Measurement of polarization observables T, P, and H in π0 and η photoproduction off quasi-free nucleons.

The target asymmetry T, recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π0 and η photoproduction off quasi-free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γp→π0p and γp→ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W=1.68GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11-partial wave.

Measurement of the helicity asymmetry E for the reaction γ p → π 0 p : The CBELSA/TAPS Collaboration.

A measurement of the double-polarization observable E for the reaction γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

[Abdominal pain and seizure in a 26-year-old student from England]. / Abdominelle Schmerzen und Krampfanfall bei einer 26-jährigen Studentin aus England.

A 26-year-old female presented to the emergency department due to abdominal pain in spite of painkillers. After extensive clinical diagnostics, no specific cause could be found. The further course was aggravated by a seizure due to hyponatremia. The combination of abdominal and neurological symptoms as well as darkening of the urine led to the diagnosis of porphyria. Drugs that were known to be triggers were avoided and treatment with heme arginate and glucose was started. In addition, treatment of the delirium and infection led to a complete remission of symptoms.

Observation of the pη

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

[Atrioventricular block and left ventricular wall mobility disorder in a 44-year-old female patient : A case report of a rarity with pitfalls]. / Atrioventrikuläre Blockierung und linksventrikuläre Wandbewegungsstörung bei einer 44-jährigen Patientin : Fallbericht über eine Rarität mit Tücken.

Eosinophilic myocarditis is a rare condition with good treatment options, which can be difficult to diagnose. The clinical presentation can vary from asymptomatic to life-threatening forms. This article describes the case of a 44-year-old woman who suffered from vertigo, chest pain and dyspnea. The woman presented with an intermittent atrioventricular (AV) block II Mobitz type II° and mild impairment of left ventricular ejection fraction. Hypereosinophilia in the peripheral blood, cardiac magnetic resonance imaging (MRI) and endomyocardial biopsy led to the diagnosis of eosinophilic myocarditis, most likely as a result of an allergic reaction to Aspergillus fumigatus. A general treatment recommendation cannot be made due to the lack of evidence-based guidelines; however, recent scientific studies confirmed timely, high-dose steroid administration over several months to be the mainstay of treatment of eosinophilic myocarditis. The following article may be helpful in the early diagnosis and treatment of this underdiagnosed and insidious disease.

Species-specific genes under selection characterize the co-evolution of slavemaker and host lifestyles.

BACKGROUND: The transition to a parasitic lifestyle entails comprehensive changes to the selective regime. In parasites, genes encoding for traits that facilitate host detection, exploitation and transmission should be under selection. Slavemaking ants are social parasites that exploit the altruistic behaviour of their hosts by stealing heterospecific host brood during raids, which afterwards serve as slaves in slavemaker nests. Here we search for evidence of selection in the transcriptomes of three slavemaker species and three closely related hosts. We expected selection on genes underlying recognition and raiding or defense behaviour. Analyses of selective forces in species with a slavemaker or host lifestyle allowed investigation into whether or not repeated instances of slavemaker evolution share the same genetic basis. To investigate the genetic basis of host-slavemaker co-evolution, we created orthologous clusters from transcriptome sequences of six Temnothorax ant species - three slavemakers and three hosts - to identify genes with signatures of selection. We further tested for functional enrichment in selected genes from slavemakers and hosts respectively and investigated which pathways the according genes belong to. RESULTS: Our phylogenetic analysis, based on more than 5000 ortholog sequences, revealed sister species status for two slavemakers as well as two hosts, contradicting a previous phylogeny based on mtDNA. We identified 309 genes with signs of positive selection on branches leading to slavemakers and 161 leading to hosts. Among these were genes potentially involved in cuticular hydrocarbon synthesis, thus species recognition, and circadian clock functionality possibly explaining the different activity patterns of slavemakers and hosts. There was little overlap of genes with signatures of positive selection among species, which are involved in numerous different functions and different pathways. CONCLUSIONS: We identified different genes, functions and pathways under positive selection in each species. These results point to species-specific adaptations rather than convergent trajectories during the evolution of the slavemaker and host lifestyles suggesting that the evolution of parasitism, even in closely related species, may be achieved in diverse ways.

Three-body nature of N(*) and Δ(*) resonances from sequential decay chains.

The Nπ^{0}π^{0} decays of positive-parity N^{*} and Δ^{*} resonances at about 2 GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances: Δ(1232), N(1520)3/2^{-}, and N(1680)5/2^{+}, with spin parities J^{P}=3/2^{+}, 3/2^{-}, and 5/2^{+}. The partial wave analysis (within the Bonn-Gatchina approach) identifies N(1440)1/2^{+} and the N(ππ)_{S wave} (abbreviated as Nσ here) as further isobars and assigns the final states to the formation of nucleon and Δ resonances and to nonresonant contributions. We observe the known Δ(1232)π decays of Δ(1910)1/2^{+}, Δ(1920)3/2^{+}, Δ(1905)5/2^{+}, Δ(1950)7/2^{+}, and of the corresponding spin-parity series in the nucleon sector, N(1880)1/2^{+}, N(1900)3/2^{+}, N(2000)5/2^{+}, and N(1990)7/2^{+}. For the nucleon resonances, these decay modes are reported here for the first time. Further new decay modes proceed via N(1440)1/2^{+}π, N(1520)3/2^{-}π, N(1680)5/2^{+}π, and Nσ. The latter decay modes are observed in the decay of N^{*} resonances and at most weakly in Δ^{*} decays. It is argued that these decay modes provide evidence for a 3-quark nature of N^{*} resonances rather than a quark-diquark structure.

Gene expression patterns associated with caste and reproductive status in ants: worker-specific genes are more derived than queen-specific ones.

Variation in gene expression leads to phenotypic diversity and plays a central role in caste differentiation of eusocial insect species. In social Hymenoptera, females with the same genetic background can develop into queens or workers, which are characterized by divergent morphologies, behaviours and lifespan. Moreover, many social insects exhibit behaviourally distinct worker castes, such as brood-tenders and foragers. Researchers have just started to explore which genes are differentially expressed to achieve this remarkable phenotypic plasticity. Although the queen is normally the only reproductive individual in the nest, following her removal, young brood-tending workers often develop ovaries and start to reproduce. Here, we make use of this ability in the ant Temnothorax longispinosus and compare gene expression patterns in the queens and three worker castes along a reproductive gradient. We found the largest expression differences between the queen and the worker castes (~2500 genes) and the smallest differences between infertile brood-tenders and foragers (~300 genes). The expression profile of fertile workers is more worker-like, but to a certain extent intermediate between the queen and the infertile worker castes. In contrast to the queen, a high number of differentially expressed genes in the worker castes are of unknown function, pointing to the derived status of hymenopteran workers within insects.

First measurement of the helicity asymmetry for γp → pπ0 in the resonance region.

The first measurement of the helicity dependence of the photoproduction cross section of single neutral pions off protons is reported for photon energies from 600 to 2300 MeV, covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between data and predictions are observed, which are traced to differences in the helicity amplitudes of well-known and established resonances. Precise values for the helicity amplitudes of several resonances are reported.

N(1520) 3/2(-) helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions.

New data on the polarization observables T, P, and H for the reaction γp→pπ(0) are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses.

[Fever, atrial fibrillation, and angina pectoris in a 58-year-old man]. / Fieber, Vorhofflimmern und Angina pectoris bei einem 58-jährigen Patienten.

Primary cardiac lymphoma (PCL) respresents a very rare type of cardiac tumour. This report illustrates a case of PCL in an immunocompetent 58-year-old man presenting with atrial fibrillation and febrile syndrome. Comprehensive imaging [computer tomography (CT), cardiac magnetic resonance imaging (cMRI), 3-dimensional transesophageal echocardiography (3D-TEE)] identified a large right atrial tumour, leading to pericardial effusion. Isolated cardiac involvement was confirmed by positron emission tomography (PET)-CT. A diffuse large B-cell lymphoma (DLBCL) was diagnosed based on the results of a TEE-guided biopsy. A normalized PET scan (PETAL study) indicated complete remission following R-CHOP 14 immunochemotherapy. Thus, an interdisciplinary and multimodal approach avoided unnecessary cardiac surgery.

Estradiol downregulates NF-κb translocation by Ikbkg transcriptional repression in dendritic cells.

To reconcile immunity and reproduction, females must allow spermatozoa to survive and control the presence of commensal microbiota and sexually transmitted pathogens during ovulation. Female steroid sex hormones exert a powerful effect on the immune system, as do the hormonal changes associated with the ovarian cycle. Dendritic cells (DCs) are immunological sentinels that link innate immunity to adaptive immunity. Upon exposure to microbial invaders in tissue, they undergo a maturational process that culminates in the lymph nodes and activates T-cell-specific immune responses. Estradiol, which is highly expressed during ovulation, has an effect on the maturation of DCs, although the molecular mechanism remains elusive. We detected that estradiol regulates expression of Ikbkg in DCs and modulates nuclear factor-κb translocation to the nucleus, thus explaining the reduced DC function observed during ovulation. This change may be an adaptive mechanism to reconcile control of infection and reproductive functions.

Female sex hormones regulate the Th17 immune response to sperm and Candida albicans.

STUDY QUESTION: What role do female sex hormones play in the antisperm immune response? SUMMARY ANSWER: We found that sperm induce a Th17 immune response and that estradiol down-regulates the antisperm Th17 response by dendritic cells. WHAT IS KNOWN ALREADY: Estradiol down-regulates the immune response to several pathogens and impairs the triggering of dendritic cell maturation by microbial products. STUDY DESIGN, SIZE, DURATION: Ex vivo and in vivo murine models of vaginal infection with sperm and Candida albicans were used to study the induction of Th17 and its hormonal regulation. PARTICIPANTS/MATERIALS, SETTING, METHODS: We analyzed the induction of Th17 cytokines and T cells in splenocytes obtained from BALB/c mice challenged with sperm and C. albicans. For the in vivo vaginal infection models, we used ovariectomized mice treated with vehicle, estradiol or progesterone, and we assessed the effect of these hormones on the immune response in the lymph nodes. MAIN RESULTS AND THE ROLE OF CHANCE: Th17 cytokines and T cells were induced by sperm antigens in both ex vivo and in vivo experiments. Estrus levels of estradiol down-regulated the Th17 response to sperm and C. albicans in vivo. LIMITATIONS, REASONS FOR CAUTION: This study was conducted using murine models; whether or not the results are applicable to humans is not known. WIDER IMPLICATIONS OF THE FINDINGS: Our results describe an adaptive mechanism that reconciles immunity and reproduction and further explains why unregulated Th17 could be linked to infertility and recurrent infections. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by research grants from the Instituto de Salud Carlos III (ISCIII) (PI10/00897) and Fundación Mutua Madrileña to M.R. M.R. holds a Miguel Servet contract from the ISCIII (CP08/00228). M.A.M.-F. was supported by (ISCIII) INTRASALUD PI09/02029. We have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: Not required.

Well-established nucleon resonances revisited by double-polarization measurements.

The first measurement is reported of the double-polarization observable G in the photoproduction of neutral pions off protons, covering the photon energy range from 620 to 1120 MeV and the full solid angle. G describes the correlation between the photon polarization plane and the scattering plane for protons polarized along the direction of the incoming photon. The observable is highly sensitive to contributions from baryon resonances. The new results are compared to the predictions from SAID, MAID, and BnGa partial wave analyses. In spite of the long-lasting efforts to understand γp→pπ(0) as the simplest photoproduction reaction, surprisingly large differences between the new data and the latest predictions are observed which are traced to different contributions of the N(1535) resonance with spin parity J(P)=1/2(-) and N(1520) with J(P)=3/2(-). In the third resonance region, where N(1680) with J(P)=5/2(+) production dominates, the new data are reasonably close to the predictions.

Systemic vasoconstriction induced by inhibition of nitric oxide synthesis is attenuated in conscious dogs with heart failure.

STUDY OBJECTIVE: The aim was to test the hypothesis that endothelium dependent vasomotor control is impaired in heart failure. DESIGN AND SUBJECTS: The haemodynamic effects of NG-nitro-L-arginine (NNA), an inhibitor of nitric oxide synthesis, were studied in five dogs with and without pacing induced heart failure. MAIN RESULTS: In healthy dogs, NNA increased total peripheral resistance and arterial pressure, decreasing cardiac output and heart rate. These effects were partially reversed by L-arginine. In dogs with heart failure, NNA did not change any haemodynamic variable. However, L-arginine decreased total peripheral resistance. CONCLUSIONS: These findings support a physiological role for endothelium derived nitric oxide in control of vascular resistance and are in agreement with the hypothesis that endothelium dependent vasomotion may be impaired in heart failure.

Aortic input impedence and neurohormonal activation in patients with mild to moderate chronic congestive heart failure.

OBJECTIVE: The aim was to investigate the interrelation between pulsatile components (assessed by determination of aortic input impedance) and neurohormonal activation in chronic congestive heart failure. METHODS: Aortic input impedance, plasma noradrenaline, renin, atrial natriuretic factor, and arginine vasopressin were measured in 20 patients with mild to moderate chronic congestive heart failure (coronary artery disease n = 12, idiopathic dilated cardiomyopathy n = 8). RESULTS: Cardiac index [2.2(SEM 0.3) litre.min-1.m-2] and left ventricular ejection fraction [38(4)%] were reduced, and pulmonary wedge pressure was increased [21(2) mmHg]. Plasma concentrations of noradrenaline [462(62) pg.ml-1], renin [12(4) ng AI.ml.h-1], atrial natriuretic factor [408(64) pg.ml-1], and--to a slight degree--arginine vasopressin [1.1(0.3) pg.ml-1] were increased. Characteristic impedance Zc [80(6) dyne.s.cm-5) and relative oscillatory aortic input pressure power [10(1)%]--both reflecting the pulsatile components of left ventricular afterload--were within the normal range. There was no significant correlation between these variables and the degree of neurohormonal activation (r values: -0.05 to -0.35). CONCLUSIONS: The data show that in patients with mild to moderate chronic congestive heart failure there is no interrelationship between the degree of neurohormonal activation and pulsatile components of left ventricular afterload. This may indicate that in these stages of heart failure there are no trophic effects of stimulated neurohormonal systems on the physical properties of the great arteries.

Development of heart failure following isoproterenol administration in the rat: role of the renin-angiotensin system.

OBJECTIVE: High dosages of catecholamines induce cardiomyocyte necrosis and interstitial fibrosis in rats. We investigated whether this initial damage is followed by the development of heart failure and assessed the particular role of the renin-angiotensin system using ramipril. METHODS AND RESULTS: Following the administration of 0 mg or 150 mg isoproterenol/kg 6 groups of Wistar rats were followed for 2 or 16 weeks: Sham, isoproterenol, isoproterenol + ramipril. Isoproterenol induced significant increases of echocardiographically measured left ventricular end-diastolic posterior wall thickness and dimension, whereas ramipril treatment significantly attenuated these changes. Left ventricular end-diastolic pressure was markedly increased in isoproterenol-treated rats and normalized following ramipril. Isoproterenol rats were further characterized by hormonal activations including transient elevations of plasma renin activity, aldosterone and cardiac angiotensin converting enzyme activity. Histomorphological characterization of isoproterenol-treated hearts demonstrated cardiomyocyte necrosis and reparative fibrosis. Ramipril treatment only slightly reduced the amount of necrosis as well as the expression of extracellular matrix proteins. CONCLUSIONS: In rats, a toxic dosage of isoproterenol caused characteristic myocardial damage that subsequently resulted in mild heart failure. Ramipril administration following isoproterenol was highly effective to attenuate hemodynamic and hormonal alterations as well as the development of left ventricular hypertrophy, but had only little influence on the expression of extracellular matrix proteins. Since angiotensin converting enzyme inhibition had no impact on the initial myocardial injury, the development of heart failure in this model seems to require functional integrity of the renin-angiotensin system.

Chronic ACE inhibition by quinapril modulates central vasopressinergic system.

OBJECTIVE: The role of the brain as a target for angiotensin converting enzyme (ACE) inhibitors in the treatment of heart failure and hypertension is unclear. To test the hypothesis that ACE inhibitors may modulate other central neuropeptide systems such as the central vasopressin system, we studied the effects of chronic treatment with the ACE inhibitor, quinapril, on ACE activity and on central vasopressin content in specific brain areas in rats. METHODS: 22 rats were chronically treated with quinapril (6 mg.kg-1 BW per gavage daily for 6 weeks; untreated controls, n = 14). ACE density in various brain regions was assessed by in vitro autoradiography using the specific ACE inhibitor, 125I-351A. Vasopressin content was determined in 19 brain areas (micropunch technique) known to be involved in cardiovascular regulation. RESULTS: Following chronic quinapril treatment ACE was significantly decreased in the thalamus (-38%), hypothalamus (-37%), hypophysis (-35%), cerebellum (-36%) choroid plexus (-20%), and locus coeruleus (-35%). Additionally, a marked reduction in serum ACE activity (-97%) was observed. Plasma levels of vasopressin were significantly decreased after quinapril treatment (0.97[s.e.m. 0.11] vs. 1.63[0.24] pg.ml-1 in controls, P < 0.05). Vasopressin content was significantly reduced in 9 of 19 specific brain areas. Regarding the hypothalamic vasopressin-producing nuclei, vasopressin was decreased in the paraventricular (292[197] vs. 2379[585] pg.mg-1 crotein in controls; P < 0.001) and supraoptic nuclei (13618[1979] vs. 24525[3894] pg.mg-1 protein; P < 0.05), but not in the suprachiasmatic nucleus. Vasopressin content was significantly reduced in brain areas connected by vasopressinergic fibres originating in the hypothalamic paraventricular nucleus: namely central gray, subcommissural organ, organum vasculosum laminae terminalis, dorsal raphe nucleus, and locus coerules. Vasopressin content was also significantly reduced in the median eminence (5887[1834] vs. 28321[4969] pg.mg-1 protein, P < 0.001), where the hormone is mainly concentrated in the hypothalamo-hypophysial tract. CONCLUSIONS: Autoradiographic studies in vitro indicate that orally administered quinapril suppresses central ACE activity after chronic treatment. ACE inhibition by quinapril strongly influences vasopressin content in important brain areas which are involved in central cardiovascular regulation. Therefore, central modulatory effects of ACE inhibitors may also contribute to overall therapeutic efficacy.

Central vasopressin in experimental aortic stenosis in the rat.

OBJECTIVE: In several forms of heart disease characterised by low cardiac output, activated neurohumoral systems including increased vasopressin plasma levels play a key role in the changes in cardiovascular function. The aim of this study was to test the hypothesis that under such conditions the central vasopressin system might also be altered, which could contribute to deranged cardiovascular control. METHODS: Aortic stenosis was produced in 22 rats by placing a Silver clip (inner diameter 0.6 mm) on the ascending aorta. After 12 weeks, haemodynamic and hormonal measurements were performed, and vasopressin content was determined in 20 microdissected brain areas (micropunch technique). Twenty two sham operated rats served as controls. RESULTS: Twelve weeks after placing the supravalvular clip, significant aortic stenosis was documented by left ventricular myocardial hypertrophy. Cardiac index was significantly reduced and the peripheral vascular resistance index was increased, while poststenotic aortic pressure was non-significantly decreased. Plasma renin concentration [6.8(SEM 0.9) v 2.1(0.2) ngAI.ml-1.h-1 in controls] and plasma vasopressin [32.9(12.5) v 18.4(6.0) pg.ml-1] were significantly increased, while plasma and urinary noradrenaline remained unaltered. The vasopressin content was significantly altered in eight out of 20 brain areas investigated. Concerning the vasopressin producing hypothalamic nuclei, concentrations were increased in the paraventricular [7494(360) v 4744(237) pg.mg-1 protein, P < 0.05] and suprachiasmatic [3613(170) v 1784(197) pg.mg-1 protein, P < 0.01], but not in the supraoptic nuclei. Rats with aortic stenosis showed significantly raised vasopressin concentrations in the median eminence [25 186(1682) v 37 367(1345) pg.mg-1 protein, P < 0.01], where the hormone is mainly concentrated in the hypothalamo-hypophysial tract. Vasopressin content was significantly decreased in locus coeruleus [49(5) v 89(6) pg.mg-1 protein], which is known to be involved in modulation of sympathetic activity. CONCLUSIONS: As well as showing increased secretion of vasopressin into the blood with consecutive peripheral antidiuretic and vasoconstrictive effects, these data suggest an alteration in the central vasopressin system in aortic stenosis which might transmit cardiovascular effects by neuromodulation and neuroregulation.