ISSN:1064-1955    

DOI:10.3109/10641959609015684

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objectives: To review critically published data concerning fetalmdash;maternal interaction at the placental bed level in normal and complicated pregnancies. Emphasis is placed on the adaptive changes of the uteroplacental vasculature of the placental bed.Methods: Histopathological and immunohistochemical data form the basis of this review. The relevance of recent studies on cultured trophoblast is considered in the light of histological findings.Results: The findings of recent experimental studies on invasive processes and trophoblastmdash;extracellular matrix interaction relate mainly to interstitial trophoblast, since no in vitro model is available for the study of vascular changes. The endovascular pathway of vascular invasion is emphasized, and mechanisms of arterial wall destruction need to be reconsidered since vascular disorganization and disruption may precede trophoblast invasion. There is a need for blood flow studies in relation to histopathological findings. Currently the role of various cytokines in trophoblast-maternal interaction is being intensively investigated, since disturbances in the cytokine network may be responsible for the inhibition of trophoblast invasion in complicated pregnancies.Conclusions: Various new techniques have led to a better insight of trophoblast invasion and its regulation. It is important that these should be interpreted in the context of histological reality as observed in the placental bed.

ISSN:1064-1955    

DOI:10.3109/10641959609015685

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: This study aimed to examine the relationships between plasma endothelial 1 and urinary 2,3-dinor-6-keto-PGF1αand other biochemical variables in normal pregnancy, preeclampsia, and the nonpregnant state using multiple regression analysis.Methods: Plasma endothelin 1 and urinary 2,3-dinor-6-keto-PGF1αwere measured after extraction by specific radioimmunoassays in 20 women with proteinuric preeclampsia and 28 normal pregnant women. The two pregnant groups were matched with each other for age and gestation before delivery, and for age with a group of nonpregnant women. Multiple regression analysis was used to create models for plasma endothelin 1 and 2,3-dinor-6-keto-PGF1αin the preeclamptic and normal pregnant groups and in the nonpregnant group.Results: Using plasma endothelin 1 as the dependent variable, a significantly negative correlation was found with urinary 2,3-dinor-6-keto-PGF1αand plasma albumin in the preeclamptic group, accounting for 53% of the variance in plasma endothelin. The same model in the normal pregnant group showed only plasma albumin to be significantly negatively correlated with plasma endothelin, and the model accounted for only 13% of the variance in plasma endothelin. Using urinary 2,3-dinor-6-keto-PGF1αas the dependent variable, an independent negative association was found with plasma endothelin 1 and a positive association with creatinine clearance in the preeclamptic group, accounting for 42% of the variance in urinary 2,3-dinor-6-keto-PGF1α. Using the same model, neither creatinine clearance nor plasma endothelin was a significant predictor of urinary 2,3-dinor-6-keto-PGF1αin normal pregnancy. In the nonpregnant group a negative association was again seen between plasma endothelin 1 and urinary 2,3-dinor-6-keto-PGF1α. The inverse relationship between plasma endothelin 1 and urinary 2,3-dinor-6-keto-PGF1αpersisted when all the nonpregnant groups were examined at 6 months postpartum (P = 0.05) but now accounted for only 7% of the variance.Conclusion: In proteinuric preeclampsia, plasma endothelin 1 is independently negatively correlated with 2,3-dinor-6-keto-PGF1αand plasma albumin. The negative relationship between these variables in preeclampsia may be due to a common underlying cause or a direct pathophysiological link. The relationship between plasma endothelin and urinary 2,3-dinor-6-keto-PGF1αin the nonpregnant state suggests that there is normally a functional relationship between these two endothelial-derived factors, which may be due to direct inhibition of gene transcription by prostacyclin. Withdrawal of such inhibition may contribute to increased endothelin levels in preeclampsia.

ISSN:1064-1955    

DOI:10.3109/10641959609015686

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: To investigate the vasoactive effects of serotonin in umbilical cord arteries from pregnancies complicated with severe or moderate pre-eclampsia or hypertension without proteinuria as compared to normotensive pregnancies matched for gestational age.Methods: Umbilical cord arteries from severe preterm preeclamptic (n = 9) and moderate term preeclamptic (n = 10) pregnancies, hypertensive term pregnancies without proteinuria (n = 7), and normotensive preterm (n = 8) and term (n = 12) pregnancies were perfused in vitro. Serotonin was administrated through a side infusion. Five umbilical cords with single umbilical artery (SUA) were included in the study.Results: Serotonin induced a monophasic pressure increase or a biphasic pressure response with a transient vasodilatation succeeded by a constrictory response. Two preparations from normotensive term pregnancies were serotonin insensitive. These were excluded from the calculations. At a serotonin dose of 10−7M, the proportion of preparations giving a biphasic response was significantly smaller in preterm as compared to term normotensive pregnancies (2/8 vs. 9/10, P<0.02). This proportion was nonsignificantly different in severe preeclampsia (3/9) as compared to the preterm normotensive group as well as between the moderate preeclamptic (8/10), hypertensive (without proteinuria) (6/7), and term normotensive groups. No significant differences were observed in the maximum constrictory responses between the groups. The vascular resistance was significantly reduced in the SUA cords as compared to the normal cords.Conclusions: In the human umbilical cord artery the serotonin response pattern seems to be dependent on gestational stage but seems not to be altered by hypertension or preeclampsia.

ISSN:1064-1955    

DOI:10.3109/10641959609015687

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: The aim of this study was to elucidate the roles of platelet-activating factor acetylhydrolase (PAF-AH) in normal and hypertensive pregnancies.Method: Changes in serum PAF-AH activity were investigated in 13 nonpregnant women, 168 normal pregnant women, 11 women in normal puerperium, and 35 pregnant women with preeclampsia (mild: 28, severe: 7). Serum PAF-AH activity was measured by the method of Stafforini et al.Results: The serum PAF-AH activity of normal pregnant women between 5 and 34 weeks gestation was significantly lower than that of nonpregnant women, increasing after 34 weeks gestation and returning to nonpregnant levels within 1 month after delivery. In the pregnant women with mild preeclampsia at 28-41 weeks gestation, serum PAF-AH activity (28.0±1.0 nmol/ min/mL, mean±SEM, n = 28) was significantly (P<0.01) higher than that in gestational-age-matched normal pregnant women (21.3±0.8 nmol/min/mL, n = 73). However, in the pregnant women with severe preeclampsia, the activity (12.5±3.9 nmol/min/mL, n = 7) was significantly lower (P<0.01). Three of 7 severe preeclamptic patients showed extraordinarily low PAF-AH activity even before the onset of preeclampsia.Conclusion: We found remarkable differences between the serum PAF-AH levels in mild and severe preeclampsia. In mild preeclampsia, the increased PAF-AH activity may play a role in regulation of the local PAF concentration. On the other hand, some of the women with severe preeclampsia showed extraordinarily low PAF-AH activity, suggesting that such a regulatory mechanism of local PAF concentration may not operate in the patients.

ISSN:1064-1955    

DOI:10.3109/10641959609015688

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: The influence of uninephrectomy and salt loading on blood pressure (BP) during pregnancy was examined in pregnant Wistar rats.Methods: BP was measured by the indirect tail-cuff method every day during pregnancy in the following five groups: group 1 (n = 18, uninephrectomy on the first day of gestation + 8% high-salt diet), group 2 (n = 8, uninephrectomy + 0.4% low-salt diet), group 3 (n = 14, sham operation + high-salt diet), group 4 (n = 8, sham operation + low-salt diet), and group 5 (n = 8, nonpregnant female rats, uninephrectomy + high-salt diet).Results: Systolic BP in Group 1 increased significantly from midpregnancy and exceeded 140 mm Hg in late pregnancy. On day 17 of gestation, systolic BP in Group 1 (140.5±4.3 mm Hg) was significantly higher than in the other four groups (114.8±3.8, 123.1±3.6, 117.9±3.8, 123.0±3.5 mm Hg, P<0.05, respectively). Systolic BP was increased in uninephrectomized and salt-loaded pregnant rats but not in rats with two kidneys, uninephrectomized rats on a low-salt diet, or uninephrectomized and salt-loaded nonpregnant rats on a high-salt diet.Conclusions: Reduced renal mass and salt loading may predispose to the development of hypertension during pregnancy.

ISSN:1064-1955    

DOI:10.3109/10641959609015689

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: In a previous study we showed neutrophil platelet-activating factor (PAF) to be reduced in preeclampsia, while plasma lyso-PAF was increased. The aim of the current study was to examine (PAF) acetyl hydrolase activity (the enzyme that degrades PAF) in plasma and urine of new groups of preeclamptic, hypertensive, and normal pregnant women, to see if alterations in the activity of this enzyme might explain the changes in neutrophil PAF and plasma lyso-PAF previously seen in severe preeclampsia.Methods: Plasma and urinary acetyl hydrolase activity was measured in 22 women with proteinuric preeclampsia and 22 age- and gestational-age-matched normal pregnant women. To determine whether alterations in acetyl hydrolase activity in preeclampsia were due to hypertension per se, a comparison was made to a group of 10 age- and gestational-age-matched pregnant women with uncomplicated essential hypertension. The pregnant women were studied prior to delivery and at 6 weeks and 6 months postpartum, and were also compared to a group of 17 age-matched nonpregnant controls.Results: Plasma acetyl hydrolase activity was elevated in the preeclamptic and essential hypertensive women at all visits. However, the elevation in these two groups was most pronounced in the postpartum period. The elevation in plasma acetyl hydrolase was accompanied by increases in the levels of LDL (low-density lipoprotein)-cholesterol (P<0.05) in the same groups over the same time period. Urinary acetyl hydrolase activity was elevated in women with preeclampsia (P<0.01) compared to all other groups before delivery, and was closely related to the amount of proteinuria.Conclusion: Increases in plasma acetyl hydrolase activity in the preeclamptic and essential hypertensive groups are most pronounced after delivery, suggesting that this elevation represents a constitutional difference between the two groups who were hypertensive during pregnancy and those who were normotensive throughout. The increase in urinary acetyl hydrolase is specific to preeclampsia and resolves after delivery, but it is not known whether it is the result of a plasma leak or reflects altered renal PAF synthesis.

ISSN:1064-1955    

DOI:10.3109/10641959609015690

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: Assess the quality of antenatal care in eclamptic patients.Methods: The medical records of all eclamptic patients in 1993 were reviewed. The place of booking for antenatal care, frequency of attendance, and failure in treatment of disorders in pregnancy related to the maternal and fetal outcome were studied retrospectively.Results: 176 of 251 eclamptic women had some form of antenatal care; 33.8% attended only once or twice and substandard care was identified in 27.8%. The number of maternal and fetal deaths was twice as high in unbooked as in booked patients.

ISSN:1064-1955    

DOI:10.3109/10641959609015691

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objectives: Preeclampsia (PET) is associated with abnormal cyto-trophoblast invasion. Serum levels of human chorionic gonadotrophin (hCG) reflect both the volume and maturity of trophoblast. Our aim was to investigate whether early midtrimester levels of maternal serum hCG in women subsequently developing preeclampsia differ from those of the normal pregnant population.Method: A retrospective analysis of serumβhCG concentrations measured, between 15 and 17 weeks, as part of antenatal serum screening for fetal Down's syndrome in women who subsequently developed PET. TheβhCG concentrations were expressed as multiples of the median value for the local population adjusted for gestational age. The women had otherwise uncomplicated singleton pregnancies and delivered chromosomally normal fetuses. A sample from the original population was taken as a control group (n = 625).Results: Forty-eight women who developed PET were identified. Their second trimesterβhCG was significantly elevated (P = 0.0008) with a median of 1.30 MOM when compared to that of the control group MOM. The mean gestational age at delivery was 35 weeks, 4 days and the population's mean birthweight was on the 40th centile. There was no difference in theα-feto-protein levels.Conclusions: This study shows that women who subsequently develop preeclampsia tend to have elevated serum hCG levels early in the second trimester compared to the population as a whole. This may be associated with abnormal early placental development, such as hyperplacentosis or delayed placental maturation.

ISSN:1064-1955    

DOI:10.3109/10641959609015692

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Objective: The pathophysiology of preeclampsia includes an imbalance of increased thromboxane and decreased prostacyclin. Recently attention has been given to lipid peroxides because their levels are abnormally increased in the maternal circulation of women with preeclampsia. Since preeclampsia occurs in the presence of the placenta or placental tissue, we examined the hypothesis that the production of lipid peroxides is significantly higher in placentas obtained from women with preeclampsia than from women with normal pregnancies.Methods: Placentas were obtained from 6 normally pregnant women and 6 women with preeclampsia. Placental tissues (350 mg) were incubated in DMEM for 48 h. Samples were collected at 0, 2, 6, 16, 28, and 48 h of incubation.Main Outcome Measures: Samples were analyzed spectrophotometrically for lipid peroxides by a peroxide equivalent assay, and for thromboxane and prostacyclin by radioimmunoassays of their stable metabolites, thromboxane B2and 6-keto PGF1α.Results: As compared to placentas obtained from normally pregnant women, placentas obtained from women with preeclampsia produced significantly more lipid peroxides (91±11 vs. 191±33 pmol/μg after 48 h of incubation) and more thromboxane (22.3±4.0 vs. 34.9±4.6 pg/μg at 48 h) but less prostacyclin (15.5±2.6 vs. 9.4±1.4 pg/μg at 48 h, respectively). The increases in lipid peroxide and thromboxane concentrations in the incubation medium were highly correlated (r = 0.769).Conclusions: Preeclamptic placentas produce significantly more lipid peroxides and thromboxane but less prostacyclin than normal. Since the placenta secretes lipid peroxides, it could be a source of increased lipid peroxides in the circulation of women with preeclampsia.

ISSN:1064-1955    

DOI:10.3109/10641959609015693

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor