electron microscopy observation. Also, the fertilization process is affected by the compound: the damaged spermatozoa are present in the vitelline coat and the egg does not cleave. An increase of microbodies, structurally similar to peroxisomes, have been detected in the egg peripheral cytoplasm, probably in relation to their role in alleviating damage to some cellular components. The results have shown that the reproduction of ascidians under unfavourable environmental conditions is prevented. Copyright © 2003 John Wiley &…
Sperm morphological abnormalities appearing in the male rabbit reproductive tract
1996
The role of the excurrent duct system in producing and/or eliminating morphologically abnormal spermatozoa may modify the semen parameters and interfere with sperm fertilizing capacity. To study this process, changes in the morphology of spermatozoa during their transit through the reproductive tract in sexually mature rabbits were investigated. The incidence of head, midpiece and tail abnormalities as well as of multiple defects in a single spermatozoon, and the position of the cytoplasmic droplet along the sperm midpiece were evaluated in samples from the testis, 6 regions of the epididymis and the vas deferens. Spermatozoa were characterized by rapid migration of the cytoplasmic droplet …
Quantitative changes in sperm head morphology during passage through the male excurrent duct system of the rabbit.
1998
A fine adjustment of sperm head size and shape occurs during maturation and storage within the male excurrent duct of the rabbit. This remodelling, as judged by morphometric values of area, perimeter, length, width, and shape factors, takes place mostly in passage from the seminiferous tubules of the testis to the distal caput of the epididymis. The dimensions of sperm heads from the distal corpus of the epididymis break the general tendency toward a reduction in size and more elliptical shapes. A period of transport and storage within the epididymal cauda and vas deferens follows in which there are no further changes in sperm head morphometry. It can be concluded that the period immediatel…
Sperm kinematics and morphometric subpopulations analysis with CASA systems: a review
2019
Sperm kinematics and morphometric subpopulations analysis with CASA systems: a review. The subjective evaluation of seminal quality has given way to the use of objective assessment techniques by CASA technology (computer-assisted semen analysis). The application of principal components (PC) and clustering methods to reveal subpopulations of spermatozoa is a powerful tool to evaluate raw semen and processed cell suspensions, but not many researchers are aware of the technique. PC analysis is a multivariate statistical method that reduces the number of variables used in subsequent calculations used to describe the data. By integrating the original variables according to their coherence in a d…
An Analysis of the Process of Fertilization and Activation of the Egg
1957
Publisher Summary Fertilization consists fundamentally in the release of a chain of metabolic reactions by virtue of which morphogenesis is started. The result of fertilization is the activation of the egg. This can be achieved also by several agents other than the spermatozoon and it is then spoken of as “artificial activation.” This chapter discusses the structural, physiological, and chemical changes that occur in the egg at fertilization that are significant in the understanding of the mechanisms of the activation. The chapter presents the hypothesis that in the cortex of the unfertilized sea urchin egg an inhibitor–enzyme complex is present. By reacting with some substance introduced b…