Biomedical subjects

J Stamm

Publications and source records attributed to J Stamm.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Influence of peritoneal fluid from spontaneous and stimulated cycles on sperm motility in vitro.

Peritoneal fluids (PFs) from spontaneous (n = 14) and gonadotrophin-stimulated cycles (n = 20) were obtained during diagnostic laparoscopy and gamete intrafallopian transfer (GIFT) procedures, respectively. The effects of these fluids on the linear component of sperm motility and on the percentage of motile spermatozoa were studied in vitro by objective motility assessments and compared to a control medium (B2-Ménézo). Overall, the two types of PFs were found to have rather similar effects on the motility parameters studied. However, the fluids from hormonally-stimulated cycles sustained motility better (i.e., sperm velocity and percentage of motile sperm) and in a rather constant manner as a function of time (narrower range distributions of the motility measurements). Furthermore, it was observed that under identical experimental conditions motility measurements depended not only on the type of PF used but also on the sperm sample. These results suggest that assisted reproduction procedures in which PF is the medium where the gametes eventually meet and interact, such as direct peritoneal insemination (DIPI) or peritoneal oocyte and sperm transfer (POST), could have different success rates if performed in spontaneous rather than in stimulated cycles. At the same time, our results may help to explain why different pregnancy rates were reported in different studies using DIP or POST.

Adult↗

PubMedDate not supplied

Bacteroides ureolyticus in men consulting for infertility.

A screening of 3196 semen analyses performed in our clinic from January 1986 to December 1990 revealed 314 (9.8%) patients whose semen was infected with Bacteroides ureolyticus. Investigating the relationship between the presence of B. ureolyticus, the seminal microflora and the conventional semen parameters, we observed that the presence of this micro-organism in the semen was coupled (1) to an increased presence of Enterococcus species, (2) to an increased number of short-tailed spermatozoa and epithelial cells, and (3) to a decreased total fructose concentration (mg ejaculate-1). These results suggest that B. ureolyticus or its toxins may influence sperm morphology and function by yet unknown mechanisms and may also increase the number of epithelial cells by soft tissue infection in vivo. The decreased fructose levels suggest that this anaerobic micro-organism might specifically colonize the seminal vesicles, while the normal zinc values recorded suggest a normal prostatic function. Overall, our data support the hypothesis that the presence of B. ureolyticus is not associated with nongonococcal urethritis.

Bacteria, Aerobic↗

PubMedDate not supplied

Computer-aided semen analysis: sperm concentration assessment by the Strömberg-Mika system.

The scope of this study was to evaluate the accuracy, precision and specificity of the sperm concentration measurements by the Strömberg-Mika Cell Motion Analyser (SM-CMA). Our data show that the instrument generally underscores the sperm concentration and therefore the uncorrected measurements must be corrected by the operator using the 'mouse'-driven option. In terms of precision, the system appears to have an excellent internal precision whereas its repeatability is influenced by the sperm concentration, the sample's homogeneity and the correction of the raw data. In order to increase the system's repeatability, we suggest that sperm counts should be carried out in various fields of the counting chamber, and the mean of the corrected values be taken as representative of the sperm concentration in the ejaculate if the various measurements show a homogeneous (poissonian) distribution. The correction of the raw data with the 'mouse'-driven correction option was also shown to improve the system's reproducibility. Concerning specificity, our data evidenced that, without technical correction, the instrument failed to correctly classify certain spermatozoa as such, thereby grossly underscoring sperm counts. This finding was more evident at low sperm counts. Overall, the SM-CMA requires additional laboratory time but the corrected sperm counts are comparable to manual counts and semi-automated counts with the added option that it provides the andrologists with various motility characteristics not possible with the latter methodologies.

Autoanalysis↗