Cytokine Production by Peripheral Blood CD4+ and CD8+ T Cells in Atopic Childhood Asthma

There are conflicting studies on T cell cytokine production in childhood asthma. In this study intracellular cytokine expression of IL-2, IL-4, IL-10, IL-13, IFN-γ, and TNF-α in CD4+ and CD8+ T cells in children with atopic asthma were measured by flow cytometry. Results. A significant increase in the percentage of CD4+ and CD8+ T cells producing IL-4 and IL-13 and decrease in the percentage of CD4+ producing IFN-γ in asthmatic children was found. The percentage of CD4+/IL-13+ was significantly higher in severe asthma than in children with intermittent disease symptoms. Severity of asthma was associated with increased both serum IgE and frequencies of CD4+/IL-13+ T cells, as well as duration of disease. Moreover, a decrease in FEV1, FEV1/FVC was observed in relation to the severity of asthma. Changes in cytokine profile in CD8+ subpopulation didn't depend on the severity of the disease. Conclusions. Increased production of IL-4 and IL-13 in both CD4+ and CD8+ T cells accompanied by decreased IFN-γ expression in CD4+ T cells may be evidence that both lymphocyte subpopulations are implicated in the pathogenesis of asthma. Relationship of CD4+/IL-13+ T cells with disease activity suggests that this lymphocyte subset may have a prominent role in childhood asthma

The polymorphism in insulin receptor substrate-1 gene and birth weight in neonates at term

Wstęp: Mutacja genu substratu 1 receptora insuliny (IRS-1, insulin receptor substrate-1) jest jednym z genetycznych czynników ryzyka, przypuszczalnie związanych z występowaniem zjawiska oporności na insulinę lub predyspozycją do wystąpienia cukrzycy typu 2. Celem niniejszego badania była ocena potencjalnych zależności między polimorfizmem Gly972Arg w genie IRS-1 a masą ciała u noworodków urodzonych o czasie. Materiał i metody: W badaniu wzięło udział 100 noworodków urodzonych o czasie (38-42 tydzień ciąży), których matki nie chorowały podczas ciąży. Po wyekstrahowaniu genomowego DNA z leukocytów krwi pępowinowej przeprowadzono z użyciem metody PCR ocenę polimorfizmu Gly972Arg genu IR-1. Wyniki: Urodzeniowa masa ciała była istotnie niższa u noworodków z polimorfizmem Gly972Arg genu IRS-1 w porównaniu z grupą kontrolną (3161,75 ± 380,86 g vs. 3427,92 ± 468,86 g). U noworodków z tym polimorfizmem zaobserwowano również mniejszą długość ciała oraz mniejszy obwód głowy (odpowiednio: 54,38 ± 3,13 cm vs. 52,69 ± 2,91 cm oraz 34,08 ± 1,47 cm vs. 33,63 ± 0,81 cm). Wnioski: Wyniki sugerują, że genotyp Gly972Arg u noworodków urodzonych o czasie wiąże się z niższą urodzeniową masą ciała, mniejszą długością ciała oraz mniejszym obwodem głowy.Background: The mutation of the IRS-1 gene is one of the genetic risk factors which, it is speculated, is associated with insulin resistance or predisposition to type 2 diabetes. The aim of our study was to evaluate the association between the Gly972Arg polymorphism in the IRS-1 gene and birth weight in newborn children with adequate gestational age. Material and methods: 100 newborn children with adequate gestational age (38–42 weeks), whose mother had no disorders during pregnancy, were studied. Genomic DNA was extracted from umbilical cord blood leukocytes, and Gly972Arg polymorphism in the IRS-1 gene was genotyped using the PCR-based method. Results: Birth weight was significantly lower in the newborn with the IRS-1 Gly972Arg polymorphism compared with a control group (3161.75 ± 380.86 g vs. 3427.92 ± 468.86 g). Body length and head circumference at birth were also lower in the neonates with that polymorphism (54.38 ± 3.13 cm vs. 52.69 ± 2.91 cm, and 34.08 ± 1.47 vs. 33.63 ± 0.81, respectively). Conclusions: The results suggest that the Gly972Arg genotype is associated with lower birth weight, body length and head circumference in neonates with adequate gestational age

Electromagnetic Transients in Multi-Voltage Transmission Lines during Non-Simultaneous Faults

It is vitally important that a transmission network provides a continuity of electricity to end users and that the transmission system operator prioritizes its safety and reliability. This article presents the possibilities of using multi-track overhead lines with varying levels of rated voltage, run on a common support structure. This solution would ensure safe operation of the system, reduce the area used for the construction of new overhead lines, and, at the same time increase the transmission network capacity. This article focuses on the method of modeling overhead lines for the analysis of electromagnetic transient states that occur during non-simultaneous disturbance phenomena. This article presents the idea of multi-circuit, multi-voltage lines and their validity of use in power systems. An analysis of electromagnetic transient states for non-simultaneous disturbances in multi-path, multi-voltage lines is presented. This analysis has been made on the basis of a network model, using ATP-EMTP (Alternative Transients Program-Electromagnetic Transients Program) software for solutions, for a Polish power system. Particular attention was paid to the most unfavorable phenomena appearing in the modeled system. The impact of the emerging electromagetic transients in multi-path, multi-voltage lines was evaluated. It was shown that the specificity and rapid changeability of the emerging electromagnetic transients and lack of a universal model of the overhead power line make the analyses of electromagnetic transients highly labor-intensive and time-consuming. Each change is connected with the necessity to create new line models for the study of electromagnetic transient states dependent on many factors

Electromagnetic Transients in Multi-Voltage Transmission Lines during Non-Simultaneous Faults

It is vitally important that a transmission network provides a continuity of electricity to end users and that the transmission system operator prioritizes its safety and reliability. This article presents the possibilities of using multi-track overhead lines with varying levels of rated voltage, run on a common support structure. This solution would ensure safe operation of the system, reduce the area used for the construction of new overhead lines, and, at the same time increase the transmission network capacity. This article focuses on the method of modeling overhead lines for the analysis of electromagnetic transient states that occur during non-simultaneous disturbance phenomena. This article presents the idea of multi-circuit, multi-voltage lines and their validity of use in power systems. An analysis of electromagnetic transient states for non-simultaneous disturbances in multi-path, multi-voltage lines is presented. This analysis has been made on the basis of a network model, using ATP-EMTP (Alternative Transients Program-Electromagnetic Transients Program) software for solutions, for a Polish power system. Particular attention was paid to the most unfavorable phenomena appearing in the modeled system. The impact of the emerging electromagetic transients in multi-path, multi-voltage lines was evaluated. It was shown that the specificity and rapid changeability of the emerging electromagnetic transients and lack of a universal model of the overhead power line make the analyses of electromagnetic transients highly labor-intensive and time-consuming. Each change is connected with the necessity to create new line models for the study of electromagnetic transient states dependent on many factors

Dynamic Equivalents in Power System Studies: A Review

In this paper, the available methods and procedures for creating equivalents for the analysis of electromagnetic transients in power systems are presented and discussed. General requirements of power system representation during simulation of electromagnetic transients are shown. The main available procedures are shown, along with an assessment of their advantages and disadvantages. Methods to search for the optimal replacement of structures in time and frequency domains are discussed. Optimization and direct methods in the frequency domain are presented. Each of these methods is discussed with respect to their possible use in determining the structure of the equivalent circuit for the study of electromagnetic phenomena. Methods to reduce a complex power system, as one of the approaches to determining the structure and parameters of the equivalent circuit, are also presented. Contraindications to the search for equivalents in the frequency domain to study electromagnetic transients are discussed. An analysis of methods for the identification of parameters of the equivalents is presented. The latest advances in the search for the structure and parameters of equivalents are presented, particularly the use of artificial neural networks in the process of replacing parts of systems. Finally, the analyses conducted in this study, together with recommendations regarding the choice of the procedure during the search for equivalents for the analysis of electromagnetic transient phenomena, are summarized

Identification of Free Components during Non-Simultaneous Complex Faults in Overhead Lines: A Review

This study concerns the identification and interpretation of current and voltage signals during complex non-simultaneous disturbances in high-voltage overhead lines. It includes topics related to both the search for the optimal model of the system during complex disturbances as well as the analysis of the obtained results. The available EMT-like tools for the analysis of these phenomena are discussed. Models of high voltage overhead transmission lines are presented along with a discussion of their suitability for the study of electromagnetic transients during the analysis of complex non-simultaneous faults. Examples of transient waveforms of currents and voltages during non-simultaneous faults are presented, and the conditions for the occurrence of delayed current zero during short circuits in the system are discussed. The maximum values of the overvoltage factors and the conditions of their occurrence are described. Faults in transmission lines with various voltage levels suspended on the same supporting structures are discussed, together with an indication of the dangerous consequences of unusual intersystem faults. In the final part of the paper, the summary and recommendations for non-simultaneous fault studies are presented

Untersuchung des Oxidationsverhaltens von orientierten Messing-Einkristallen zur Aufklärung der Bildung von Zinkoxid auf kupferähnlichen Oberflächen

Im Rahmen dieser Arbeit wurde die Bildung von Zinkoxid auf Messing-Einkristalloberflächen untersucht. Mit dem Rastertunnelmikroskop konnte erstmals die Struktur von Zinkoxid, das sich auf einer kupferähnlichen Messing(111)-Oberfläche gebildet hat, atomar aufgelöst werden. Nach Sauerstoffexposition bei Raumtemperatur bildet sich Zinkoxid in Terrassendefekten und an Stufenkanten in einer hexagonalen Struktur, die Aufgrund der Gitterfehlanpassung axial verzerrt wird. Nach Oxidation bei höheren Kristalltemperaturen kommt es zur Bildung von amorphen Zinkoxid-Clustern an Stufenkanten. Eine Kupferoxidation ist nur beim Messingkristall mit geringem Zinkgehalt beobachtbar. Dabei bilden sich nach der Oxidation bei Raumtemperatur Kupfer-Sauerstoff-Reihen auf den Terrassen. Diese Reihen folgen der Kristallsymmetrie des Substrates. Nach Sauerstoffexposition bei höherer Kristalltemperatur kommt es zur Bildung verschiedener Kupferoxidspezies auf den Terrassen

Metabolic control in type 2 diabetes is associated with sulfonylurea receptor-1 (SUR-1) but not with KCNJ11 polymorphisms

Background ----- The sulfonylureas are hypoglycemic agents used for promotion of insulin secretion in type 2 diabetics. They bind to sulfonylurea receptor-1 (SUR-1), which is a functional subunit of the ATP-sensitive potassium channel (KATP). The other component of potassium channel is Kir6.2, encoded by gene KCNJ11. Polymorphisms in these genes may lead to modulated response to sulfonylurea therapy. Aim ----- Aim of this study was to determine a relationship between SUR-1 [exon 16 (-3C/T), exon 31 (Arg1273Arg; AGG→AGA) and exon 33 (S1369A)] and KCNJ11 (E23K) polymorphisms and following parameters of metabolic control in type 2 diabetes: fasting plasma glucose (FPG), postprandial glucose (PPG) and HbA1c in Caucasian type 2 diabetics of the European origin. Methods ----- A total of 228 unrelated patients with type 2 diabetes on sulfonylurea therapy were included in the study. Genotyping of all polymorphisms was performed by PCR-RFLP method; biochemical parameters were determined using standard laboratory methods. Results ----- There was no difference in FPG and PPG concentration in any of the genotype subgroups. However, diabetics with wild type C/C genotype of the SUR-1 exon 16 polymorphism had significantly lower HbA1c concentration compared to the patients with variant T/T genotype [6.9 (6.2-7.7) mmol/L vs. 8.1 (6.7-8.8) mmol/L; p = 0.009]. Also, patients with wild type G/G genotype of the SUR-1 exon 31 polymorphism had significantly higher HbA1c concentration compared to the patients with variant A/A genotype [7.8 (6.9-8.8) mmol/L vs. 6.3 (5.7-6.8) mmol/L; p < 0.001]. Conclusion ----- SUR-1 exon 16 and exon 31 polymorphisms are significantly associated with HbA1c concentration