Biomedical subjects

Tomizo Nishiguchi

Publications and source records attributed to Tomizo Nishiguchi.

5 recordsLinked to original sources

PubMed2005

Des-gamma-carboxyprothrombin (PIVKA-II) levels in maternal serum throughout gestation.

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.

Adult↗

PubMed2005

Antiphospholipid syndrome: characteristics and obstetrical management.

Antiphospholipid syndrome (APS) is characterized by a combination of clinical features consisted of thrombotic or pregnancy-related events and autoimmune antiphospholipid antibodies. In the 1998 International Consensus Preliminary Criteria, APS is defined by the concomitant presence of these clinical features and laboratory tests, including solid immunoassay and lupus anticoagulant (LAC). Current concept of antiphospholipid antibodies directed against plasma proteins with affinity for negatively charged phospholipids, mainly beta2-glyoprotein 1 (beta2GP1) and prothrombin, that is, anti-beta2GP1 and anti-prothrombin antibodies have been shown as a key antibody in the APS, while the pathophysiological mechanisms remain still uncertain. In the recent investigations potential mechanisms, such as endothelial activation induced by bivalent-formed antiphospholipid antibodies and complement activation, have emerged. Recurrent pregnancy losses or fetal death, and increased rates of preeclampsia and placental insufficiency are the clinical features in the APS. It is now accepted that unfractionated or low-molecular-weight heparin in combination with low-dose aspirin represents the current standard treatment for pregnant women with anti-phospholipid antibodies, and high-dose immunoglobulin is considered as a salvage therapy for refractory APS. This review highlights the characteristics of APS and the recent consensus for obstetrical managements in APS.

Adult↗

PubMed2002

Coagulation index to distinguish severe preeclampsia from normal pregnancy.

The purpose of this study was to establish a new coagulation index to distinguish severe preeclampsia from normal pregnancy using optimal coagulation parameters. The difference between platelet counts in early gestation and before delivery (DeltaPlt = [platelet counts before delivery] - [platelet counts in early gestation]) was calculated as an index of changes in platelet counts. Antithrombin (AT) activity, thrombin-antithrombin (TAT) complex, fibrin degradation products (FDP) D-dimer, and DeltaPlt were investigated in 72 cases of normal pregnant women in the third trimester of pregnancy and 56 cases of severe preeclampsia. The new coagulation index was calculated using multivariate logistic regression analysis. As a result, in a case using four parameters, the following formula was obtained: Y = (-0.019 x AT activity) + (0.067 x TAT) + (0.067 x D-dimer) + (-0.064 x DeltaPlt) + 0.706. According to this formula, coagulation indices in normal pregnant women and in patients with severe preeclampsia were -0.77 +/- 0.51 and 1.41 +/- 1.56, respectively (p < 0.0001). Among patients with severe preeclampsia, coagulation and fibrinolysis disorders before delivery were typical in patients terminated by cesarean section (coagulation index = 1.62 +/- 1.66) compared with those with successful vaginal delivery (coagulation index = 0.52 +/- 0.34) (p < 0.05). These facts suggest that an excessive hypercoagulable state is associated with the termination of pregnancy resulting from the aggravation of preeclampsia. From the viewpoint of coagulation and fibrinolysis disorders, the predictive value in order to decide the optimal time for the termination of pregnancy could be recommended when the coagulation index exceeded 1.20.

Antithrombins↗

PubMed2002

Anticholinergics induce eclamptic seizures.

Severe preeclampsia is a pathophysiological disorder specific to pregnancy and characterized by vasoconstriction and hypercoagulability. Eclampsia (convulsion associated with preeclampsia) and hemolysis, elevated liver enzymes, and low platelet count associated with preeclampsia (HELLP syndrome) are serious complications in patients with severe preeclampsia. They are thought to be characterized by generalized vasoconstriction and reduction in blood flow to various organs that may be explained by increased sensitivity of the vascular smooth muscles and increased vasopressors. Liver involvement in eclampsia and preeclampsia is referred to as HELLP syndrome, and epigastric and right upper quadrant pain is often a symptom of severe preeclampsia and may be indicative of imminent convulsions. In addition, marked dilatation of the stomach and the colon is often demonstrated in these patients. These phenomena result from the hyperactivity of the sympathetic nervous system but are not caused by the hyperactivity of the parasympathetic nervous system. The authors experienced two cases of eclamptic seizures after the administration of an anticholinergic (scopolamine butylbromide) in patients with severe preeclampsia complicated by HELLP syndrome. Anticholinergics, blocking agents of the parasympathetic nervous system, can enhance the hyperactivity of the sympathetic nervous system; therefore, vasospasms of the vessels may be easily aggravated, and eclamptic seizures may be induced in patients with severe preeclampsia, especially in those complicated by HELLP syndrome. The administration of anticholinergics should be avoided in patients with severe preeclampsia, especially when there is epigastralgia.

Adult↗

PubMed2002

Improvement of vitamin K status of breastfeeding infants with maternal supplement of vitamin K2 (MK40).

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.

Biomarkers↗