It has been reported that various structural and functional changes occur on the surface of the plasma membrane of the ovum and embryo during fertilisation and cleavage in preparation for implantation. Glycoproteins are thought to be one of the factors in cell attachment. Thus, we investigated the changes in glycoprotein expression on the cell surface membrane of the mouse embryo by using lectins. Among seven types of lectin (ConA, WGA, UEA-I, MPA, LCA, DBA and PNA), the fluorescent intensities of ConA and WGA markedly increased from unfertilised ova to blastocysts. By quantitative analysis using immuno-scanning electron microscopy, the numbers of ConA-gold particles were small until 4-cell cleavage, but increased significantly at the blastocyst stage. In contrast, an increased number of WGA-gold particles was detected even at the 4-cell stage, and this increase continued to the blastocyst stage. From the above observations, we conclude that the numbers of sugar chains bound to both ConA and WGA increases with blastocyst formation and earlier expression is observed with WGA. The present study clearly shows that glycoproteins on the cell membrane surface of the mouse embryo quantitatively increase at the time of implantation, and the possibility has been indicated that glycoproteins are involved in intercellular recognition and adhesion between the embryo and endometrial epithelium.

The present study is aimed at evaluating the efficacy of maternal vitamin K2 supplementation on the vitamin K status of newborn infants using the measurement of des-gamma-carboxyprothrombin (PIVKA-II [protein induced by vitamin K absence]) and the hepaplastin test (HPT). PIVKA-II and HPT were measured at the 1st month of age in two groups: 31 infants with maternal vitamin K supplementation (15 mg/d Menatetrenone since the 14th day after parturition) (group 1) and 46 without maternal supplementation (group 2). All infants received vitamin K2 syrup twice within the 1st week of life. The PIVKA-II levels of 31 infants (group 1) were 23.6 mAU/mL (standard deviation [SD] 5.8), showing extremely low levels, and close to healthy adult levels, with a smaller deviation than what was seen in group 2. The levels of the 46 infants in group 2 were 27.8 (SD 16.0). This does not differ significantly from group 1, but a small number of infants showed a modestly high level in PIVKA-II. There also was no significant difference between the two groups in the HPT. These data would indicate that maternal vitamin K supplementation can maintain the vitamin K status throughout the late neonatal period and prevent an onset of vitamin K-deficient hemorrhage.

The status of vitamin K in pregnant women was investigated using the highly sensitive method for des-gamma-carboxyprothrombin (protein induced by vitamin K absence [PIVKA-II]), electrochemiluminescence immunoassay. A gradual elevation of PIVKA-II related to gestational weeks was observed in healthy pregnant women, suggesting that a modest vitamin K deficiency takes place in gestation. Furthermore, throughout gestation the majority of pregnant women exceeded the healthy adult levels in PIVKA-II. Among complicated gestations of preeclampsia, a remarkable elevation of PIVKA-II was observed in severe preeclampsia, in which a high correlation between PIVKA-II level and coagulation parameters, including thrombin-antithrombin (TAT) complexes, was revealed. These data were suggestive that the vitamin K status readily decreased into a deficient status in hypercoagulative conditions. Among other complicated gestations, a moderate elevation of PIVKA-II was demonstrated in hyperemetic conditions, and, if at all, only a slight elevation of PIVKA-II was observed in other maternal diseases. The present study is the first report regarding the changes of PIVKA-II in pregnant women.

The variation of des-gamma-carboxyprothrombin (PIVKA-II, protein induced by vitamin K absence) levels in umbilical cord blood throughout gestation was examined using a highly sensitive method, electrochemiluminescence immunoassay (ECLIA). PIVKA-II levels in infants without any complications were low, but modestly high, exceeding the normal range of healthy adults during the preterm period, followed by a remarkable increase after the 37th week of gestation. Among infants complicated with severe preeclampsia a marked increase of PIVKA-II levels was observed in preterm infants, showing a good correlation with the existence ofinfarctions on the placenta. On the other hand, among infants complicated with preterm premature rupture of the membranes (PROM) in which antibiotics were administered during the prenatal period, a moderate elevation of PIVKA-II levels was observed. These data suggest that the normal range of PIVKA-II in fetuses is modestly high compared with adults and any deficient status of vitamin K would not exist throughout the preterm period. Nevertheless, the vitamin K status might readily fall into a deficient condition in term infants. Furthermore, it is notable that vitamin K deficiency would be induced in complicated gestation with severe preeclampsia and medication with antibiotics.

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