Treatment of end-stage peripheral artery disease by neuromodulation.

BACKGROUND: Neuromodulation is a therapeutic option to improve limb salvage in end-stage peripheral arterial disease (PAD), but there is no consensus on its indication for spinal cord stimulation (SCS) in PAD patients. OBJECTIVE: The aim of this study was to present the outcome of end-stage PAD patients treated with SCS. METHODS: This study is a retrospective analysis based on a local prospective registry. Neuromodulation was performed if there was: 1) no revascularisation option, 2) no septicemia, 3) and Rutherford stage 4-6. The primary endpoint of the study was limb salvage. Secondary endpoints were reduction in pain or simply pain reduction pain (assessed using a visual anlog scale/VAS) and improvement in walking distance. RESULTS: Limb salvage was reached in 30/34 patients (88%). Patients reported a significant reduction in pain on the 10-point VAS scale from baseline (median = 7.5, IQR = 7-8) to follow-up at 2 years (median = 0, IQR 0-2.75), p < 0.001. Walking distance also improved from preoperative (median = 50 m, IQR = 20-50 m) to follow-up at 2 years (median = 150 m, IQR 50-272 m), p < 0.001. RESULTS: SCS implantation in patients with end-stage PAD can enable limb salvage in a high percentage of cases and increase mobility due to pain reduction. The role of microcirculation in these improvements needs to be investigated in further studies.

The Power of mind: Blocking visual perception by hypnosis.

The present study investigated the effects of suggestion on the processing of visual stimuli. Participants counted rare visual stimuli presented on a screen, once during a hypnosis condition where they were suggested that their vision of the screen is blocked by a virtual wooden board in front of their eyes and once during a control condition without suggestion. In the hypnosis condition, counting performance was about 20% worse than in the control condition. At the same time, the P3b amplitude of the event-related brain potential was about 37% reduced. Smaller P3b amplitudes were significantly associated with deficient counting performance, and this effect was largest in participants who reported the blockade as real. In contrast, earlier brain responses (N1, P2) that reflect basic processing of the visual stimuli were not affected by the suggested blockade. We conclude that the suggestion of the blockade affects later stages of visual perception, leaving early processes intact. This illustrates the impact of suggestions and the power of mind.

The Auditory Kuleshov Effect: Multisensory Integration in Movie Editing.

Almost a hundred years ago, the Russian filmmaker Lev Kuleshov conducted his now famous editing experiment in which different objects were added to a given film scene featuring a neutral face. It is said that the audience interpreted the unchanged facial expression as a function of the added object (e.g., an added soup made the face express hunger). This interaction effect has been dubbed "Kuleshov effect." In the current study, we explored the role of sound in the evaluation of facial expressions in films. Thirty participants watched different clips of faces that were intercut with neutral scenes, featuring either happy music, sad music, or no music at all. This was crossed with the facial expressions of happy, sad, or neutral. We found that the music significantly influenced participants' emotional judgments of facial expression. Thus, the intersensory effects of music are more specific than previously thought. They alter the evaluation of film scenes and can give meaning to ambiguous situations.

Impact of perceptual ability and mental imagery training on simulated laparoscopic knot-tying in surgical novices using a Nissen fundoplication model.

BACKGROUND: Performing minimally invasive surgery requires training and visual-spatial intelligence. The aim of our study was to examine the impact of visual-spatial perception and additional mental training on the simulated laparoscopic knot-tying task performed by surgical novices. METHODS: A total of 40 medical students randomly assigned to two groups underwent two sessions of laparoscopic basic training on a VR simulator (SimSurgery®, Oslo, Norway). The variables time and tip trajectory (total path length of the instrument tip trajectory) were used to assess the performance of the intracorporeal knot-tying task using a laparoscopic Nissen fundoplication model. The experimental group completed additional mental practice during the interval between the two training sessions. All performed a cube subtest of a standard intelligence test (I-S-T 2000 R) to evaluate visual-spatial ability. RESULTS: All participants achieved an improvement in time (t = 9.861; p < 0.001) and tip trajectory (t = 6.833; p < 0.001) in the second training session. High scores on the visual-spatial test correlated with a faster performance (r = -0.557; p < 0.001) and more precise movements (r = -0.377; p = 0.016). Comparison of the two groups did not show any statistical significant differences in the parameters time and tip trajectory. CONCLUSIONS: Visual-spatial intelligence tested by a cube test correlated with simulated laparoscopic knot-tying skills in surgical novices. Additional mental practice did not improve the overall knot-tying performance. Further studies are therefore required to determine whether mental practice might be beneficial for experienced laparoscopic surgeons or for more complex tasks.

GARP: a key receptor controlling FOXP3 in human regulatory T cells.

Recent evidence suggests that regulatory pathways might control sustained high levels of FOXP3 in regulatory CD4(+)CD25(hi) T (T(reg)) cells. Based on transcriptional profiling of ex vivo activated T(reg) and helper CD4(+)CD25(-) T (T(h)) cells we have identified GARP (glycoprotein-A repetitions predominant), LGALS3 (lectin, galactoside-binding, soluble, 3) and LGMN (legumain) as novel genes implicated in human T(reg) cell function, which are induced upon T-cell receptor stimulation. Retroviral overexpression of GARP in antigen-specific T(h) cells leads to an efficient and stable re-programming of an effector T cell towards a regulatory T cell, which involves up-regulation of FOXP3, LGALS3, LGMN and other T(reg)-associated markers. In contrast, overexpression of LGALS3 and LGMN enhance FOXP3 and GARP expression, but only partially induced a regulatory phenotype. Lentiviral down-regulation of GARP in T(reg) cells significantly impaired the suppressor function and was associated with down-regulation of FOXP3. Moreover, down-regulation of FOXP3 resulted in similar phenotypic changes and down-regulation of GARP. This provides compelling evidence for a GARP-FOXP3 positive feedback loop and provides a rational molecular basis for the known difference between natural and transforming growth factor-beta induced T(reg) cells as we show here that the latter do not up-regulate GARP. In summary, we have identified GARP as a key receptor controlling FOXP3 in T(reg) cells following T-cell activation in a positive feedback loop assisted by LGALS3 and LGMN, which represents a promising new system for the therapeutic manipulation of T cells in human disease.

[The Six Factor Test--a personality questionnaire for clinical practice and research]. / Der Sechs-Faktoren-Test zur Erfassung der Persönlichkeit in der klinischen Praxis und Forschung.

BACKGROUND: The Six factor Test (SFT) is a personality questionnaire for assessment of the "big five" (neuroticism, extraversion, conscience, aggressivity, openness to experiences) and piety in patients with mental disorders and healthy subjects. METHODS: In a study of 360 probands (125 depressive and bipolar patients, 150 first-degree relatives of these patients, and 85 controls), the reliability and validity of the SFT was examined. Thirty-five controls and 79 relatives were reinvestigated after around 6.5 years. RESULTS: The factorial structure could be replicated, and the concurrent validity was moderate to high. Acceptable internal consistency was observed, with the exceptions of "openness" and "agreeableness". The retest reliability was high, with the exception of "openness". Patients differed from controls in neuroticism and "openness". These factors were also predictive for the first onset of psychiatric disorders in controls and relatives, respectively. CONCLUSION: The SFT is a short und simple instrument for the assessment of personality in clinical samples and controls. Reliability and validity of the three main scales (neuroticism, extraversion, and conscience) were acceptable. The corresponding coefficients of the three shorter scales, in particular of openness, were partly much lower.

Laser-evoked potentials to noxious stimulation during hypnotic analgesia and distraction of attention suggest different brain mechanisms of pain control.

Psychological accounts of hypnosis have hypothesized that hypnosis and attention might share similar mechanisms and that hypnosis simply represents an extensive state of reduced attention. This assumption implies that reports of pain and electrocortical brain responses to painful stimulation should be similarly reduced when subjects are exposed to suggestions of hypnotic analgesia (HA) or requested to distract their attention from painful stimuli (distraction of attention: DA) as compared to a control condition (CC). To test this hypothesis, we recorded event-related electrical brain potentials to noxious laser-heat stimuli and pain reports during HA, DA, and CC from subjects highly susceptible to hypnotic suggestions. Pain reports were significantly reduced during HA and DA as compared to CC. The amplitudes of the late laser-evoked brain potential (LEP) components N200 and P320 were also significantly smaller during DA than during CC. However, no significant difference of these late LEP amplitudes was obtained for HA as compared to CC. Results indicate that hypnotic analgesia and distraction of attention represent different mechanisms of pain control and involve different brain mechanisms.

Artificial gravity: head movements during short-radius centrifugation.

Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feet at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed. Grant numbers: NCC 9-58.

Production of selenomethionine-labelled proteins using simplified culture conditions and generally applicable host/vector systems.

The amino acid analogue selenomethionine (SeMet) is shown to be efficiently incorporated into recombinant proteins expressed in Escherichia coli grown in a simple minimal medium without the addition of synthetic amino acids. Furthermore, satisfactory SeMet incorporation is obtained with a methionine-prototrophic strain transformed with commonly used vector systems. As examples, purified tryparedoxin 1 from Crithidia fasciculata, alkylhydroperoxide reductase (AhpC) from Mycobacterium marinum and the 16-kDa antigen from M. tuberculosis are shown to be efficiently labelled with SeMet, using the culture conditions and the host/vector systems described here. Enzymatic analysis reveals no differences between native and SeMet-labelled tryparedoxin 1 enzyme. Both proteins yield crystals under similar conditions. The culture conditions and host vector systems described greatly facilitate selenium-labelling of proteins for 3-D structure determination.

Crystal structures of human gephyrin and plant Cnx1 G domains: comparative analysis and functional implications.

The molybdenum cofactor (Moco) consists of a unique and conserved pterin derivative, usually referred to as molybdopterin (MPT), which coordinates the essential transition metal molybdenum (Mo). Moco is required for the enzymatic activities of all Mo-enzymes, with the exception of nitrogenase and is synthesized by an evolutionary old multi-step pathway that is dependent on the activities of at least six gene products. In eukaryotes, the final step of Moco biosynthesis, i.e. transfer and insertion of Mo into MPT, is catalyzed by the two-domain proteins Cnx1 in plants and gephyrin in mammals. Gephyrin is ubiquitously expressed, and was initially found in the central nervous system, where it is essential for clustering of inhibitory neuroreceptors in the postsynaptic membrane. Gephyrin and Cnx1 contain at least two functional domains (E and G) that are homologous to the Escherichia coli proteins MoeA and MogA, the atomic structures of which have been solved recently. Here, we present the crystal structures of the N-terminal human gephyrin G domain (Geph-G) and the C-terminal Arabidopsis thaliana Cnx1 G domain (Cnx1-G) at 1.7 and 2.6 A resolution, respectively. These structures are highly similar and compared to MogA reveal four major differences in their three-dimensional structures: (1) In Geph-G and Cnx1-G an additional alpha-helix is present between the first beta-strand and alpha-helix of MogA. (2) The loop between alpha 2 and beta 2 undergoes conformational changes in all three structures. (3) A beta-hairpin loop found in MogA is absent from Geph-G and Cnx1-G. (4) The C terminus of Geph-G follows a different path from that in MogA. Based on the structures of the eukaryotic proteins and their comparisons with E. coli MogA, the predicted binding site for MPT has been further refined. In addition, the characterized alternative splice variants of gephyrin are analyzed in the context of the three-dimensional structure of Geph-G.

Motor learning enhances perceptual judgment: a case for action-perception transfer.

Transfer from perception to action is well documented, for instance in the form of observational learning. Transfer from action to perception, on the other hand, has not been researched. Such action-perception transfer (APT) is compatible with several learning theories and has been predicted within the framework of common coding of perceptual and motor events (Prinz, 1992, 1997). Our first experiment aimed at an empirical evaluation of APT and involved motor practice of timed two-cycle arm movements on verbal command without visual feedback. In a transfer test, visual judgments of similar patterns had to be made. In addition, transfer from the visual to the motor task was studied. In Experiment 2 we separated kinesthetic aspects of motor practice from preparatory and efferent contributions to APT. The experiments provide evidence that transfer between perception and action is bi-directional. Transfer from perception to action and, more importantly, from action to perception was found. Furthermore, APT was equally pronounced for participants who had actively practiced movements during training and for passive participants who had received merely kinesthetic feedback about the movement. This kinesthetic-visual transfer is likely to be achieved via visuomotor-kinesthetic matching or via timekeeping mechanisms that are involved in both motor and visual performance.

New developments in atherosclerosis imaging: electron beam tomography.

Recently published data have greatly expanded the applicability of electron beam tomography (EBT) and electron beam angiography (EBA). The prognostic power of coronary artery calcium scoring for cardiac events and associated obstructive disease far surpasses that of conventional risk factors, and will increasingly be incorporated into risk assessment and treatment guidelines. EBT leads to the identification of treatable, non-low-density lipoprotein metabolic disorders that contribute to plaque formation, and to appropriate selection of stress test candidates. Change in calcium score can be used to assess the efficacy of lipid therapy and will serve as a surrogate marker in drug studies. EBA provides effective, noninvasive visualization of native coronary arteries and bypass grafts.

Lipid disorders and plaque imaging.

Electron-beam tomography (EBT) plaque imaging has the potential to fundamentally change the practice of prevention, through application of the following principles: (1) Asymptomatic patients with significant calcified plaque should be considered to have a clinical coronary artery disease risk equivalent. (2) Measurement of nontraditional parameters should be incorporated into the evaluation of patients with calcified plaque. (3) Drug treatment should focus on the asymptomatic patient with subclinical atherosclerosis. (4) Change in plaque rather than change in lipid values should guide treatment.

Metabolic disorders contribute to subclinical coronary atherosclerosis in patients with coronary calcification.

This investigation determined the prevalence of low-density lipoprotein (LDL) subclass distribution abnormalities, elevated lipoprotein(a) (Lp(a)), and elevated total plasma homocysteine in asymptomatic subjects with subclinical coronary artery disease determined by electron beam tomography (EBT). Fifty-five percent of subjects were classified as higher risk patients and 45% as lower risk patients, employing the National Cholesterol Education Program (NCEP) lipid criteria. EBT was performed in 296 consecutive asymptomatic subjects, and blood was analyzed for total, LDL, and high-density lipoprotein (HDL) cholesterol, triglycerides, LDL subclass distribution by S(3) gradient gel electrophoresis, Lp(a), and total homocysteine. Disorders of LDL subclass distribution were the most common disorder with 60.6% of the population expressing a distribution in the small regions IIIa + IIIb of >20%; and this was more common in the NCEP higher risk group (LDL cholesterol > or =130 and/or HDL cholesterol <35 mg/dl) (p <0.0004). A Lp(a) value >25 mg/dl was found significantly more often in the NCEP higher (36.9%) compared with lower (14.3%) risk group (p <0.001). None of the laboratory measurements correlated with the calcium score or calcium score percentile rank, with the exception of a weak correlation of mean LDL peak particle diameter and calcium percentile (r = 0.14, p = 0.02). Determination of metabolic disorders in addition to LDL cholesterol and HDL cholesterol increased the diagnostic yield from 55.1%, based on NCEP lipid criteria, to 84.1% with the addition of LDL subclass distribution, Lp(a), and total homocysteine. We conclude that: (1) disorders of LDL subclass distribution and elevated Lp(a) occur frequently in NCEP higher risk patients with subclinical coronary artery disease and are the only identifiable disorders in lower NCEP risk patients; and (2) electron beam tomographic evaluation and determination of LDL subclass distribution and Lp(a) should be considered for incorporation into primary prevention guidelines.

Electron beam tomography and National Cholesterol Education Program guidelines in asymptomatic women.

OBJECTIVES: This investigation was designed to determine the relationship between National Cholesterol Education Program (NCEP) ATP-II lipid guidelines and subclinical atherosclerosis, defined by electron beam tomography (EBT) calcified coronary plaque, in asymptomatic women. BACKGROUND: NCEP guidelines are used to identify women at increased risk for coronary artery disease (CAD) on the basis of low density lipoprotein cholesterol (LDLC) and high density lipoprotein cholesterol (HDLC) values. The relationship of the guidelines to subclinical atherosclerosis is unknown. METHODS: A total of 304 asymptomatic women underwent lipid and EBT evaluation and were classified as: 1) NCEP higher risk, with LDLC > or =130 mg/dl and/or HDLC <35 mg/dl, or lower risk with LDLC <130 mg/dl and HDLC > or =35 mg/dl; and 2) EBT+ if any calcified plaque was noted or EBT- if there was no calcified plaque. RESULTS: Forty-two percent of patients were EBT+, with a mean score of 227 and percentile of 73%; 58% were EBT-. Women who were EBT+ had significantly higher total cholesterol, LDLC and triglycerides than EBT- women, but only with ages < or =55 years; women >55 years demonstrated no differences. NCEP higher risk women made up 53.5% of the EBT+ and 37.7% of the EBT- groups; NCEP lower risk women accounted for 46.5% of the EBT+ and 62.3% of the EBT- groups. Assuming a higher risk in subjects with EBT-defined subclinical CAD than in those without, only 58.6% of the total group would be correctly identified by NCEP guidelines as either higher or lower risk, with correct identification of 65.5% of the younger and 52.2% of the older women. There was no correlation between either calcium percentile or score and any lipid measurement. CONCLUSIONS: This study demonstrates the shortcomings of employing NCEP guidelines to identify asymptomatic women with subclinical CAD, particularly women >55 years, and suggests increased utilization of EBT for primary prevention in the female population.

Structures of tryparedoxins revealing interaction with trypanothione.

Tryparedoxins (TXNs) catalyse the reduction of peroxiredoxin-type peroxidases by the bis-glutathionyl derivative of spermidine, trypanothione, and are relevant to hydroperoxide detoxification and virulence of trypanosomes. The 3D-structures of the following tryparedoxins are presented: authentic tryparedoxin1 of Crithidia fasciculata, CfTXN1; the his-tagged recombinant protein, CfTXN1H6; reduced and oxidised CfTXN2, and an alternative substrate derivative of the mutein CfTXN2H6-Cys44Ser. Cys41 (Cys40 in TXN1) of the active site motif 40-WCPPCR-45 proved to be the only solvent-exposed redox active residue in CfTXN2. In reduced TXNs, its nucleophilicity is increased by a network of hydrogen bonds. In oxidised TXNs it can be attacked by the thiol of the 1N-glutathionyl residue of trypanothione, as evidenced by the structure of 1N-glutathionylspermidine-derivatised CfTXN2H6-Cys44Ser. Modelling suggests Arg45 (44), Glu73 (72), the Ile110 (109) cis-Pro111 (110)-bond and Arg129 (128) to be involved in the binding of trypanothione to CfTXN2 (CfTXN1). The model of TXN-substrate interaction is consistent with functional characteristics of known and newly designed muteins (CfTXN2H6-Arg129Asp and Glu73Arg) and the 1N-glutathionyl-spermidine binding in the CfTXN2H6-Cys44Ser structure.

Recombinant tyrosine aminotransferase from Trypanosoma cruzi: structural characterization and site directed mutagenesis of a broad substrate specificity enzyme.

The gene encoding tyrosine aminotransferase (TAT, EC 2.6.1.5) from the parasitic protozoan Trypanosoma cruzi was amplified from genomic DNA, cloned into the pET24a expression vector and functionally expressed as a C-terminally His-tagged protein in Escherichia coli BL21(DE3)pLysS. Purified recombinant TAT exhibited identical electrophoretic and enzymatic properties as the authentic enzyme from T. cruzi. Both recombinant and authentic T. cruzi TATs were highly resistant to limited tryptic cleavage and contained no disulfide bonds. Comprehensive analysis of its substrate specificity demonstrated TAT to be a broad substrate aminotransferase, with leucine, methionine as well as tyrosine, phenylalanine, tryptophan and alanine being utilized efficiently as amino donors. Valine, isoleucine and dicarboxylic amino acids served as poor substrates while polar aliphatic amino acids could not be transaminated. TAT also accepted several 2-oxoacids, including 2-oxoisocaproate and 2-oxomethiobutyrate, in addition to pyruvate, oxaloacetate and 2-oxoglutarate. The functionality of the expression system was confirmed by constructing two variants; one (Arg389) being a completely inactive enzyme; the other (Arg283) retaining its full activity, as predicted from the recently solved three-dimensional structure of T. cruzi TAT. Thus, only one of the two strictly conserved arginines which are essential for the enzymatic activity of subfamily Ialpha aspartate and aromatic aminotransferases is critical for T. cruzi's TAT activity.

Heterocyclic ortho-quinones, a novel type of Photosystem II inhibitors.

Members of the new chemical class of 7-substituted 6-bromo-benzo[4,5]imidazo[1,2alpha]pyridin-8,9-diones were found to be excellent inhibitors at the Q(B) site of the photosystem II D1 reaction center protein. The best inhibitors with pI(50)-values of >7 are: dimethyl-propyl, 7.05; i-pentyl, 7.36; t. butyl, 7.47; and i-propyl, 7.51. Displacement experiments with [14C]atrazine revealed that the 8,9-diones behave non-competitively in respect of Photosystem II herbicides and, hence, have to be considered as a new type of Photosystem II inhibitors. This notion is further corroborated by their inhibitory activity in D1 mutants of Chlamydomonas reinhardtii.