Inducing α-Helicity in Peptides by Silver Coordination to Cysteine

Short peptide sequences consisting of two cysteine residues separated by three other amino acids display complete change from random coil to α-helical secondary structure in response to addition of Ag+ ions. The folded CXXXC/Ag+ complex involves formation of multinuclear Ag+ species and is stable in a wide pH range from below 3 to above 8. The complex is stable through reversed-phase HPLC separation as well as towards a physiological level of chloride ions, based on far-UV circular dichroism spectroscopy. In electrospray MS under acidic conditions a peptide dimer with four Ag+ ions bound was observed, and modelling based on potentiometric experiments supported this to be the dominating complex at neutral pH together with a peptide dimer with 3 Ag+ and one proton at lower pH. The complex was demonstrated to work as a N-terminal nucleation site for inducing α-helicity into longer peptides. This type of silver-mediated peptide assembly and folding may be of more general use for stabilizing not only peptide folding but also for controlling oligomerization even under acidic conditions.

Revisiting the hydrolysis of ampicillin catalyzed by Temoneira-1 β-lactamase, and the effect of Ni(II), Cd(II) and Hg(II)

β-Lactamases grant resistance to bacteria against β-lactam antibiotics. The active center of TEM-1 β-lactamase accommodates a Ser-Xaa-Xaa-Lys motif. TEM-1 β-lactamase is not a metalloenzyme but it possesses several putative metal ion binding sites. The sites composed of His residue pairs chelate borderline transition metal ions such as Ni(II). In addition, there are many sulfur-containing donor groups that can coordinate soft metal ions such as Hg(II). Cd(II) may bind to both types of the above listed donor groups. No significant change was observed in the circular dichroism spectra of TEM-1 β-lactamase on increasing the metal ion content of the samples, with the exception of Hg(II) inducing a small change in the secondary structure of the protein. A weak nonspecific binding of Hg(II) was proven by mass spectrometry and 119m Hg perturbed angular correlation spectroscopy. The hydrolytic process of ampicillin catalyzed by TEM-1 β-lactamase was described by the kinetic analysis of the set of full catalytic progress curves, where the slow, yet observable conversion of the primary reaction product into a second one, identified as ampilloic acid by mass spectrometry, needed also to be considered in the applied model. Ni(II) and Cd(II) slightly promoted the catalytic activity of the enzyme while Hg(II) exerted a noticeable inhibitory effect. Hg(II) and Ni(II), applied at 10 μM concentration, inhibited the growth of E. coli BL21(DE3) in M9 minimal medium in the absence of ampicillin, but addition of the antibiotic could neutralize this toxic effect by complexing the metal ions.

First report of Coniella granati causing leaf spot of pomegranate (Punica granatum L.) in Hungary

Pomegranate (Punica granatum L.), the hystoric fruit and ornamental crop native to Iran and North India is widely planted in the Mediterranean and became popular in the house gardens of northest parts of Europe (Fernandez et al. 2014) including Hungary. In August 2020 necrotic black lesions and serious defoliation were observed on 60% of 1-3 year old pomegranate trees (cv. Wonderful) in a horticultural nursery near Gödöllő, Hungary (47°36'00.9"N 19°21'26.5"E). Symptoms started as small irregular dark brown spots on the leaves, which later increased in size (2.6 ± 0.9 mm). Ultimately, the entire leaf turned yellow, defoliation resulted in damage on (6) - 8 - (15)% of the leaves. Then, black pycnidia with unicelled, elliptical to fusiform, colourless conidia (Avg. 50 conidia: 2.4 - (3.6) - 3.9 × 10.2 - (13,1) - 17.9 µm) developed on the surface. These morphological features matched those described earlier by Van Niekerk et al. (2004) and Alvarez et al. (2016) for C. granati. Conidia from pycnidia were directly transferred to potato dextrose agar (PDA) by sterile needle. The plates were incubated at 24°C in the dark. Light yellow colonies with whitish aerial mycelia and later black globose pycnidia were observed. Mass of conidia oozed from pycnidia after 15 days of incubation. Pathogenicity tests were carried out on 1-year-old potted P. granatum trees (cv. Wonderful) with 5 replicates in the greenhouse. Ten, randomly selected leaves were inoculated per plant. 7-mm mycelial plugs from the edge of 10-day-old colonies were placed directly on disinfested (2% NaOCl solution, than sterile distilled water) leaves. The plants were covered with plastic film for 3 days after inoculation (26±3°C and 87±3% relative humidity). Pathogenicity was also tested on nonwounded, surface-disinfested fruits by mycelial plugs in 3 × 3 replicates. Inoculated fruits were placed in large grass vessels for 15 days (24±2°C and 80±5% relative humidity). Uncolonized, sterile PDA plugs were used as controls in both cases. Dark brown legions developed after 9-12 days on the plants in the greenhouse. On pomegranate fruits, the fungus colonized the fruit after 7-8 days, followed by fruit rot. In some cases, after 2 weeks pycnidia developed on the skin surface. No decay were present on control leaves or fruits. The pathogen was reisolated from all infected tissues and identified as C. granati, thus fulfilling Koch's postulates. For molecular identification, total genomic DNA of the isolate was extracted from the growing margins of colonies on PDA and partial sequence of internal transcribed spacer (ITS) and translation elongation factor 1-alpha (tef1) were amplified by PCR using primers described by Alvarez et al. (2016). Sequence data of the Hungarian isolate of the ITS region (GenBank acc. no. MW581953) showed 99.8% identity (559 bp out of 560 bp) with C. granati sequences deposited in GeneBank (Acc. nos. MH860368, MH855389 and KX833582). Considering tef1 sequence of the Hungarian isolate (OM908764) obtained had complete identity with other published C. granati isolates (KX833676, KX833682). C. granati has been previously reported on pomegranate from Europe (Palou et al. 2010, Pollastro et al. 2016). Based on morphological and molecular studies, this is the first record of C. granati in Hungary. The economic importance of this disease in currently limited in Hungary due to pomegranate is rather an ornamental crop, however, the first cultivation trials have been already started. There is a risk that the spread of the pathogen began with the infected propagating material, as a result the disease may outbreak anywhere in the country.

Children-menus in restaurants of Portuguese, Hungarian and Croatian shopping centres: A qualitative study

Background

Families to eat out frequently use shopping centres and, there is evidence that children's menus are poor nutritional quality. Obesity rates have increased all over the world, and it has been associated to the observed out of home food consumption. This study aimed to characterise children's menus in shopping center restaurants in Portugal, Hungary and Croatia, as a preliminary study to further develop strategies to intervene.

Methods

An observational cross-sectional study was carried out in shopping centres in Portugal, Hungary and Croatia. Only the ones providing a children's menu were selected. Data collection tool was developed by the research team, consisting of a three-section form to identify and characterise the restaurant and analyses the quality of children's menu.

Results

Researcher visited 295 restaurants, from which only 69 provided a children's menu. From these 12 restaurants offered gifts associated with it. The most frequently featured items on the menu were hamburgers (22%), grilled or fried chicken (19%), nuggets (17%) and pizza (12%). Potato chips were the most frequent side dish option (33%). Only 11 restaurants offered vegetable soup or vegetables. Although water was available, a variety of soft drinks and sugary fruit juices were also options. Sweet dessert is a common part of the menu. Nutritional information is present in only 13% of the menus. Menu prices do not differ much, Portugal having the higher average (x ̅ = €5.35±1.45). Hungary had the lower average (x ̅ = €4.30±1.50) and Croatia the lowest range (min=€3.00, max=€7.40).

Conclusions

Children's menu options have poor quality. Shifting foods offered to children in restaurants has the potential to improve diet quality, reduce excess energy intake and promote healthy eating habits.

Key messages

European strategies are needed to promote children healthy food environment. Following aim is to develop and test balanced menus for children among food chains.

A simple molecular identification method of the Thrips tabaci (Thysanoptera: Thripidae) cryptic species complex

The onion thrips (Thrips tabaci Lindeman, 1889) is a key pest of a wide range of crops because of its ecological attributes such as polyphagy, high reproduction rate, ability to transmit tospoviruses and resistance to insecticides. Recent studies revealed that T. tabaci is a cryptic species complex and it has three lineages (leek-associated arrhenotokous L1-biotype, leek-associated thelytokous L2-biotype and tobacco-associated arrhenotokous T-biotype), however, the adults remain indistinguishable. T. tabaci individuals were collected from different locations of Hungary to create laboratory colonies from each biotypes. Mitochondrial COI (mtCOI) region was sequenced from morphologically identified individuals. After sequence analysis SNPs were identified and used for CAPS marker development, which were suitable for distinguishing the three T. tabaci lineages. Genetic analysis of the T. tabaci species complex based on mtCOI gene confirmed the three well-known biotypes (L1, L2, T) and a new biotype because the new molecular evidence presented in this study suggests T-biotype of T. tabaci forming two distinct (sub)clades (T1 and T2). This genetic finding indicates that the genetic variability of T. tabaci populations is still not fully mapped. We validated our developed marker on thrips individuals from our thrips colonies. The results demonstrated that the new marker effectively identifies the different T. tabaci biotypes. We believe that our reliable genotyping method will be useful in further studies focusing on T. tabaci biotypes and in pest management by scanning the composition of sympatric T. tabaci populations.

Orthopaedic metallic artefact reduction algorithm facilitates CT evaluation of the urinary tract after hip prosthesis

AIM

To examine the improvement in the visualisation of bladder and ureteric pathologies next to a hip prosthesis with metallic artefact reduction for orthopaedic implants (O-MAR).

MATERIALS AND METHODS

Thirty-four patients who underwent pelvic computed tomography (CT) for non-prosthesis-related causes were enrolled retrospectively. Portal venous phase scans were reconstructed both with standard iterative reconstruction (ITR) and with O-MAR. The density of the ureters and the bladder was measured at both sides in the plane of the prosthesis. A semi-quantitative score was also used to assess visibility. The R (version 3.4.1) package was used for statistical analysis.

RESULTS

The average (μ) density of the 41 prosthesis side ureters was significantly lower on ITR images (μ=-94.76±150.48 [±SD] HU) than on O-MAR images (μ=-13.40±36.37 HU; p<0.0004). The difference between the ITR and O-MAR (μ=-138.62±182.64 versus -35.55±40.21 HU; p<0.0003) was also significant at the prosthesis side of the bladder. The visibility of the prosthesis side ureters was improved: 53.7% was obscured on ITR series compared to 4.9% on O-MAR. The visibility score was also better across all levels (p<0.001) with O-MAR. In four cases (13%), the O-MAR images significantly changed the diagnosis: in two cases ureteric stones, in one case each a bladder stone and a bladder tumour were discovered.

CONCLUSIONS

O-MAR reconstruction of CT images significantly improves the visibility of the urinary tract adjacent to metallic hip implants. Thus, O-MAR is essential for detecting ureteric and bladder pathologies in patients with a hip prosthesis.

Sleep loss and recovery after administration of drugs related to different arousal systems in rats

Sleep is homeostatically regulated suggesting a restorative function. Sleep deprivation is compensated by an increase in length and intensity of sleep. In this study, suppression of sleep was induced pharmacologically by drugs related to different arousal systems. All drugs caused non-rapid eye movement (NREM) sleep loss followed by different compensatory processes. Apomorphine caused a strong suppression of sleep followed by an intense recovery. In the case of fluoxetine and eserine, recovery of NREM sleep was completed by the end of the light phase due to the biphasic pattern demonstrated for these drugs first in the present experiments. Yohimbine caused a long-lasting suppression of NREM sleep, indicating that either the noradrenergic system has the utmost strength among the examined systems, or that restorative functions occurring normally during NREM sleep were not blocked. Arousal systems are involved in the regulation of various wakefulness-related functions, such as locomotion and food intake. Therefore, it can be hypothesized that activation of the different systems results in qualitatively different waking states which might affect subsequent sleep differently. These differences might give some insight into the homeostatic function of sleep in which the dopaminergic and noradrenergic systems may play a more important role than previously suggested.

Toward the Full Quantum Dynamical Description of Photon Induced Processes in D2. J Phys Chem A 2016;120:9411-9421. [PMID: 27934332 DOI: 10.1021/acs.jpca.6b09623]

The dissociative ionization (multiphoton regime) of the D₂⁺ ion by ultrashort laser pulses has been studied theoretically using ab initio calculations. The combined ionization and dissociation spectrum was explored for fixed molecular axis orientations. In accordance with previous investigations, the dominant features in the obtained joint energy spectrum were multiphoton peaks. In addition to this, in the present work, photoelectron angular distributions were analyzed as well. By performing a partial wave analysis for each multiphoton peak, we have identified the number of absorbed photons. Moreover, we also found that the angular distribution can significantly change inside a multiphoton peak as a function of electron and nuclear kinetic energy.

Mammalian meiotic silencing exhibits sexually dimorphic features

During mammalian meiotic prophase I, surveillance mechanisms exist to ensure that germ cells with defective synapsis or recombination are eliminated, thereby preventing the generation of aneuploid gametes and embryos. Meiosis in females is more error-prone than in males, and this is in part because the prophase I surveillance mechanisms are less efficient in females. A mechanistic understanding of this sexual dimorphism is currently lacking. In both sexes, asynapsed chromosomes are transcriptionally inactivated by ATR-dependent phosphorylation of histone H2AFX. This process, termed meiotic silencing, has been proposed to perform an important prophase I surveillance role. While the transcriptional effects of meiotic silencing at individual genes are well described in the male germ line, analogous studies in the female germ line have not been performed. Here we apply single- and multigene RNA fluorescence in situ hybridization (RNA FISH) to oocytes from chromosomally abnormal mouse models to uncover potential sex differences in the silencing response. Notably, we find that meiotic silencing in females is less efficient than in males. Within individual oocytes, genes located on the same asynapsed chromosome are silenced to differing extents, thereby generating mosaicism in gene expression profiles across oocyte populations. Analysis of sex-reversed XY female mice reveals that the sexual dimorphism in silencing is determined by gonadal sex rather than sex chromosome constitution. We propose that sex differences in meiotic silencing impact on the sexually dimorphic prophase I response to asynapsis.

The novel cardiac myosin activator omecamtiv mecarbil increases the calcium sensitivity of force production in isolated cardiomyocytes and skeletal muscle fibres of the rat

BACKGROUND AND PURPOSE

Omecamtiv mecarbil (OM) is a novel cardiac myosin activator drug for inotropic support in systolic heart failure. Here we have assessed the concentration-dependent mechanical effects of OM in permeabilized cardiomyocyte-sized preparations and single skeletal muscle fibres of Wistar-Kyoto rats under isometric conditions.

EXPERIMENTAL APPROACHES

Ca²⁺ -dependent active force production (F_active ), its Ca²⁺ sensitivity (pCa₅₀ ), the kinetic characteristics of Ca²⁺ -regulated activation and relaxation, and Ca²⁺ -independent passive force (F_passive ) were monitored in Triton X-100-skinned preparations with and without OM (3nM-10 μM).

KEY RESULTS

In permeabilized cardiomyocytes, OM increased the Ca²⁺ sensitivity of force production (ΔpCa₅₀ : 0.11 or 0.34 at 0.1 or 1 μM respectively). The concentration-response relationship of the Ca²⁺ sensitization was bell-shaped, with maximal effects at 0.3-1 μM OM (EC₅₀ : 0.08 ± 0.01 μM). The kinetics of force development and relaxation slowed progressively with increasing OM concentration. Moreover, OM increased F_passive in the cardiomyocytes with an apparent EC₅₀ value of 0.26 ± 0.11 μM. OM-evoked effects in the diaphragm muscle fibres with intrinsically slow kinetics were largely similar to those in cardiomyocytes, while they were less apparent in muscle fibres with fast kinetics.

CONCLUSIONS AND IMPLICATIONS

OM acted as a Ca²⁺ -sensitizing agent with a downstream mechanism of action in both cardiomyocytes and diaphragm muscle fibres. The mechanism of action of OM is connected to slowed activation-relaxation kinetics and at higher OM concentrations increased F_passive production.

Myeloperoxidase evokes substantial vasomotor responses in isolated skeletal muscle arterioles of the rat

Aims

Myeloperoxidase (MPO) catalyses the formation of a wide variety of oxidants, including hypochlorous acid (HOCl), and contributes to cardiovascular disease progression. We hypothesized that during its action MPO evokes substantial vasomotor responses.

Methods

Following exposure to MPO (1.92 mU mL⁻¹) in the presence of increasing concentrations of hydrogen peroxide (H₂O₂), changes in arteriolar diameter of isolated gracilis skeletal muscle arterioles (SMAs) and coronary arterioles (CAs) and in the isometric force in basilar arteries (BAs) of the rat were monitored.

Results

Myeloperoxidase increased vascular tone to different degrees in CAs, SMAs and BAs. The mechanism of increased vasoconstriction was studied in detail in SMAs. MPO-evoked vasoconstrictions were prevented by the MPO inhibitor 4-aminobenzhydrazide (50 μm), by endothelium removal in the SMAs. Surprisingly, the HOCl scavenger L-methionine (100 μm), the thromboxane A2 (TXA2) antagonist SQ-29548 (1 μm) or the non-specific cyclooxygenase (COX) antagonist indomethacin (1 μm) converted the MPO-evoked vasoconstrictions to pronounced vasodilations in SMAs, not seen in the presence of H₂O₂. In contrast to noradrenaline-induced vasoconstrictions, the MPO-evoked vasoconstrictions were not accompanied by significant increases in arteriolar [Ca²⁺] levels in SMAs.

Conclusion

These data showed that H₂O₂-derived HOCl to be a potent vasoconstrictor upon MPO application. HOCl activated the COX pathway, causing the synthesis and release of a TXA2-like substance to increase the Ca²⁺ sensitivity of the contractile apparatus in vascular smooth muscle cells and thereby to augment H₂O₂-evoked vasoconstrictions. Nevertheless, inhibition of the HOCl–COX–TXA2 pathway unmasked the effects of additional MPO-derived radicals with a marked vasodilatory potential in SMAs.

ORM-10103, a novel specific inhibitor of the Na+/Ca2+ exchanger, decreases early and delayed afterdepolarizations in the canine heart

BACKGROUND AND PURPOSE

At present there are no small molecule inhibitors that show strong selectivity for the Na(+) /Ca(2+) exchanger (NCX). Hence, we studied the electrophysiological effects of acute administration of ORM-10103, a new NCX inhibitor, on the NCX and L-type Ca(2+) currents and on the formation of early and delayed afterdepolarizations.

EXPERIMENTAL APPROACH

Ion currents were recorded by using a voltage clamp technique in canine single ventricular cells, and action potentials were obtained from canine and guinea pig ventricular preparations with the use of microelectrodes.

KEY RESULTS

ORM-10103 significantly reduced both the inward and outward NCX currents. Even at a high concentration (10 μM), ORM-10103 did not significantly change the L-type Ca(2+) current or the maximum rate of depolarization (dV/dtmax ), indicative of the fast inward Na(+) current. At 10 μM ORM-10103 did not affect the amplitude or the dV/dtmax of the slow response action potentials recorded from guinea pig papillary muscles, which suggests it had no effect on the L-type Ca(2+) current. ORM-10103 did not influence the Na(+) /K(+) pump or the main K(+) currents of canine ventricular myocytes, except the rapid delayed rectifier K(+) current, which was slightly diminished by the drug at 3 μM. The amplitudes of pharmacologically- induced early and delayed afterdepolarizations were significantly decreased by ORM-10103 (3 and 10 μM) in a concentration-dependent manner.

CONCLUSIONS AND IMPLICATIONS

ORM-10103 is a selective inhibitor of the NCX current and can abolish triggered arrhythmias. Hence, it has the potential to be used to prevent arrhythmogenic events.

First Report of Bacterial Bark Canker of Walnut Caused by Brenneria nigrifluens in Hungary

During August 2012, vertical oozing cankers were sporadically observed on trunks and branches of walnut trees (Juglans regia) in the city of Zánka, near Lake Balaton and other parts of Hungary including Budapest, Győr, and Tatabánya cities. Cankers were observed on trunks and branches where brownish-black exudates staining the bark appeared mainly in the summer. Isolations were performed primarily from exudates but also from infected tissues using King's medium B (KB) (3) and EMB medium (2). Colonies similar in appearance to Brenneria nigrifluens (syn.: Erwinia nigrifluens) (1,5) were isolated. The bacterium, first reported in California, was also recorded in Iran, Spain, France, and several Italian locations, on walnut trees. The bacterial strain was gram negative and did not induce a hypersensitive response on tobacco (Nicotiana tabacum L. 'White Burley') leaves. The bacterium grew at 26°C. Colonies on KB were white and non-fluorescent, but on EMB medium were a typical dark purple with metallic green sheen. The results of substrate utilization profiling using the API 20E kit (Biomérieux, Marcy l'Etoile, France) showed that the bacterium belonged to the Enterobacteriaceae. The strain was positive for citrate utilization, H₂S, and acetoin production and urease, glucose, inositol, saccharose, and arabinose reactions. Pathogenicity was tested by injecting five young healthy walnut branches on two separate 2-year-old grafted potted plants with a bacterial suspension containing 10⁷ CFU/ml. Negative controls were walnut branches injected with sterile distilled water. Branches were enclosed in plastic bags and incubated in a greenhouse under 80% shade at 26°C day and 17°C night temperatures. Three months after inoculation, necrotic lesions were observed in the inner bark and dark lines were observed in internal wood, but no external cankers were observed on inoculated branches. The negative control appeared normal. B. nigrifluens was re-isolated from lesions on inoculated branches and identified as described above; thus, Koch's postulates were fulfilled. For molecular identification of the pathogen, 16S rDNA amplification was performed using genomic DNA from strain Bn-WalnutZa-Hun1 with a universal bacterial primer set (63f and 1389r) (4). The PCR products were cloned into a pGEM T-Easy vector (Promega, Madison, WI) and transformed into Escherichia coli DH5α cells. A recombinant plasmid (2A2.5) was sequenced using M13 forward and reverse primers. The sequence was deposited in NCBI GenBank (Accession No. HF936707) and showed 99% sequence identity with a number of B. nigrifluens strains, including type strains Z96095.1, AJ233415.1, JX484740.1, JX484739.1, JX484738.1, and FJ611884.1. On the basis of the symptoms, colony morphology, biochemical tests, and 16S rDNA sequence identity, the pathogen was identified as Brenneria nigrifluens. To our knowledge, this is the first report of a natural outbreak of bacterial bark canker on walnut in Hungary and the presence of the pathogen may seriously influence in local orchards and garden production in the future. References: (1) L. Hauben et al. Appl Microbiol 21:384, 1998. (2) J. E. Holt-Harris and O. Teague. J. Infect. Dis. 18:596, 1916. (3) E. O. King et al. J. Lab. Clin. Med. 44:301, 1954. (4) A. M. Osborn et al. Environ. Microbiol. 2:39, 2000. (5) E. E. Wilson et al. Phytopathology 47:669, 1957.

Emergence of VIM-4 metallo-β-lactamase-producing Klebsiella pneumoniae ST15 clone in the Clinical Centre University of Pécs, Hungary

Since November 2009 carbapenemase-producing Klebsiella pneumoniae isolates have been detected in increasing numbers at the Clinical Centre University of Pécs. Molecular typing was performed for 102 clinical isolates originating from different time periods and various departments of the Clinical Centre. Pulsed-field gel electrophoresis revealed the predominance of a single clone (101/102), identified as sequence type ST15. PCR and sequencing showed the presence of blaCTX-M-15 and blaVIM-4 genes. The blaVIM-4 was located on a class 1 integron designated In238b. To our knowledge, this is the first description of a blaVIM-4 gene in the predominant CTX-M-15 extended spectrum β-lactamase-producing Hungarian Epidemic Clone/ST15.

Effect of particle size on the surface properties and morphology of ground flax

Flax fibers were ground with a ball-mill and four fractions with different size ranges were collected by sieving. These were tested for water sorption, degree of polymerization (DP), copper number, hydroxyl number and analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and inverse gas chromatography (IGC). Significant differences were found between the properties of the flax fiber and those of the ground versions, including fragmentation of fibers, increase of water sorption, copper number, hydroxyl number and surface O/C ratio, and decrease of DP, crystallite size and dispersive component of surface energy (γs(d)). Some parameters depended on the particle size: O/C ratio and hydroxyl number had local maxima at 315-630 μm, while γs(d) increased steadily with the decrease of particle size. These relationships were explained by fiber disintegration, destruction of waxy surface layer, exposure of cellulosic components, increase of surface area and crystalline imperfections.

Iteratively refined guide trees help improving alignment and phylogenetic inference in the mushroom family Bolbitiaceae

Reconciling traditional classifications, morphology, and the phylogenetic relationships of brown-spored agaric mushrooms has proven difficult in many groups, due to extensive convergence in morphological features. Here, we address the monophyly of the Bolbitiaceae, a family with over 700 described species and examine the higher-level relationships within the family using a newly constructed multilocus dataset (ITS, nrLSU rDNA and EF1-alpha). We tested whether the fast-evolving Internal Transcribed Spacer (ITS) sequences can be accurately aligned across the family, by comparing the outcome of two iterative alignment refining approaches (an automated and a manual) and various indel-treatment strategies. We used PRANK to align sequences in both cases. Our results suggest that--although PRANK successfully evades overmatching of gapped sites, referred previously to as alignment overmatching--it infers an unrealistically high number of indel events with natively generated guide-trees. This 'alignment undermatching' could be avoided by using more rigorous (e.g. ML) guide trees. The trees inferred in this study support the monophyly of the core Bolbitiaceae, with the exclusion of Panaeolus, Agrocybe, and some of the genera formerly placed in the family. Bolbitius and Conocybe were found monophyletic, however, Pholiotina and Galerella require redefinition. The phylogeny revealed that stipe coverage type is a poor predictor of phylogenetic relationships, indicating the need for a revision of the intrageneric relationships within Conocybe.

Action–Sound Coincidences Suppress Evoked Responses of the Human Auditory Cortex in EEG and MEG

The N1 auditory ERP and its magnetic counterpart (N1[m]) are suppressed when elicited by self-induced sounds. Because the N1(m) is a correlate of auditory event detection, this N1 suppression effect is generally interpreted as a reflection of the workings of an internal forward model: The forward model captures the contingency (causal relationship) between the action and the sound, and this is used to cancel the predictable sensory reafference when the action is initiated. In this study, we demonstrated in three experiments using a novel coincidence paradigm that actual contingency between actions and sounds is not a necessary condition for N1 suppression. Participants performed time interval production tasks: They pressed a key to set the boundaries of time intervals. Concurrently, but independently of keypresses, a sequence of pure tones with random onset-to-onset intervals was presented. Tones coinciding with keypresses elicited suppressed N1(m) and P2(m), suggesting that action–stimulus contiguity (temporal proximity) is sufficient to suppress sensory processing related to the detection of auditory events.

Structure-activity relationships of vanilloid receptor agonists for arteriolar TRPV1

BACKGROUND AND PURPOSE

The transient receptor potential vanilloid 1 (TRPV1) plays a role in the activation of sensory neurons by various painful stimuli and is a therapeutic target. However, functional TRPV1 that affect microvascular diameter are also expressed in peripheral arteries and we attempted to characterize this receptor.

EXPERIMENTAL APPROACH

Sensory TRPV1 activation was measured in rats by use of an eye wiping assay. Arteriolar TRPV1-mediated smooth muscle specific responses (arteriolar diameter, changes in intracellular Ca(2+)) were determined in isolated, pressurized skeletal muscle arterioles obtained from the rat and wild-type or TRPV1(-/-) mice and in canine isolated smooth muscle cells. The vascular pharmacology of the TRPV1 agonists (potency, efficacy, kinetics of action and receptor desensitization) was determined in rat isolated skeletal muscle arteries.

KEY RESULTS

Capsaicin evoked a constrictor response in isolated arteries similar to that mediated by noradrenaline, this was absent in arteries from TRPV1 knockout mice and competitively inhibited by TRPV1 antagonist AMG9810. Capsaicin increased intracellular Ca(2+) in the arteriolar wall and in isolated smooth muscle cells. The TRPV1 agonists evoked similar vascular constrictions (MSK-195 and JYL-79) or were without effect (resiniferatoxin and JYL-273), although all increased the number of responses (sensory activation) in the eye wiping assay. Maximal doses of all agonists induced complete desensitization (tachyphylaxis) of arteriolar TRPV1 (with the exception of capsaicin). Responses to the partial agonist JYL-1511 suggested 10% TRPV1 activation is sufficient to evoke vascular tachyphylaxis without sensory activation.

CONCLUSIONS AND IMPLICATIONS

Arteriolar TRPV1 have different pharmacological properties from those located on sensory neurons in the rat.

Hot spots in density fingering of exothermic autocatalytic chemical fronts

Measurements of two-dimensional (2D) temperature fields are performed by an interferometric method during density fingering of the autocatalytic chlorite-tetrathionate reaction in a Hele-Shaw cell. These measures confirm that, because of heat losses through the glass walls of the reactor, the temperature profile across the front is a pulse rather than a front. Moreover, the full 2D temperature field shows the presence in the reactive zone of hot spots where the temperature exceeds the maximum temperature measured in a stable planar front. We investigate here experimentally the increase of temperature in the hot spots when the composition of the reactants is varied to increase the exothermicity of the reaction. We back up these experimental observations by nonlinear simulations of a reaction-diffusion-convection model which show that the maximum temperature reached in the system depends on the intensity of convection.

Cardiac calmodulin kinase: a potential target for drug design

Therapeutic strategy for cardiac arrhythmias has undergone a remarkable change during the last decades. Currently implantable cardioverter defibrillator therapy is considered to be the most effective therapeutic method to treat malignant arrhythmias. Some even argue that there is no room for antiarrhythmic drug therapy in the age of implantable cardioverter defibrillators. However, in clinical practice, antiarrhythmic drug therapies are frequently needed, because implantable cardioverter defibrillators are not effective in certain types of arrhythmias (i.e. premature ventricular beats or atrial fibrillation). Furthermore, given the staggering cost of device therapy, it is economically imperative to develop alternative effective treatments. Cardiac ion channels are the target of a number of current treatment strategies, but therapies based on ion channel blockers only resulted in moderate success. Furthermore, these drugs are associated with an increased risk of proarrhythmia, systemic toxicity, and increased defibrillation threshold. In many cases, certain ion channel blockers were found to increase mortality. Other drug classes such as ßblockers, angiotensin-converting enzyme inhibitors, aldosterone antagonists, and statins appear to have proven efficacy for reducing cardiac mortality. These facts forced researchers to shift the focus of their research to molecular targets that act upstream of ion channels. One of these potential targets is calcium/calmodulin-dependent kinase II (CaMKII). Several lines of evidence converge to suggest that CaMKII inhibition may provide an effective treatment strategy for heart diseases. (1) Recent studies have elucidated that CaMKII plays a key role in modulating cardiac function and regulating hypertrophy development. (2) CaMKII activity has been found elevated in the failing hearts from human patients and animal models. (3) Inhibition of CaMKII activity has been shown to mitigate hypertrophy, prevent functional remodeling and reduce arrhythmogenic activity. In this review, we will discuss the structural and functional properties of CaMKII, the modes of its activation and the functional consequences of CaMKII activity on ion channels.

Role of Ca²+-sensitive K+ currents in controlling ventricular repolarization: possible implications for future antiarrhytmic drug therapy

Normal heart function and repolarization of the cardiac action potential (AP) is to a high extent subjective to synchronized activity of sarcolemmal K(+) channels, expressed in both ventricular and atrial myocardium, largely contributing to regulation of the resting potential, the pacemaker activity, and the shape and duration of the AP. Clinical observations and experimental studies in cardiomyocytes and multicellular preparations provided firm evidence for the sensitivity of some major outward K+ currents and the corresponding ion channels to shifts in intracellular Ca(2+) concentration ([Ca(2+)](i)). Direct regulation via interaction between [Ca(2+ )](i) and the channel protein or indirect modulation via Ca(2+ ) signaling pathways of these currents have strong implications to mechanical and electrical performance of the heart, and its physiological adaptation to altered load. It may also lead to severe cardiac dysfunction, if [Ca(2+ )](i) handling is disturbed in a variety of pathological conditions. In this review we attempt to summarize the present state of the topic on two ubiquitous repolarizing K(+) currents (I(to1) and I(K1)) with documented Ca(2+)-sensitivity and critical significance in cellular antiarrhythmic defense, to highlight fields where clue data are missing, and discuss the apparently unsolved "mystery" of the cardiac small conductance Ca(2+ )-activated K(+ ) (SK) channels. We have collected the available information on the known novel, although usually still not enough selective inhibitors and activators of these currents justifying the need for more selective ones. Finally, we emphasize a few related therapeutical perspectives to be considered for future experimental research and particularly in pharmaceutical development.

Dissemination of ST274 Klebsiella pneumoniae epidemic clone in newborn and adult hospital settings harbouring SHV-2A or CTX-M-15 type extended spectrum β-lactamases-producing known plasmids

Molecular epidemiology and genetic features of an extended-spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae epidemic clone (KP-EC) with elevated ciprofloxacin MIC (minimum inhibitory concentration) values from multiple nosocomial outbreaks and sporadic cases between 2006 and 2008 in Hungary were investigated. As a result of continuous monitoring of ESBL-producing KP-ECs, 27 isolates collected from five healthcare facilities were selected for macrorestriction profile analysis by PFGE (pulsed field gel electrophoresis). Of these, 12 strains were isolated from adult inpatients, while 15 strains were from newborns. The MIC values for several antibiotics were determined by agar dilution technique. Molecular typing was further performed by PCR (polymerase chain reaction) and sequencing of several antibiotic resistance genes, plasmid profile analysis, transfer of resistance determinants and multilocus sequence typing (MLST). All isolates showed moderate resistance to ciprofloxacin (MICs ranged from 0.5 to 8 mg L(-1)). PFGE revealed the existence of only one genetic cluster defined as EC IV. PstI digestion of plasmid DNA revealed two highly diverse restriction patterns in "adult" and "newborn" isolates corresponding to plasmids from the Hungarian Epidemic Clone and plasmids isolated from a neonatal nosocomial outbreak in 1998, respectively. Sequence analysis of β-lactamase genes from plasmids of 14 selected isolates detected bla SHV-2a in strains isolated exclusively from newborns and bla CTX-M-15 in strains isolated exclusively from adult inpatients. MLST established that strains of the PFGE cluster belonged to a novel sequence type ST274. ESBL-producing K. pneumoniae isolates belonging to the novel sequence type ST274 appeared in the newborn and adult hospital settings in Hungary and acquired SHV-2a or CTX-M-15 type enzymes, respectively. Thus, a new antimicrobial resistance strategy for successful conformation to distinct hospital settings was found.

Insertion/deletion polymorphism of the angiotensin-converting enzyme predicts left ventricular hypertrophy after renal transplantation

BACKGROUND

Kidney transplant recipients show a higher risk for cardiovascular complications, such as left ventricular hypertrophy and heart failure, leading to the premature death in many cases.

METHODS

We investigated the contribution of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism to the development of left ventricular hypertrophy (LVH), an indicator of heart disease progression among kidney transplant recipients.

RESULTS

We observed a significant correlation between graft function and left ventricular mass index. The occurrence of LVH or severe LVH was significantly greater among patients with at least one D-allele (ID or DD).

CONCLUSION

The use of ACE inhibitors or angiotensin receptor blockers seemed to be advantageous for patients with the ID and especially, the DD genotype.

Insertion/Deletion polymorphism of Angiotensin-converting enzyme as a risk factor for chronic allograft nephropathy

Angiotensin-converting enzyme (ACE) inhibitor therapy is widely used to treat chronic allograft nephropathy (CAN), which suggests a possible role of the renin-angiotensin system in the pathologic mechanism of the disease. The objective of this study was to investigate the possible link between CAN and ACE. The ACE insertion/deletion polymorphism and the amount and activity of ACE were determined in cadaver kidney recipients with CAN (n = 38) or normal renal function (n = 34). The DD genotype was observed significantly more frequently in the CAN group compared with the group with normal renal function. Moreover, the DD genotype was associated with a higher serum ACE concentration and greater serum ACE activity, compared with II genotype homozygotes. The insertion/deletion polymorphism of ACE affects ACE expression and activity in serum, and, therefore, may have an important role in the pathogenesis of CAN. These findings suggest that determination of the ACE genotype may be useful in identifying patients at high risk. In particular, the DD genotype may be considered an indication for ACE inhibitor therapy.

The role of cardiovascular magnetic resonance imaging in cardiac resynchronisation therapy

Cardiac electromechanical resynchronisation therapy (CRT) is an effective non-pharmacological treatment of patients suffering from drug refractory heart failure. However, approximately 20–30% of patients are non-responder. Cardiac magnetic resonance imaging (CMR) may play significant role in clarifying many questions in this patient population. Forty-five patients, suffering from severe drug refractory heart failure, underwent CMR before applying CRT. Left ventricular end-diastolic, end-systolic volumes, ejection fraction, myocardial mass, wall motion disturbances, localisation of non-viable myocardium were determined. Left ventricular dyssynchrony was determined by illustrating wall-time thickening in short-axis slices of left ventricle from basis to apex. CMR-proved underlying heart disease were postinfarction heart failure, dilated cardiomyopathy and non-compaction cardiomyopathy in 62, 27 and in 11%, respectively. Mean left ventricular ejection fraction was 24.5±10%, intraventricular dyssynchrony was 200±78 ms. In four patients, requiring surgical revascularisation after unsuccessful coronary sinus electrode implantation, optimal position for epicardial screw-in electrode was selected. According to the results of CMR, biventricular device was not implanted in 7 patients. During the follow-up of the 38 patients, 5 patients (13.16%) were non-responders, despite the approximately 22% non-responder ratio in our whole patient population treated by CRT but without performing previous CMR examination. In this patient population CMR may have a significant role in the selection of responder patient population.

Navigating complex labyrinths: optimal paths from chemical waves

The properties of excitable media are exploited to find minimum-length paths in complex labyrinths. Optimal pathways are experimentally determined by the collection of time-lapse position information on chemical waves propagating through mazes prepared with the Belousov-Zhabotinsky reaction. The corresponding velocity fields provide maps of optimal paths from every point in an image grid to a particular target point. Collisions of waves that were temporarily separated by obstacles mark boundary lines between Significantly different paths with the same absolute distance. The pathfinding algorithm is tested in very complex mazes with a simple reaction-diffusion model.

Successful surgical restoration of a giant immature left ventricular aneurysm with computer assisted ventricle engineering

Background: Although circular ventricle resection techniques are the gold standard of left ventricle restoration, these techniques can lead to suboptimal results. Postoperative systolic resection line can be inadequate, as it must be planned on a heart stopped in diastole. The impaired geometry and contractility may lead to increased short- and long-term mortality. Moreover, postoperative low cardiac output due to insufficient left ventricular volume results in a potentially unstable condition, and cannot be corrected. Our aim was to find a preoperative method to minimize risk and maximize outcome with left ventricle restoration. Methods: We have created a novel method combining surgery with modern imaging techniques to construct a preoperative 3D systolic heart model. The model was utilized to determine resection could be intraoperatively used to create the new left ventricle. Results: The computer assisted ventricle engineering technique is described step by step through a successful aneurysmectomy of a 61-year-old female patient with a complicated giant left ventricle aneurysm. Conclusions: Using this model we are able to find the optimal resection line providing excellent postoperative result, thus minimizing the risk of low cardiac output syndrome. This is the first report of our new combined approach to left ventricle restoration.

Investigation of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae outbreaks in Hungary between 2005 and 2008

Fourteen outbreaks in Hungary between 2005 and 2008 caused by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) were epidemiologically investigated and the isolated pathogens were characterized by molecular techniques. Ten of the fourteen outbreaks occurred in adult wards and four in neonatal units affecting a total number of 73 patients. The 54% [40] of the patients developed bloodstream infections and 21.9%-21.9% [16] pneumonia and surgical site infections, respectively. The overall rate of mortality proved high: 36.9% [27]. Outbreaks in adults affected more patients, had higher attack rates, were more prolonged in duration and had a 6.9-fold higher mortality rate than outbreaks observed in neonates. The outbreaks in neonates were caused by SHV-type ESBL-producing klebsiellae, while in the "adult outbreaks" exclusively CTX-M-type ESBL-KP strains were involved. While the outbreak strains isolated from neonatal units could be assigned to a variety of pulsotypes, the previously described K. pneumoniae epidemic clones, ST15 and ST147, could be identified among the pathogens causing outbreaks in adult units.

Precipitation pattern formation in the copper(II) oxalate system with gravity flow and axial symmetry

Chemical systems that are far from thermodynamic equilibrium may form complex temporal and spatiotemporal structures. In our paper, we present unusual precipitation patterns that have been observed in the system of Cu(II)-oxalate. Starting with a pellet of copper sulfate immersed in or by pumping copper sulfate solution into a horizontal layer of sodium oxalate solution, we have observed the formation of a precipitate ring and an array of radially oriented thin fingers. The development of these patterns is related to the internal structure of the different crystals, the gravity flow, and the circular symmetry of the experimental arrangement.

Risk factors and outcomes for bloodstream infections with extended-spectrum beta -lactamase-producing Klebsiella pneumoniae ; Findings of the nosocomial surveillance system in Hungary

Risk factors for and outcomes of bloodstream infections (BSIs) caused by ESBL-producing and by ESBL-non-producing Klebsiella pneumoniae were compared in a four-year multicenter study in Hungary. One hundred ESBL-positive and one hundred ESBL-negative patients were included as cases and controls. Investigated risk factors were related to demographics, comorbid conditions, treatments, invasive procedures, surgery prior bacteremia, presence of additional nosocomial infections and preceding hospital admission within a year. Measured outcomes were crude mortality, mortality related to infection and delay in introducing appropriate therapy (DAT). Though some risk factors for infection (admission to intensive care units, having central venous and/or urinary catheter, mechanical ventilation) were shared by both groups, in other respects cases and controls were found to differ substantially. The 36 percent of patients with BSIs with ESBL-producing Klebsiella died versus 23 percent of controls (odds ratio [OR]: 2.5; 95% confidence interval [CI]: 1.0-5.4; p = 0.02). The 18 percent of deaths in cases versus 9% in controls could be attributed to infection (OR: 5.0; 95% CI: 1.5-16.2; p = 0.006). Cases more often received previous antibiotic therapy than controls (OR: 2.7; 95% CI: 1.1-6.7; p = 0.02) and delay in the introduction of appropriate antibiotic treatment was observed in 44% of cases versus 19% of controls (OR: 3.4; 95% CI: 1.6-7.3; p = 0.001). The results demonstrate that BSIs caused by ESBL-producing K. pneumoniae are related to previous antibiotic therapy and are associated with a high rate of mortality that is often linked to delay in the introduction of appropriate antibiotic therapy. This confirms that besides infection control measures the early identification and antibiotic resistance profiling of the infecting pathogen is salient in the control of BSIs caused by ESBL-producing K. pneumoniae .

Influence of thermal effects on buoyancy-driven convection around autocatalytic chemical fronts propagating horizontally

The spatiotemporal dynamics of vertical autocatalytic fronts traveling horizontally in thin solution layers closed to the air can be influenced by buoyancy-driven convection induced by density gradients across the front. We perform here a combined experimental and theoretical study of the competition between solutal and thermal effects on such convection. Experimentally, we focus on the antagonistic chlorite-tetrathionate reaction for which solutal and thermal contributions to the density jump across the front have opposite signs. We show that in isothermal conditions the heavier products sink below the lighter reactants, providing an asymptotic constant finger shape deformation of the front by convection. When thermal effects are present, the hotter products, on the contrary, climb above the reactants for strongly exothermic conditions. These various observations as well as the influence of the relative weight of the solutal and thermal effects and of the thickness of the solution layer on the dynamics are discussed in terms of a two-dimensional reaction-diffusion-convection model parametrized by a solutal R(C) and a thermal R(T) Rayleigh number.