Safety of low-volume PEG-asc bowel cleansing preparation for colonoscopy: identifying patients at risk for hypokalemia in a prospective cohort study.

The aim of bowel cleansing preparation should be high-quality results and conformance with safety standards. Previously, we reported that hypokalemia occurred in 23.6 % of patients after bowel preparation in a high-risk population on diuretics or hospitalized and referred for colonoscopy.

Value of biomarkers in predicting mortality in older medical emergency department patients: a Dutch prospective study.

Objective: Older emergency department (ED) patients are at high risk of mortality, and it is important to predict which patients are at highest risk. Biomarkers such as lactate, high-sensitivity cardiac troponin T (hs-cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), D-dimer and procalcitonin may be able to identify those at risk. We aimed to assess the discriminatory value of these biomarkers for 30-day mortality and other adverse outcomes.

Prevalence of pseudonatremia in a clinical laboratory - role of the water content.

Background: Sodium concentration is a frequently used marker to discriminate between differential diagnoses or for clinical follow-up. Pseudonatremia, as a result of indirect ion-selective electrode (ISE) measurements in automated chemistry analyzers, can lead to incorrect diagnosis and treatment. We investigated whether the estimated water content, based on total protein and lipid concentrations, can be used to reduce diagnoses of pseudonatremia.

Collection of blood specimens by venipuncture for plasma-based coagulation assays: necessity of a discard tube.

The Clinical and Laboratory Standards Institute (CLSI) recently abandoned its recommendation for drawing a discard tube when performing a prothrombin time (PT)/international normalized ratio (INR) or an activated partial thromboplastin time (APTT). Because there is currently no evidence that a discard tube is necessary for more specialized coagulation assays, we studied the need for a discard tube for some of these tests. Blood was obtained from 88 subjects in 2 subsequent citrate tubes.

The effect of paraproteins on the erythrocyte sedimentation rate: a comparison between the StarrSed and TEST 1.

Background: The principle of the erythrocyte sedimentation rate (ESR) as assessed by TEST 1 is different from that of Westergren-based methods. This could result in different influences on the tests by paraproteins.

Methods: We investigated the effect of paraproteins on ESR readings by TEST 1 (y) and the StarrSed (x), a Westergren-based method, in 142 patients with paraproteinaemia.

The transient increase of oxidative stress during normal pregnancy is higher and persists after delivery in women with pre-eclampsia.

Objectives: Glutathione, an intracellular tripeptide, functions in the protection of cells against free radicals and toxins of endogenous and exogenous origin. To maintain the intracellular redox status in presence of reactive oxygen species, glutathione (GSH) and other thiols are oxidized. The oxidative status of thiols is reflected by the free-to-oxidized ratio and is a real-time measure for oxidative stress.

A longitudinal study of antioxidant status during uncomplicated and hypertensive pregnancies.

Background: To study the possible involvement of an (im)balance between oxidants and antioxidants in pre-eclampsia concentrations of intra- and extracellular blood antioxidants in women with uncomplicated and hypertensive pregnancies, they were studied preconceptionally and throughout pregnancy.

Methods: In uncomplicated pregnancies (n = 19) and hypertensive pregnancies (n = 6) concentrations of whole blood and plasma thiols, plasma vitamins/E and C, hemoglobin, and hematocrit were assessed at preconception, 6, 10, 20, and 37 weeks of gestational age, as well as six weeks postpartum. A repeated mixed model was used for statistical analysis.

Oral N-acetylcysteine administration does not stabilise the process of established severe preeclampsia.

Objective: To stabilise the disease process in women with early onset severe preeclampsia and/or HELLP syndrome by enhancing maternal antioxidants effects of glutathione.

Study Design: In a randomised, double-blind, placebo-controlled trial, women with severe preeclampsia and/or HELLP syndrome received oral N-acetylcysteine. Primary outcome measures were disease stabilisation expressed as treatment-to-delivery interval and biochemical assessment of glutathione and parameters of oxidative stress.

N-acetyl-transferase phenotype and risk for preeclampsia.

Objective: This study was undertaken to determine whether the N-acetyltransferase (NAT) phenotype contributes to the susceptibility for the development of preeclampsia.

Study Design: The NAT acetylator status was determined by measuring urinary caffeine metabolites in 134 nonpregnant women with a history of preeclampsia and in 109 control women with uncomplicated pregnancy. The chi(2) and logistic regression analyses were used for statistical evaluation of differences in acetylator status.

Physical well-being in women with a history of severe preeclampsia.

Objective: To evaluate the physical and mental health of women with a history of severe preeclampsia.

Methods: In a historical cohort study 131 former patients with a history of severe preeclampsia and 127 control patients received questionnaires about experienced physical and mental complaints after delivery. At a follow-up visit blood pressure, body mass index, and proteinuria were measured and venous blood was drawn.

Maternal antioxidant concentrations after uncomplicated pregnancies.

Background: To analyse the post-partum concentrations of intra- and extra-cellular blood antioxidants in women with uncomplicated pregnancies.

Methods: Whole blood and plasma thiols, plasma vitamin E and C, serum cholesterol and triglyceride, ferric reducing ability of plasma (FRAP) concentrations were compared between women delivered by caesarean section (n=17) or spontaneous delivery (n=10). A repeated mixed model was used for statistical analysis.

Low plasma levels of oxidized low density lipoprotein in preeclampsia.

Background: Markers of lipid peroxidation are commonly used to assess oxidative stress in preeclampsia. The aim of this study was to assess the concentration of oxidized low density lipoprotein (oxLDL), a novel marker for lipid peroxidation, and that of the thiobarbituric acid reactive substances (TBARS) in the pathogenesis of severe preeclampsia and to investigate the influence of gestational age on these parameters.

Method: Plasma levels of oxLDL and TBARS were assayed in women with severe preeclampsia (n = 40), normotensive pregnant controls matched for gestational age (n = 24) and normotensive pregnant controls at full term (n = 16).

The Tyr113His polymorphism in exon 3 of the microsomal epoxide hydrolase gene is a risk factor for perinatal mortality.

Background: A genetic predisposition to impaired detoxification of oxidative or chemical stress could play a role in the etiology of perinatal mortality. In this pilot study we investigated the risk of perinatal mortality in relation to genetic polymorphism in microsomal epoxide hydrolase (EPHX) and glutathione S-transferase P1 (GSTP1) in women who experienced perinatal mortality caused by placental pathology, congenital disorders and complications of premature delivery and their male partners.

Methods: Genomic DNA of couples (72 females and 46 males) with a history of perinatal mortality and control couples (71 females and 66 males) with no complications in their obstetric history were analyzed for the presence of the polymorphisms in exon 3 of EPHX (Tyr113His) and GSTP1 (Ile105Val).

Oxidative stress and preeclampsia: rationale for antioxidant clinical trials.

Preeclampsia remains a frequent and potentially dangerous complication of pregnancy. The cause remains largely unknown, but oxidative stress and a generalized inflammatory state are features of the maternal syndrome. The placenta appears to be the principal source of free radical synthesis but maternal leukocytes and the maternal endothelium are also likely contributors.

N-acetylcysteine restores nitric oxide-mediated effects in the fetoplacental circulation of preeclamptic patients.

Objective: Preeclampsia is associated with an imbalance between oxidants and antioxidants, resulting in reduced effects of the endothelium-derived, relaxing-factor nitric oxide (NO). Antioxidants, like N-acetylcysteine (NAC), remove reactive oxygen species, resulting in an improvement of endothelial function. We aimed to investigate the effect of NAC on the NO-pathway in the human fetoplacental circulation in preeclampsia and control pregnancies.

Thiol status and antioxidant capacity in women with a history of severe pre-eclampsia.

Objective: To investigate a possible mechanism that could lead to the subsequent development of cardiovascular diseases (CVD) in women with a history of severe pre-eclampsia.

Design: Case-control study.

Setting: University Medical Centre Nijmegen, The Netherlands.

Umbilical glutathione levels are higher after vaginal birth than after cesarean section.

Glutathione plays an important role in quenching reactive oxygen species, resulting in oxidation of glutathione, which in times of prolonged oxidative stress may be excreted from the erythrocyte. We investigated arterial and venous umbilical cord levels of glutathione in neonates born by vaginal delivery (n = 140) or cesarean section (n = 38). In a subset of neonates who were delivered vaginally maternal levels were assessed in parallel (n = 14).

N-Acetylcysteine improves the disturbed thiol redox balance after methionine loading.

Methionine loading seems to be accompanied by increased oxidative stress and damage. However, it is not known how this oxidative stress is generated. We performed the present crossover study to further elucidate the effects of methionine loading on oxidative stress in the blood of healthy volunteers, and to examine possible preventative effects of N -acetylcysteine (NAC) administration.

Glutathione and glutathione S-transferases A1-1 and P1-1 in seminal plasma may play a role in protecting against oxidative damage to spermatozoa.

Objective: To study the levels of glutathione, glutathione S-transferase A1-1, and glutathione S-transferase P1-1 in seminal fluid of fertile and subfertile men.

Design: Retrospective case-control study.

Setting: Departments of gastroenterology, obstetrics and gynecology, and epidemiology and biostatistics in a university medical center.

Distribution of components of the glutathione detoxification system across the human placenta after uncomplicated vaginal deliveries.

The function of the glutathione-related detoxification system plays an important role to ensure an uncomplicated pregnancy outcome. This study was performed to investigate whether the components of the glutathione-related detoxification system are equally distributed among the different cotelydons in the human placenta. We measured glutathione, cysteine, glutathione S-transferase (GST) isoenzyme levels (GSTA1+A2, GSTP1, GSTM1 and GSTT1), enzyme activities of glutathione S-transferase and glutathione peroxidases, protein carbonyl levels, and antioxidant capacities at twelve different standardized positions in six placentae from healthy women after uncomplicated pregnancy and vaginal delivery.

Effects of oral N-acetylcysteine on plasma homocysteine and whole blood glutathione levels in healthy, non-pregnant women.

Oral N-acetylcysteine supplementation in nine young healthy females induced a quick and highly significant decrease in plasma homocysteine levels and an increase in whole blood concentration of the antioxidant glutathione. N-acetylcysteine impresses as an efficient drug in lowering homocysteine concentration and might be beneficial for individuals with hyperhomocysteinemia who are at increased risk of cardiovascular disease.