Oxidized low-density lipoprotein (Oxidized LDL) and the risk of preeclampsia.

Oxidative stress plays an important role in the pathophysiology of preeclampsia. In a case-control study of 99 women with preeclampsia and 99 controls, we assessed maternal plasma oxidized low-density lipoprotein (oxidized LDL) in relation to preeclampsia risk. Logistic regression procedures were used to derive odds ratios (OR) and 95 % confidence intervals (CI). Plasma oxidized LDL was determined using enzyme immunoassay. Maternal plasma oxidized LDL was significantly positively correlated with lipids in both cases and controls. After adjusting for nulliparity, pre-pregnancy body mass index, physical inactivity, family history of chronic hypertension and plasma vitamin C concentrations, women who had elevated oxidized LDL concentrations ( > or = 50 U/l) experienced a 2.9-fold increased risk of preeclampsia when compared with women having lower oxidized LDL concentrations (95 % CI 1.4-5.9). The risk of preeclampsia was markedly increased in women who had both elevated oxidized LDL and elevated triglyceride concentrations (OR=8.9, 95 % CI 3.1-26.2). Women with both elevated oxidized LDL and low vitamin C concentrations experienced a 9.8-fold increased risk of preeclampsia (95 % CI 3.0-32.2). Our results confirm the role of oxidative stress in the pathogenesis of preeclampsia. Prospective studies are needed to determine if elevated oxidized LDL concentrations can predict the occurrence of preeclampsia.

Maternal plasma VEGF, sVEGF-R1, and PlGF concentrations in preeclamptic and normotensive pregnant Zimbabwean women.

Vascular endothelial growth factor (VEGF), a disulphide-linked homodimeric glycoprotein that is selectively mitogenic for endothelial cells, plays an important role in vasculogenesis and angiogenesis. Preeclampsia, a relatively common complication of pregnancy that is characterized by diffuse endothelial dysfunction possibly secondary to impaired trophoblast invasion of the spiral arteries during implantation, has recently been associated with alterations in maternal serum/plasma concentrations of VEGF, and other related growth factors and their receptors. We examined the relationship of maternal plasma VEGF, sVEGF-R1 and PlGF levels to the risk of preeclampsia among women delivering at Harare Maternity Hospital, Zimbabwe. 131 pregnant women with preeclampsia and 175 controls were included in a case-control study. Maternal plasma concentrations of each biomarker were measured using enzymatic methods. We used logistic regression to calculate odds ratios (OR) and 95 % confidence intervals (CI). Preeclampsia risk was inversely related with quartiles of plasma VEGF (OR: 1.0, 1.0, 0.7, and 0.5, with the lowest quartile as reference; p for trend=0.06). We noted a strong positive association between preeclampsia risk and sVEGF-R1 concentrations (OR: 1.0, 6.5, 9.7, 31.6, with the first quartile as the referent group; p for trend<0.001). After adjusting for confounders, we noted that women with sVEGF-R1 concentrations in the highest quartile (>or=496 pg/ml), as compared with those in the lowest quartile (<62 pg/ml) had a 31.6-fold increased risk of preeclampsia (OR=31.6, 95 % CI 7.7-128.9). There was no clear evidence of a linear relation in risk of preeclampsia with PlGF concentrations. In conclusion, plasma VEGF, sVEGF-R1 and PlGF concentrations (measured at delivery) were altered among Zimbabwean women with preeclampsia as compared with normotensive women. Our results are consistent with some, though not all, previous reports. Prospective studies are needed to: 1) identify modifiable determinants of maternal plasma concentrations VEGF, sVEGF-R1, and PlGF; and 2) evaluate the temporal relationship between observed alterations of these biological markers in preeclamptic pregnancies.

Maternal recreational physical activity is associated with plasma leptin concentrations in early pregnancy.

BACKGROUND: A limited amount of literature suggests that plasma leptin concentrations are reduced with habitual physical activity in men and non-pregnant women. We investigated the relationship between maternal physical activity and plasma leptin during early pregnancy. METHODS: The study population included 879 normotensive, non-diabetic pregnant women who reported physical activity type, frequency, and duration in early pregnancy. Plasma leptin, measured in blood samples collected <16 weeks gestation, were determined using enzyme immunoassays. Weekly duration (h/week) and energy expended on recreational physical activity [metabolic equivalent score (MET)-h/week] were categorized by tertiles among active women. Physical activity intensity was categorized as none, moderate (<6 MET) and vigorous (> or =6 MET). Differences in leptin concentrations across categories were estimated using linear regression procedures. RESULTS: Mean leptin was 5.8 ng/ml lower among active versus inactive women (P=0.001). Mean leptin was lower among women in the highest levels (>12.8 h/week) of time performing physical activity (-8.1 ng/ml, P<0.001) and energy expenditure (>70.4 MET-h/week) (-8.3 ng/ml, P=0.001) compared with inactive women. Leptin was inversely associated with the intensity of physical activity. CONCLUSIONS: Our findings are consistent with other reports suggesting an independent inverse relationship between habitual physical activity and leptin concentrations. Our findings extend the literature to include pregnant women.

Leptin, soluble leptin receptor and leptin gene polymorphism in relation to preeclampsia risk.

Few investigators have simultaneously evaluated leptin, soluble leptin receptor (SLR) and leptin gene polymorphisms in preeclampsia cases and controls. We examined these three biomolecular markers in 40 preeclampsia cases and 39 controls. Plasma leptin and SLR concentrations were determined using immunoassays. Genotype for the tetranucleotide repeat (TTTC)(n), polymorphism in the 3 -flanking region of the leptin gene was determined using PCR. Alleles of the polymorphism were characterized by size distributions [short repeats (class I); and long repeats (class II)]. Logistic regression was used to calculate odds ratios (OR) and 95 % confidence intervals (CI). Leptin concentrations were higher in our cases than in the controls (53.1 4.7 vs. 17.7+/-2.4 ng/ml, p<0.05). SLR concentrations were slightly lower in our patients than in the controls (25.7+/-1.9 vs. 29.1+/-1.1 ng/ml, p>0.05). Elevated leptin (? 14.5 ng/ml) was associated with a 3.8-fold (CI 1.0-14.4) increased risk; whereas low SLR (< 28.5 ng/ml) was associated with a 6.3-fold (CI 1.7-23.2) increased risk of preeclampsia. The I/II genotype was associated with a 3.8-fold increased risk of preeclampsia (OR=3.8; 95 % CI 0.8-18.0); and the II/II genotype was not observed among our cases (0 % vs. 33 % p<0.001). Larger studies would be needed to confirm and further clarify the relations between functional variants in the leptin gene and preeclampsia risk.

Relationship of maternal plasma leptin and risk of pre-eclampsia: a prospective study.

OBJECTIVE: We measured maternal plasma leptin concentrations in 55 women with pre-eclampsia and 487 normotensive women to determine whether elevated leptin concentrations were associated with the occurrence of pre-eclampsia. METHODS: Maternal blood samples were collected at 13 weeks' gestation, on average. Plasma leptin concentrations were determined using immunoassay. Logistic regression procedures were used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: Leptin concentrations were 78% higher in cases than control subjects (median 34.6 vs. 19.5 ng/ml; p < 0.001). Relative to women with leptin concentrations of < 27.4 ng/ml, those with elevated leptin concentrations (> or = 27.4 ng/ml) experienced a 2.3-fold increased risk of pre-eclampsia (OR 2.3; 95% CI 1.1-4.6). We observed evidence of a strong linear component of trend in risk of pre-eclampsia with increasing maternal plasma leptin concentration. Each 10-ng/ml increase in leptin concentration was associated with a 30% increase in pre-eclampsia risk (OR 1.3; 95% CI 1.1-1.5). Overweight women with elevated leptin concentrations experienced the highest risk of pre-eclampsia (OR 6.4; 95% CI 3.1-13.2) as compared with lean women with no leptin elevations. CONCLUSION: Elevated plasma leptin concentration and maternal overweight status appear to be independently associated with an increased risk of pre-eclampsia.

Opsonic capacity of a hyperimmune serum against outer membrane proteins of Klebsiella pneumoniae.

The opsonic capacity of a hyperimmune rabbit serum against a porin-rich outer membrane protein preparation of a strain of K. pneumoniae was evaluated. By immunoblot, the antiserum recognized mainly the porins from an outer membrane protein preparation. Using an ELISA, the titer of anti-porin antibodies was determined. Through a chemiluminescence assay, the increase in the respiratory burst of murine hyperimmune serum was recorded. These data correlate with the results of the microbicidal assays and with the electron microscopy preparations obtained where a great number of bacteria were seen within the macrophages. The in vitro data show that there is a greater bacterial killing when the macrophage is infected with bacteria opsonized with the hyperimmune serum.