The influence of organic myocardial damage on parameters of signal-averaged electrocardiogram in patients with electrically-induced atrial fibrillation

The aim of this study was to assess the effects of myocardium organic damage on time-domain parameters of atrial signal-averaged ECG (ASAECG) in patients with electrically induced paroxysmal atrial fibrillation (PAF). The investigation was done in 120 patients with subjective symptoms of cardiac rhythm disorders suggesting atrial fibrillation and for further analysis were selected 51 patients in whom atrial PAF was induced during transoesophageal pacing (TEP). Patients were divided according to organic damage of myocardium-38 pts (24 male and 14 female, mean age 52.1 +/- 11.6-group I) and without-13 pts (9 male and 4 female, mean age 35.4 +/- 9.9 -group II). In all two dimensional echocardiographic examination, 24-hours Holter monitoring, exercise testing and TEP were made. Recording of ASAECG was done with a commercially available system HIPEC-200 HA Aerotel. The following time-domain parameters of ASAECG were calculated: the root mean square voltage of the terminal 10, 20, 30 ms of the filtered P-wave (RMS 10, 20, 30) and time duration of filtered P-wave (PWD) and also time duration of P-wave from Frank's leads X, Y, Z (XP, YP, ZP). Atrial late potentials (ALP) were defined as the presence of two parameters: RMS 10 < 4 microV and PWD > 123 ms. If we compared time-domain parameters of ASAECG between examined groups it occurred that only the values of PWD attained statistically significant differences, respectively 123.3 +/- 15.4 ms vs 115 +/- 11.2 ms, p < 0.05. In 14 (36.8%) patients from first group and in 2 (15.4%) patients from second ALP were confirmed. We concluded that presence of myocardium organic damage have essentially influenced on time duration of filtered P-wave.     

Usefulness of transcutaneous oximetry in detection of diabetic microangiopathy in lower limbs

The purpose of the work was an assessment of the usefulness of transcutaneous measurement of O2 pressure in the foot (in recumbent position, recumbent with venostasis, elevated and erect position) for the detection of microcirculation disturbances in patients with diabetes mellitus. The studies included 43 patients with type I and II diabetes without haemodynamically significant stenoses of the axial arteries of the lower limbs, and a control group of 14. It was found that already in the period preceding the development of obliterative lesions in the arteries, microcirculation disturbances in the lower limbs became manifest causing statistically significant decrease of tcPO2 in patients with type I and II diabetes mellitus. The values of tcPO2 in position with limb elevation differentiate best these two groups of patients.     

A Polish multicenter survey of antimicrobial susceptibility and prevalence of beta-lactamase production among bacterial pathogens isolated from hospitalized and ambulatory patients

The aim of the study was to establish the frequency of occurrence of bacterial pathogens with beta-lactamase activity, and pattern of resistance among aerobic and anaerobic strains isolated from: respiratory tract, urinary tract, skin and soft tissues (hospitalized patients) and throat swabs (ambulatory patients). The study was conducted in 1994 year in 6 bacteriological laboratories in four Polish towns (Warszawa, Kraków, Katowice, Gdańsk) according to the protocol. Sensitivity of bacteria was tested by the disc method on the Müeller-Hinton agar or chocolate agar according to NCCLS, activity of beta-lactamase was tested with nitrocephin. A total 2038 clinical strains--1869 aerobic and 169 anaerobic was well-defined and tested for susceptibility to ten antibiotics--amoxicilin, augmentin, ofloxacin, gentamycin, cefradin, erythromycin, cefuroxim, kotrimoxazol, cefalexin and cefaclor. Among the isolated aerobes Staphylococcus aureus (25.1%), E. coli (23.2%) and Haemophilus influenzae (14.0%) were most frequent, and in the group of anaerobes the most frequent were Bacteroides spp (40.8%) We have found 45.8% of all tested aerobic strains with beta-lactamase production, the highest proportion in pathogens isolated from respiratory tract--51.4%, 46.6% from urinary tract, and 48.4% from skin and soft tissues. Among the isolated anaerobic--68.8% of Bacteroides and 28.6% others produced beta-lactamase. Forty percentage of all strains were sensitive to amoxicilin, 70-90% of aerobic bacteria were sensitive to augmentin. Augmentin had a high activity against anaerobic bacteria too. Only a small proportion of the tested aerobic bacteria (12.2%) were resistant to ofloxacin, gentamycin showed a sufficient activity against tested strains (24.4% were resistant). The most frequent pathogen--Staphylococcus aureus was resistant to amoxicilin in 83.1% hospitalized patients, and in 73.9% in ambulatory patients.     

The Profile of MicroRNA Expression and Potential Role in the Regulation of Drug-Resistant Genes in Doxorubicin and Topotecan Resistant Ovarian Cancer Cell Lines

Epithelial ovarian cancer has the highest mortality among all gynecological malignancies. The main reasons for high mortality are late diagnosis and development of resistance to chemotherapy. Resistance to chemotherapeutic drugs can result from altered expression of drug-resistance genes regulated by miRNA. The main goal of our study was to detect differences in miRNA expression levels in two doxorubicin (DOX)- and two topotecan (TOP)-resistant variants of the A2780 drug-sensitive ovarian cancer cell line by miRNA microarray. The next aim was to recognize miRNAs as factors responsible for the regulation of drug-resistance genes. We observed altered expression of 28 miRNA that may be related to drug resistance. The upregulation of miR-125b-5p and miR-935 and downregulation of miR-218-5p was observed in both DOX-resistant cell lines. In both TOP-resistant cell lines, we noted the overexpression of miR-99a-5p, miR-100-5p, miR-125b-5p, and miR-125b-2-3p and decreased expression of miR-551b-3p, miR-551b-5p, and miR-383-5p. Analysis of the targets suggested that expression of important drug-resistant genes such as the collagen type I alpha 2 chain (COL1A2), protein Tyrosine Phosphatase Receptor Type K (PTPRK), receptor tyrosine kinase—EPHA7, Roundabout Guidance Receptor 2 (ROBO2), myristoylated alanine-rich C-kinase substrate (MARCK), and the ATP-binding cassette subfamily G member 2 (ABCG2) can be regulated by miRNA.     

Insect Gut Bacteria Promoting the Growth of Tomato Plants (Solanum lycopersicum L.)

Simple SummaryA new sources of plant growth-promoting (PGP) bacteria are needed to increase the agricultural crops without increasing the usage of chemicals. The aim of this study was to test the hypothesis that insect-gut bacteria promote tomato plant growth. The insect gut bacteria were screened for the presence of PGP traits. The plants treated with bacterial consortium showed a significant increase in fruit yield, in both number of fruits (+41%) and weight of fruits (+44%). Our results showed that: (i) D. virgifera gut’s bacteria significantly promote the growth of tomato plants, and (ii) bacteria other than plant-related can be considered as PGP. It must be underlined that even though the insect gut bacteria were proven to stimulate the plant’s growth, their practical usage must be preceded by an examination of their influence on ecological and biological safety.AbstractWe investigated gut bacteria from three insect species for the presence of plant growth properties (PGP). Out of 146 bacterial strains obtained from 20 adult specimens of Scolytidae sp., 50 specimens of Oulema melanopus, and 150 specimens of Diabrotica virgifera, we selected 11 strains displaying the following: PGP, phosphate solubility, production of cellulase, siderophore, lipase, protease, and hydrogen cyanide. The strains were tested for growth promotion ability on tomato (Lycopersicon esculentum) plants. Each strain was tested individually, and all strains were tested together as a bacterial consortium. Tomato fruit yield was compared with the negative control. The plants treated with bacterial consortium showed a significant increase in fruit yield, in both number of fruits (+41%) and weight of fruits (+44%). The second highest yield was obtained for treatment with Serratia liquefaciens Dv032 strain, where the number and weight of yielded fruits increased by 35% and 30%, respectively. All selected 11 strains were obtained from Western Corn Rootworm (WCR), Diabrotica virgifera. The consortium comprised: Ewingella americana, Lactococcus garvieae, L. lactis, Pseudomonas putida, Serratia liquefaciens, and S. plymuthica. To our knowledge, this is the first successful application of D. virgifera gut bacteria for tomato plant growth stimulation that has been described.     

Effect of Antibiotic Amphotericin B Combinations with Selected 1,3,4-Thiadiazole Derivatives on RPTECs in an In Vitro Model

4-(5-methyl-1,3,4-thiadiazole-2-yl) benzene-1,3-diol (C1) and 4-[5-(naphthalen-1-ylmethyl)-1,3,4-thiadiazol-2-yl] benzene1,3-diol (NTBD) are representative derivatives of the thiadiazole group, with a high antimycotic potential and minimal toxicity against normal human fibroblast cells. The present study has proved its ability to synergize with the antifungal activity of AmB. The aim of this work was to evaluate the cytotoxic effects of C1 or NTBD, alone or in combination with AmB, on human renal proximal tubule epithelial cells (RPTECs) in vitro. Cell viability was assessed with the MTT assay. Flow cytometry and spectrofluorimetric techniques were used to assess the type of cell death and production of reactive oxygen species (ROS), respectively. The ELISA assay was performed to measure the caspase-2, -3, and -9 activity. ATR-FTIR spectroscopy was used to evaluate biomolecular changes in RPTECs induced by the tested formulas. The combinations of C1/NTBD and AmB did not exert a strong inhibitory effect on the viability/growth of kidney cells, as evidenced by the negligible changes in the apoptotic/necrotic rate and caspase activity, compared to the control cells. Both NTBD and C1 displayed stronger anti-oxidant activity when combined with AmB. The relatively low nephrotoxicity of the thiadiazole derivative combinations and the protective activity against AmB-induced oxidative stress may indicate their potential use in the therapy of fungal infections.     

Analysis of indole compounds in edible Basidiomycota species after thermal processing

Methanolic extracts of processed fruiting bodies of six edible mushroom species (Basidiomycota) - Armillaria mellea, Boletus badius, Boletus edulis, Cantharellus cibarius, Lactarius deliciosus collected from natural habitats and Pleurotus ostreatus of commercial origin - were analysed for the presence of non-hallucinogenic indole compounds. Thermal processing was designed in such a way that it mimicked conditions used for cooking of mushroom dishes, since only a narrow group of mushrooms can be eaten raw, while indole compounds are thermolabile. All processed extracts were shown to contain l-tryptophan (up to 8.92 mg/100 g dw). The contents of the remaining compounds, 5-methyltryptophan, tryptamine, melatonin, indoleacetonitrile and indole, varied in different species (from 0.71 to 6.55 mg/100 g dw). Extract of processed C. cibarius fruiting bodies contained l-tryptophan, 5-methyltryptophan, tryptamine, melatonin, indoleacetonitrile and indole (1.96-4.94 mg/100 g dw) whereas l-tryptophan (2.78 mg/100 g dw) and tryptamine (2.77 mg/100 g dw) were the only indole compounds identified in the processed fruiting bodies of A. mellea.     

Taking advantage of the quasiharmonic polynomials for analysis of stationary electromagnetic fields by Trefftz's method

Contents In the paper quasi-harmonic polynomials have been applied for solving the Laplace and Poisson equations by means of Trefftz's method. These polynomials are a generalization of the commonly used harmonic polynomials for field theoretic problems of axial symmetry. The proposed method is illustrated by examples of the analysis of scalar and vector fields having axial symmetry.

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Anwendung der quasiharmonischen Polynome zur Analyse der stationären elektromagnetischen Felder mit Hilfe der Trefftzschen Methode

Übersicht In der Arbeit wird die Anwendung der sogenannten quasiharmonischen Polynome zur Lösung von Aufgaben, die mit Hilfe der Laplaceschen und Poissonschen Gleichungen beschrieben werden, nach der Methode von Trefftz vorgeschlagen. Diese Polynome sind eine Erweiterung der bisher verwendeten harmonischen Polynome auf axialsymmetrische Felder.Die vorgeschlagene Methode wird mit Hilfe von Beispielen über die Analyse von axialsymmetrischen Skalar- und Vektorfeldern veranschaulicht.

     

Analysis of spontaneous electrochemical oscillations by energy distribution technique

Analysis of non-stationary electrochemical oscillations emerges utilization of the techniques allowing an observation of time evolution of their parameters such as instantaneous frequency, amplitude or frequency band. An algorithm of extraction of these parameters can be based on one of linear or quadratic time-frequency representations of oscillations record. In this paper, the authors present representatives of such transformations (Choi-Williams and Cone-shaped) originating from one of the most popular joint time-frequency energy distribution—Wigner-Ville distribution. Short introduction to the mathematics of the topic discussed is provided, then the authors present an example of application in the analysis of current oscillations of copper dissolution process.