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Mervi Halttunen

Publications and source records attributed to Mervi Halttunen.

6 recordsLinked to original sources
PubMed2003

Differences in glycosylation and sperm-egg binding inhibition of pregnancy-related glycodelin.

Glycodelin is a glycoprotein produced in many glands, particularly those of reproductive tissues. It appears as different glycoforms in amniotic fluid (glycodelin-A) and seminal plasma (glycodelin-S), but only glycodelin-A inhibits gamete adhesion. In the present study, glycodelin from secretory-phase endometrium, first-trimester pregnancy decidua, and midtrimester amniotic fluid was studied with respect to physicochemical properties, including glycosylation patterns and inhibitory activity of sperm-egg binding. Purified glycodelins from all these sources were similar in isoelectric focusing and in lectin immunoassays using lectins from Wisteria floribunda and Sambucus nigra. Likewise, the glycodelins inhibited sperm-egg binding in a dose-dependent manner, as measured by hemizona-binding assay. However, subtle quantitative physicochemical and biological differences were found between glycodelins from different sources as well as within the same tissue/fluid between different individuals. Differences were most pronounced between endometrial glycodelins from nonpregnancy and first-trimester pregnancy. The glycan structures studied by fast-atom bombardment mass spectrometry of individual amniotic fluid glycodelin-A samples also showed interindividual quantitative differences. In conclusion, glycodelins from different female reproductive tract tissues and amniotic fluid share substantial similarity, allowing all of them to be called glycodelin-A. However, these glycodelins exhibit quantitative physicochemical and functional differences between different sources and individuals.

Adult↗
PubMed2002

Monoclonal antibodies, immunofluorometric assay, and detection of human semenogelin in male reproductive tract: no association with in vitro fertilizing capacity of sperm.

Semenogelin plays an important role in sperm clotting and is degraded into smaller fragments by prostate-specific antigen (PSA) during clot liquefaction. Semenogelin and its fragments inhibit sperm motility in vitro. We studied the expression of semenogelin I mRNA and its localization in various tissues of the male genital tract. We also studied semenogelin concentrations with respect to sperm parameters and the outcome of in vitro fertilization. Semenogelin protein was detected by immunohistochemical staining and semenogelin I mRNA was detected by Northern blot analysis in the seminal vesicles and ampullary part of the vas deferens, whereas specimens from the prostate, epididymis, testis, and the female genital tract were negative. Using monoclonal antibodies against semenogelin, an immunofluorometric assay was developed to measure semenogelin levels in seminal plasma and to evaluate possible correlations with sperm parameters and fertilization in vitro. No correlation was found between the semenogelin concentration and the volume of the ejaculate, sperm concentration, sperm motility, or in vitro fertilization rate. Semenogelin levels were positively correlated with the total protein concentration in seminal plasma, and there was an inverse correlation between the concentration of semenogelin and that of PSA. The levels of semenogelin appear to bear no relationship to the in vitro fertilization capacity of the spermatozoa.

Adult↗