Investigating the Effect of Contextual Cueing with Face Stimuli on Electrophysiological Measures in Younger and Older Adults

Extracting repeated patterns from our surroundings plays a crucial role in contextualizing information, making predictions, and guiding our behavior implicitly. Previous research showed that contextual cueing enhances visual search performance in younger adults. In this study, we investigated whether contextual cueing could also improve older adults' performance and whether age-related differences in the neural processes underlying implicit contextual learning could be detected. Twenty-four younger and 25 older participants performed a visual search task with contextual cueing. Contextual information was generated using repeated face configurations alongside random new configurations. We measured RT difference between new and repeated configurations; ERPs to uncover the neural processes underlying contextual cueing for early (N2pc), intermediate (P3b), and late (r-LRP) processes; and multiscale entropy and spectral power density analyses to examine neural dynamics. Both younger and older adults showed similar contextual cueing benefits in their visual search efficiency at the behavioral level. In addition, they showed similar patterns regarding contextual information processing: Repeated face configurations evoked decreased finer timescale entropy (1-20 msec) and higher frequency band power (13-30 Hz) compared with new configurations. However, we detected age-related differences in ERPs: Younger, but not older adults, had larger N2pc and P3b components for repeated compared with new configurations. These results suggest that contextual cueing remains intact with aging. Although attention- and target-evaluation-related ERPs differed between the age groups, the neural dynamics of contextual learning were preserved with aging, as both age groups increasingly utilized more globally grouped representations for repeated face configurations during the learning process.

Exploring the role of working memory gate opening process in creativity: An ERP study using the reference-back paradigm

We investigated the relationship between the gate opening process of working memory and an individual's proficiency in divergent (DT) and convergent thinking (CT) using the reference-back paradigm. Event-related potentials and reaction times were measured across groups with varying DT (N = 40, 27.35 ± 5.05 years) and CT levels (N = 40, 27.88 ± 4.95 years). Based on the role of striatal dopamine in supporting cognitive flexibility, which facilitates DT, and considering the significance of phasic dopamine activity as the gate opening signal originating from the basal ganglia, we assumed that the gate opening process may contribute differently to DT and CT. Despite the absence of behavioural differences in gate opening costs, distinct neural patterns emerged. In the early time windows (P1, N1), gate opening effects were detected in both DT and CT groups, with a notable interaction influenced by the level of DT, resulting in significant effects within the lower DT group. The P2 component showed a gate opening effect only in the higher DT group. In the P3 time window, the process unfolded comparably in all groups. Our results suggest that groups with different levels of convergent thinking (based on Matrix reasoning) and those with lower DT (based on Creativity Index) tend to select and activate the prefrontal cortex representation containing the required task information at an earlier stage, compared to those with better DT. This could be beneficial especially in the early phase of idea generation, as more elements become available to create associations and original ideas.

The investigation of post-thaw chilled storage and the applicability of large-scale cryopreservation in chub (Squalius cephalus) sperm

Chub (reophillic cyprinids) is one of the most sensitive bioindicator fish of environmental changes following anthropogenic activities. The improvement of different biotechnological procedures could help support its conservation and strengthen the natural populations. The aim of this study was to compare the effects of two different hormonal agents (carp pituitary extract and Ovopel™) on various motility parameters (pMOT-%, DAP-μm, VCL μm s-1, VSL-μm s-1, LIN-%, ALH-μm, BCF-Hz) of fresh and cryopreserved/thawed sperm (stored at 4 °C for 6 h). Additionally, we sought to develop a novel, large-scale cryopreservation method for chub sperm, assessing freezing methods (Styrofoam box and a controlled-rate freezer) and different containers (0.5, 5 mL straw and 4 mL cryotube) for sperm cryopreservation. The results of this study indicated no difference between the carp pituitary extract and Ovopel treated groups in either the fresh or frozen/thawed sperm (at 0, 3, 6, hour post thawing, P = 0.4351). In contrast, the quality of the thawed chub sperm was negatively affected after 3 h chilled storage in both hormonal treatments (P = 0.0036, P < 0.0001). When assessing the motility parameters of the sperm between the 5 mL straw and 4 mL cryotube groups cryopreserved in a Styrofoam Box, no difference was observed (P = 0.103). Additionally, sperm loaded in 4 mL cryotubes showed no difference in motility when cryopreserved with either the Styrofoam box or controlled-rate freezer methods (P = 0.109). A similar hatching rate was observed in sperm preserved using the Styrofoam box (35 ± 7 %) and controlled rate freezer (25 ± 9 %) methods (P = 0.300). In a second fertilization trial, hatching rate was similar between control (72 ± 19 %) and cryopreserved (4 mL cryotube and Styrofoam box, 61 ± 5 %) groups. (P = 0.257). Based on our findings and its standard features (less species specific, precise dose calculation), Ovopel can be a good candidate for the stimulation of spermiation in chub sperm prior to cryopreservation. Furthermore, our study presents a novel and applicable method for the large-scale cryopreservation of chub sperm.

Mechanisms of spatial contextual cueing in younger and older adults

The contextual cueing effect is the phenomenon observed when response time (RT) becomes faster in visual search in repeated context compared with a new one. In the present study, we explored whether the mechanisms involved in the effect are age dependent. We investigated it in younger (N = 20, 12 women, 21.2 ± 1.75 years) and older (N = 19, nine women, 67.05 ± 3.94 years) adults. We found a faster target identification in the repeated configurations with similar magnitude in the two age groups, which indicates that this contextual cueing effect remained intact even in the older participants. To shed light on the underlying mechanisms, we measured and compared the amplitude of three event-related potentials: N2pc, P3, and response-locked LRP. In the younger group, the larger contextual cueing effect (novel-minus-repeated RT difference) correlated positively with a larger difference in amplitude for repeated compared with novel configurations for both the N2pc and the P3 components, but there was no correlation with the response-locked lateralized readiness potential (rLRP) amplitude difference. However, in the older group, only the rLRP amplitude difference between novel and repeated configurations showed an enhancement with larger contextual cueing. These results suggest that different mechanisms are responsible for the contextual effect in the two age groups. It has both an early and an intermediate locus in younger adults: effective attentional allocation and successful stimulus categorization, or decision-making confidence are involved; while in older adults, a late locus was identified: a more efficient response organization led to a faster reaction.

Investigating the involvement of cognitive control processes in innovative and adaptive creativity and their age-related changes

Introduction

Based on the two-factor model of creativity, two distinct types of creative problem solving can be differentiated: innovative ("do things differently") and adaptive ("do things better"). Flexible cognitive control is a crucial concept in connection with both general and specific styles of creativity: innovative problem-solving benefits from broader attention and flexible mental set shifting; while adaptive creativity relies on focused attention and persistent goal-oriented processes. We applied an informatively cued task-switching paradigm which is suitable for measuring different cognitive control processes and mechanisms like proactive and reactive control. We hypothesized that adaptive creativity is connected to effective proactive control processes, while innovative creativity is based on reactive task-execution. As we have found no previous evidence how age-related changes in cognitive control affects creative cognition; we also examined the effect of healthy aging on different problem-solving styles in an explorative way.

Methods

Our participants, 37 younger (18-30 years) and 37 older (60-75 years) adults, were divided into innovative and adaptive creative groups according to the Torrance Test of Creative Thinking's Figural Subtest (Hungarian version).

Results

Our results showed that among younger adults the adaptively creative group had larger cue-locked CNV component (effective preparatory activity connected to proactive control), while the innovatively creative group had a larger target-locked P3b component (effective target evaluation and categorization in line with reactive control) which supports a functional difference in the two creative styles. By contrast, in older adults innovative problem-solving showed larger mixing costs (less effective maintenance and selection of task sets), and the lack of trial type effect on target-locked N2b (target-induced goal reactivation and less effective conflict resolution); while adaptive problem-solving caused them to make fewer errors (accuracy-oriented behavior).

Discussion

All in all, innovative and adaptive creativity is based on distinct cognitive control mechanisms in both age-groups, but their processing level is affected by age-related changes.

Does Creativity Influence Visual Perception? - An Event-Related Potential Study With Younger and Older Adults

We do not know enough about the cognitive background of creativity despite its significance. Using an active oddball paradigm with unambiguous and ambiguous portrait paintings as the standard stimuli, our aim was to examine whether: creativity in the figural domain influences the perception of visual stimuli; any stages of visual processing; or if healthy aging has an effect on these processes. We investigated event related potentials (ERPs) and applied ERP decoding analyses in four groups: younger less creative; younger creative; older less creative; and older creative adults. The early visual processing did not differ between creativity groups. In the later ERP stages the amplitude for the creative compared with the less creative groups was larger between 300 and 500 ms. The stimuli types were clearly distinguishable: within the 300–500 ms range the amplitude was larger for ambiguous rather than unambiguous paintings, but this difference in the traditional ERP analysis was only observable in the younger, not elderly groups, who also had this difference when using decoding analysis. Our results could not prove that visual creativity influences the early stage of perception, but showed creativity had an effect on stimulus processing in the 300–500 ms range, in indexing differences in top-down control, and having more flexible cognitive control in the younger creative group.

Older Adults Automatically Detect Age of Older Adults' Photographs: A Visual Mismatch Negativity Study

The human face is one of the most frequently used stimuli in vMMN (visual mismatch negativity) research. Previous studies showed that vMMN is sensitive to facial emotions and gender, but investigations of age-related vMMN differences are relatively rare. The aim of this study was to investigate whether the models' age in photographs were automatically detected, even if the photographs were not parts of the ongoing task. Furthermore, we investigated age-related differences, and the possibility of different sensitivity to photographs of participants' own versus different ages. We recorded event-related potentials (ERPs) to faces of young and old models in younger (N = 20; 18-30 years) and older groups (N = 20; 60-75 years). The faces appeared around the location of the field of a tracking task. In sequences the young or the old faces were either frequent (standards) or infrequent (deviants). According to the results, a regular sequence of models' age is automatically registered, and faces violating the models' age elicited the vMMN component. However, in this study vMMN emerged only in the older group to same-age deviants. This finding is explained by the less effective inhibition of irrelevant stimuli in the elderly, and corresponds to own-age bias effect of recognition studies.

Older Adults Encode Task-Irrelevant Stimuli, but Can This Side-Effect be Useful to Them?

We studied whether, due to deteriorating inhibitory functions, older people are more likely to process irrelevant stimuli; and if so, could they later use this information better than young adults. In the study phase of our experiment, a Posner-type gaze-cued version of a Simon task was performed in which we presented task-irrelevant cues, where faces or patches with either left- or right-looking dots for the pupil of the eye preceded the task to press a button congruent or incongruent with the presentation side of the target stimulus. In the follow-up test phase, participants completed an unexpected facial recognition test. In the study phase not only a decreased P1, but also an increased N170 amplitude of the event-related potentials (ERPs) were found in older, compared to younger adults, and also for faces compared to patches. Even though in the test phase both age-groups could recognize the faces better than statistically by chance, neither the older nor the younger participants could discriminate them effectively. The late positive component (LPC)—the ERP correlates of the old/new effect, being the higher amplitude for the earlier presented stimuli when compared with the unseen stimuli during the recognition test—was not evolved in the older group, while a reversed old/new effect was seen in younger participants: higher amplitude was found in New-Right and Old-Wrong conditions (for faces they did not recognize independent of seeing them before) compared to Old-Right and New-Wrong conditions (for faces they thought they recognized from the study phase). In conclusion, although older adults showed enhanced processing of task-irrelevant stimuli compared to younger adults, as indicated by the N170 amplitude, however, they were not able to utilize this information in a later task, as was suggested by the recognition rate and LPC amplitude results.

Age Effects on Distraction in a Visual Task Requiring Fast Reactions: An Event-Related Potential Study

We investigated the effects of distractors in older and younger participants in choice and simple reaction time tasks with concurrent registration of event-related potentials. In the task the participants had to prevent a disk from falling into a bin after a color or luminosity change (target stimuli). Infrequently, task-irrelevant stimuli (schematic faces or threatening objects) were superimposed on the target stimuli (distractors), or the bin disappeared which required no response (Nogo trials). Reaction time was delayed to the distractors, but this effect was similar in the two age groups. As a robust age-related difference, in the older group a large anterior positivity and posterior negativity emerged to the distractors within the 100-200 ms post-stimulus range, and these components were larger for schematic faces than for threatening objects. sLORETA localized the age-specific effect to the ventral stream of the visual system and to anterior structures considered as parts of the executive system. The Nogo stimuli elicited a late positivity (Nogo P3) with longer latency in the older group. We interpreted the age-related differences as decreased but compensated resistance to task-irrelevant change of the target stimuli.

The effect of hand motion and object orientation on the automatic detection of orientation: A visual mismatch negativity study

We investigated the effects of voluntary hand movements and continuously present objects on the automatic detection of deviant stimuli in a passive oddball paradigm. The visual mismatch negativity (vMMN) component of event-related potentials (ERPs) was measured as the index of automatic deviant detection. The stimuli were textures consisting of parallel, oblique bars with frequent (standard) and infrequent (deviant) orientation. Traditional vMMN was measured by the difference between ERPs to frequent (standard) and infrequent (deviant) textures. Additionally, we measured 'genuine' vMMN by comparing the ERPs to deviant and control textures in the equal probability procedure. Compatible and incompatible hand movement directions to the standard texture had no influence on 'traditional' vMMN and elicited no 'genuine' vMMN. However, the deviant texture elicited 'genuine' vMMN if the orientation of a continuously present rectangle was different from the standard (and identical to the deviant) texture orientation. Our results suggest that the direction of voluntary hand movement and the orientation of task-irrelevant visual patterns do not acquire common memory representation, but a continuously present object contributes to the detection of sequential regularity violation.

Cost-effectiveness analysis of low-dose computed tomography screening for lung cancer in Hungary

Background

Hungary has the highest incidence of lung cancer in the world (GLOBOCAN, 2018). Since lung cancer is rarely treatable in its advanced stage, one possible way to reduce mortality is early diagnosis and subsequent treatment. The possibility and necessity of introducing low-dose computed tomography (LDCT) lung cancer screening as a public health programme is a current and relevant health policy issue.

Methods

A Markov cohort model was built to assess the cost-effectiveness of such a risk group screening programme in Hungary. The model was populated with transition probabilities and resource utilization data derived from the HUNCHEST Hungarian lung cancer screening trial. The model results are presented in incremental cost-effectiveness ratio.

Results

A closed cohort of 10,000 smokers with the average starting age of 59 years was followed over life-time horizon and screened for lung cancer annually until the age of 74. Compared to the current scenario of no organized lung cancer screening in Hungary, the model resulted in an additional 0.1614 life-year gained per individual and an additional 0.2924 disease-free life-year gained per individual with annual screening frequency. The incremental cost-effectiveness ratio was EUR 608 indicating that assessed intervention is cost-effective in the analyzed setting. Sensitivity analyses confirmed the robustness of the model results.

Conclusions

Results suggest that introducing low-dose computed tomography screening for lung cancer is a cost-effective intervention in Hungary. Considering the exceptionally high incidence and mortality of lung cancer in Hungary, the population could benefit from such a risk group screening programme.

Key messages

Low-dose computed tomography screening for lung cancer is cost-effectiveness in the Hungarian setting. Policy makers are encouraged to consider the introduction of a risk group screening programme.

Application of hydroxypropyl methylcellulose as a protective agent against magnesium stearate induced crystallization of amorphous itraconazole

Itraconazole is a fungicide drug which has low bioavailability due to its poor water solubility. Amorphous solid dispersion (ASD) is a tool that has the potential to greatly increase the dissolution rate and extent of compounds. In this work, the dissolution of tablets containing the ASD of itraconazole with either hydroxypropyl methylcellulose (HPMC) or vinylpyrrolidone-vinyl acetate copolymer (PVPVA) was compared in order to find a formulation which can prevent the drug from the precipitation caused by magnesium stearate. Formulations containing the PVPVA-based ASD with HPMC included in various forms could reach 90% dissolution in 2 h, while HPMC-based ASDs could release 100% of the drug. However, HPMC-based ASD had remarkably poor grindability and low bulk density, which limited its processability and applicability. The latter issue could be resolved by roller compacting the ASD, which significantly increases the bulk density and the flowability of the powder blends used for tableting. This roller compaction step might be a base for the industrial application of HPMC-based, electrospun ASDs.

Note: 4-bounce neutron polarizer for reflectometry applications

A neutron polarizer using four successive reflections on m = 2.5 supermirrors was built and installed at the GINA neutron reflectometer at the Budapest Neutron Centre. This simple setup exhibits 99.6% polarizing efficiency with 80% transmitted intensity of the selected polarization state. Due to the geometry, the higher harmonics in the incident beam are filtered out, while the optical axis of the beam remains intact for easy mounting and dismounting the device in an existing experimental setup.

Investigation of Deteriorated Dissolution of Amorphous Itraconazole: Description of Incompatibility with Magnesium Stearate and Possible Solutions

Disadvantageous crystallization phenomenon of amorphous itraconazole (ITR) occurring in the course of dissolution process was investigated in this work. A perfectly amorphous form (solid dispersion) of the drug was generated by the electroblowing method (with vinylpyrrolidone-vinyl acetate copolymer), and the obtained fibers were formulated into tablets. Incomplete dissolution of the tablets was noticed under the circumstances of the standard dissolution test, after which a precipitated material could be filtered. The filtrate consisted of ITR and stearic acid since no magnesium content was detectable in it. In parallel with dissolution, ITR forms an insoluble associate, stabilized by hydrogen bonding, with stearic acid deriving from magnesium stearate. This is why dissolution curves do not have the plateaus at 100%. Two ways are viable to tackle this issue: change the lubricant (with sodium stearyl fumarate >95% dissolution can be accomplished) or alter the polymer in the solid dispersion to a type being able to form hydrogen bonds with ITR (e.g., hydroxypropyl methylcellulose). This work draws attention to one possible phenomenon that can lead to a deterioration of originally good dissolution of an amorphous solid dispersion.

Food and water intake, body temperature and metabolic consequences of interleukin-1β microinjection into the cingulate cortex of the rat

In order to elucidate whether cytokine mechanisms of the cingulate cortex (cctx) are important in the central regulation of homeostasis, in the present study, feeding-metabolic effects of direct bilateral microinjection of interleukin-1β (IL-1β) into the cctx of the rat have been investigated. Short- (2h), medium (12h) and long-term (24h) food and water intakes and body temperature were measured after the intracerebral administration of this primary cytokine or vehicle solution, with or without paracetamol pretreatment. The effect of IL-1β on the blood glucose level of animals was examined in glucose tolerance test (GTT), and concentrations of relevant plasma metabolites (total cholesterol, HDL, LDH, triglycerides, uric acid) were additionally also determined following the above microinjections. In contrast to causing no major alteration in the food and water intakes, the cytokine treatment evoked significant increase in the body temperature of the rats. Prostaglandin-mediated mechanisms were shown to have important role in the mode of this action of IL-1β, since paracetamol pretreatment partially prevented the development of the above mentioned hyperthermia. In the GTT, no considerable difference was observed between the blood glucose levels of the cytokine treated and control animals. Following IL-1β microinjection, however, significant decrease of HDL and total cholesterol was found. Our present findings indicate that elucidating the IL-1β mediated homeostatic control mechanisms in the cingulate cortex may lead to the better understanding not only the regulatory entities of the healthy organism but also those found in obesity, diabetes mellitus and other worldwide rapidly spreading feeding-metabolic disorders.

Adipokines as atherothrombotic risk factors in obese subjects: Associations with haemostatic markers and common carotid wall thickness

BACKGROUND AND AIMS

Some crucial associations between obesity-related altered adipokine levels and the main factors of atherosclerotic, atherothrombotic processes are not fully known. We analysed the relationships of classic adipokines, namely leptin, resistin, adiponectin, tumour necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) with the markers of platelet activation, including mean platelet volume (MPV), platelet surface/soluble P-selectin, platelet-derived microparticles (PMPs), the parameters of coagulation abnormalities and common carotid intima-media thickness (IMT) in obese patients with or without atherosclerotic comorbidities in comparison to age- and sex-matched controls.

METHODS AND RESULTS

We enrolled 154 obese individuals, including 98 suffering from atherosclerotic concomitant conditions, 56 free of atherosclerotic comorbidities and 62 healthy controls. Plasma levels of leptin, resistin, adiponectin, TNF-α, IL-6, soluble P-selectin, and plasminogen activator inhibitor-1 antigen (PAI-1 ag) were analysed by ELISA. Platelet surface P-selectin and PMPs were measured by flow cytometry. IMT was detected by ultrasonography. Adipokines were closely associated with markers of platelet hyperactivity, hypercoagulability, hypofibrinolysis and IMT. Significant independent associations were found between leptin and platelet count (p < 0.0001), MPV (p = 0.019), PMPs (p < 0.0001), fibrinogen (p = 0.001), factor VIII (FVIII) activity (p = 0.035); adiponectin and PAI-1 ag (p = 0.035); resistin and soluble P-selectin (p = 0.002); TNF-α and PAI-1 ag (p < 0.0001); and IL-6 and fibrinogen (p = 0.011). Finally, leptin (p = 0.0005), adiponectin (p = 0.019), IL-6 (p = 0.001), MPV (p = 0.0003), PMP (p = 0.008), and FVIII activity (p = 0.043) were independent predictors of IMT.

CONCLUSION

Overall, we suggest that in obese subjects altered adipokine levels play a key role in common carotid atherosclerosis both directly and through haemostatic parameters.

Impaired glucose tolerance after streptozotocin microinjection into the mediodorsal prefrontal cortex of the rat

The mediodorsal prefrontal cortex (mdPFC) is a key structure of the central glucose-monitoring (GM) neural network. Previous studies indicate that intracerebral streptozotocin (STZ) microinjection-induced destruction of local chemosensory neurons results in feeding and metabolic alterations. The present experiments aimed to examine whether STZ microinjection into the mdPFC causes metabolic deficits. To do so, glucose tolerance test (GTT) and measurements of plasma metabolites were performed in STZ-treated or control rats. Intraperitoneal D-glucose load was delivered 20 min or 4 weeks following the intracerebral microinjection of STZ or saline (acute or subacute GTT, respectively). The STZ-treated rats displayed acute glucose intolerance: at the 120th min of the test, blood glucose level of these rats was significantly higher than that of the ones in the control group. When determining the plasma level of various metabolites, 30 min following the intracerebral STZ or saline microinjection, the triglyceride concentration of the STZ-treated rats was found to be reduced compared with that of the control rats. The GM neurons of the mdPFC are suggested to be involved in the organization of complex metabolic processes by which these chemosensory cells contribute to adaptive control mechanisms of the maintenance of homeostasis.

Genetic Changes in Sporadic Keratocystic Odontogenic Tumors (Odontogenic Keratocysts)

Little is known about the genetic background of keratocystic odontogenic tumors (KCOT, odontogenic keratocysts). Our aim was to characterize genomic aberrations in sporadic KCOT using cDNA-expression arrays and array-comparative genomic hybridization. For cDNA-expression arrays, 10 KCOT specimens and 20 fetal tooth germs were studied. Quantitative real-time reverse-transcription/polymerase chain-reaction and immunohistochemical studies were also undertaken. Several genes were over-expressed in 12q13, including cytokeratin 6B ( KRT6B) (≈ 10-fold), epidermal growth factor receptor ERBB3 (~ 4.7-fold), and glioma-associated oncogene homologue 1 ( GLI1) (~ 5- to 12-fold). One amplicon (~ 0.7 Mega base pairs [Mbp]), covering several genes involved in the regulation of cell growth, was found in 12q13.2. Deletions were found in 3q13.1, 5p14.3, and 7q31.3, including the cell-adhesion-related gene cadherin 18 ( CDH18) and leukocyte cell adhesion molecule ( ALCAM, MEMD). Over-expressed and amplified genes in 12q13, also reported in several other tumors and cell lines, may contribute to the persistent growth characteristics of KCOT.

Plasma E-selectin levels can play a role in the development of diabetic retinopathy

PURPOSE

Diabetic retinopathy is one of the leading causes of blindness. There are several risk factors, such as the duration of diabetes or glycemic control of the patient; however, several biochemical factors also alter the process. Our aim was to investigate the role of soluble E-selectin in the formation of diabetic retinopathy.

PATIENTS AND METHODS

Fifty-seven patients (37 female and 20 male, aged 61.71 ± 12.31 years) and 14 healthy control subjects (ten female and four male, aged 63.06 ± 10.46 years) were enrolled in the study. We measured the soluble E-selectin level in the plasma of patients by ELISA. All patients underwent careful ophthalmological examination, including ophthalmoscopy and color fundus photography, while diabetic retinopathy grading was performed in line with the 2012 classification of the American Academy of Ophthalmology (AAO).

RESULTS

The soluble E-selectin level was significantly higher in patients with diabetes compared to controls (32.95 ng/ml vs. 26.55 ng/ml, p = 0.03). Dividing patients into groups by the presence of retinopathy, the E-selectin level was also significantly higher in the retinopathy group (p < 0.05). When we examined diabetic patients by the severity of retinopathy (groups A, B, and C, by the guidelines of the AAO), however, we did not find any significant difference in soluble E-selectin levels, although it tended to be higher in group B.

CONCLUSIONS

An elevated E-selectin level can play a role in the development of diabetic retinopathy, but it does not seem to alter disease severity. However, glycemic control and the reduction of cardiovascular risk factors may also alter the level of E-selectin that might play a role in the prevention of diabetic retinopathy.

Virulence and antimicrobial resistance determinants of verotoxigenic Escherichia coli (VTEC) and of multidrug-resistant E. coli from foods of animal origin illegally imported to the EU by flight passengers

The aim of this study was to reveal phenotype/genotype characteristics of verotoxigenic Escherichia coli (VTEC) and multidrug resistant E. coli in food products of animal origin confiscated as illegal import at Austrian, German and Slovenian airports. VTEC isolates were obtained by using ISO guidelines 16654:2001 for O157 VTEC or ISO/ TS13136:2012 for non-O157 VTEC, with additional use of the RIDASCREEN® Verotoxin immunoassay. The testing of 1526 samples resulted in 15 VTEC isolates (1.0%) primarily isolated from hard cheese from Turkey and Balkan countries. Genotyping for virulence by using a miniaturized microarray identified a wide range of virulence determinants. One VTEC isolate (O26:H46) possessing intimin (eae) and all other essential genes of Locus of Enterocyte Effacement (LEE) was designated as enterohemorrhagic E. coli (EHEC). None of the other VTEC strains belonged to serogroups O157, O145, O111, O104 or O103. VTEC strains harbored either stx(1) (variants stx1(a) or stx(1c)) or st(x2) (variants stx(2a), stx(2b), stx(2a/d) or stx(2c/d)) genes. Pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) demonstrated high genetic diversity and identified three new sequence types (STs): 4505, 4506 and 4507. Food samples collected from the Vienna airport were also tested for E. coli quantities using the ISO 16649:2001, and for detection of multidrug resistant phenotypes and genotypes. The resulting 113 commensal E. coli isolates were first tested in a pre-screening against 6 selected antimicrobials to demonstrate multidrug resistance. The resulting 14 multidrug resistant (MDR) E. coli isolates, representing 0.9% of the samples, were subjected to further resistance phenotyping and to microarray analyses targeting genetic markers of antimicrobial resistance and virulence. Genotyping revealed various combinations of resistance determinants as well as the presence of class 1, class 2 integrons. The isolates harbored 6 to 11 antibiotic resistance genes as well as 1 to 14 virulence genes. In this panel of 14 MDR E. coli two strains proved to carry CTX-M type ESBLs, and one single isolate was identified as enteropathogenic E. coli (EPEC). In general, isolates carrying a high number of resistance determinants had lower number of virulence genes and vice versa. In conclusion, this first pilot study on the prevalence of VTEC and of MDR/ESBL E. coli in illegally imported food products of animal origin suggests that these strains could represent reservoirs for dissemination of potentially new types of pathogenic and MDR E. coli in Europe.

Insulin and leptin plasma levels after the microinjection of interleukin-1β into the nucleus accumbens of the rat

The nucleus accumbens (NAcc), an important basal forebrain structure, has a central integratory function in the control of feeding and metabolism. The primary cytokine interleukin-1β (IL-1β) exerts its neuromodulatory effects on the endocrine functions both centrally and peripherally. The present study was designed to elucidate the possible consequences of direct administration of IL-1β into the NAcc on the endocrine regulation of metabolism. Plasma concentrations of insulin and leptin, two key hormones in the homeostatic control were determined 15 minutes after a single bilateral microinjection of IL-1β into the NAcc of adult male Wistar rats, and the effects were compared with those found in vehicle treated control animals. Insulin plasma levels of the cytokine treated animals were significantly higher than those parameters of the control rats. No differences were found in leptin plasma concentrations between the two groups. Our findings show that IL-1β mediated processes in the NAcc have important roles in the central neuroendocrine control.

GINA--a polarized neutron reflectometer at the Budapest Neutron Centre

The setup, capabilities, and operation parameters of the neutron reflectometer GINA, the recently installed "Grazing Incidence Neutron Apparatus" at the Budapest Neutron Centre, are introduced. GINA, a dance-floor-type, constant-energy, angle-dispersive reflectometer is equipped with a 2D position-sensitive detector to study specular and off-specular scattering. Wavelength options between 3.2 and 5.7 Å are available for unpolarized and polarized neutrons. Spin polarization and analysis are achieved by magnetized transmission supermirrors and radio-frequency adiabatic spin flippers. As a result of vertical focusing by a five-element pyrolytic graphite monochromator, the reflected intensity from a 20 × 20 mm(2) sample has been doubled. GINA is dedicated to studies of magnetic films and heterostructures, but unpolarized options for non-magnetic films, membranes, and other surfaces are also provided. Shortly after its startup, reflectivity values as low as 3 × 10(-5) have been measured by the instrument. The instrument capabilities are demonstrated by a non-polarized and a polarized reflectivity experiment on a Si wafer and on a magnetic film of [(62)Ni/(nat)Ni](5) isotope-periodic layer composition. The facility is now open for the international user community. Its further development is underway establishing new sample environment options and spin analysis of off-specularly scattered radiation as well as further decreasing the background.

Potential therapeutic targeting of platelet-mediated cellular interactions in atherosclerosis and inflammation

Cellular interactions among platelets, leukocytes and endothelial cells are considered as a major cause of inflammation and atherosclerosis in many diseases. Via exposed surface receptors and released soluble substances, activated platelets play a crucial role in the initiation of inflammatory processes, resulting in endothelial injury and leading to formation of atherosclerotic plaque with possible thrombotic complications. Classic anti-platelet treatments (e.g. cyclooxygenase inhibitor or ADP-receptor antagonist) have favorable effects in patients with vascular diseases, but they also have several limitations such as increased bleeding risk or non-responsiveness. Thus, the need and opportunities for developing novel therapeutic inhibitors for platelet-mediated events are obvious. Animal and (pre)clinical human studies have suggested that some recently produced specific antagonists of P-selectin from α-granules, as well as its main ligand/receptor P-selectin Glycoprotein Ligand-1, the two major platelet chemokines CXCL4 and CCL5, as well as CD40L, may be considered potential new candidates in the treatment of atherogenesis and inflammation. In this review, we summarize the pathophysiological roles of these effectors in platelet activation and acute or chronic inflammation, and discuss the latest findings on promising antagonistic agents in basic and clinical studies in the prevention of platelet-mediated cellular interactions.

PP004. Study of the methylenetetrahydrofolate reductase and the reduced-folate carrier-1 gene polymorphism in healthy and severe pre-eclamptic patients

INTRODUCTION

One-carbon cycle is involved in two essential physiological processes: The synthesis of purins and pyrimidines required for DNA synthesis and repair. The other is the methylation with the methionine cycle. These one-carbon groups are served by the tetrahydrofolate and the S-adenosylmethionine. Deficiencies of the folate, or other abnormalities within the methionine pathway lead to elevated homocysteine levels. These disorders have been implicated in placental diseases. Earlier studies have shown that homocysteine levels are elevated by patients with severe pre-eclampsia than by healthy pregnant normotensive women. Methylenetetrahydrofolate reductase (MTHFR) gene C677T missense mutation has a high frequency by patients with HELLP syndrome and connected with elevated serum homocysteine levels. The reduced-folate carrier (RFC-1) facilitates the internalization of 5-methyltetrahydrofolate from the blood into peripheral cells. The mutation G80A this gene leads to higher plasma folate.

OBJECTIVES

Our aim was to identify the polymorphism of these two genes in samples of severe pre-eclamptic patients and healthy controls.

METHODS

Blood samples were collected from healthy pregnant normotensive women (n=82) and women with pre-eclampsia (n=75). DNA was isolated and quantitative real-time PCR method combined with melting curve analysis was performed for the detection of the two polymorphisms. Statistical analysis was performed with the STATISTICA software package.

RESULTS

The frequency of the A allele in the RFC-1 gene was 46.57% by healthy pregnant and 41% by severe pre-eclamptic patients. The overall distribution of genotypes was not significantly different between the control and pre-eclamptic groups (p=0.58). In the study groups by the MTHFR gene the frequency of the T was 32% in pre-eclamptics, and 35.92% in controls. Similarly the overall distribution of genotypes was not significantly different between the two study groups (p=0.15).

CONCLUSION

In hypertensive disorders of the pregnancy the one-carbon cycle is disturbed. We studied single nucleotide mutations in the genes of two enzymes involved in the cycle. We determined the allele and genotype frequencies in healthy control and pre-eclamptic patients and found no significant differences. Further examinations of other genetical compounds can help to understand the elevated homocysteine levels in pre-eclampsia.

Exploitation of intestinal colonization-inhibition between salmonella organisms for live vaccines in poultry: potential and limitations

Immunization represents one of the most important methods to increase the resistance of chickens against Salmonella infection. In addition to the development of an adaptive immune response, oral administration of live Salmonella strains to day-old chicks provides protection against infection within hours by intestinal colonization-inhibition. For the exploitation of this phenomenon, practical information on colonization-inhibition between Salmonella organisms is needed. Colonization-inhibition capacity between Salmonella strains from serogroups B, C1, C2, D and G was assessed in chickens. The most profound level of intestinal colonization-inhibition occurred between isogenic strains. Inhibition between strains of the same serovar was greater than that between strains of different serovars. The degree of inhibition between different serovars was not sufficiently high to identify a single strain which might inhibit a wide range of other Salmonella organisms. However, as Salmonella Enteritidis is the dominant serovar in poultry in many countries and because of the profound colonization-inhibition within this serovar there is a considerable potential to exploit this phenomenon in the development of novel live S. Enteritidis vaccines. Treatment of young chicks with mixtures of different Salmonella serovars resulted not only in a very strong growth inhibition of the isogenic strains but also in a substantial inhibition of heterologous serovars. The potential of mixtures of heterologous Salmonella strains as a 'Salmonella Inhibition Culture' and as a 'live Salmonella vaccine' should be further explored.