Identification of cyclopropyl fatty acids in walnut (Juglans regia L.) oil

Aim: Identification of cyclopropyl fatty acids in walnut oil. Method: GC/MS method was developed for the determination of eight cyclopropyl fatty acids in walnut (Juglans regia) oil. Results: Monocyclopropane acids: methyl 9-cyclopropyl-nonanoate, 6,7-methylene-, 8,9-methylene-, 9,10-methylene-, 11,12-methylene octadecanoates, and dicyclic acid - methyl 9,10,12,13-dimethylene octadecanoate, tricyclic acid - methyl 9,10,12,13,15,16-trimethylene octadecanoate, and unsaturated - methyl 2-octylcyclopropene-1-octanoate were detected in walnut oil by GC-MS and their mass spectra studied. Four cyclic fatty acids were identified for the fist time in seed oils. Conclusions: Eight cyclopropyl fatty acids were detected in the Mediterranean nuts for the first time.     

Simultaneous transport of different localized mRNA species revealed by live-cell imaging

Intracellular mRNA localization is a common mechanism to achieve asymmetric distributions of proteins. Previous studies have revealed that in a number of cell types, different mRNA species are localized by the same transport machinery. However, it has been unclear if these individual mRNA species are specifically sorted into separate or common ribonucleoprotein (RNP) particles before or during transport. Using budding yeast as a model system, we analyzed the intracellular movement of individual pairs of localized mRNA in live cells. Yeast cells localize more than 20 different mRNAs to the bud with the help of the Myo4p/She3p/She2p protein complex. For live cell imaging, mRNA pairs were tagged with tandem repeats of either bacteriophage MS2 or lambda boxB RNA sequences and fluorescently labeled by fusion protein constructs that bind to the RNA tag sequences. Using three-dimensional, single-particle tracking with dual-color detection, we have tracked the transport of two different localized mRNA species in real time. Our observations show that different localized mRNAs are coassembled into common RNP particles and cotransported in a directional manner to the target site. Nonlocalized mRNAs or mutant mRNAs that lack functional localization signals form separate particles that are not transported to the bud. This study reveals a high degree of co-ordination of mRNA trafficking in budding yeast.     

Removal of immune-stimulatory components from surfaces by plasma discharges

Immune-stimulating microbiological components like lipopolysaccharide (LPS), lipoteichoic acid (LTA) and zymosan bound onto surfaces lead to severe problems when brought in contact with the organism via surgical instruments or implants. We have shown, in recent studies, that it is possible to detect different immune-stimulating components directly on the surface, via an indirect detection method, using human whole-blood and the monocyte reaction to measure the inflammatory mediator release (IL-1beta) by ELISA. With regard to the inactivation of pyrogenic substances, we present a method based on the application of a low-pressure microwave plasma discharge working at low temperatures. We found a fast (10 s to a few minutes) removal rate of the immune-stimulating competence for LPS, LTA and zymosan. To mimic the bacterial cell-wall, LPS in combination with muramyl dipeptide was employed and the decreasing rate of the inflammatory signal did not differ from pure LPS.     

Polymorphisms of the TPMT gene in the Czech healthy population and patients with inflammatory bowel disease

Genetic variation in thiopurine S-methyltransferase (TPMT) is a major factors for wide variation in the metabolism and safety of thiopurine drugs. We investigated the frequency of functional gene polymorphisms in 396 patients with inflammatory bowel disease and 300 healthy subjects. Frequencies of functionally deficient alleles TPMT*2, TPMT*3A, TPMT*3B, and TPMT*3B in the patient group were 0.1%, 4.3%, 0.1%, and 0.4%, respectively, and were similar to those of healthy subjects in the Czech population. Our results provide necessary information for pharmacoeconomic studies in the Czech Republic.     

Statistical approach in search for optimal signal in simple olfactory neuronal models

Several models (concentration detectors and a flux detector) for coding of odor intensity in olfactory sensory neurons are investigated. Behavior of the system is described by different stochastic processes of binding the odorant molecules to the receptors and their activation. Characteristics how well the odorant concentration can be estimated from the knowledge of response, the number of activated neurons, are studied. The approach is based on the Fisher information and analogous measures. These measures of optimality are computed and applied to locate the odorant concentration which is most suitable for coding. The results are compared with the classical deterministic approach which judges the optimal odorant concentration via steepness of the input-output function.     

Serum levels of selenium, manganese, copper, and iron in colorectal cancer patients

This article describes a study in which four trace elements (Se, Mn, Cu, and Fe) were analyzed in the blood serum of the patients with colorectal cancer from the Moravian region of the Czech Republic. Atomic absorption spectrometry with graphite furnace atomization was used for analysis of selenium and manganese and with flame atomization for analysis of copper and iron. The observed serum concentrations in adenocarcinoma colorectal patients of selenium were significantly lower (41.8 ± 11.6 μg/L) and those of manganese (16.3 ± 4.5 μg/L) and iron (2.89 ± 1.23 mg/L) were significantly higher as compared to the age-matched control group. Copper serum content (0.95 ± 0.28 mg/L) did not significantly differ as compared to healthy population.     

Growth model and metabolic activity of brewing yeast biofilm on the surface of spent grains: a biocatalyst for continuous beer fermentation

In the continuous systems, such as continuous beer fermentation, immobilized cells are kept inside the bioreactor for long periods of time. Thus an important factor in the design and performance of the immobilized yeast reactor is immobilized cell viability and physiology. Both the decreasing specific glucose consumption rate (q(im)) and intracellular redox potential of the cells immobilized to spent grains during continuous cultivation in bubble-column reactor implied alterations in cell physiology. It was hypothesized that the changes of the physiological state of the immobilized brewing yeast were due to the aging process to which the immobilized yeast are exposed in the continuous reactor. The amount of an actively growing fraction (X(im)act) of the total immobilized biomass (X(im)) was subsequently estimated at approximately X(im)act = 0.12 g(IB) g(C)(-1) (IB = dry immobilized biomass, C = dry carrier). A mathematical model of the immobilized yeast biofilm growth on the surface of spent grain particles based on cell deposition (cell-to-carrier adhesion and cell-to-cell attachment), immobilized cell growth, and immobilized biomass detachment (cell outgrowth, biofilm abrasion) was formulated. The concept of the active fraction of immobilized biomass (X(im)act) and the maximum attainable biomass load (X(im)max) was included into the model. Since the average biofilm thickness was estimated at ca. 10 microm, the limitation of the diffusion of substrates inside the yeast biofilm could be neglected. The model successfully predicted the dynamics of the immobilized cell growth, maximum biomass load, free cell growth, and glucose consumption under constant hydrodynamic conditions in a bubble-column reactor. Good agreement between model simulations and experimental data was achieved.     

Generalized analysis of molecular variance

Many studies in the fields of genetic epidemiology and applied population genetics are predicated on, or require, an assessment of the genetic background diversity of the individuals chosen for study. A number of strategies have been developed for assessing genetic background diversity. These strategies typically focus on genotype data collected on the individuals in the study, based on a panel of DNA markers. However, many of these strategies are either rooted in cluster analysis techniques, and hence suffer from problems inherent to the assignment of the biological and statistical meaning to resulting clusters, or have formulations that do not permit easy and intuitive extensions. We describe a very general approach to the problem of assessing genetic background diversity that extends the analysis of molecular variance (AMOVA) strategy introduced by Excoffier and colleagues some time ago. As in the original AMOVA strategy, the proposed approach, termed generalized AMOVA (GAMOVA), requires a genetic similarity matrix constructed from the allelic profiles of individuals under study and/or allele frequency summaries of the populations from which the individuals have been sampled. The proposed strategy can be used to either estimate the fraction of genetic variation explained by grouping factors such as country of origin, race, or ethnicity, or to quantify the strength of the relationship of the observed genetic background variation to quantitative measures collected on the subjects, such as blood pressure levels or anthropometric measures. Since the formulation of our test statistic is rooted in multivariate linear models, sets of variables can be related to genetic background in multiple regression-like contexts. GAMOVA can also be used to complement graphical representations of genetic diversity such as tree diagrams (dendrograms) or heatmaps. We examine features, advantages, and power of the proposed procedure and showcase its flexibility by using it to analyze a wide variety of published data sets, including data from the Human Genome Diversity Project, classical anthropometry data collected by Howells, and the International HapMap Project.     

Immunoaffinity chromatography of abscisic acid combined with electrospray liquid chromatography-mass spectrometry

Polyclonal antibodies with high specificity for C1-immobilised (+)-cis,trans-abscisic acid (ABA) were raised, characterised by enzyme-linked immunosorbent assay (ELISA) and used for preparation of an immunoaffinity chromatography (IAC) gel. The detection limit of the ELISA was approximately 4.6x10(-10)mol/L. Sensitive electrospray liquid chromatography-mass spectrometry (LC-ESI-MS) methods were also developed with detection limits below 0.1x10(-12)mol. The IAC allowed quick, single-step processing of samples prior to the analyses. The LC-ESI-MS and LC-ELISA techniques were used for comparative estimation of endogenous ABA levels in immunoaffinity purified extracts of normal and water-stressed Nicotiana tabacum L. leaves. The analytical approaches were validated using deuterium- and tritium-labelled internal standards, respectively. The IAC method was found to be highly effective, sensitive and convenient for isolating the target analyte from plant material.     

Highly hydrophilic cationic gold nanorods stabilized by novel quaternary ammonium surfactant with negligible cytotoxicity

The photothermal cancer therapy using cationic gold nanorods (GNRs) stabilized by quaternary ammonium salts (QAS) have a great potential to enhance conventional cancer treatment as it promises the effective eradication of cancer cells including cells resistant to radio‐ and chemo‐therapy and the stimulation of anti‐tumor immune response. However, as the cytotoxicity of the conventional alkanethiol‐QAS compounds limits their utility in medicine, here we developed GNRs modified by novel highly hydrophilic cationic surfactant composed of the quaternary ammonium group and ethylene glycol chain N,N,N‐trimethyl‐3,6,9,12,15‐pentaoxaheptadecyl‐17‐sulfanyl‐1‐ammonium bromide (POSAB) showing insignificant cytotoxicity in the free state. Surface modification of GNRs by POSAB allowed to prepare nanoparticles with good stability in water, high cellular uptake and localization in lysosomes that are a promising alternative to alkanethiol‐stabilized GNRs especially for biomedical applications.