Ophthalmic artery Doppler at 36 weeks' gestation in prediction of pre-eclampsia: validation and update of previous model.

OBJECTIVE: To validate and extend a model incorporating maternal ophthalmic artery Doppler at 35-37 weeks' gestation in the prediction of subsequent development of pre-eclampsia (PE). METHODS: This was a prospective validation study of screening for PE (defined according to the 2019 American College of Obstetricians and Gynecologists criteria) by maternal ophthalmic artery peak systolic velocity (PSV) ratio in 6746 singleton pregnancies undergoing routine care at 35 + 0 to 36 + 6 weeks' gestation (validation dataset). Additionally, the data from the validation dataset were combined with those of 2287 pregnancies that were previously used for development of the model (training dataset), and the combined data were used to update the original model parameters. The competing-risks model was used to estimate the individual patient-specific risk of delivery with PE at any time and within 3 weeks from assessment by a combination of maternal demographic characteristics and medical history with PSV ratio alone and in combination with the established PE biomarkers of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and serum soluble fms-like tyrosine kinase-1 (sFlt-1). We evaluated the predictive performance of the model by examining, first, the ability to discriminate between the PE and non-PE groups using the area under the receiver-operating-characteristics curve and the detection rate (DR) at fixed screen-positive (SPR) and false-positive rates of 10% and, second, calibration by measuring the calibration slope and calibration-in-the-large. McNemar's test was used to compare the performance of screening by a biophysical test (maternal factors, MAP, UtA-PI and PSV ratio) vs a biochemical test (maternal factors, PlGF and sFlt-1), low PlGF concentration (< 10th percentile) or high sFlt-1/PlGF concentration ratio (> 90th percentile). RESULTS: In the validation dataset, the performance of screening by maternal factors and PSV ratio for delivery with PE within 3 weeks and at any time after assessment was consistent with that in the training dataset, and there was good agreement between the predicted and observed incidence of PE. In the combined data from the training and validation datasets, good prediction for PE was achieved in screening by a combination of maternal factors, MAP, UtA-PI, PlGF, sFlt-1 and PSV ratio, with a DR, at a 10% SPR, of 85.0% (95% CI, 76.5-91.4%) for delivery with PE within 3 weeks and 65.7% (95% CI, 59.2-71.7%) for delivery with PE at any time after assessment. The performance of a biophysical test was superior to that of screening by low PlGF concentration or high sFlt-1/PlGF concentration ratio but not significantly different from the performance of a biochemical test combining maternal factors with PlGF and sFlt-1 for both PE within 3 weeks and PE at any time after assessment. CONCLUSION: Maternal ophthalmic artery PSV ratio at 35-37 weeks' gestation in combination with other biomarkers provides effective prediction of subsequent development of PE. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Screening for pre-eclampsia by maternal serum glycosylated fibronectin and angiogenic markers at 36 weeks' gestation.

OBJECTIVES: First, to examine the predictive performance of maternal serum glycosylated fibronectin (GlyFn) at 35 + 0 to 36 + 6 weeks' gestation in screening for delivery with pre-eclampsia (PE) and delivery with gestational hypertension (GH) at ≥ 37 weeks' gestation, both within 3 weeks and at any time after the examination. Second, to compare the predictive performance for delivery with PE and delivery with GH of various combinations of biomarkers, including GlyFn, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1). Third, to compare the predictive performance for delivery with PE and delivery with GH by serum PlGF concentration, sFlt-1/PlGF concentration ratio and the competing-risks model with different combinations of biomarkers as above. Fourth, to compare the predictive performance of screening at 11 + 0 to 13 + 6 weeks vs 35 + 0 to 36 + 6 weeks for delivery with PE and delivery with GH at ≥ 37 weeks' gestation. METHODS: This was a case-control study in which maternal serum GlyFn was measured in stored samples from a non-intervention screening study in singleton pregnancies at 35 + 0 to 36 + 6 weeks' gestation using a point-of-care device. We used samples from women who delivered at ≥ 37 weeks' gestation, including 100 who developed PE, 100 who developed GH and 600 controls who did not develop PE or GH. In all cases, MAP, UtA-PI, PlGF and sFlt-1 were measured during the routine visit at 35 + 0 to 36 + 6 weeks. We used samples from patients that had been examined previously at 11 + 0 to 13 + 6 weeks' gestation. Levels of GlyFn were transformed to multiples of the expected median (MoM) values after adjusting for maternal demographic characteristics and elements from the medical history. Similarly, the measured values of MAP, UtA-PI, PlGF and sFlt-1 were converted to MoM. The competing-risks model was used to combine the prior distribution of the gestational age at delivery with PE, obtained from maternal risk factors, with various combinations of biomarker MoM values to derive the patient-specific risks of delivery with PE. The performance of screening of different strategies was estimated by examining the detection rate (DR) at a 10% fixed false-positive rate (FPR) and McNemar's test was used to compare the DRs between the different methods of screening. RESULTS: The DR, at 10% FPR, of screening by the triple test (maternal risk factors plus MAP, PlGF and sFlt-1) was 83.7% (95% CI, 70.3-92.7%) for delivery with PE within 3 weeks of screening and 80.0% (95% CI, 70.8-87.3%) for delivery with PE at any time after screening, and this performance was not improved by the addition of GlyFn. The performance of screening by a combination of maternal risk factors, MAP, PlGF and GlyFn was similar to that of the triple test, both for delivery with PE within 3 weeks and at any time after screening. The performance of screening by a combination of maternal risk factors, MAP, UtA-PI and GlyFn was similar to that of the triple test, and they were both superior to screening by low PlGF concentration (PE within 3 weeks: DR, 65.3% (95% CI, 50.4-78.3%); PE at any time: DR, 56.0% (95% CI, 45.7-65.9%)) or high sFlt-1/PlGF concentration ratio (PE within 3 weeks: DR, 73.5% (95% CI, 58.9-85.1%); PE at any time: DR, 63.0% (95% CI, 52.8-72.4%)). The predictive performance of screening at 35 + 0 to 36 + 6 weeks' gestation for delivery with PE and delivery with GH at ≥ 37 weeks' gestation was by far superior to screening at 11 + 0 to 13 + 6 weeks. CONCLUSION: GlyFn is a potentially useful biomarker in third-trimester screening for term PE and term GH, but the findings of this case-control study need to be validated by prospective screening studies. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

C2 by-pass: Cross-talk between the complement classical and alternative pathways.

Several disorders associated with the total or partial absence of components of the human complement system are known. Deficiencies of classical pathway (CP) components are generally linked to systemic lupus erythematosus (SLE) or SLE-like syndromes. However, only approximately one-third of patients who lack C2 show mild symptoms of SLE. The relatively high frequency of homozygous C2 deficiency without or with minor disease manifestation suggests that there might be a compensatory mechanism which allows the activation of the CP of complement without the absolute requirement of C2. In this study we show that factor B (FB), the C2 homologue of the alternative pathway (AP) of complement, can substitute for C2. This was confirmed by using C4b as immobilised ligand and FB as analyte in Surface Plasmon Resonance (BIACORE). C2 binding to the immobilised C3b-like molecule C3(CH3NH2) was not seen. The estimated binding constant for C4bB complex formation was 2.00 * 10-5 [M]. We were further able to demonstrate that C4b supports the cleavage of Factor B by Factor D. Finally, cleavage of 125I-C3 by C4bBb was evaluated and gave strong evidence that the "hybrid" convertase C4bBb can cleave and activate C3 in vitro. Cleavage activity is very low, but consistent with some of the "C2-bypass" observations of others.

Cell cycle-dependent acetylation of Rb2/p130 in NIH3T3 cells.

The retinoblastoma protein (pRb) and the pRb-related proteins, p130 and p107, form the 'pocket protein' family of cell cycle regulatory factors. A well characterized function of these proteins is the cell cycle-dependent regulation of E2F-responsive genes. The biological activity of pocket proteins is regulated by phosphorylation and for the founding member pRb it has been shown that acetylation also has an important role in modulating its function during the cell cycle. Here, we show that hyperphosphorylated retinoblastoma 2 (Rb2)/p130 also exists in an acetylated form in NIH3T3 cells. Acetylated p130 is present in the nucleus but not in the cytoplasm. Acetylation is cell cycle dependent, starting in S-phase and persisting until late G(2)-period. Using recombinant p130 and truncated forms for in vitro acetylation by the acetyltransferase p300, we could identify K1079 in the C-terminal part as the major acetylation site by mass spectrometry. Minor acetylation sites were pinpointed to K1068 and K1111 in the C-terminus, and K128 and K130 in the N-terminus. The human papilloma virus 16 protein-E7 preferentially binds to acetylated p130 and significantly increases in vitro p130 acetylation by p300.

The relationship between oxygen consumption and body acceleration in a range of species.

The ability to measure the energy expenditure of free-ranging animals is of great importance but the techniques available each have their limitations. Recently, as an alternative to more established techniques, an integrated measure of body acceleration termed overall dynamic body acceleration (ODBA) has been used as a calibrated proxy for rate of oxygen consumption (V(O(2))) and hence metabolic rate. The present study tested the potential of this technique, firstly by expanding the range of species for which the V(O(2))-ODBA relationship has been defined and secondly by undertaking a validation exercise to explore the accuracy of predictions made using ODBA. V(O(2))-ODBA relationships during terrestrial locomotion were established for several bipedal and quadrupedal endotherms and compiled with similar relationships previously determined in other species. A model incorporating all of these species showed that ODBA is an excellent predictor of V(O(2)) but there is variation in the V(O(2))-ODBA relationship between species, and further variation within some species. Including measurements such as body mass and structural size in prediction equations might further improve the predictive power of the 'ODBA technique' and eliminate species-specific differences. In the validation exercise, estimate errors were calculated for the species-specific predictive equations. The use of ODBA to estimate V(O(2)) was valid across all species examined and may show a greater potential for estimating energy expenditure for individual animals than other techniques.

Resistance of the Echinococcus granulosus cyst wall to complement activation: analysis of the role of InsP6 deposits.

The larva of the cestode Echinococcus granulosus (hydatid cyst) is protected by the acellular laminated layer (LL). The mechanisms that make this thick coat a poor activator of host complement are incompletely understood. The structure binds, through unknown motifs, the host regulator of the alternative complement pathway (ACP), factor H. A second potential mechanism of ACP regulation, the inhibition of factor B activation, was detected in assays employing purified components (Immunopharmacology 42 : 91). The inhibitor was subsequently identified as myo-inositol hexakisphosphate (InsP(6)), which in the form of nano-deposits is a major component of the LL (Biochem J 362 : 297; J Cell Biochem 93 : 1272; FEBS J 273 : 3192). In this report we show that colloidal InsP(6 )solids inhibit factor B activation, through adsorption and associated impairment of C3b binding. However, this interaction is not relevant in the presence of serum proteins. In serum, InsP(6) deposits instead bind C1q, and initiate complement activation. This activation is curtailed through efficient C3b inactivation, previously shown to be entirely factor H-dependent, and now observed to be independent of the InsP(6) deposits. Therefore the complement resistance of the LL must be based on functional factor H binding sites present on the mucin-based meshwork that is its other major constituent.

Atorvastatin suppresses interferon-gamma -induced neopterin formation and tryptophan degradation in human peripheral blood mononuclear cells and in monocytic cell lines.

Inhibitors of 3-hydroxy-3methylglutaryl-co-enzyme A (HMG-CoA) reductase, so-called statins, are used in medical practice because of their lipid-lowering effect and to reduce the risk of coronary heart disease. Recent findings indicate that statins also have anti-inflammatory properties and can modulate the immune response. In vitro, we investigated the effect of atorvastatin on the T cell/macrophage system in peripheral blood mononuclear cells (PBMC) and in the human monocytic cell lines THP-1 and MonoMac6. We monitored neopterin production and tryptophan degradation in PBMC after treatment with 10 micro m and 100 micro m atorvastatin in the presence or absence of 100 U/ml IFN-gamma, 10 micro g/ml phytohaemagglutinin (PHA) or 10 micro g/ml concanavalin A (ConA) and in monocytic cell lines THP-1 and MonoMac6 with or without stimulation with 100 U/ml IFN-gamma or 10 ng/ml to 1 micro g/ml lipopolysaccharide (LPS). In stimulated PBMC 100 micro m atorvastatin inhibited neopterin formation and tryptophan degradation completely, whereas 10 micro m atorvastatin was only partially effective. Also in monocytic cell lines THP-1 and MonoMac6, atorvastatin was able to suppress IFN-gamma- and LPS-induced formation of neopterin and degradation of tryptophan. Our data from PBMC agree well with previous investigations that statins inhibit T cell activation within the cellular immune response. In addition we demonstrate that atorvastatin directly inhibits IFN-gamma-mediated pathways in monocytic cells, suggesting that both immunoreactivity of T cells and of monocyte-derived macrophages are down-regulated by this statin.

Moderate hyperhomocysteinaemia and immune activation in Parkinson's disease.

Moderate hyperhomocysteinaemia has been linked to an increased risk for cardiovascular diseases. Increased homocysteine concentrations may follow folate depletion due to insufficient dietary intake of the vitamin, but there is also some indication that immune activation could play a role. In this preliminary study, homocysteine, folate, and vitamin B(12) concentrations were measured in 19 patients with Parkinson's disease, 61-90 years of age, and compared to a healthy control group of similar age and to neopterin concentrations as an indicator of immune activation. A subgroup of patients presented with increased homocysteine and low folate concentrations. Homocysteine levels correlated inversely with vitamins folate and B(12) and positively with neopterin concentrations. Disturbed homocysteine metabolism in Parkinson's disease may be associated with vitamin deficiency and with immune system activation which may underlie folate depletion.

Hyperhomocysteinemia, pteridines and oxidative stress.

Tetrahydrofolate is an essential cofactor for the conversion of homocysteine to methionine, and hyperhomocysteinemia is considered as a risk factor for cardiovascular and cerebrovascular diseases. In subjects with hyperhomocysteinemia usually an inverse relationship exists to folic acid levels, and supplementation with folic acid is able to lower homocysteine concentrations. The pathogenesis of most if not all diseases which are accompanied with moderate hyperhomocysteinemia involves cellular immune activation and therefore in patients very often exists also a positive correlation between homocysteine concentrations and the degree of immune activation which is indicated, e.g. by increased neopterin concentrations. Since neopterin concentrations also serves as an estimate of oxidative stress merging from immune system activation, this association suggests that cellular immune activation and oxidative stress could be involved in the development of hyperhomocysteinemia. Because tetrahydrofolate is very susceptible to oxidation, an increased oxidative degradation of tetrahydrofolates may become relevant under oxidative stress conditions. In this way folate deficiency may develop despite normal dietary intake of the vitamin. In our patients, hyperhomocysteinemia is considered as an indirect consequence of hyperconsumption of antioxidant vitamins during prolonged states of immune activation.

Complement C4bC2 complex formation: an investigation by surface plasmon resonance.

Complex formation between the human complement proteins C4b and C2 was investigated by surface plasmon resonance. C4b was immobilised and C2 was used in the fluid phase to measure interaction at different ionic strengths (30-830 mM NaCl) and in the absence and presence of MgCl2. Maximum binding was observed at 30 mM NaCl, and was negligible above 300 mM NaCl. Binding was not greatly influenced by variation in Mg(2+) in the range of 2.5-15 mM. C4bC2 affinity (Kd) was determined by steady-state analysis to be 7.2x10(-8) M in physiological conditions (10 mM Hepes, 2.5 mM MgCl2, 0.75 mM CaCl2 and 140 mM NaCl, pH 7.4). For C4(H2O)C2 complex formation, a Kd of 4.0x10(-8) M was calculated. As far as detected by the applied method, complex formation does not involve conformational changes of one of the binding partners. Consistent with previous reports, C4bC2 binding takes place as a multiple-site binding event in the presence of Mg2+. C4bC2 complex formation in 10 mM Hepes, 2.5 mM EDTA and 140 mM NaCl (pH 7.4) was also observed and the interaction showed characteristics of a single-site binding event. Kd was 1.5x10(-8) M. Complement factor B (FB) was also tested for its binding to immobilised C4b. Weak interaction was observed at FB concentrations in the physiological range (500-1000 nM). Kd was 1.2x10(-6) M, indicating possible cross-reactivity between classical and alternative pathways of the activation of the complement system.

Serine proteases of the complement system.

The complement system in blood plasma is a major mediator of innate immune defence. The function of complement is to recognize, then opsonize or lyse, particulate materials, including bacteria, yeasts and other microrganisms, host cell debris and altered host cells. Recognition occurs by binding of complement proteins to charge or saccharide arrays. After recognition, a series of serine proteases is activated, culminating in the assembly of complex unstable proteases called C3/C5 convertases. These activate the complement protein C3, which acts as an opsonin. The complement serine proteases include the closely related C1r, C1s, MASPs 1-3 (80-90 kDa), C2 and Factor B (100 kDa), Factor D (25 kDa) and Factor I (85 kDa). Each of these has unusually restricted specificity and low enzymic activity. The C1r, C1s and MASP group occur as proenzymes. When activated, they are regulated, like many plasma serine proteases, by a serpin, C1-inhibitor. C2 and Factor B, however, have complex multiple regulation by a group of complement proteins called the Regulation of Complement Activation (or RCA) proteins, whereas Factors I and D appear to have no natural inhibitors. Advances in structure determination and protein-protein interaction properties are leading to a more detailed understanding of the complement-system proteases, and are indicating possible new routes for potential therapeutic control of complement.

The gastric H,K-ATPase blocker lansoprazole is an inhibitor of chloride channels.

1. It was postulated that swelling dependent chloride channels are involved in the proton secretion of parietal cells. Since omeprazole, lansoprazole and its acid activated sulphenamide form AG2000 are structurally related to phenol derivatives known to block swelling dependent chloride channels, we set out to test, whether these substances--which are known to block the H,K-ATPase--could also lead to an inhibition of swelling-dependent chloride channels. Swelling-dependent chloride channels--characterized in many different cell types--show highly conserved biophysical and pharmacological features, therefore we investigated the effect of omeprazole, lansoprazole and its acid activated sulphenamide form AG2000 on swelling-dependent chloride channels elicited in fibroblasts, after the reduction of the extracellular osmolarity. 2. Omeprazole, lansoprazole and its acid activated sulphenamide form AG2000 are able to block swelling-dependent chloride channels (IClswell). 3. Lansoprazole and its protonated metabolite AG2000 act on at least two different sites of the IClswell protein: on an extracellular site which seems to be in a functional proximity to the nucleotide binding site, and on an intracellular site which allows the formation of disulfide-bridges. 4. The inhibition of the proton pump and the simultaneous blocking of chloride channels by omeprazole, lansoprazole and its acid activated sulphenamide form AG2000, as described here could be an effective mode to restrict proton secretion in parietal cells.

Structure and expression of the human small cytokine B subfamily member 11 (SCYB11/formerly SCYB9B, alias I-TAC) gene cloned from IFN-gamma-treated human monocytes (THP-1).

Among CXC chemokines, monokine induced by interferon-gamma (IFN-gamma) (MIG) and IGN-gamma-inducible protein, 10 kDa (INP10), constitute a distinct group because of their sequence and function. We studied genomic structure and expression of a third, recently identified member of this group named small inducible cytokine B subfamily member 11 (SCYB11, formerly SCYB9B) or IFN-inducible T cell alpha chemoattractant (I-TAC). The cDNA (1445 bp) for this 94 amino acid protein (Mr 10,364) was cloned from IFN-gamma-treated human myelomonocytic cells (THP-1). The reading frame of SCYB11 is distributed to 4 exons spanning 1197 bp of the genomic sequence. In vitro transcription/translation yielded a single protein of about 10 kDa, indicating that the deduced reading frame is translated by eukaryotic ribosomes. The recombinant 73 amino acid mature protein overexpressed in Escherichia coli was chemotactic for interleukin-2 (IL-2)-selected T memory cells. Studying various cytokines and lipopolysaccharide in THP-1 cells identified IFN-gamma as the major stimulus for SCYB11 mRNA expression, followed by IFN-alpha and IFN-beta, which were about 25 times less effective. Of a panel of different human cells tested, SCYB11 mRNA was also induced in umbilical vein endothelial cells, dermal fibroblasts, and tumor cell lines from various organs, whereas it was not found in T lymphocytes activated via anti-CD3 antibodies or via IL-2.

ICln: a chloride channel paramount for cell volume regulation.

Cell volume regulation is a ubiquitous cell regulatory mechanism based on meticulously controlled ion transport mechanisms. Keeping the absolute volume constant seems to be of the highest priority for most cells and is achieved at the expense of altered intracellular ion concentrations. We have been able to demonstrate that ICln, a chloride channel cloned from epithelial cells, is paramount for the ability of swollen cells to regulate their volume back to that under resting conditions. A unique feature of ICln is the distinct sensitivity of these channels for nucleotides and nucleoside analogues added to the extracellular fluid. In addition, cromolyn sodium and nedocromil sodium, drugs used by patients with asthma, are able to impede the function of these channels.

Antiviral drugs from the nucleoside analog family block volume-activated chloride channels.

BACKGROUND: The antiviral drugs AZT and acyclovir are generally used in the treatment of infections with human immunodeficiency virus (HIV) and herpes simplex virus (HSV). These substances are known to impede virus replication by premature nucleic acid chain termination. It is not yet clear, however, if this is the sole mechanism responsible for the antiviral and/or the numerous side effects observed in patients treated with these agents. We investigated the swelling-induced chloride current in fibroblasts, which we demonstrated is closely related or identical to a cloned epithelial chloride channel, ICln: This chloride channel can be blocked by nucleotides. MATERIALS AND METHODS: Electrophysiological, fluorescence optical, and volume measurements were made to determine the effect of nucleoside analogs on the swelling-dependent chloride current (ICl) in NIH 3T3 fibroblasts and in human T cell lymphoma (H9) cells and the cAMP-dependent chloride current in CaCo cells. RESULTS: AZT and acyclovir block the swelling-dependent chloride current and the chloride flux in fibroblasts, and the regulatory volume decrease (RVD) and ICl in H9 cells. This immediate effect can be substantially reduced by the simultaneous incubation of the cells with thymidine-5'-diphosphate (TDP) or uridine, both of which are by themselves unable to affect ICl. CONCLUSIONS: We show here a novel molecular mechanism by which antiviral drugs of the nucleoside analog family could lead to impairments of the kidney, bone marrow, gastrointestinal, and neuronal functions, and how these side effects could possibly be restricted by the presence of TDP or uridine.