PubMed · 4930351
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J A Schiff. 1970. Developmental interactions among cellular compartments in Euglena.. https://pubmed.ncbi.nlm.nih.gov/4930351/
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OBJECTIVE: To evaluate pregnancy rates (PRs) in women undergoing artificial insemination with sperm alternately prepared by one of five techniques: sperm washing, Percoll gradient centrifugation, swim-up, swim-down, or refrigeration/heparin treatment. DESIGN: Each treatment group alternated in a different order through the five sperm preparations. Pregnancy rates were compared for each sperm preparation. SETTING: Two infertility centers, one located in an academic institution and the other a regional hospital. PATIENT(S): Three hundred sixty-three women undergoing 898 artificial inseminations with husband semen with a progressive motile sperm count of >20 million sperm per mL were randomly placed in the five treatment groups. MAIN OUTCOME MEASURE(S): Pregnancy rates. RESULT(S): The overall ongoing PR per insemination was 9.7% (87/898), including 6.12% for natural cycles (n = 196), 12.8% for clomiphene citrate-stimulated cycles (n = 101), and 10.3% for gonadotropin-stimulated cycles (n = 601). The highest ongoing PRs for sperm preparations followed the swim-up technique (13.2%, 26/197) and the Percoll gradient centrifugation technique (12.7%, 26/204). CONCLUSION(S): These data suggest that the swim-up and Percoll gradient preparations result in higher PRs than the wash, swim-down, and refrigeration/heparin techniques.
OBJECTIVE: To evaluate two commonly used methods of sperm preparation with respect to their effects on sperm morphology (strict criteria). DESIGN: Auto-controlled, split sample study performed on the semen of 74 male partners of couples enrolled for IVF. SETTING: In vitro fertilization and andrology laboratories at a tertiary care, major teaching hospital. PATIENT(S): Seventy-four male partners of couples who were scheduled to undergo IVF. INTERVENTION(S): Equal halves of the same semen sample were evaluated for strict criteria sperm morphology before and after preparation by differential gradient centrifugation using Percoll (Pacific Andrology, Montrose, CA) and by the standard swim-up method. MAIN OUTCOME MEASURE(S): The percentage of morphologically normal sperm was assessed using strict criteria before and after the two methods of sperm preparation. Specific parameters studied were individual abnormalities of the head, midpiece, and tail. RESULT(S): Sperm preparation using differential gradient centrifugation with Percoll produced a significantly greater number of specimens with normal sperm morphology and also showed higher absolute quantitative improvement over the swim-up method. The two methods were comparable in regard to their effects on specific sperm abnormalities (i.e., head, midpiece, and tail defects). CONCLUSION(S): The differential gradient sperm separation method using Percoll is superior to the swim-up method for selecting sperm with normal morphology as assessed by strict criteria. Because sperm morphology as assessed by strict criteria is a good predictor of oocyte fertilization, this method can be recommended as the method of choice for assisted reproductive technology laboratories. Use of this method may help improve outcome by increasing fertilization rates.
The urokinase-type plasminogen activator (uPA) binds to cells via a specific receptor attached to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor. Despite the lack of a transmembrane domain, the urokinase receptor (uPAR) is capable of transducing extracellular signals affecting growth, migration, and adhesion. Several Tyr kinases of the src family as well as beta1, beta2, and beta3 integrins were found to be associated with the uPAR. We found that in the human kidney epithelial line TCL-598, also components of the JAK1/STAT1 signal transduction pathway including gp130, are associated with uPAR as revealed by coimmunoprecipitation and are co-localized in caveolae. Upon clustering of uPA.uPAR complex by a monoclonal antibody, JAK1 associates with uPAR, which in turn leads to STAT1 phosphorylation, dimerization, specific binding to DNA, and gene activation. To prove the dependence of STAT1 activation on the uPAR, TCL-598 cells were treated with sense and antisense uPAR oligonucleotides. In antisense-treated cells in which uPAR expression was reduced to less then one third, activation of STAT1 by the clustering antibody was abolished while STAT1 activation by interferon-gamma was unaffected. Therefore, in this cell line, uPA.uPAR also utilizes the JAK1/STAT1 pathway for signaling, and gp130 might be the transmembrane adapter for this signal transduction pathway.