Biomedical subjects

M J Munuce

Publications and source records attributed to M J Munuce.

8 recordsLinked to original sources

PubMed2006

[Is there an association between sperm normal morphology and their kinetic displacement?].

OBJECTIVE: To evaluate if there exist an association between the % of normal forms and the kinetic characteristics in human spermatozoa MATERIAL AND METHODS: A retrospective study was performed to analyze semen samples of 203 patients by Computer Assisted Semen Analysis. Sperm morphology was evaluated by the aid of a micrometric objective according to strict criteria. Only the patients presenting >20 x 106 sperm/ml and > 50% of progressive motility were included. Data from 168 patients were divided according to the % of normal forms in three groups a) <4% (n=22), b) between 4-13% (n=89) and c) >14% (n=57). Data collected among groups were compared. In order to select a motile sperm population 35 samples were treated by a discontinuous gradient and the % of normal forms as well as motility parameters evaluated before and after selection. RESULTS: The kinetic analysis showed that sperm concentration, the % of motile and rapid spermatozoa (>25 microm/s) as well as the average path velocity (VAP) and the lateral head displacement (LHD) were increased in association with the % of normal spermatozoa presenting the lowest values in the group <4% with respect to the > or = 14% group, (p<0.05). Linearity (LIN) remained constant among groups. Kinetic parameters and sperm morphology were significantly increased (p<0.0001) in the selected samples Results showed that the use of gradients even in teratozoospermic samples improves significantly the % of normal forms respect to baseline values (p<0.0002). CONCLUSIONS: Our results would support the hypothesis that morphologically better spermatozoa would be associated with those with better movement parameters measured in an objective way. In this manner we could suggest that in vivo the best spermatozoa would comprise one "elite" in the journey through the fertilization site.

Humans↗

PubMed2004

Modulation of human sperm function by follicular fluid.

Human follicular fluid (hFF), present in the ampullary environment, can reduce the number of sperm bound to the zona pellucida. The aim of the present study was to investigate the effects of follicular fluid on sperm function. The presence of 50% v/v follicular fluid resulted in a significant reduction in the number of bound spermatozoa with respect to control medium (12.7 +/- 5.5 sp HZ(-1) versus 24.6 +/- 5.7 sp HZ(-1), P = 0.03) as measured by the hemizona binding assay. This reduction in zona binding capacity was not associated with a loss of sperm viability, motility or a premature acrosomal reaction. When capacitated spermatozoa were previously exposed 1 h to follicular fluid, a significant reduction in the number of alpha-d-mannose binding sites on sperm head was detected (23.7 +/- 3.1% versus 15.5 +/- 2.4%, P < 0.05). In addition, sperm fertilizing capacity (assessed as the acrosome reaction to ionophore challenge score) in the presence of follicular fluid was also diminished (38.0 +/- 4.8% versus 22.6 +/- 4.9%, P < 0.01). No modification in the pattern of protein tyrosine phosphorylation which occurs during capacitation was observed in the presence of the fluid. Taken together, the results indicate that the decrease in sperm zona-binding capacity observed in the presence of hFF was related to a lower number of sperm containing alpha-d-mannose receptors.

Acrosome Reaction↗

PubMed2000

Relationship between antisperm antibodies, sperm movement, and semen quality.

The presence of antisperm antibodies might impair fertilization by affecting sperm function in different ways. The aim of this study was to analyze the incidence of antisperm antibodies and evaluate its impact on sperm movement, in normozoospermic and abnormal semen samples. Samples from 144 patients were classified as normozoospermic or abnormal, according to WHO guidelines and Kruger's strict criteria. Motilility was assessed by a computer-assisted system by placing a drop of semen in a Makler chamber. Antisperm antibodies were detected using the Mar Test and Immunobead tests to identify immunoglobulin location and isotype. Results showed no association between the presence of antisperm antibodies and semen quality. Antibody incidence was 15 and 9.5% for normozoospermic and abnormal semen samples, respectively. Motion analysis showed that, although sperm linearity was significantly reduced in abnormal patients with antibodies, the existence of an immune response did not affect the sperm pathway in most cases. This study suggests that sperm motion analysis would not be of great assistance in the screening of an immunological male fertility factor.

Adult↗

PubMed1996

Mammalian sperm-egg fusion: the development of rat oolemma fusibility during oogenesis involves the appearance of binding sites for sperm protein "DE".

Rat epididymal protein DE mediates gamete fusion through complementary sites localized on the egg surface. To investigate whether these egg components are involved in the development of rat oolemma fusibility, both the presence of DE-binding components and the ability of the oolemma to fuse with sperm during oogenesis were examined. Localization of DE-complementary sites by indirect immunofluorescence revealed the absence of fluorescent labeling on growing oocytes with a diameter < 50 microns, and the presence of a uniform staining over the entire surface of germinal vesicle oocytes with a diameter > 50 microns. This localization of oolemma components changed progressively to a patchy distribution during maturation. Whereas sperm incorporation was observed only in maturing oocytes, the development of the Hoechst transfer technique to evaluate membrane fusion revealed that germinal vesicle oocytes with a diameter > 50 microns were already competent to fuse with sperm. The involvement of the DE-complementary sites in the oolemma fusibility of these oocytes was confirmed by the fact that the presence of DE during gamete coincubation significantly (p < 0.001) reduced the percentage of oocytes with fused sperm. Together, these observations indicate that the acquisition of fusibility by the rat oolemma occurs during the growth period and involves the appearance of DE-binding components on the oocyte surface. This study provides novel information on the molecular mechanism by which the mammalian egg plasma membrane becomes competent to fuse with sperm during oogenesis.

Animals↗

PubMedDate not supplied

Does the hypoosmotic swelling test predict human sperm viability?

Human sperm viability is essential for successful fertilization. Eosin Y is the usually accepted method for sperm viability assessment, though the hypoosmotic swelling test has been proposed for the selection of viable spermatozoa in procedures such as intracytoplasmic sperm injection. The present study was designed to determine the value of hypoosmotic swelling test in the prediction of sperm viability. For this purpose, hypoosmotic swelling and eosin Y were performed in parallel and in combination, on both fresh and freeze-thawed semen. Rates for eosin Y were significantly higher than for the hypoosmotic swelling test in fresh semen, with a weak, though significant correlation between the two tests (r = 0.47, p < 0.05). When both tests were performed in succession (hypoosmotic swelling test followed by eosin Y), 14.6% of swollen sperm incorporated the dye. Following exposure to hypoosmotic conditions, sperm viability decreased by 35%. When sperm were killed by freezing, hypoosmotic swelling test rates were higher than eosin Y. Results indicate that these two tests cannot be used interchangeably, since 15% of the swollen sperm apparently died, suggesting that plasma membrane integrity is lost before the capacity to maintain osmotic equilibrium.

Freezing↗

PubMedDate not supplied

Semen culture, leukocytospermia, and the presence of sperm antibodies in seminal hyperviscosity.

Seminal hyperviscosity is generally thought to reveal genitourinary infection. The aim of the present work was to study this hypothesis. A total of 65 semen samples were obtained from males presenting for infertility screening. The samples were evaluated according to WHO criteria and microbiologically investigated, including culturing for Mycoplasma hominis and Ureaplasma urealyticum, and microscopic observation of Chlamydia trachomatis by a direct fluorescence assay. Determination of local antisperm antibodies was performed. Semen was categorized according to consistency: normal (n = 31) and high (n = 34). No difference was recorded either in the number of positive cultures, or in the number of species found in each sample. The number of white blood cells and the percentage of antibody-bound sperm showed no difference in the groups under study. There was no association between seminal hyperviscosity, positivity in semen cultures, number of species isolated in semen cultures, leukospermia, or presence of sperm antibodies. Further studies should be performed considering the evolution of the genital-infected patients to clarify the etiology of the hyperviscosity.

Autoantibodies↗

PubMedDate not supplied

Sperm motility analysis using multi-exposure photography (MEP): validity of the method with normal and abnormal patterns.

Spermatozoon motility is an important semen parameter that can be correlated with fertilizing capacity. It can be evaluated by subjective or objective methods such as the multiple exposure photography technique (MEP). This technique was: (1) validated in terms of accuracy and sensitivity, and (2) used to investigate the possibility of differentiating patient subgroups on the basis of sperm motility. The method was shown to be accurate. The within and between assay variation coefficients were less than 6% and 17% respectively. Maximal sensitivity required 100 spermatozoa, since coefficients of variation were high when counting smaller numbers. A significant difference between fertile, normozoospermic and asthenozoospermic groups on the basis of the population pattern was found in a retrospective study. Moreover, the asthenozoospermic group could be divided into three subgroups, depending on whether one, two, or three motility variables were altered.

Humans↗

PubMedDate not supplied

Sperm motility and ATP content in seminal hyperviscosity.

Objective spermatic motility (Hamilton Thorne Research), the rapid progressive spermatozoa (grade A) recovery after swim-up, and the spermatozoa ATP content (bioluminescence) were studied in normoviscous and hyperviscous asthenospermic samples. The amplitude of lateral head displacement (ALH) was significantly lower in hyperviscous semen (normal: 4.6 +/- 0.7 microns [n = 20], high: 3.5 +/- 1.2 microns [n = 16]; p < .05). The grade A recovery percentage after swim-up was significantly higher in semens with high consistency (normal: 71.0 +/- 38.0 [n = 14], high: 181.3 +/- 108.9 [n = 6]; p < .05). The ATP content per living spermatozoa was in the normal consistency group 449.4 +/- 65.1 pmol per million living spermatozoa (n = 29) and in the high consistency batch 605.1 +/- 242.8 (n = 9), p < .05. In asthenospermia, the spermatozoa from hyperviscous samples have minor ALH values, better response to swim-up, and high ATP content than those from normoviscous ejaculates.

Adenosine Triphosphate↗