Biomedical subjects

J F Guerin

Publications and source records attributed to J F Guerin.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Movement characteristics of human spermatozoa collected from different layers of a discontinuous Percoll gradient.

In order to evaluate the functional state of human spermatozoa separated on discontinuous Percoll gradient, sperm provided by 15 healthy volunteers were recovered from different layers (60, 70, 80, 90, 100%) of the gradient, then submitted to a complete analysis of sperm movement characteristics. This one was performed using a computer assisted system (Cellsoft, Cryo Resources, Ltd., NY, USA). In all fractions sperm motility was highly maintained during 24 h and all movement characteristics, with the exception of ALH, were different from that observed in seminal plasma. Curvilinear velocity (VCL), linearity (LIN), and percentage of hyper-activated sperm (HA) increased in relation to the Percoll concentration. Nevertheless there was no dramatic difference, concerning motion parameters, between 100%, 90%, and 80% Percoll fractions, which can thereby be pooled in case of insufficient sperm recovering in 100% fraction. On the contrary there is some doubt about the fertilizing ability of spermatozoa recovered in 70% and 60% Percoll layers, since VCL, LIN, and especially HA are severely decreased.

Cell Separation↗

PubMedDate not supplied

Seminal alpha-glucosidase activity as a marker of epididymal pathology in nonazoospermic men consulting for infertility.

Glucosidase (alpha G) activity was measured in sperm free seminal plasma from 1200 patients consulting for primary infertility, in whom clinical examination of epididymides revealed some abnormalities and histories of genital infections. They constituted the group with epididymal pathology (P) that was compared with a reference group (R) of 246 men without any epididymal pathology. The distribution of alpha G was significantly different between the two groups, even if we considered only the subjects in group P with normal sperm count (PN: 353 men: p less than 10(-6). 15.9% of subjects in group PN exhibited alpha G values as low as vasectomized men, versus 1.2% in group R. A linear relationship was established between alpha G and sperm content in both groups, but alpha G activities were systematically lower in group P (y = 0.19 x + 64) than in group R (y = 0.30 x + 86). There was no correlation between alpha G and the percent of sperm motility. On the contrary, we found statistically more clinical epididymal abnormalities in cases of decreased alpha G activity than in cases of normal alpha G activity (p less than .01).

Analysis of Variance↗

PubMedDate not supplied

[Relationships between seminal enzymes and fertility (author's transl)].

Various enzyme activities can be detected in human seminal plasma; these are mainly hydrolases which traduct high proteolytic activities. Acid phosphatase constitutes the best prostatic marker, while alpha glucosidase characterizes well epididymal function. The enzymatic equipment of spermatozoa -excepted for acrosin- is very similar to that of seminal plasma, which suggests that most of sperm enzymes are incorporated from male genital secretions. Tight relationships exist between the enzymatic equipment of spermatozoa and their fertilizing capacity: motility is depending of enzymes contained in sperm mid piece and flagellum; acrosomal enzymes are necessary for penetration of oocytes. However we could only very rarely explain some case of male sterility by defect of semen enzymes.

Acid Phosphatase↗

PubMedDate not supplied

Applications of laser scanning confocal microscopy to the observation of human oocytes and embryos.

Laser scanning confocal microscopy (LSCM) is a powerful and useful tool in developmental biology. The diverse applications of LSCM in biomedical field has led to advances in the microscopes themselves and the synthesis of novel specific probes for the observation of biological structures and the hypothesis of physiological process. LSCM was used to visualize the cellular actin cortex together with the chromatin in human arrested preimplantation embryos and in unfertilized oocytes obtained by in vitro fertilization. In embryos, we observed a majority of multinucleated blastomeres and some with fragmented nuclei or anucleated. LSCM also showed nuclei displaying the chromatin condensation and fragmentation patterns suggesting the phenomenon of apoptosis. Moreover, in arrested fragmented embryos of poor morphology, unequal sized blastomeres often showed cellular fragments without nuclei, compatible with aspects of apoptotic bodies.

Actins↗