Closing the Digitalis Divide: Back to the Basics of Randomized Controlled Trials.

PURPOSE: Publishe d decades after several randomized controlled trials (RCT) demonstrating decreased hospitalizations and no effect on all-cause mortality with digoxin use, a series of meta-analyses linking digoxin treatment and mortality have contributed to a narrower application of this medication for the management of heart failure (HF) and atrial fibrillation (AF). Given the conflicting data from the earlier RCTs and more recent meta-analyses, there is a growing polarization among providers for and against the use of digoxin in managing these conditions. METHODS: To help close this divide, we provide a perspective on the literature with special attention to the quality of both older and more recent studies on this subject. RESULTS: The data from the highest quality studies we have, RCTs, suggest that digoxin use in patients with HF and/or AF is associated with improvement in several areas of outcomes including functional capacity, symptom management, reduced hospitalizations, fewer deaths due to HF, and treatment of refractory chronic heart failure with rEF, and may even have overall mortality benefit when serum digoxin concentrations are within therapeutic range. These effects are more pronounced in patients with EF < 25% and NYHA Class II-IV and at highest risk for hospitalization. CONCLUSION: As the risk of confounding factors was minimized by the study design, the likelihood that positive outcomes were identified with digoxin use increased. Clinicians and researchers need further adequately designed and powered RCTs exploring the connection between digoxin therapy and mortality, hospitalizations, and symptom management.

Chlorella mirabilis as a Potential Species for Biomass Production in Low-Temperature Environment.

Successful adaptation/acclimatization to low temperatures in micro-algae is usually connected with production of specific biotechnologically important compounds. In this study, we evaluated the growth characteristics in a micro-scale mass cultivation of the Antarctic soil green alga Chlorella mirabilis under different nitrogen and carbon sources followed by analyses of fatty acid contents. The micro-scale mass cultivation was performed in stable (in-door) and variable (out-door) conditions during winter and/or early spring in the Czech Republic. In the in-door cultivation, the treatments for nitrogen and carbon sources determination included pure Z medium (control, Z), Z medium + 5% glycerol (ZG), Z medium + 5% glycerol + 50 µM KNO3 (ZGN), Z medium + 5% glycerol + 200 µM NH4Cl (ZGA), Z medium + 5% glycerol + 1 mM Na2CO3 (ZNC), Z medium + 5% glycerol + 1 mM Na2CO3 + 200 µM NH4Cl (ZGCA) and Z medium + 5% glycerol + 1 mM Na2CO3 + 50 µM KNO3 (ZGCN) and were performed at 15°C with an irradiance of 75 µmol m(-2) s(-1). During the out-door experiments, the night-day temperature ranged from -6.6 to 17.5°C (daily average 3.1 ± 5.3°C) and irradiance ranged from 0 to 2,300 µmol m(-2) s(-1) (daily average 1,500 ± 1,090 µmol m(-2) s(-1)). Only the Z, ZG, ZGN, and ZGC treatments were used in the out-door cultivation. In the in-door mass cultivation, all nitrogen and carbon sources additions increased the growth rate with the exception of ZGA. When individual sources were considered, only the effect of 5% glycerol addition was significant. On the other hand, the growth rate decreased in the ZG and ZGN treatments in the out-door experiment, probably due to carbon limitation. Fatty acid composition showed increased production of linoleic acid in the glycerol treatments. The studied strain of C. mirabilis is proposed to be a promising source of linoleic acid in low-temperature-mass cultivation biotechnology. This strain is a perspective model organism for biotechnology in low-temperature conditions.

GC-MS-MS analysis of bacterial fatty acids in heavily creosote-contaminated soil samples.

Phospholipid fatty acid profiles of soil samples enable rapid and reproducible measurement and characterization of the dominant soil microbial communities. When extensive polycyclic aromatic hydrocarbon (PAH) pollution is present in the soil it is very difficult, or even impossible, to distinguish specific fatty acids in GC-MS chromatograms in full-scan mode, because of the PAHs which, because of their lipophilic character, are co-extracted with the lipids. Selected ions in the samples were scanned in MS-MS mode to eliminate the aromatic hydrocarbon signals and obtain clear chromatograms of the fatty acids. By using this technique it was possible to clearly distinguish at least eleven fatty acids in heavily creosote-contaminated soil samples (PAH concentration approximately 15 g kg(-1) dry weight of soil).

Physiology and microbial community structure in soil at extreme water content.

A sandy loam soil was brought to 6 water contents (13-100% WHC) to study the effects of extreme soil moistures on the physiological status of microbiota (represented by biomass characteristics, specific respiration, bacterial growth, and phospholipid fatty acid, PLFA, stress indicators) and microbial community structure (assessed using PLFA fingerprints). In dry soils, microbial biomass and activity declined as a consequence of water and/or nutrient deficiency (indicated by PLFA stress indicators). These microbial communities were dominated by G+ bacteria and actinomycetes. Oxygen deficits in water-saturated soils did not eliminate microbial activity but the enormous accumulation of poly-3-hydroxybutyrate by bacteria showed the unbalanced growth in excess carbon conditions. High soil water content favored G bacteria.

Variability of catechin and 4-hydroxyacetophenone distribution in Norway spruce needles in relation to their position, age, and growing conditions.

The amount of catechin and 4-hydroxyacetophenone in the methanolic extract of the Norway spruce needles at the locality Bílý Kríz (Moravian-Silesian Beskydy Mts.) was found in the range 2.8-12.1 mg g(-1) (dry weight) and 0.2-17.7 mg g(-1) (dry weight), respectively. Total amount of catechin (sum of the last three needle year-classes) is statistically higher (p<0.01) in the sparse areas compared to the dense ones and similar trends were recorded for catechin content in current and one-year-old needles. These results may support an idea about primary control of phenolic production by the incident solar radiation, which depends on the social position of the tree and canopy closure degree.

Application of ARDRA and PLFA analysis in characterizing the bacterial communities of the food, gut and excrement of saprophagous larvae of Penthetria holosericea (Diptera: Bibionidae): a pilot study.

Amplified ribosomal DNA restriction analysis (ARDRA) was used to compare the bacterial communities of the food, the gut sections (ceca, anterior and posterior midgut, hindgut) and the excrement of the litter feeding bibionid larvae of Penthetria holosericea. For universal eubacterial primers ARDRA patterns were complex with only minor differences among samples. Taxon specific primers were also applied to characterize the samples. Fragment composition was transformed to presence/absence binary data and further analyzed. Cluster analysis revealed that bacterial communities of gut highly resembled each other with the exception of the ceca. ARDRA patterns of consumed leaves clustered together with the intact leaves but differed from those of the excrement. ARDRA results were compared with microbial community structure based on phospholipid fatty acid (PLFA) fingerprints. The cluster analysis of PLFA (presence/absence binary) data resulted in a pattern similar to the ARDRA data. The PCA analysis of PLFA relative content separated microbial communities into five groups: (1) anterior and posterior midgut, (2) hindgut, (3) ceca, (4) consumed and intact litter, (5) excrement. Both methods indicated that conditions in the larval gut result in formation of a specific microbial community which differs from both the food and excrement ones. Particularly ceca--(blind appendages, harbor very specific microbial community) are divided from the rest of the gut by perithropic membrane.

Soil microbial community of abandoned sand fields.

Microbiological evaluation of sandy grassland soils from two different stages of secondary succession on abandoned fields (4 and 8 years old fallow) was carried out as a part of research focused on restoration of semi-natural vegetation communities in Kiskunság National Park in Hungary. There was an apparent total N and organic C enrichment, stimulation of microbial growth and microbial community structure change on fields abandoned by agricultural practice (small family farm) in comparison with native undisturbed grassland. A successional trend of the microbial community was found after 4 and 8 years of fallow-lying soil. It consisted in a shift of r-survival strategy to more efficient C economy, in a decrease of specific respiration and metabolic activity, forced accumulation of storage bacterial compounds and increased fungal distribution. The composition of microbial phospholipid fatty acids mixture of soils abandoned at various times was significantly different.

Analysis of poly-beta-hydroxybutyrate in environmental samples by GC-MS/MS.

Application of gas chromatography-mass spectrometry (GC-MS) can significantly improve trace analyses of compounds in complex matrices from natural environments compared to gas chromatography only. A GC-MS/MS technique for determination of poly-beta-hydroxybutyrate (PHB), a bacterial storage compound, has been developed and used for analysis of two soils stored for up to 319 d, fresh samples of sewage sludge, as well as a pure culture of Bacillus megaterium. Specific derivatization of beta-hydroxybutyrate (3-OH C4:0) PHB monomer units by N-tert-butyl-dimethylsilyl-N-methyltrifluoracetamide (MTBSTFA) improved chromatographic and mass spectrometric properties of the analyte. The diagnostic fragmentation scheme of the derivates tert-butyldimethylsilyl ester and ether of beta-hydroxybutyric acid (MTBSTFA-HB) essential for the PHB identification was shown. The ion trap MS was used, therefore the scan gave the best sensitivity and with MS/MS the noise decreased, so the S/N was better and also with second fragmentation the amount of ions increased compared to SIM. The detection limit for MTBSTFA-HB by GC-MS/MS was about 10(-13) g microL(-1) of injected volume, while by GC (FID) and GC-MS (scan) it was around 10(-10) g microL(-1) of injected volume. Sensitivity of GC-MS/MS measurements of PHB in arable soil and activated sludge samples was down to 10 pg of PHB g(-1) dry matter. Comparison of MTBSTFA-HB detection in natural soil sample by GC (FID), GC-MS (scan) and by GC-MS/MS demonstrated potentials and limitations of the individual measurement techniques.

The use of mosses and pine needles to detect persistent organic pollutants at local and regional scales.

Polycyclic aromatic hydrocarbons (PAHs) were analysed in mosses (Hypnum cupressiforme) and pine needles (Pinus sylvestris) collected in the Czech Republic between 1988-94 at a regional background site in Kosetice, south Bohemia (1988-94) and two industrial sources. One industrial site (sampled 1989-91) in middle Moravia, was near a factory producing PAHs, carbon black and phthalates, the other (sampled 1991-93) near a coal and gas fuel production plant in western Bohemia. Selected chlorinated pesticides and polychlorinated biphenyl congeners were also analysed in samples at the regional background site. This study clearly shows that vegetation sampling can be used to show spatial differences in the atmospheric burden of a range of persistent organic pollutants with differences in the mixtures of compounds reflecting differences in their regional or local use/atmospheric emission.

[Ensuring the quality of cytodiagnosis in the cervix]. / Zajistení kvality cytodiagnostiky cervixu.

The quality of cytodiagnosis depends on a number of operations. It is associated with collection of cellular material, it depends on its processing in the laboratory and on the evaluation of the processed preparation by the cytologist who establishes the diagnosis. In collaboration with three laboratories we tried to evaluate the role of the used nomenclature in the evaluation system. According to the abbreviated classification of Papanicolau 8185 cytological preparations were evaluated which comprised 206 suspect smears, i.e. 2.5%. According to the Munich nomenclature II 22 212 cytologies were evaluated. They comprised 155 suspect ones, i.e. 0.69%. Of 50 540 screening smears evaluated by the Bethesda system, 0.4% were suspect in the category HGSIL. The best results (i.e. agreement with the histological picture, the lowest false positivity and false negativity) was found in the evaluation of cytological smears according to the Bethesda nomenclature (TBS). It will be therefore most probably the best basis for so-called "Quality Assurance".

Microbiological, chemical and toxicological characterization of contaminated sites in Czechoslovakia.

We investigated the contaminated area near the wood-preserving factory at the town Sobeslav in South Bohemia. The factory has been working for approximately 90 years. The soils of this area are extremely contaminated with the polyaromatic hydrocarbons (PAHs) derived from the creosote oils and heavy metals (predominantly Zn, Cu, Hg). The biological activities of sample contaminated soils are very low compared with unpolluted soil. The comparison of actual and potential activity between samples is evaluated for the prediction of the efficiency of application of a bioremediation processes. The testing of frequency of occurrence of a bacterium resistant to heavy metals (Zn and Cu) is used for prediction of possible negative effects on the biodegradation of organic pollutants at the concentrations of heavy metals in soils. A concentration of 2 mmol/l zinc in medium (according Houba-Remarcle) does not negatively influence the number of bacteria. A concentration of 2 mmol/l copper practically does not influence the number of bacteria. Several bacterial strains are able to survive concentrations of 20 mmol/l zinc, 8.5 mmol/l copper and 2 mmol/l cadmium. The preliminary results show that practically all strains which are resistant to heavy metals are able to degrade fluoranthene, as a representative PAH. The real concentrations of heavy metals in soils are below the levels where heavy metals negatively influence the growth of bacteria.

Identification of xanthine and hypoxanthine as components of assembly pheromone in excreta of argasid ticks.

In addition to guanine, xanthine and hypoxanthine were identified in white spherules in excreta of five species of Argas and Ornithodoros ticks by a reverse-phase high-performance liquid chromatography (HPLC) and a gas chromatographic method with mass spectrometric detection (GC/MS). The mutual relationships of these purines in excreta of Argas (Persicargas) persicus were found to be less than 1.5% for hypoxanthine, less than 9.0% for xanthine and 89.8-98.6% for guanine. In excreta of other species, the relationships of purines were similar, with the exception of Argas (A.) reflexus and A. (A.) polonicus, where the amount of hypoxanthine was rather elevated. Uric acid was also identified in some cases. The assembly efficacy of xanthine and hypoxanthine is similar to that of guanine, but xanthine significantly enhances the assembly efficacy of commercial guanine when mixed in ratio of about 1:25. Thus, xanthine seems to be the second important component of assembly pheromone of argasid ticks.

[The relation of nucleoli to precancerous conditions of the cervix]. / Vztah nukleolu k prekancerózám cervixu.

Oestrogens act at the nuclear level. To these steroids also a cancerogenic effect is ascribed. By staining for nuclear structures according to Smetana and Busch the authors proved morphological structures of the nucleolus in vaginal epithelia and in cells from cervical lesions. This applies to solid nucleoli -- which are active, annular nucleoli which are resting and nucleoli which have completed their activity -- micronucleoli. Hyperoestrogenic women have in their vaginal epithelia of the upper third of the vagina more active nucleoli (11.4%) than hypooestrogenic women (2.1%). Women suffering from cervical carcinoma during the menopause have more active nucleoli in the vaginal epithelia (30.8%), as compared with healthy hyperoestrogenic women of productive age. Patients during the menopause with grade III dysplasias have fewer active nucleoli in cervical epithelia than women with cervical cancer (25.0%), however, as compared with hyperoestrogenic women of productive age, much more. A large number of active nucleoli was proved by staining by Smetana's method also in cells taken from cervical lesions carcinoma type and grade III dysplasia in postmenopausal patients. Evaluation of morphological changes of the nucleoli suggests their activity, the activity of the whole nucleolus and is a sensitive indicator of the activity of the whole cell.

Separation of alpha-amino acid enantiomers by reversed-phase high-performance liquid chromatography after derivatization with o-phthaldialdehyde and a sodium salt of 1-thio-beta-D-glucose.

A sensitive system for D,L-amino acid analysis has been developed, using fluorescence derivatization with o-phthaldialdehyde in the presence of sodium salt of 1-thio-beta-D-glucose. The reagents rapidly form fluorescent diastereoisomeric derivatives with primary amino acids. These derivatives are efficiently separated on a conventional reversed-phase column with an analysis time of 60 min. Simultaneous determination of enantiomers of various amino acids was achieved by a simple binary gradient elution with methanol in 0.05 M aqueous sodium acetate.