Biomedical subjects

H Kodama

Publications and source records attributed to H Kodama.

761 records · Page 43Linked to original sources

PubMedDate not supplied

Blocking of immunofluorescence in the titration of membrane and intracellular reactive antibodies associated with herpesvirus of turkeys.

Blocking of the direct immunofluorescence (IF) reaction allowed titration of anti-membrane antigen (MA) or anti-intracellular antigen (IA) antibodies induced by herpesvirus of turkeys (HVT). The titers (blocking index) obtained by the blocking IF test were well correlated with those determined by the IF test. The results suggest that the blocking IF test was a simpler and better method for titration of a large number of serum samples from chickens infected with HVT.

Animals↗

PubMedDate not supplied

Is long-protocol gonadotropin releasing hormone agonist administration superior to the short protocol in ovarian stimulation for in vitro fertilization?

OBJECTIVE: To compare the long and short protocols of gonadotropin releasing hormone agonist (GnRH-a) administration for ovarian stimulation. SETTING: University hospital. SUBJECTS: 90 patients on their first attempt at in vitro fertilization and embryo transfer (IVF-ET). METHOD: The results of two stimulation protocols were compared with respect to number of follicles greater than 17 mm, peak serum estradiol level, number of oocytes retrieved and fertilized, fertilization rate per oocyte, number of embryos transferred, and pregnancy rate per initiated cycle. RESULTS: The number of follicles greater than 17 mm and the peak estradiol level were significantly (P < .05) higher in the long protocol than those in the short protocol. The number of oocytes retrieved and fertilized, the number of embryos transferred, and the pregnancy rate per initiated cycle were also significantly (P < .001) higher in the long protocol than those in the short protocol. The fertilization rates per oocyte retrieved did not differ significantly between groups. CONCLUSION: The long protocol of gonadotropin releasing hormone agonist administration for ovarian stimulation in IVF-ET may be the preferred method when GnRH-a is used.

Adult↗

PubMedDate not supplied

Effect on sperm-immobilizing antibodies on the spontaneous and calcium-ionophore (A23187)-induced acrosome reaction.

OBJECTIVE: To study the effect of sperm-immobilizing antibodies on spontaneous and A23187-induced acrosome reactions. MATERIAL AND METHODS: Swim-up spermatozoa obtained from a fertile donor were incubated with 16 sera containing sperm-immobilizing antibodies obtained from infertile women and 3 control sera obtained from healthy females. The acrosome loss, either occurring spontaneously or induced by 10-microM A23181, were examined by staining sperm with Pisum sativum agglutinin labeled with fluorescein isothiocyanate. RESULTS: The incidence of the spontaneous acrosome reaction of spermatozoa incubated with anti-sperm antibodies (6.25 +/- 1.4%) was significantly (P < .001) lower than that of the spermatozoa incubated with control sera (12 +/- 0.8%). The incidence of A23187-induced and inducible (incidence of induced minus spontaneous) acrosome reactions of spermatozoa incubated with sera-positive for sperm antibodies (10.4 +/- 1.3% and 4.2 +/- 1.5%) was also significantly lower (P < .001) than that of spermatozoa incubated with control sera (30.7 +/- 0.5% and 18.7 +/- 1.2%). CONCLUSION: Sperm immobilizing antibodies interfere with fertilization by inhibiting the acrosome reaction.

Acrosome↗

PubMedDate not supplied

Effect of sperm lipid peroxidation on fertilization.

This study was aimed at determining, with homologous mouse gametes, whether a level of membrane lipid peroxidation insufficient to affect sperm motility parameters can alter sperm fertilizing potential. The addition of ferrous ions and ascorbic acid (Fe2+/ Asc) to mouse sperm suspensions increases the formation of thiobarbituric acid-reactive substances (TBARS), an indicator of lipid peroxide breakdown products, without significantly affecting the level of sulfhydryl groups. In the presence of Fe2+/Asc concentrations above > 0.4/2.0 mM, spermatozoa become immotile. However, at concentrations < or = 0.4/2.0 mM of Fe2+/Asc, i.e., conditions in which the TBARS formation is increased by < or = 4.6-fold over that of controls, motility remains unaffected for up to 3 hours. In the presence of 0.4/ 2.0 mM Fe2+/Asc, treated spermatozoa increase their fertilizing potential by 50%, as measured by the formation of two-cell embryos. This increase is not caused by improvements in sperm motility parameters (percentage, linearity, velocity, hyperactivation) or sperm capacitation. On the other hand, there is a significant increase in the capacity of mouse spermatozoa to bind to homologous zona pellucida. In conclusion, mild peroxidative conditions, that increase lipid peroxide formation 4.6-fold without significantly modifying free sulfhydryl groups and sperm motility parameters, improve the fertilizing potential of spermatozoa by increasing their binding capacity to zona pellucida.

Animals↗

PubMedDate not supplied

Evidence of proacrosin molecule abnormality as a possible cause of low acrosin activity and unexplained failure of fertilization in vitro.

The aim of this study was to investigate whether the molecular abnormality of proacrosin is associated with an unexplained failure of in vitro fertilization (IVF) and low acrosin activity in human infertility. Seventeen infertile men, whose spermatozoa appeared to be normal but did not fertilize using a conventional IVF technique, were included in this study. Proacrosin molecules from each patient were screened with electrophoresis and Western blotting using either anti-human proacrosin or anti-boar acrosin polyclonal antibodies. The bands of proacrosin appeared equally on the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) at an identical site and reacted equally with human proacrosin antibodies in all patients studied. The anti-boar acrosin antibodies cross-reacted with the proacrosin bands of the patients in all but two cases. The two patients also demonstrated lower levels of total acrosin activity and different peptide maps of the isolated proacrosin. In conclusion, the molecular abnormality of proacrosin, which is reflected by a lack of cross-reactivity to the anti-boar acrosin antibodies, is associated with low acrosin activity and may explain some cases of unexplained failure of human IVF treatment.

Acrosin↗