High plasma levels of a ouabain-like factor in normal pregnancy and in pre-eclampsia

Recent reports have described high levels of one or more substances which cross-react with digoxin antibodies in the serum of women with pre-eclampsia. We measured plasma ouabain-like activity and intraerythrocyte sodium and potassium concentrations, in addition to performing routine hypertensive laboratory tests, in 13 normotensive non-pregnant subjects, 15 normotensive pregnant women and 16 pre-eclamptic women (gestational age: 33-36 weeks). Plasma ouabain-like activity, measured as plasma-induced variations in ouabain binding to human erythrocytes, proved significantly higher in both groups of pregnant subjects as compared to normotensive non-pregnant women, and a significant difference was also found between pre-eclamptic and normotensive pregnant women, the former exhibiting higher plasma ouabain-like activity. No differences in intracellular sodium and potassium levels were detected among the three groups studied. Though there is reason to believe that the high plasma levels found both in normal and hypertensive pregnancy may depend on placental production, we are not in a position to define with any degree of certainty what the mechanism or mechanisms are that regulate ouabain-like factor production.     

Plasma lipid and lipoprotein concentrations in pregnancy induced hypertension

OBJECTIVES: Aim of this study was to evaluate implication of pregnancy induced hypertension on maternal plasma lipid, lipoprotein, apolipoprotein concentrations and lipid peroxidation products by a comparison of normal pregnancy vs. preeclampsia. DESIGN AND METHODS: Thirty-four women with preeclampsia and 32 healthy pregnant women (controls) in the third trimester were recruited for this study. RESULTS: In the preeclamptic group plasma total triglyceride, low density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA) and apolipoprotein B (apo-B) were significantly increased, while plasma high density lipoprotein cholesterol (HDL-C) was significantly decreased compared to that of control group. There was no significant difference in total cholesterol and apolipoprotein A1 (apo-A1) concentrations. CONCLUSION: Our findings suggest that preeclampsia share some metabolic characteristics with coronary artery disease such as dislipidemia and increased lipid peroxidation. However lipoprotein concentrations may be better biochemical markers of dislipidemia in the preeclamptic state than the corresponding apolipoproteins.     

Impact of pseudotumor cerebri (idiopathic intracranial hypertension) in pregnancy: a case report

This case report reviews anesthetic management and medical considerations for a pregnant patient with a history of pseudotumor cerebri (PTC). The 24-year-old woman, gravida 2, paragravida 0, spontaneous abortion 1, was in active labor at an estimated 38 weeks' gestation and had been given a diagnosis of PTC 4 years earlier. This patient first experienced global headaches and blurred vision at age 20 years. At the time of onset of her headache symptoms, she underwent a full diagnostic workup and detailed neurologic examination, including magnetic resonance imaging (MRI) of the brain and a lumbar puncture. The MRI was normal. Her lumbar puncture showed elevated cerebral spinal fluid (CSF) pressures and normal CSF composition. The patient's initial symptoms of headache and blurred vision were managed with medication and serial lumbar punctures. The patient was free of PTC symptoms on admission for labor. A lumbar epidural was placed for labor analgesia. The patient delivered a healthy infant after approximately 10.5 hours of patient-controlled epidural analgesia.     

Atrial natriuretic factor (ANF) in experimental and human hypertension

The plasma levels of immunoreactive (IR)-ANF have been evaluated by radioimmunoassay in several models of experimental hypertension and in human hypertension. In all models of experimental hypertension so far studied, the plasma levels of IR-ANF are consistently increased. This is accompanied by a decrease, at certain time intervals, of the IR-ANF levels in the left atrium. In human essential hypertension, the plasma levels of IR-ANF are not increased except in the severe form (diastolic blood pressure above 110 mmHg). In renovascular hypertension, the peripheral levels of IR-ANF are not different from the normal levels but are increased above normal in aortic blood.     

Plasma vascular endothelial growth factor as a marker for early vascular damage in hypertension

Elevation of plasma VEGF (vascular endothelial growth factor) has been noted in patients with hypertension or atherosclerosis. VEGF has been regarded as a marker for endothelial dysfunction. However, the role of VEGF in hypertension-induced vascular injury and its relationship with endothelial function have not been studied. This study included 20 untreated hypertensive men with grade 1 or 2 hypertensive retinopathy, 10 untreated hypertensive men without hypertensive retinopathy and 10 healthy controls. None of the hypertensive patients had diabetes, renal impairment or overt vascular diseases. Plasma VEGF and adhesion molecules were measured using ELISAs. Endothelial function was measured by FMD (flow-mediated vasodilation) of the brachial artery. Plasma levels of VEGF, excluding adhesion molecules, were significantly higher in hypertensive patients with retinopathy when compared with patients without retinopathy (152.4+/-80.8 pg/ml versus 104.7+/-27.2 pg/ml, P = 0.035) or controls (152.4+/-80.8 pg/ml versus 98.9+/-23.7 pg/ml, P = 0.025). Levels of FMD were significantly lower in hypertensive patients than controls, but there were no significant differences between patients with or without retinopathy. Degrees of FMD were inversely correlated with VEGF levels (r = -0.351, P = 0.031). Elevation of plasma VEGF was associated with hypertensive retinopathy. Plasma VEGF could be used as a marker of early vascular damage induced by hypertension.     

Immunoassays developed for pregnancy-associated plasma protein-A (PAPP-A) in pregnancy may not recognize PAPP-A in acute coronary syndromes

BACKGROUND: Pregnancy-associated plasma protein-A (PAPP-A) concentrations are increased in the circulation of patients with acute coronary syndromes (ACS) and are associated with future adverse cardiac events. PAPP-A in ACS differs from PAPP-A in pregnancy in that PAPP-A in ACS is not complexed with the proform of eosinophil major basic protein (proMBP). We investigated the effect of antibody selection on the utility of PAPP-A assays for measurement of PAPP-A in pregnancy and/or ACS, and whether immunoassays for PAPP-A in pregnancy are suitable for PAPP-A in ACS. METHODS: We constructed 2-site sandwich time-resolved immunofluorometric assays using 22 monoclonal antibodies raised against pregnancy serum PAPP-A. All antibodies were studied in pairs, with each antibody used as either capture or tracer. We compared the reactivity of each antibody combination with PAPP-A/proMBP complex derived from pregnancy sera or with uncomplexed PAPP-A extracted from atherosclerotic plaques. Recombinant human PAPP-A and proMBP were also used to determine the specificity of the antibodies. We confirmed all major findings with serum samples collected from patients with myocardial infarction. RESULTS: Six monoclonal antibodies reacted with the proMBP subunit of the PAPP-A/proMBP complex. Epitopes of 3 proMBP-reactive antibodies largely overlapped, but were well separated from those of another group of 3 proMBP-reactive antibodies. Assays using any of the 6 proMBP-reactive antibodies failed to detect PAPP-A in ACS. In addition, some 2-site assays capable of detecting PAPP-A in pregnancy were almost incapable of detecting PAPP-A in ACS, although the individual epitopes remained detectable in PAPP-A in ACS. CONCLUSIONS: Immunoassays developed for PAPP-A in pregnancy may not be suitable for PAPP-A in ACS. Assays for PAPP-A in ACS should be based on careful antibody selection and subjected to extensive testing with clinical ACS samples.     

Diagnostic accuracy of transient elastography in diagnosing clinically significant portal hypertension in patients with chronic liver disease: a systematic review and meta-analysis

Purpose

Liver stiffness measurement using transient elastography (TE-LSM) is a promising noninvasive alternative to hepatic venous pressure gradient (HVPG) for diagnosing clinically significant portal hypertension (CSPH). However, previous studies have yielded conflicting results. We evaluated the correlation between TE-LSM and HVPG and the performance of TE-LSM in diagnosing CSPH (HVPG?≥?10 mmHg).

Methods

We conducted a systematic review and meta-analysis by searching PubMed and Scopus databases for relevant literature evaluating the clinical usefulness of TE for diagnosing CSPH in patients with chronic liver disease.

Results

Twenty-six studies (4337 patients with valid TE and HVPG) met our inclusion criteria. The median correlation coefficient of TE with HVPG was 0.70 (range 0.36–0.86). The weighted mean of optimal cut-off of liver stiffness value for diagnosing CSPH was 22.8 kPa (95% CI 22.7–23.0 kPa). The summary sensitivity and specificity were 79% (95% CI 74–84%) and 88% (95% CI 84–91%), respectively. The area under the hierarchical summary receiver operating characteristic (HSROC) curve was 0.91 (95% CI 0.88–0.93) according to the bivariate model. One limitation of the study was significant heterogeneity in the results of summary sensitivity and specificity (I² 83 and 74%, respectively). The heterogeneity could be explained by the variable liver stiffness cut-offs used in studies. The meta-regression plot revealed that as the optimal cut-off increased, the sensitivity decreased, the specificity increased, and vice versa.

Conclusions

Liver stiffness measurement using TE correlates well with HVPG, and a liver stiffness cut-off value of 22.8 kPa shows a high accuracy for diagnosing CSPH. Thus, use of TE should be integrated into clinical practice for noninvasive diagnosis of CSPH.

     

Lipoprotein(a)-cholesterol: a significant component of serum cholesterol

BackgroundLipoprotein(a) [Lp(a)] is known to be a cholesterol-rich lipoprotein, however, the contribution of Lp(a)-cholesterol [Lp(a)-C] to the serum cholesterol and LDL-C levels has not yet been fully evaluated.MethodsWe determined the serum Lp(a)-C in 55 subjects with serum Lp(a) concentrations ranging from 9 to 129 mg/dl. To measure the serum Lp(a)-C concentrations, we developed an immunoaffinity gel assay; serum was incubated with Sepharose 4B gel coupled with immunoglobulin G (IgG) prepared from a polyclonal anti-Lp(a) goat antiserum. After separating Lp(a) from other lipoproteins, we determined the serum Lp(a)-C concentrations. Validation of the assay showed satisfactory results in terms of the specificity and reproducibility.ResultsThe mean cholesterol content of Lp(a), determined as Lp(a)-C/Lp(a), was 29.5 ± 10.4%. The serum Lp(a)-C values were found to be highly correlated with the serum Lp(a) mass (r = 0.923, p < 0.001). At serum Lp(a) levels of over 50 mg/dl, the contribution of Lp(a)-C to the serum total cholesterol was 10.2%. Further, the Friedewald formula overestimated the serum LDL-C by 20.4%.ConclusionsLp(a) contains approximately 30% cholesterol in each molecule. In subjects with markedly elevated serum Lp(a) concentrations, the Lp(a)-C values should be taken into account when evaluating the serum LDL-C.     

妊娠期高血压病患者血清与胎盘IL-4水平的变化及意义

目的观察妊娠期高血压病患者血清与胎盘白介素4（IL-4）水平的变化，探讨这些变化与妊娠期高血压痫的关系。方法本院37例妊娠期高血压病患者和32例正常孕妇（对照组），采用放射免疫分析法测定血清和胎楹组织提取液中IL-4浓度，比较妊娠期高血压病组与对照组血清、胎盘IL-4水平的差异。结果与对照组比较，妊娠期高血压病组血清IL-4水平增高，差异有显著性（P〈0．05）；妊娠期高血压病组胎舒IL-4水平高于对照组，差异接近但尚未达到显著性水平（P〉0．05）。妊娠期高血压、轻度、重度子前期患者血清和胎盘IL-4水平差异均无显著性（P〉0．05）。妊娠期高血压病组血清与胎盘IL-4水平均无显著相关性（P〉0．05）。结论血清IL-4水平增高是妊娠期高血压病的重要病理变化，可能在妊娠期高虹压病的发生与变化发展过程中起了作用。     

Obstetric and neonatal outcome following chronic hypertension in pregnancy among different ethnic groups

We retrospectively studied pre-eclampsia rate and obstetric outcome in a cohort of 436 pregnancies amongst 318 women of different ethnic backgrounds attending an antenatal hypertension clinic from 1980-1997, identifying 152 women (213 pregnancies) with chronic essential hypertension. The ethnic breakdown was: White, 64 (30.0%) pregnancies in 48 (31.5%) women; Black/Afro-Caribbean, 79 (37.1%) pregnancies in 56 (36.8%) women; and Indo-Asians, 70 (32.3%) pregnancies in 48 (31.6%) women. The prevalences of pre-eclampsia in White, Black and Indo-Asian women were 17.2%, 12.7% and 18.6%, respectively (p = 0.58). Pregnancies of Indo-Asian women were of shorter gestation, and babies in this group also had lower birth weight and ponderal index compared to those of White and Black women (all p < 0.05). The proportions of overall perinatal mortality were 1.6% for Whites (1/64), 3.8% for Blacks (3/79) and 10.0% for Indo-Asians (7/70), suggesting increased risk in the Indo-Asian group. Indo-Asian women with chronic essential hypertension need careful antenatal care and observation during pregnancy.     

Plasma volume in cirrhosis of the liver: its relation of portal hypertension, ascites, and renal failure

Plasma volume was measured by using albumin-¹³¹I- and ⁵¹Cr-labeled erythrocytes in 24 control subjects, 140 patients with hepatic cirrhosis, and 10 patients with various portal-systemic shunts for the relief of noncirrhotic portal hypertension. The cirrhotic patients included subgroups with ascites, functional renal failure, and portacaval anastomoses. Elevated values for plasma volume, by both methods, were found in each group of patients.     

大鼠慢性低氧肺动脉高压对氯化钾收缩离体肺主动脉环效应影响

目的 通过观察氯化钾对常氧以及慢性低氧肺动脉高压大鼠离体肺主动脉环的收缩效应，探讨慢性低氧肺动脉高压对氯化钾收缩大鼠肺主动脉的影响。方法 制备低氧1、2周肺动脉高压大鼠模型，用60mmol／L氯化钾收缩分离自常氧组及低氧组大鼠的肺主动脉环，观察其收缩效应。结果 60mmol/L氯化钾对常氧组、低氧组大鼠肺主动脉环的收缩幅度无显著性差异。结论 慢性低氧肺动脉高压不会影响高浓度氯化钾对大鼠肺主动脉的收缩效应。