Altered element homeostasis and transmethylation ability in short-term polyphenol rich supplementation in hyperlipidemic animal model

Non-alcoholic fatty liver disease is one of the most common chronic liver diseases with unclarified pathomechanism and without evidence-proven therapy. Dietary polyphenols, targeting oxidative stress, are at the center of investigations. Our aim was to examine the effects of a polyphenol rich extract on metal element homeostasis and transmethylation ability in non-alcoholic fatty liver model. A ten-day rat model was used (control group, hyperlipidemic group with fat-rich diet, hyperlipidemic group with fat-rich diet and polyphenol supplementation, N = 8 in each group). The hyperlipidemic diet increased the concentration of the majority of the elements with significantly higher contents of B, Co, Cu, Fe, Mg, Mn, Na, Ni, P, Se, Si, and Zn in the liver. Further elevation of Al, Pb, and Sn concentrations could be observed in polyphenol supplemented animals. The polyphenol supplement unexpectedly decreased the transmethylation ability of the liver (132.00 vs. 114.15 vs. 92.25 HCHO μg g−1) further. The results emphasize the possible role of altered metal and non-metal element concentrations and decreased transmethylation ability in the pathomechanism of fatty liver disease. Dietary supplementation with natural compounds may have undesirable effect as well, there is the necessity to improve the efficacy of polyphenol formulations because of their low oral bioavailability.

Association between common cardiovascular risk factors and clinical phenotype in patients with hypertrophic cardiomyopathy from the European Society of Cardiology (ESC) EurObservational Research Programme (EORP) Cardiomyopathy/Myocarditis registry

AIMS

The interaction between common cardiovascular risk factors (CVRF) and hypertrophic cardiomyopathy (HCM) is poorly studied. We sought to explore the relation between CVRF and the clinical characteristics of patients with HCM enrolled in the EURObservational Research Programme (EORP) Cardiomyopathy registry.

METHODS AND RESULTS

1739 patients with HCM were studied. The relation between hypertension (HT), diabetes (DM), body mass index (BMI), and clinical traits was analysed. Analyses were stratified according to the presence or absence of a pathogenic variant in a sarcomere gene. The prevalence of HT, DM, and obesity (Ob) was 37, 10, and 21%, respectively. HT, DM, and Ob were associated with older age (P<0.001), less family history of HCM (HT and DM P<0.001), higher New York Heart Association (NYHA) class (P<0.001), atrial fibrillation (HT and DM P<0.001; Ob p = 0.03) and LV (left ventricular) diastolic dysfunction (HT and Ob P<0.001; DM P = 0.003). Stroke was more frequent in HT (P<0.001) and mutation-positive patients with DM (P = 0.02). HT and Ob were associated with higher provocable LV outflow tract gradients (HT P<0.001, Ob P = 0.036). LV hypertrophy was more severe in Ob (P = 0.018). HT and Ob were independently associated with NYHA class (OR 1.419, P = 0.017 and OR 1.584, P = 0.004, respectively). Other associations, including a higher proportion of females in HT and of systolic dysfunction in HT and Ob, were observed only in mutation-positive patients.

CONCLUSION

Common CVRF are associated with a more severe HCM phenotype, suggesting a proactive management of CVRF should be promoted. An interaction between genotype and CVRF was observed for some traits.

Transmembrane signal transduction by cofactor transport

Information processing and cell signalling in biological systems relies on passing chemical signals across lipid bilayer membranes, but examples of synthetic systems that can achieve this process are rare. A synthetic transducer has been developed that triggers catalytic hydrolysis of an ester substrate inside lipid vesicles in response to addition of metal ions to the external vesicle solution. The output signal generated in the internal compartment of the vesicles is produced by binding of a metal ion cofactor to a head group on the transducer to form a catalytically competent complex. The mechanism of signal transduction is based on transport of the metal ion cofactor across the bilayer by the transducer, and the system can be reversibly switched between on and off states by adding cadmium(ii) and ethylene diamine tetracarboxylic acid input signals respectively. The transducer is also equipped with a hydrazide moiety, which allows modulation of activity through covalent conjugation with aldehydes. Conjugation with a sugar derivative abolished activity, because the resulting hydrazone is too polar to cross the bilayer, whereas conjugation with a pyridine derivative increased activity. Coupling transport with catalysis provides a straightforward mechanism for generating complex systems using simple components.

Synthetic transducers transport externally added metal ion cofactors across the lipid bilayer membrane of vesicles to trigger catalysis of ester hydrolysis in the inner compartment. Signal transduction activity is modulated by hydrazone formation.

Redox switching of an artificial transmembrane signal transduction system

Transmission of chemical signals across lipid bilayer membranes can be achieved using membrane-anchored molecules, where molecular motion across the bilayer is controlled by switching the polarity of two different head groups. An external redox signal delivered by ascorbic acid was used to trigger membrane translocation in a synthetic transduction system.

Hydroxy Channels-Adaptive Pathways for Selective Water Cluster Permeation

Artificial water channels (AWCs) are known to selectively transport water, with ion exclusion. Similarly to natural porins, AWCs encapsulate water wires or clusters, offering continuous and iterative H-bonding that plays a vital role in their stabilization. Herein, we report octyl-ureido-polyol AWCs capable of self-assembly into hydrophilic hydroxy channels. Variants of ethanol, propanediol, and trimethanol are used as head groups to modulate the water transport permeabilities, with rejection of ions. The hydroxy channels achieve a single-channel permeability of 2.33 × 10⁸ water molecules per second, which is within the same order of magnitude as the transport rates for aquaporins. Depending on their concentration in the membrane, adaptive channels are observed in the membrane. Over increased concentrations, a significant shift occurs, initiating unexpected higher water permeation. Molecular simulations probe that spongelike or cylindrical aggregates can form to generate transient cluster water pathways through the bilayer. Altogether, the adaptive self-assembly is a key feature influencing channel efficiency. The adaptive channels described here may be considered an important milestone contributing to the systematic discovery of artificial water channels for water desalination.

Liposome Enhanced Detection of Amyloid Protein Aggregates

Thioflavin-T is used to image amyloid aggregates because of the excellent turn-on fluorescence properties, but binding affinities are low. By mounting multiple dye units on the surface of a vesicle, the binding affinity for α-synuclein fibrils is increased by three orders of magnitude, and the optical response is increased. Cooperative interactions of the dye headgroup and lipid with the protein provide a general strategy for the construction of multivalent amyloid probes based on vesicles.

Triaminopyrimidine derivatives as transmembrane HCl transporters

A series of triaminopyrimidine-based anion transporters has been described, capable of diminishing proton gradients across lipid bilayers at physiologically relevant pH.

Oriented chiral water wires in artificial transmembrane channels

Aquaporins (AQPs) feature highly selective water transport through cell membranes, where the dipolar orientation of structured water wires spanning the AQP pore is of considerable importance for the selective translocation of water over ions. We recently discovered that water permeability through artificial water channels formed by stacked imidazole I-quartet superstructures increases when the channel water molecules are highly organized. Correlating water structure with molecular transport is essential for understanding the underlying mechanisms of (fast) water translocation and channel selectivity. Chirality adds another factor enabling unique dipolar oriented water structures. We show that water molecules exhibit a dipolar oriented wire structure within chiral I-quartet water channels both in the solid state and embedded in supported lipid bilayer membranes (SLBs). X-ray single-crystal structures show that crystallographic water wires exhibit dipolar orientation, which is unique for chiral I-quartets. The integration of I-quartets into SLBs was monitored with a quartz crystal microbalance with dissipation, quantizing the amount of channel water molecules. Nonlinear sum-frequency generation vibrational spectroscopy demonstrates the first experimental observation of dipolar oriented water structures within artificial water channels inserted in bilayer membranes. Confirmation of the ordered confined water is obtained via molecular simulations, which provide quantitative measures of hydrogen bond strength, connectivity, and the stability of their dipolar alignment in a membrane environment. Together, uncovering the interplay between the dipolar aligned water structure and water transport through the self-assembled I-quartets is critical to understanding the behavior of natural membrane channels and will accelerate the systematic discovery for developing artificial water channels for water desalting.

Imidazole derivatives as artificial water channel building-blocks: structural design influence on water permeability

A series of mono- and di-ureidoethylimidazole derivatives were tested as self-assembled supramolecular channels for water transport across a vesicle bilayer. Structural modifications of the selected compounds were related to permeability variation.

A class of carbonic anhydrase I - selective activators

A series of ureido and bis-ureido derivatives were prepared by reacting histamine with alkyl/aryl-isocyanates or di-isocyanates. The obtained derivatives were assayed as activators of the enzyme carbonic anhydrase (CA, EC 4.2.1.1), due to the fact that histamine itself has this biological activity. Although inhibition of CAs has pharmacological applications in the field of antiglaucoma, anticonvulsant, anticancer, and anti-infective agents, activation of these enzymes is not yet properly exploited pharmacologically for cognitive enhancement or Alzheimer's disease treatment, conditions in which a diminished CA activity was reported. The ureido/bis-ureido histamine derivatives investigated here showed activating effects only against the cytosolic human (h) isoform hCA I, having no effect on the widespread, physiologically dominant isoform hCA II. This is the first report in which CA I-selective activators were identified. Such compounds may constitute interesting tools for better understanding the physiological/pharmacological effects connected to activation of this widespread CA isoform, whose physiological function is not fully understood.

Controlled supramolecular structure of guanosine monophosphate in the interlayer space of layered double hydroxide

Guanosine monophosphates (GMPs) were intercalated into the interlayer space of layered double hydroxides (LDHs) and the molecular arrangement of GMP was controlled in LDHs. The intercalation conditions such as GMP/LDH molar ratio and reaction temperature were systematically adjusted. When the GMP/LDH molar ratio was 1:2, which corresponds to the charge balance between positive LDH sheets and GMP anions, GMP molecules were well-intercalated to LDH. At high temperature (100 and 80 °C), a single GMP molecule existed separately in the LDH interlayer. On the other hand, at lower temperature (20, 40 and 60 °C), GMPs tended to form ribbon-type supramolecular assemblies. Differential scanning calorimetry showed that the ribbon-type GMP assembly had an intermolecular interaction energy of ≈101 kJ/mol, which corresponds to a double hydrogen bond between guanosine molecules. Once stabilized, the interlayer GMP orientations, single molecular and ribbon phase, were successfully converted to the other phase by adjusting the external environment by stoichiometry or temperature control.

Supramolecular rulers enabling selective detection of pure short ssDNA via chiral self-assembly

TPA propellers appear to be compatible with the general requirements for amplified chiral supramolecular rulers used to determine the number of base pairs of short ssDNAs.

Technical Approach Determines Inflammatory Response after Surgical and Transcatheter Aortic Valve Replacement

OBJECTIVE

To investigate the periprocedural inflammatory response in patients with isolated aortic valve stenosis undergoing surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) with different technical approaches.

MATERIAL AND METHODS

Patients were prospectively allocated to one of the following treatments: SAVR using conventional extracorporeal circulation (CECC, n = 47) or minimized extracorporeal circulation (MECC, n = 15), or TAVI using either transapical (TA, n = 15) or transfemoral (TF, n = 24) access. Exclusion criteria included infection, pre-procedural immunosuppressive or antibiotic drug therapy and emergency indications. We investigated interleukin (IL)-6, IL-8, IL-10, human leukocyte antigen (HLA-DR), white blood cell count, high-sensitivity C-reactive protein (hs-CRP) and soluble L-selectin (sCD62L) levels before the procedure and at 4, 24, and 48 h after aortic valve replacement. Data are presented for group interaction (p-values for inter-group comparison) as determined by the Greenhouse-Geisser correction.

RESULTS

SAVR on CECC was associated with the highest levels of IL-8 and hs-CRP (p<0.017, and 0.007, respectively). SAVR on MECC showed the highest descent in levels of HLA-DR and sCD62L (both p<0.001) in the perioperative period. TA-TAVI showed increased intraprocedural concentration and the highest peak of IL-6 (p = 0.017). Significantly smaller changes in the inflammatory markers were observed in TF-TAVI.

CONCLUSION

Surgical and interventional approaches to aortic valve replacement result in inflammatory modulation which differs according to the invasiveness of the procedure. As expected, extracorporeal circulation is associated with the most marked pro-inflammatory activation, whereas TF-TAVI emerges as the approach with the most attenuated inflammatory response. Factors such as the pre-treatment patient condition and the extent of myocardial injury also significantly affect inflammatory biomarker patterns. Accordingly, TA-TAVI is to be classified not as an interventional but a true surgical procedure, with inflammatory biomarker profiles comparable to those found after SAVR. Our study could not establish an obvious link between the extent of the periprocedural inflammatory response and clinical outcome parameters.

Treatment of Iron Deficiency with or without Anaemia with Intravenous Ferric Carboxymaltose in Gynaecological Practices - A Non-Interventional Study

In this multi-centre, prospective, non-interventional study, the effectiveness and tolerance of ferric carboxymaltose (ferinject®; FCM) was tested through use in standard gynaecological practice. In total, data from 273 patients was evaluated. 193 of these patients displayed iron deficiency anaemia (IDA), and 68 had iron deficiency without anaemia (ID). The reasons for the ID/IDA were hypermenorrhoea (HyM) (n = 170), post-partum condition (PP) (n = 53) or another indication (n = 53). The average age of the patients was 40 years old, with 8 % of them being vegetarians. Half of the patients had already been treated for anaemia, primarily with oral iron products (94 %). The primary, serious accompanying symptoms of anaemia were fatigue (72 %), lack of concentration (42 %), pale mucous membranes (42 %), headache (26 %) and sleep disorders (21 %). Only one patient did not show serious symptoms at the start of the study. The most frequent indications for parenteral therapy were the need for rapid iron substitution to reduce symptoms (> 70 %), followed by the lower effectiveness or intolerance of oral products (42 % each) as well as patients not completing the course of treatment with oral products (12 %). Patient information was collected at both the beginning and the end of the observation period, which lasted 15 weeks on average. FCM was most frequently administered via infusion (92 %; average infusion duration 21 minutes). Seven percent of patients received bolus injections. The average total iron dosage per patient was 788.7 mg (median 550 mg; range: 50-3000 mg); the median individual dosage was 500 mg (range: 50-1000 mg). The total dosage was, in most cases, administered through a single application (range: 1-10). Symptoms, blood values (Hb), iron stores (serum-ferritin [S-ferritin]) and transport iron (transferrin saturation [TSAT]) normalised to a large extent. In all subgroups, 92 % of women displayed a marked improvement in all of their symptoms. The average increase in Hb-value in the group as a whole was statistically significant, increasing from 10.5 to 13.0 g/dl. In the group with anaemia, the value increased from 9.9 to 13.3 g/dl, with 80 % of women reaching normal Hb-values. The average S-ferritin value increased by a statistically significant > 70 µg/L from 17.2 to 88.8 µg/l and the value for the TSAT increased from 16.3 % to 22.8 %. Seven patients reported experiencing side effects. None of the results were severe. Overall, as part of this non-interventional study for everyday routine in a gynaecological practice, a rapid improvement in symptoms accompanied by the rectification of iron deficiency and anaemia was shown with low occurrences of mild undesirable events, and therefore the data obtained from controlled clinical studies on the effectiveness and tolerance of intravenous ferric carboxymaltose could be confirmed.

Self-sorting of dynamic metallosupramolecular libraries (DMLs) via metal-driven selection

“Metal-driven” selection between finite mononuclear and polymeric metallosupramolecular species can be quantitatively achieved.

CD62L (L-selectin) shedding for assessment of perioperative immune sensitivity in patients undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVE

To investigate the suitability of blood granulocyte and monocyte sensitivity, as measured by the quantity of different agonists required to induce CD62L shedding, for assessment of perioperative immune changes in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

Patients scheduled for aortocoronary bypass grafting or for valve surgery were included in this prospective observational study. Blood samples were drawn before anesthesia induction, directly after surgery and 48 hours after anesthesia induction. We determined the concentration of two different inflammatory stimuli--lipoteichoic acid (LTA) and tumor necrosis factor alpha (TNF)--required to induce shedding of 50% of surface CD62L from blood granulocytes and monocytes. In parallel monocyte surface human leukocyte antigen (HLA)-DR, and plasma interleukin (IL)-8, soluble (s)CD62L, soluble (s)Toll-like receptor (TLR)-2 and ADAM17 quantification were used to illustrate perioperative immunomodulation.

RESULTS

25 patients were enrolled. Blood granulocytes and monocytes showed decreased sensitivity to the TLR 2/6 agonist Staphylococcus aureus LTA immediately after surgery (p = 0.001 and p = 0.004 respectively). In contrast, granulocytes (p = 0.01), but not monocytes (p = 0.057) displayed a decreased postoperative sensitivity to TNF. We confirmed the presence of a systemic inflammatory response and a decreased immune sensitivity in the post-surgical period by measuring significant increases in the perioperative plasma concentration of IL-8 (p ≤ 0.001) and sTLR (p = 0.004), and decreases in monocyte HLA-DR (p<0.001), plasma sCD62L (p ≤ 0.001). In contrast, ADAM17 plasma levels did not show significant differences over the observation period (p = 0.401).

CONCLUSIONS

Monitoring granulocyte and monocyte sensitivity using the "CD62L shedding assay" in the perioperative period in cardiac surgical patients treated with the use of cardiopulmonary bypass reveals common changes in sensitivity to TLR2/6 ligands and to TNF stimulus. Further long-term follow-up studies will address the predictive value of these observations for clinical purposes.

Effect of dietary fatty acid pattern on growth, body fat composition and antioxidant parameters in broilers

The effects of dietary fat supplementation on performance, fatty acid (FA) composition of tissues and antioxidant defence system of broilers were studied. Male broilers were placed in 20 floor pens (60 broilers per pen). The broilers were fed by diets with added different energy sources: lard (L); sunflower oil (SFO); soybean oil (SBO); and linseed oil (LSO). The treatments did not modify significantly growth performance and feed intake of the broilers. There was no effect of dietary FA pattern on reduced glutathione level and glutathione peroxidase activity of plasma, erythrocyte and liver samples. However, higher PUFA content of the diet resulted in a significant increase in malondialdehyde level of erythrocytes and liver. The broilers fed LSO diet more effectively maintained their antioxidant status with enhanced plasma radical scavenger capacity. FA composition in tissues reflected the FA pattern of the diets, although proportion of FAs with four or more double bonds was metabolic specific. LSO diet increased the level of C18:3, C20:5 and C22:6 in tissue lipids in relation to L, SFO and SBO diets. Significantly increased plasma radical scavenging capacity in concert with the enhanced C20:5 and C22:6 proportion in liver and muscle during LSO feeding indicate metabolic changes to counteract the oxidative injury. This may be related to the compounds produced after different biochemical pathways of n-6 and n-3 FAs.

The effect of citrus flavonoids on the redox state of alimentary-induced fatty liver in rats

Both chronic venous insufficiency (CVI) and fatty liver may develop at the same time. Hesperidin and diosmin are used for the treatment CVI. There is no information, however, on the effect of these flavonoids in the redox state of fatty liver. In this study, male Wistar albino rats were fed a lipid-rich diet with or without 450 mg diosmin-50 mg hesperidin-containing drug (60 mg kg(-1) body weight/day, per os) for 9 days to determine the impact of treatment on antioxidant defence system of the fatty liver. We detected free SH-group concentration (SHC), hydrogen-donating ability (HDA), and natural scavenger capacity were decreased and hepatic malonaldehyde content and dien conjugate (DC) content in rats with fatty liver were increased compared to the control. After treatment in fatty liver, these parameters (except DC) significantly improved and approached the control value. Our results indicate that diosmin-hesperidin-containing drug may be a useful agent in improving the antioxidant defensive system in alimentary-induced fatty liver disease.

Three mechanisms in the pathogenesis of pre-eclampsia suggested by over-represented transcription factor-binding sites detected with comparative promoter analysis

Microarray studies generating lists of genes with altered expression in placentas from pregnancies complicated with pre-eclampsia (PE) have so far been published in several different studies. Working under the assumption that altered gene expression in PE may be the result of altered expression of regulatory transcription factors (TFs), we looked for over-represented TF-binding sites (TFBSs)-which indicate the involvement of TFs in gene regulatory networks-in lists of genes (n = 143) compiled in these studies. We compared the prevalence of TFBSs in the promoter regions of 68 genes with the background prevalence of TFBSs in promoters of the human genome. The prevalence of the E47, sterol regulatory element binding protein (SREBP) and NFKB-p50 TFBSs was higher (P < 0.005) in the promoter sequences of the PE gene lists than in the background model. Each of these TFBSs could be implicated in the development of PE. The E47 protein is an E-protein or basic helix-loop-helix (bHLH) TF. Data support the role of bHLHs in the differentiation of placental tissue. SREBP-1, a lipid-sensing sterol regulatory element-binding protein, is a critical regulator of fatty acid homeostasis in the placenta. The target genes of NFKB-p50 determine inflammatory response, and aberrant cytokine homeostasis is a further sign of PE. These TFs may provide an insight into the pathogenesis of the disease.

Bilateral striatal lesion associated with varicella

Bilateral striatal lesion is characterised by a specific clinical syndrome (encephalopathy with rigidity, irritability, variable pyramidal, and extrapyramidal symptoms, speech abnormalities) and symmetrical lesion of the basal ganglia including the caudate nucleus, the putamen, and occasionally other nuclei. We report three cases in whom bilateral striatal lesion developed in association with varicella. Each patient recovered completely and showed no signs of cognitive deficiency, chorea or hyperkinetic syndrome, all of which have been reported as sequelae of BSL associated with other conditions. These cases suggest that bilateral striatal lesion may be an immune-mediated complication of varicella.

Angiotensin II type 1 receptor A1166C polymorphism and prophylactic indomethacin treatment induced ductus arteriosus closure in very low birth weight neonates

Altered pulmonary vascular resistance might be a factor for delayed closure of the ductus arteriosus (DA) in preterm infants. Angiotensin II plays a central role in the elevation of pulmonary vascular resistance. Angiotensin II exerts its vasoconstrictor effect on the angiotensin II type 1 receptor (AT1R). Homozygous carriers of the AT1R A1166C genetic variant present an exaggerated vasoconstrictor response to angiotensin II. We have investigated whether the presence of AT1R CC1166 influences the effect of prophylactic indomethacin treatment on the closure of DA until the fifth postnatal day in preterm infants. In this retrospective study detailed medical history of the first postnatal week was obtained in 159 infants born before the 33rd gestational week. All were treated by prophylactic indomethacin to induce permanent closure of the DA. On the sixth postnatal day the DA was still open in 56, whereas it was permanently closed in 103. The AT1R A1166C genotype of the infants was determined from Guthrie spots. Stepwise binary logistic regression analysis was used to assess the effect of medical conditions and genotype on the risk of patent DA (PDA). Birth weight, infantile respiratory distress, and severe hypotension were independent risk factors for PDA (p < 0.01, p < 0.05, p < 0.05, respectively). The carrier state of AT1R CC1166 was protective against PDA (p < 0.05; odds ratio, 0.067). AT1R AC1166 genotype was not associated with PDA. Our results indicate that the risk of PDA might be lower in infants of AT1R CC1166 than in those with AC or AA genotypes.

HbA1c levels and erythrocyte transport functions in complication-free type 1 diabetic children and adolescents

Higher erythrocyte sodium-lithium countertransport activity (SLC) is implicated in the development of diabetic nephropathy. Altered glucose homeostasis and genetic susceptibility are claimed to play a role in the elevation of SLC. We aimed to test whether metabolic control or the genetic variants of G protein beta 3 (Gb3) subunits determine SLC and other erythrocyte transport activities in complication-free stage of type 1 diabetes. A total of 96 complication-free type 1 diabetic children and adolescents were enrolled. SLC, Na(+)/K(+)-ATPase (NAK) and Ca(2+)-ATPase (CA) were measured by functional assays in erythrocytes. Gb3-C825T polymorphism was determined by PCR-RFLP. Results were related to HbA(1c) and were compared to those of 97 healthy controls. SLC activity was higher in diabetics (387+/-146 vs. 280+/-65 mmol/RBC. hour) and correlated with HbA(1c) levels (y=0.004x+6.42, r=0.33, n=96, p<0.01). NAK and CA activities were unaltered. The prevalence of (825)T allele was similar in the patient and control groups (0.34 vs 0.37) and no differences in enzyme activities were observed between the (825)T allele-positive and negative subjects. Although metabolic control correlated with SLC, other membrane functions were not affected. Therefore we hypothesize that the relationship between advanced glycation and SLC elevation is not causative. Rather, a genetic susceptibility for the coexistence of poor metabolic control and higher SLC is more likely. However, the presence of Gb3-C825T variant is not likely to be a risk factor for SLC-elevation and altered metabolic control diabetes.

Short-term omeprazole treatment does not influence biochemical parameters of bone turnover in children

Gastric proton pump inhibitors are widely used in the treatment of dyspeptic problems and for the eradication of H. pylori infection. Data are not available on whether omeprazole, a representative of proton pump inhibitors, influences the function of osteoclastic H+-pump in children. We studied the impact of short-term omeprazole administration on the biochemical parameters of bone turnover in pediatric patients. Urinary calcium excretion, serum total alkaline phosphatase activity, collagen type 1 crosslinked C-telopeptide, and osteocalcin levels were determined in 34 children [20 girls (9 prepubertal) and 14 boys (6 prepubertal)] before and after 2 weeks of omeprazole treatment at a dose of 20 mg/day. The measured parameters were within the healthy reference range in each patient. None of them altered during the study in any age or in any gender. We conclude that omeprazole, at a dose of 20 mg/day, does not significantly influence the investigated biochemical parameters of osteoclast and osteoblast function in pediatric patients.

Expression and activity of the Ca(2+)-atpase enzyme in human neonatal erythrocytes

The plasma membrane Ca(2+)-ATPase (PMCA) is one of the main regulators of Ca(2+) homeostasis. We studied the perinatal alteration of the abundance and the activity of PMCA molecules in human erythrocytes in pre-term and full-term neonates and children at the age of 1-4 years. The lower abundance of the 4b isoform was associated with lower enzyme activity in full-term neonates compared to children. Although the number of PMCA molecules was higher in pre-term neonates, their total PMCA activities were identical to those of full-term neonates. Our findings suggest that the abundance of PMCA molecules changes during the perinatal development. The same activity at higher enzyme molecule numbers might indicate a potential immaturity of the enzyme in the pre-term infant.

Plasma concentration of myeloperoxidase enzyme in pre- and post-climacterial people: related superoxide anion generation

Neutrophil granulocytes are involved in the pathogenesis of atherosclerosis also through their free radical generation. The aim of the study was to test how extracellular levels of myeloperoxidase (MPO; a granulocyte enzyme playing role in free radical production) change by age and what effect this change has on the production of the free radical superoxide anion by neutrophils. We also wanted to examine whether the antioxidant effect of different steroid hormones is realized through the MPO. Plasma myeloperoxidase concentrations of healthy blood donors were quantified by ELISA. Superoxide anion production was measured by photometry. Myeloperoxidase concentration was significantly lower in plasmas obtained from older women and men than in those from younger subjects. Adding the MPO inhibitors 4-aminobenzoic acid hydrazide (ABAH) and indomethacin to the granulocytes, the generation of superoxide anion increased and the decreasing effect of the steroids on superoxide production was inhibited. Incubating the neutrophils with the product of the reaction catalyzed by MPO itself (hypochlorite anion), we found significant decrease in superoxide generation. According to our results MPO seems to diminish the production of superoxide anion and so probably has an antioxidant ability. Therefore, its lower plasma levels may contribute to the increasing incidence of atherosclerosis and other free radical mediated disorders in old people. Thus, after further studies MPO might become one of the indicators of cardiovascular risk and the scavenger capacity in general.

Variance of ACE and AT1 receptor gene does not influence the risk of neonatal acute renal failure

High neonatal activity of the renin-angiotensin system (RAS) is crucial for the maintenance of glomerular filtration of the newborn. The aim of the present study was to investigate whether genetic polymorphisms leading to lower angiotensin converting enzyme activity (ACE) or impaired functionality of angiotensin II (AII) type 1 receptor (AT1R) might predispose very low birth weight newborns (VLBWs) to the development of acute renal failure (ARF). The medical records of 110 VLBW infants were analyzed. ARF developed in 42 of them during the first postnatal week, while 68 neonates exhibited normal renal function. The ACE I/D polymorphism and the A1166C variants of AT1R were determined from dried blood samples. The frequency of the ACE I allele did not differ in ARF and non-ARF groups (0.307 and 0.284); the frequency of the AT1R C1166 variant was also the same in ARF and non-ARF groups (0.250 and 0.227). Although low activity of RAS has been implicated in the development of neonatal ARF and data indicated that the functionality of RAS is influenced by the I/D variants of the ACE gene and the A1166C variant of the AT1R gene, we could not demonstrate any effect of these polymorphisms on the development of ARF in VLBW infants.

Genetic variants of the tumour necrosis factor-alpha promoter gene do not influence the development of necrotizing enterocolitis

Previous studies indicated that elevated tumour necrosis factor-alpha (TNF-alpha) levels may play a role in the development of necrotizing enterocolitis (NEC). The A(-308) and A(-238) variants of the promoter region of the TNF-alpha gene are reportedly associated with altered TNF-alpha production. The aim of our study was to determine the impact of these gene polymorphisms on the development and course of NEC in very-low-birthweight (VLBW) infants. Dried blood samples from 46 VLBW neonates with NEC were analysed using the method of restriction fragment length polymorphism. Samples from 90 VLBW neonates without NEC were used as controls. The prevalence of alleles with guanine-adenine transition in the -308 and -238 positions was the same in NEC and control subjects (12% vs 10% and 3% vs 4%, respectively).

CONCLUSION

The investigated genetic variants of the TNF-alpha gene promoter region have no influence on the risk and course of NEC in VLBW infants.

Abundance and activity of Ca2+-ATPase in hypercalciuric children

The plasma membrane Ca2+-ATPase (PMCA) is one of the main regulators of cell Ca2+ homeostasis. The aim of our study was to determine whether the abundance and activity of PMCA are altered in erythrocytes of children with idiopathic hypercalciuria. Twenty-four children with idiopathic hypercalciuria (13 girls and 11 boys, mean age 10.6+/-4.8 years; mean urinary calcium concentration 0.85+/-0.20 mmol/mmol creatinine) and 30 healthy age-matched children were enrolled. PMCA protein abundance was determined by Western blot analysis. Enzyme activity was determined spectrophotometrically. The abundance of PMCA did not differ in hypercalciuric patients from that of control subjects (98+/-22% vs 100+/-18%). Moreover, the activity was not different between the studied groups (3141+/-1494 vs 2953+/-780 nmol ATP/mg protein/h). The extent of hypercalciuria did not correlate with enzyme abundance or activity. Assuming that erythrocytes may reflect the renal tubular transporting processes, our data suggest that other Ca2+-transport mechanisms than PMCA might be involved in the development of idiopathic hypercalciuria in children.

Percutaneous ureterolithotomy: direct method for removal of impacted ureteral stones

PURPOSE

We report 52 percutaneous urterolithotomies in 51 patients having large, impacted middle ureteral stones. Direct percutaneous stone removal can be performed as successfully as in cases of renal stones treated with percutaneous nephrolithotomy.

METHODS

The operation is performed under local anesthesia; therefore, the procedure is quicker and simpler than the laparoscopic or retroperitoneoscopic intervention. All patients became stone free. In two patients (4%), ultrasound disintegration was necessary; in the remaining cases, there was no need for any fragmentation: the stone was removed intact. A retroperitoneal drain was always left at the end of the procedure. With the exception of two cases, the ureter was always stented without closure of the ureteral incision.

RESULTS

Fever (> or = 38 degrees C) was observed in 15 patients (29%) for 2 days. Retroperitoneal hematoma 5 cm in diameter was seen in one patient. One patient had urine leakage through the retroperitoneal drain in the postoperative period for 18 days. Also, one patient came back 3 days after discharge with urine leakage through the percutaneous retroperitoneal tract.

CONCLUSION

Direct percutaneous ureterolithotomy is an effective way to remove impacted middle ureteral stones but is advisable only for endourologists with considerable experience.

Oxidative damage in alcoholic liver disease

OBJECTIVE

The metabolic effects of alcohol are due both to its direct action and to that of its first metabolite, and can also be connected with the changes in redox state. Differences in ethanol distribution, bioavailability and hepatic metabolism can provide insight into the protective and predisposing factors in alcoholism, as well as gender differences of alcohol toxicity. Oxidative stress occurs following various conditions of ethanol consumption.

DESIGN

Twenty-six Caucasian patients with alcoholism and 32 healthy, abstinent controls of both sexes were investigated with special regard to reduction-oxidation status and ad hoc free-radical-antioxidant balance.

METHOD

Plasma free SH-group concentration, H-donating ability, and reducing power property were measured by simple spectrophotometric methods. Total scavenger capacity was determined by a newly developed chemiluminometric method in plasma and erythrocytes.

RESULTS

Alcoholics showed a decrease of free SH-group concentration, hydrogen-donating ability and an increase of reducing power property in plasma. A decreased total scavenger capacity of erythrocytes and plasma of alcoholic patients, combined with gender differences, could be detected.

CONCLUSIONS

Alcoholic dependence causes gradual exhaustion of the antioxidant capacity of erythrocytes, therefore this non-invasive measurement may be useful as a follow-up of the evolution of alcoholic liver disease. The results also suggest a gender susceptibility of alcohol toxicity.

Developmental changes in erythrocyte Na(+),K(+)-ATPase subunit abundance and enzyme activity in neonates

AIM

To study the relation between erythrocyte Na(+),K(+)-ATPase subunit isoform composition, Na(+),K(+)-ATPase activity, and cation pump function in preterm and term neonates.

DESIGN

Erythrocyte Na(+),K(+)-ATPase subunit isoform abundance, Na(+),K(+)-ATPase activity, and cation pump function were studied in blood samples obtained from 56 preterm neonates of 28-32 weeks gestation (group 1), 58 preterm neonates of 33-36 weeks gestation (group 2), and 122 term neonates (group 3) during the first two postnatal days.

RESULTS

alpha(1) isoform abundance was higher and beta(2) isoform abundance was lower in group 1 than in group 3 (p = 0.0002). alpha(2) and beta(1) isoform abundance did not change with maturation and there was no evidence for the presence of the alpha(3) isoform. Gestational age was inversely related to Na(+), K(+)-ATPase activity (p = 0.0001) and directly related to intracellular Na(+) concentration (p = 0.0025).

CONCLUSIONS

Expression of the alpha(1) and beta(2) Na(+),K(+)-ATPase subunit isoforms is developmentally regulated. The increased abundance of alpha(1) isoforms of immature neonates translates to increased ATPase activity. The lower intracellular Na(+) concentration of immature neonates suggests that their erythrocyte Na(+),K(+)-ATPase cation pump function may also be increased.

Determination of H+/K+-ATPase activity in human gastric biopsy specimens

The aim of our work was to develop a method to determine the the H+/K+-ATPase activity of human gastric biopsy samples. Our method is based on the phosphatase activity and the K+-inducible property of the enzyme. K+-inducible pNPPase activity was determined from homogenated corpus and antrum biopsy samples. H+/K+-ase activity was calculated as the difference between the corpus and antrum K+-inducible pNPPase activities. Quality control measurements were done during 20 successive days from pooled homogenates. The total, between-day and between-run, within-day and within-run coefficients of variations were between 10 and 16%. The healthy mean and reference range of K+-inducible pNPPase activity in the corpus was 95.8 (95% CI: 83.4-108.2 mU/mg protein); in the antrum it was 28.3 (21.6-35.0) mU/mg protein. The calculated H+/K+-ATPase activity was 67.2 (56.9-77.5) mU/mg protein. The measured activities were independent of the age and gender. Summarizing our results we have concluded, that our novel method might be a potential tool to gather data about the functional acid producing capability of human gastric mucosa.

[Changes in the myeloperoxidase activity of human neutrophilic granulocytes and the amount of enzyme deriving from them under the effect of estrogen]

Free radicals which are produced constantly in the human body have a significant role in the development of atherosclerosis. The responsibility of leukocytes for vascular disease has been proved in several ways. Hormonally active women are protected much more against myocardial infarction than men, which fact can be explained partly by endocrinological reasons, too. The authors have set the aim to investigate whether estrogen therapy effects on the one hand the intracellular activity of the granulocyte-enzyme, myeloperoxidase (MPO), which takes place in free radical reactions and on the other hand the amount of MPO released from neutrophils. In the case of women having menopause and being treated with hormone replacement (n = 11) the intracellular activity and the amount of MPO-release increased significantly as compared to the level at the time of starting taking the medicine (p < 0.001). Based on the results it can be supposed that the vasoprotective effect of estrogens is fulfilled through their influence on the MPO enzyme, too. Besides the fact that intensified MPO activity through enhanced consumption might induce the decreased accumulation of H2O2 (a reactive oxygen species, substrate of MPO), MPO also has a role in the termination of the whole process of free radical production in granulocytes by the inactivation of the NADPH-oxidase system. This means that the growing intracellular MPO activity and the increased amount of enzyme released induce the decrease of the amount of free radicals produced during the "respiratory burst" and this is advantageous from the point of view of vasoprotection. The increased MPO activity and the NADPH-oxidase inactivation supposed to be elicited by it, might have further positive consequences since MPO has an effect on HDL-metabolism and the outflow of cholesterol from "foam cells", NADPH-oxidase has a suspected role in LDL-oxidation and NADPH is one of the cofactors of NO-synthase (NOS). The decreased superoxide anion level on the other hand may mitigate the chance of the neutralizing of nitric oxide (NO) by it. The superoxide anion is a potent vasoconstrictor and therefore, its diminished production may be beneficial, i.e. decreases the risk of coronary spasm. The new conceptual synthesis worked out by the authors may provide a possible explanation of the increased susceptibility to infections during steroid treatment, too.

[Free radical reactions in juvenile rats treated with streptozotocin]

Male, weaned Wistar albino rats (n = 8) were treated by single dose of intravenous 50 mg/bodyweight-kg streptozotocin (STZ) injection. Changes in carbohydrate and lipid metabolism, and scavenger capacity of red blood cells and liver homogenates were evaluated and compared to the respective values of the control group (n = 9) after 3 weeks. HbAlc was significantly higher (p < 0.005) in the STZ treated group. Plasma triglyceride also showed a marked elevation compared to the control group (p < 0.05). Scavenger capacity in erythrocytes was significantly (p < 0.05) higher in treated animals while no change was observed in liver homogenates. No alteration was observed in the superoxide dismutase activity of treated animals, but catalase activity was weaker (p < 0.05). Thiobarbituric acid reactive substances were in higher concentration in plasma of STZ treated animals (p < 0.01) and were in comparable amount in homogenates. The results suggest that 3 weeks after STZ treatment of rats, alterations can be observed in the scavenger system and of the examined tissues changes are most prominent in erythrocytes.