Determination of Mean Cluster Sizes by Fluorescence Detection upon Site-Specific Photoexcitation

Electronic excitations in the valence shell of Ne clusters were studied by fluorescence spectroscopy. The measured fluorescence excitation functions contain information about the nature and number of excitonic states and the mean cluster size of the produced size distribution. Mean cluster sizes were determined by comparing surface and bulk contributions using a multidimensional fitting algorithm, with good agreement to commonly used scaling laws. The influence of different size distributions, which were not considered in previous investigations, on homogeneous noble gas cluster jets is implemented in the proposed model. The present work is the first approach using fluorescence spectroscopy for the determination of the mean size of Ne cluster jets created by supersonic expansion.

Setup for multicoincidence experiments of photons in the extreme ultraviolet to visible spectral range and charged particles-The solid angle maximization approach

The coincident detection of particles is a powerful method in experimental physics, enabling the investigation of a variety of projectile-target interactions. The vast majority of coincidence experiments is performed with charged particles, as they can be guided by electric or magnetic fields to yield large detection probabilities. When a neutral species or a photon is one of the particles recorded in coincidence, its detection probability typically suffers from small solid angles. Here, we present two optical assemblies considerably enhancing the solid angle for photon detection in the extreme ultraviolet to visible spectral range. The efficiency and versatility of these assemblies are demonstrated for electron-photon coincidence detection, where electrons and photons emerge from fundamental processes after photoexcitation of gaseous samples by synchrotron radiation.

Recovery of High-Energy Photoelectron Circular Dichroism through Fano Interference

It is commonly accepted that the magnitude of a photoelectron circular dichroism (PECD) is governed by the ability of an outgoing photoelectron wave packet to probe the chiral asymmetry of a molecule. To be able to accumulate this characteristic asymmetry while escaping the chiral ion, photoelectrons need to have relatively small kinetic energies of up to a few tens of electron volts. Here, we demonstrate a substantial PECD for very fast photoelectrons above 500 eV kinetic energy released from methyloxirane by a participator resonant Auger decay of its lowermost O 1s excitation. This effect emerges as a result of the Fano interference between the direct and resonant photoionization pathways, notwithstanding that their individual effects are negligibly small. The resulting dichroic parameter has an anomalous dispersion: It changes its sign across the resonance, which can be considered as an analogue of the Cotton effect in the x-ray regime.

Reticulose pagetoide em um cão: relato de caso

RESUMO Reticulose pagetoide é a expressão utilizada para uma das mais raras formas de linfoma descritas em cães. Trata-se de um distúrbio linfoproliferativo cutâneo que emerge de linfócitos T intraepidérmicos. Descreve-se aqui um caso de reticulose pagetoide com apresentação localizada, muito semelhante à doença de Woringer-Kolopp dos humanos, que acometeu um cão, Boxer, fêmea de 10 anos de idade. O paciente foi atendido devido ao aparecimento de um nódulo na região nasolabial, com evolução clínica de cerca de 30 dias. Histologicamente o nódulo era composto por uma proliferação linfoide intraepidérmica e anexal. Os linfócitos neoplásicos, células T confirmadas por meio da imunomarcação positiva para CD3 e negativa para CD79, eram grandes células redondas e monomórficas. Apesar de rara, a reticulose pagetoide é um distúrbio linfoproliferativo de fácil suspeita com base apenas na morfologia celular. Esse neoplasma deverá ser lembrado sempre que um padrão linfoide intraepidérmico estiver presente.

Symmetry breakdown of electron emission in extreme ultraviolet photoionization of argon

Short wavelength free-electron lasers (FELs), providing pulses of ultrahigh photon intensity, have revolutionized spectroscopy on ionic targets. Their exceptional photon flux enables multiple photon absorptions within a single femtosecond pulse, which in turn allows for deep insights into the photoionization process itself as well as into evolving ionic states of a target. Here we employ ultraintense pulses from the FEL FERMI to spectroscopically investigate the sequential emission of electrons from gaseous, atomic argon in the neutral as well as the ionic ground state. A pronounced forward-backward symmetry breaking of the angularly resolved emission patterns with respect to the light propagation direction is experimentally observed and theoretically explained for the region of the Cooper minimum, where the asymmetry of electron emission is strongly enhanced. These findings aim to originate a better understanding of the fundamentals of photon momentum transfer in ionic matter.

Note: Soft X-ray transmission polarizer based on ferromagnetic thin films

A transmission polarizer for producing elliptically polarized soft X-ray radiation from linearly polarized light is presented. The setup is intended for use at synchrotron and free-electron laser beamlines that do not directly offer circularly polarized light for, e.g., X-ray magnetic circular dichroism (XMCD) measurements or holographic imaging. Here, we investigate the degree of ellipticity upon transmission of linearly polarized radiation through a cobalt thin film. The experiment was performed at a photon energy resonant to the Co L₃-edge, i.e., 778 eV, and the polarization of the transmitted radiation was determined using a polarization analyzer that measures the directional dependence of photo electrons emitted from a gas target. Elliptically polarized radiation can be created at any absorption edge showing the XMCD effect by using the respective magnetic element.

Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning

Free-electron lasers providing ultra-short high-brightness pulses of X-ray radiation have great potential for a wide impact on science, and are a critical element for unravelling the structural dynamics of matter. To fully harness this potential, we must accurately know the X-ray properties: intensity, spectrum and temporal profile. Owing to the inherent fluctuations in free-electron lasers, this mandates a full characterization of the properties for each and every pulse. While diagnostics of these properties exist, they are often invasive and many cannot operate at a high-repetition rate. Here, we present a technique for circumventing this limitation. Employing a machine learning strategy, we can accurately predict X-ray properties for every shot using only parameters that are easily recorded at high-repetition rate, by training a model on a small set of fully diagnosed pulses. This opens the door to fully realizing the promise of next-generation high-repetition rate X-ray lasers.

Nucleic Acid Immunity

Organisms throughout biology need to maintain the integrity of their genome. From bacteria to vertebrates, life has established sophisticated mechanisms to detect and eliminate foreign genetic material or to restrict its function and replication. Tremendous progress has been made in the understanding of these mechanisms which keep foreign or unwanted nucleic acids from viruses or phages in check. Mechanisms reach from restriction-modification systems and CRISPR/Cas in bacteria and archaea to RNA interference and immune sensing of nucleic acids, altogether integral parts of a system which is now appreciated as nucleic acid immunity. With inherited receptors and acquired sequence information, nucleic acid immunity comprises innate and adaptive components. Effector functions include diverse nuclease systems, intrinsic activities to directly restrict the function of foreign nucleic acids (e.g., PKR, ADAR1, IFIT1), and extrinsic pathways to alert the immune system and to elicit cytotoxic immune responses. These effects act in concert to restrict viral replication and to eliminate virus-infected cells. The principles of nucleic acid immunity are highly relevant for human disease. Besides its essential contribution to antiviral defense and restriction of endogenous retroelements, dysregulation of nucleic acid immunity can also lead to erroneous detection and response to self nucleic acids then causing sterile inflammation and autoimmunity. Even mechanisms of nucleic acid immunity which are not established in vertebrates are relevant for human disease when they are present in pathogens such as bacteria, parasites, or helminths or in pathogen-transmitting organisms such as insects. This review aims to provide an overview of the diverse mechanisms of nucleic acid immunity which mostly have been looked at separately in the past and to integrate them under the framework nucleic acid immunity as a basic principle of life, the understanding of which has great potential to advance medicine.

Circular dichroism measurements at an x-ray free-electron laser with polarization control

A non-destructive diagnostic method for the characterization of circularly polarized, ultraintense, short wavelength free-electron laser (FEL) light is presented. The recently installed Delta undulator at the LCLS (Linac Coherent Light Source) at SLAC National Accelerator Laboratory (USA) was used as showcase for this diagnostic scheme. By applying a combined two-color, multi-photon experiment with polarization control, the degree of circular polarization of the Delta undulator has been determined. Towards this goal, an oriented electronic state in the continuum was created by non-resonant ionization of the O2 1s core shell with circularly polarized FEL pulses at hν ≃ 700 eV. An also circularly polarized, highly intense UV laser pulse with hν ≃ 3.1 eV was temporally and spatially overlapped, causing the photoelectrons to redistribute into so-called sidebands that are energetically separated by the photon energy of the UV laser. By determining the circular dichroism of these redistributed electrons using angle resolving electron spectroscopy and modeling the results with the strong-field approximation, this scheme allows to unambiguously determine the absolute degree of circular polarization of any pulsed, ultraintense XUV or X-ray laser source.

Source Functions of CO2 and Future CO2 Burden in the Atmosphere

A logistic source function for CO2 was derived which takes into account the input arising from the burning of fossil fuels, the stimulation of photosynthesis by the increasing partial pressure of CO2, and the decrease of biomass through deforestation etc. The parameters in a 5-box-model for the kinetics of CO2 were adjusted to fit the new Mauna Loa data on CO2 concentrations in air. Using these parameters and a buffer factor ξ(t) for the absorption of CO2 into the sea, the future CO2 burden was calculated for status quo conditions and for different values of the growth coefficient of fossil fuel consumption.

The results show that one can change the deforestation factor in rather wide limits without changing very much the future CO2 concentration in air during the next 80 years or so (cf. Figure 4). On the other hand, the future C02 burden depends strongly on the growth rate of fossil fuel consumption and will double under status quo conditions early in the next century (cf. Figure 5).

Efficient solid-phase synthesis of pppRNA by using product-specific labeling

A novel solid-phase synthesis and purification strategy for 5'-triphosphate oligonucleotides by using lipophilic tagging of the triphosphate moiety is reported. This is based on triphosphate synthesis with 5'-O-cyclotriphosphate intermediates, whereby a lipophilic tag, such as decylamine, is introduced during the ring-opening reaction to give a linear gamma-phosphate-tagged species. This method enables the highly efficient synthesis of 5'-triphosphorylated RNA derivatives and their gamma-phosphate-substituted analogues and will especially facilitate the advancement of therapeutic approaches that make use of 5'-triphosphate oligonucleotides as potent activators of the cytosolic immune sensor RIG-I.

Angular momentum sensitive two-center interference

In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

[Emotional state variations in rats during recall of passive avoidance reactions after neurotensin administration into nucleus accumbens of the brain]

Behavioral effects of neurotensin administration into the nucleus accumbens were studied in rats with neurotoxic lesions of serotoninergic structures of the dorsal raphe nucleus or periaqueductal grey matter. Changes in recall of passive avoidance conditioned reactions and aftereffects of painful stimulation in the locomotor activity were studied in the "open field" and elevated plus-maze and T-maze tests. The toxin administration into the dorsal raphe nucleus did not impair the recall of the passive avoidance reactions, but enhanced the oppressive aftereffects of painful stimulation, which can specify the development of anxiety in rats. The toxin administration into the periaqueductal grey matter had an opposite effect, which can be considered as a manifestation of the panic state. Neurotensin weakened the above mentioned effects of the toxin and, depending on the evoked emotional disorders, produced the anxiolytic or antipanic effects.

Effects of an active immunization on the immune response of laying Japanese quail (Coturnix coturnix japonica) fed with or without genetically modified Bacillus thuringiensis-maize

Potentially adverse effects of diets containing transgenic plants are a concern for many consumers, particularly in Europe. For Bacillus thuringiensis-maize, several studies in livestock and poultry showed that the zootechnical data provide no indication for such adverse effects. These studies were all done in homeostatic situations; it remained open whether a deflection of the regulatory physiological systems might yield divergent dynamic responses in B. thuringiensis-maize-fed animals. We therefore tested the effect of an active immunization using BSA as antigen in a feeding regimen with or without B. thuringiensis-maize using quail as a model organism. Newly hatched Japanese quail were randomly allocated to 2 groups (n=120 per group) fed with diets containing either B. thuringiensis-maize or isogenic maize of the same cultivar. The diets did not differ in concentrations of the mycotoxins deoxynivalenol and zearalenone, which were both far below guidance values. After 16 wk on the experimental diets, one-half of each group was immunized against BSA. The remaining birds were injected with saline. Thirty-six hours after the injection, half of the BSA-injected subgroup (n=30) and half of the saline subgroup (n=30) from B. thuringiensis-maize- and isogenic-fed birds were killed and blood samples were collected and analyzed for serum zinc levels, indicative for acute phase response. For determining IgY-mediated immune responses, eggs were collected every other week for 6 wk after the injections from the remaining birds and total IgY concentrations and BSA-specific IgY titers were measured in egg yolk. The BSA injections did not elicit significant decreases of serum zinc concentrations. The serum zinc levels were significantly higher in B. thuringiensis-maize-fed quail. Expectedly, total IgY as well as BSA-specific IgY titers increased with time in the BSA-immunized quail. The response of both variables to the BSA injection did not differ between the feeding groups. Our results indicate that feeding of B. thuringiensis-maize does not impair the immune system of Japanese quail and thus gives no indication for respective concerns.

Effect of morphine on hypothalamic catecholamine and serotonin level in relation to the stress-induced pituitary-adrenocortical activation in the rat

The relationship between the hypothalamic catecholamine and serotonin level as well as the activation of the pituitary-adrenal axis was investigated after administration or morphine (MO) in the rat. Five mg/kg b. wt. of MO induced a significant increase in norepinephrine and a 78%, but insignificant, increase in dopamine level of the hypothalamus within 60 min without changing corticosterone secretion. Electric footshock, in addition to elevating hypothalamic norepinephrine and dopamine levels, significantly increased the pituitary-adrenocortical response in the MO pretreated rats. Five mg/kg b. wt. of MO, or electric footshock alone did not influence the hypothalamic serotonin level within 60 min, but the hypothalamic serotonin level decreased significantly in the MO pretreated, electrically shocked animals. We conclude, that 1) low dose of MO may induce changes of the hypothalamic catecholamine levels without influencing pituitary-adrenocortical activation. 2) enhanced hypothalamic catecholamines by MO did not prevent increasing pituitary-adrenocortical response elicited by stress. It appears, that the hypothalamic catecholaminergic mechanism which may inhibit ACTH release during stimulation does not function in the MO treated rats.

Relationship between the monoamine and gonadotropin content in follicular fluid of preovulatory graafian follicles after superovulation treatment

Noradrenaline (NA), serotonin (5HT), dopamine (DA), FSH, LH and prolactin (PRL) content was determined in 104 preovulatory follicular fluids obtained from 44 patients undergoing in vitro fertilization. The patients were given human menopausal gonadotropin (HMG) for ovarium stimulation, ovulation was induced with 10000 IU human chorionic gonadotropin (HCG) 34-36 hours prior to the follicular aspiration by vaginal ultrasound. Classification of the oocytes was performed by direct microscopic evaluation differentiating three groups of oocytes: Group I.: prophase I; Group II.: metaphase I; Group III.: metaphase II. There was no significant difference in monoamine and FSH content of follicular fluid at different stage of the oocyte maturation. LH and PRL significantly increased parallel with oocyte maturation (38.9; 48.8; 56.7 IU/l and 1324; 2382; 3134 IU/l). significant negative correlation was observed in Group I. between 5HT-LH (r = -0.64); in Group II. between NA-LH (r = -0.62) and NA-PRL (r = -0.51). Significant positive correlation were found in Group I. between FSH-LH (r = 0.63), in Group II. between LH-PRL (r = 0.56), in Group III. between NA-5HT (r = 0.66), NA-DA (r = 0.80) and 5HT-DA (r = 0.66). These observations suggest that action of LH and PRL may be negatively modulated by 5HT and NA in the final stage of oocyte maturation.

JC papovavirus leukencephalopathy in a patient with B-CLL receiving long-term chemotherapy in combination with an anti-CD20-antibody

e18007

Background: Progressive multifocal leukencaphalopathy (PML) is a rare demyelinating infection of the central nervous system caused by viruses (CMV, JC, BK). It is almost exclusively described in profound immunocompromised patients developed as a primary infection or by reactivation of the virus after a latent infection. PML is typically observed among patients with severe immunodeficiency like HIV or in the setting of autologous or allogenic transplantation. Methods: Our patient was a 64-year-old woman with B-CLL diagnosed in 2000 in state B of Binet treated with 12 cycles of fludarabin until July 2007 in a B-cell and lymphoma-reducing manner. For the reason of progressive disease 3 cycles of rituximab, fludarabin, mitoxantrone, and cyclophosphamide were added (dose reduced causing hematologic toxicity) until October 2007 continuing rituximab once a month up to Mai 2008. Results: In a CT scan mixed response was observed with progressive disease infradiafragmatic and regression supradiafragmatic. Corticosteroids could stop B-symptoms and leads to a distinct shrinkage of the lymphomas within 2 weeks. Later on she presented with confusion and disorientation. An MRI of the brain showed subcortical and periventricular lesions with increased signal on T2-weighted and fluid attentuated inversion recovery (FLAIR) suggestive of a vascular origin. Her symptoms progressed by aphasia and weakness of the right leg corresponding to increased size and number of cerebral lesions. A lumbar puncture showed no malignant cells and no evidence of inflammation. A PCR analysis was negative for Toxoplasma gondii, HSV, VCV, CMV, EBV, and enterovirus but positive for JC-DNA (215.000 copies/ml). A rapid progression leads to death two months after onset of symptoms. Conclusions: Antibody deficiency syndrome corresponding to CLL under treatment with chemotherapy and rituximab lead to a severe immunosuppression enabling unusual viral infections such as PML.

No significant financial relationships to disclose.

An accelerator for neural networks with pulse-coded model neurons

The labeling of features by synchronization of spikes seems to be a very efficient encoding scheme for a visual system. Simulation of a vision system with millions of pulse-coded model neurons, however, is almost impossible on the base of available processors including parallel processors and neurocomputers. A "one-to-one" silicon implementation of pulse-coded model neurons suffers from communication problems and low flexibility. On the other hand, acceleration of the simulation algorithm of pulse-coded leaky integrator neurons has proved to be straightforward, flexible, and very efficient. Thus we decided to develop an accelerator for a special version of the French and Stein neurons with modulatory inputs which are advantageous for simulation of synchronization mechanisms. Moreover, our accelerator also provides a Hebbian-like learning rule and supports adaptivity. Up to 128 K neurons with a total number of 16 M freely allocatable synapses are simulated within one system. The size of networks, however, is not at all limited by these numbers as the system may be arbitrarily expanded. Simulation speed obviously depends on the number of interconnections and on the average activity within the network. In the case of locally interconnected networks for simulation of vision mechanisms there is only a very low percentage of simultaneously active neurons: stimuli are not simultaneously presented in all orientations and at all positions of the visual field. In these cases our accelerator provides close to real-time behavior if one second of a biological neuron is simulated by 1000 time slots.

[Involvement of serotoninergic brain structures in the mechanisms of neurotensin effect on passive avoidance in rats]

The purpose of the research was to reveal the features of neurotensin (administered in substantia nigra or dorsal raphe nucleus) effect on recall of passive avoidance reactions in rats. It was shown that the effect of neurotensin injected into the substantia nigra was characterized by a sharp reduction of passive avoidance reactions. On the contrary, injection of the substance in the dorsal raphe nucleus led to an intensification of these reactions and delay of their extinction. The effects of microinjections of serotonin 1A receptor agonist, 8-hydroxy-dipropylaminotetralin (8-OH-DPAT), into the mentioned brain structures was similar to that of neurotensin. Changes in the content of serotonin and its metabolite 5- hydroxyindoleacetic acid (5-HIAA) in the caudate nucleus corresponded to various behavioral effects. The conclusion was made that neurotensin effect on the passive avoidance behavior is related to regulation of emotional state of animals mediated by its action on the function of the serotoninergic brain structures.

Beyond double-stranded RNA-type I IFN induction by 3pRNA and other viral nucleic acids

Production of type I IFN is the key response to viral infection. Since the discovery of type I IFNs in 1957, long double-stranded RNA formed during replication of many viruses was thought to be responsible for type I IFN induction, and for decades double-stranded RNA-activated protein kinase (PKR) was thought to be the receptor. Recently, this picture has dramatically changed. It now became evident that not PKR but two members of the Toll-like receptor (TLR) family, TLR7 and TLR9, and two cytosolic helicases, RIG-I and MDA-5, are responsible for the majority of type I IFNs induced upon recognition of viral nucleic acids. In this review, we focus on the molecular mechanisms by which those innate immune receptors detect viral infection. Based on the recent progress in the field, we now know that TLR7, TLR9, and RIG-I do not require long double-stranded RNA for type I IFN induction.

Calculation of stopping power ratios for carbon ion dosimetry

Water-to-air stopping power ratio calculations for the ionization chamber dosimetry of clinical carbon ion beams with initial energies from 50 to 450 MeV/u have been performed using the Monte Carlo technique. To simulate the transport of a particle in water the computer code SHIELD-HIT v2 was used, which is a newly developed version where substantial modifications were implemented on its predecessor SHIELD-HIT v1 (Gudowska et al 2004 Phys. Med. Biol. 49 1933-58). The code was completely rewritten replacing formerly used single precision variables with double precision variables. The lowest particle transport specific energy was decreased from 1 MeV/u down to 10 keV/u by modifying the Bethe-Bloch formula, thus widening its range for medical dosimetry applications. In addition, the code includes optionally MSTAR and ICRU-73 stopping power data. The fragmentation model was verified and its parameters were also adjusted. The present code version shows excellent agreement with experimental data. It has been used to compute the physical quantities needed for the calculation of stopping power ratios, s(water,air), of carbon beams. Compared with the recommended constant value given in the IAEA Code of Practice, the differences found in the present investigations varied between 0.5% and 1% at the plateau region, respectively for 400 MeV/u and 50 MeV/u beams, and up to 2.3% in the vicinity of the Bragg peak for 50 MeV/u.

Comparative efficiency of the multi-leaf collimator and variable-aperture collimator in intensity-modulated radiotherapy

The potential of the variable-aperture collimator (VAC) in intensity-modulated radiation therapy (IMRT) has been evaluated by comparing its performance with that of the multi-leaf collimator (MLC). This comparison used a decomposition algorithm to find the series of collimator segments that would treat a given intensity-modulated beam (IMB). Collimator performance was measured using both the number of segments required to complete the IMB and the monitor-unit efficiency of the treatment. The VAC was modelled with aperture sizes from 4 x 4 cm to 20 x 20 cm, and these apertures were allowed to be located anywhere within the IMB. To enable a direct comparison, a similar scanning MLC was modelled at the same range of aperture sizes. Using both collimators, decompositions were run on 10 x 10 and 20 x 20 random IMBs with integer bixel values ranging from 1 to 10. Clinical IMBs from lung, head and neck, and pelvic patients were taken from a Pinnacle treatment-planning system and tested in the same manner. It was found that for all treatment sites, a small, scanning MLC performs as well or better than an equivalent sized VAC in both number of segments and monitor-unit efficiency, and would be an efficient choice for centres looking for a simple collimator for IMRT.

No Indication for a Defect in Toll-Like Receptor Signaling in Patients with Hyper-IgE Syndrome

Hyper-IgE syndrome is a rare primary immunodeficiency of unknown etiology characterized by recurrent infections of the skin and respiratory system, chronic eczema, elevated total serum IgE, and a variety of associated skeletal symptoms. Recent reports about susceptibility to pyogenic bacterial infections and high IgE levels in patients and animals with defects in toll-like receptor (TLR) signaling pathways prompted us to search for TLR signaling defects as an underlying cause of hyper-IgE syndrome. Blood samples from six patients with hyper-IgE syndrome were analyzed for serum cytokine levels, intracellular cytokine production in T cells after stimulation with PMA/ionomycin, and cytokine production from peripheral blood mononuclear cells stimulated by TLR ligands and bacterial products including LPS (TLR4), peptidoglycan (TLR2), PolyIC (TLR3), R848 (TLR7/8), CpG-A, and CpG-B (TLR9), zymosan and heat killed Listeria monocytogenes. All results were compared to data from healthy controls. A reduction in IFN-gamma, IL-2, and TNF-alpha producing T cells after PMA stimulation suggested a reduced inflammatory T cell response in patients with hyper-IgE syndrome. Increased serum levels of IL-5 indicated a concomitant Th2 shift. However, normal production of cytokines (TNF-alpha, IL-6, IL-10, IFN-alpha, IP-10) and upregulation of CD86 on B cells and monocytes after TLR stimulation made a defect in TLR signaling pathways highly unlikely. In summary, our data confirmed an imbalance in T cell responses of patients with hyper-IgE syndrome as previously described but showed no indication for an underlying defect in toll-like receptor signaling.

[Effects of neurotensin on active and passive avoidance performance in rats with lesions of serotoninergic neurons]

After a lesion of serotoninergic neurons performed by administration of 5.7-dihydroxytriptamine into the dorsal raphe nucleus, effects of neurotensin microinjections into the substantia nigra on rat behavior were investigated. Serotoninergic lesions resulted in enhanced fear of rats manifested as an increase in the number of intersignal avoidance reactions and intensification of escape reactions. Neurotensin microinjections into the substantia nigra diminished the neurotoxin action thus increasing the adaptive character of defensive behavior of rats with deficit of functions of serotonin neurons.

Effects of 5-HT1Areceptor agonist and antagonist on anxiety in intact and ovariectomized female rats

The purpose of this work was to study the role of 5-HT1A receptors on the level of anxiety in adult intact and ovariectomized (OVX) female rats. The influence of chronic administration of 5-HT1A receptor agonist 8-OH-DPAT (0.05 mg/kg, s.c.) and 5-HT1A receptor antagonist NAN-190 (0.1 mg/kg, i.p.) given for 14 days alone or in combination with 17beta-estradiol (0.5 microg i.m./rat/day) was studied on behavior in the elevated plus maze. In intact females administration of NAN-190 resulted in significant increase in the number of enterings and the time spent on the open arms in every phase of the estrous cycle, however, 8-OH-DPAT failed to modify these parameters. In OVX females 8-OH-DPAT alone or in combination with 17beta-estradiol significantly increased the number of enterings and time spent on the open arms. On the contrary, NAN-190 alone or in combination with 17beta-estradiol in OVX females failed to evoke behavioral changes in the elevated plus maze. Thus, the 5-HT1A receptor antagonist NAN-190 induced anxiolytic effect in intact female rats, while 5-HT1A receptor agonist 8-OH-DPAT produced an anxiolytic profile on OVX rats. Results of this work specify the involvement of 5-HT1A receptors in behavioral mechanisms of anxiety in OVX female rats.

Involvement of 5-HT1?receptors in passive avoidance learning in intact and ovariectomized female rats

The influence of chronic administration of 5-HT1A receptor agonist 8-OH-DPAT (0.05 mg/kg, s.c.) and 5-HT1A receptor antagonist NAN-190 (0.1 mg/kg, i.p.) injected for 14 days alone or in combination with 17beta-estradiol (0.5 microg i.m./rat/day) was studied on passive avoidance performance (PAR) and on behavior in the open field test in adult intact and ovariectomized (OVX) female rats. Administration of 5-HT1A receptor antagonist NAN-190 alone significantly improved PAR (p<0.05) in intact females with proestrus and estrus and in OVX females. Administration of 5-HT1A receptor agonist 8-OH-DPAT alone or in combination with 17beta-estradiol significantly (p<0.05) improved PAR in OVX rats and failed to normalize PAR in intact rats with proestrus and estrus. Results of the work specify the involvement of 5-HT1A receptors in the mechanisms of passive avoidance learning in OVX female rats.