Phantom-limb pain: characteristics,causes, and treatment

Phantom-limb pain is a common sequela of amputation, occurring in up to 80% of people who undergo the procedure. It must be differentiated from non-painful phantom phenomena, residual-limb pain, and non-painful residual-limb phenomena. Central changes seem to be a major determinant of phantom-limb pain; however, peripheral and psychological factors may contribute to it. A comprehensive model of phantom-limb pain is presented that assigns major roles to pain occurring before the amputation and to central as well as peripheral changes related to it. So far, few mechanism-based treatments for phantom-limb pain have been proposed. Most published reports are based on anecdotal evidence. Interventions targeting central changes seem promising. The prevention of phantom-limb pain by peripheral analgesia has not yielded consistent results. Additional measures that reverse or prevent the formation of central memory processes might be more effective.     

Amino-acid sequence comparison of nepovirus coat proteins

The amino acid sequence of the coat proteins of several nepoviruses was determined by a combination of peptide and nucleic acid sequencing (grapevine fanleaf virus, arabis mosaic virus, tomato blackring virus, grapevine chrome mosaic virus). These sequences were compared and showed homologies ranging from 10% to 69%, and 96.7% for the two arabis mosaic virus strains. 10% homology does not reflect any relationship between viruses, and our results implicate, that nepoviruses, considering the homology of the coat protein sequences of viruses as a parameter for virus taxonomy, may be divided into several subgroups.     

Differential activation of the dorsal striatum by high-calorie visual food stimuli in obese individuals

The neural systems regulating food intake in obese individuals remain poorly understood. Previous studies applied positron emission tomography and manipulated hunger and satiety to investigate differences in appetitive processing between obese and normal-weight individuals. However, it is not known whether manipulation of stimulus value may yield different neural activity in obese as compared to control subjects when intrinsic physiological states are kept constant. We used functional magnetic resonance imaging to investigate 13 obese and 13 normal-weight subjects and manipulated food motivation by presenting visual food stimuli differing in their caloric content and energy density. In contrast to controls, obese women selectively activated the dorsal striatum while viewing high-caloric foods. Moreover, in the high-calorie condition body mass index (BMI) predicted activation in the dorsal striatum, anterior insula, claustrum, posterior cingulate, postcentral and lateral orbitofrontal cortex. The results indicate that in obese individuals simple visual stimulation with food stimuli activates regions related to reward anticipation and habit learning (dorsal striatum). Additionally, high-calorie food images yielded BMI-dependent activations in regions associated with taste information processing (anterior insula and lateral orbitofrontal cortex), motivation (orbitofrontal cortex), emotion as well as memory functions (posterior cingulate). Collectively, the results suggest that the observed activation is independent of the physiological states of hunger and satiation, and thus may contribute to pathological overeating and obesity. Some of the observed activations (dorsal striatum, orbitofrontal cortex) are likely to be dopamine-mediated.     

Plaque-associated endothelial dysfunction in apolipoprotein E-deficient mice on a regular diet. Effect of human apolipoprotein AI

OBJECTIVE: Apolipoprotein E-deficient mice (apoE(-/-)) on a regular diet become hypercholesterolemic and develop atherosclerosis, but endothelium-dependent relaxation remains undisturbed for up to 6 months. We investigated whether vasomotor dysfunction develops in aged apoE(-/-), whether the defect was systemic (hypercholesterolemia-dependent) or focal (plaque-related), and the effect of human apolipoprotein AI transgenesis (apoAI/E(-/-)). METHODS: Arteries of apoE(-/-) (n=5), apoAI/E(-/-) (n=6) and C57Bl/6J (WT, n=4) mice (18 months) were systematically dissected for isometric tension recording and subsequent morphometry. RESULTS: Acetylcholine (ACh)-induced relaxation was impaired (P<0.01) in atherosclerotic segments of apoE(-/-) (26+/-14%) as compared to WT mice (93+/-2%). Similar reduced (P<0.01) responses to adenosine 5'-triphosphate (apoE(-/-) 38+/-14, WT 94+/-3%) and the calcium ionophore A23187 (apoE(-/-) 19+/-6%, WT 97+/-2%) pointed to a post-receptor defect. Indeed, responses to exogenous nitric oxide were impaired in atherosclerotic segments as well (apoE(-/-) 71+/-7%, WT 92+/-1%, P<0.05). Furthermore, relaxations inversely correlated with plaque size (ACh r(s)=-0.74, P<0.01). In adjacent plaque-free segments however, responses to ACh (apoE(-/-) 92+/-3%, WT 97+/-1%) and all other agents were preserved, despite the prolonged hypercholesterolemia. ApoAI improved vasomotor responses in atherosclerotic segments. However, negative correlations between maximal relaxation and plaque area remained in apoAI/E(-/-) mice (ACh r(s)=-0.67, P<0.01). Indeed, covariate analysis of variance did not point to direct protection of vasomotor function by apoAI when the smaller lesions were taken into account. CONCLUSIONS: Endothelial dysfunction in apoE(-/-) mice is not affected by hypercholesterolemia alone, but is strictly associated with plaque formation. Human apoAI transgenesis-known to raise HDL-attenuated atherogenesis, thereby indirectly improving relaxation responses in apoE(-/-) mice.     

Einfache klinische Testmethode zur Prüfung der Merkfähigkeit

Ohne Zusammenfassung     

Oppositional COMT Val158Met effects on resting state functional connectivity in adolescents and adults

Prefrontal dopamine levels are relatively increased in adolescence compared to adulthood. Genetic variation of COMT (COMT Val158Met) results in lower enzymatic activity and higher dopamine availability in Met carriers. Given the dramatic changes of synaptic dopamine during adolescence, it has been suggested that effects of COMT Val158Met genotypes might have oppositional effects in adolescents and adults. The present study aims to identify such oppositional COMT Val158Met effects in adolescents and adults in prefrontal brain networks at rest. Resting state functional connectivity data were collected from cross-sectional and multicenter study sites involving 106 healthy young adults (mean age 24 ± 2.6 years), gender matched to 106 randomly chosen 14-year-olds. We selected the anterior medial prefrontal cortex (amPFC) as seed due to its important role as nexus of the executive control and default mode network. We observed a significant age-dependent reversal of COMT Val158Met effects on resting state functional connectivity between amPFC and ventrolateral as well as dorsolateral prefrontal cortex, and parahippocampal gyrus. Val homozygous adults exhibited increased and adolescents decreased connectivity compared to Met homozygotes for all reported regions. Network analyses underscored the importance of the parahippocampal gyrus as mediator of observed effects. Results of this study demonstrate that adolescent and adult resting state networks are dose-dependently and diametrically affected by COMT genotypes following a hypothetical model of dopamine function that follows an inverted U-shaped curve. This study might provide cues for the understanding of disease onset or dopaminergic treatment mechanisms in major neuropsychiatric disorders such as schizophrenia and attention deficit hyperactivity disorder.     

Wirkfaktor Bühne Bühne und Raum im Psychodrama

Zusammenfassung Als Gestaltung, die im Augenblick entsteht, stellt Psychodrama eine besondere Herausforderung dar, die im Frühwerk Morenos anklingt. Ausgehend von der Bühne wird der psychodramatische Raum, den sie mit der Gruppe bildet, beschrieben. Die diesem Raum innewohnende Dynamik wird in Anlehnung an Konzepte von Winnicott und Bion herauszuarbeiten versucht. Die beschriebenen Wahrnehmungs- und Interaktionsprozesse geh?ren dem nichtsprachlichen Bereich an. Sie k?nnen als Folie verstanden werden, die dem Handlungsraum der Gruppe Transparenz verleihen.

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Summary (The stage and its impact. Stage and space in psychodrama) As spontaneous creation, psychodrama represents a special challenge whose significance is addressed in Moreno’s early works. The psychodramatic space created by the stage and the group are focus of this analysis. Based on the concepts of Winnicott and Bion an attempt is made to elucidate the dynamics inherent in psychodrama. The processes of perception and interaction described belong to the nonverbal realm. They can be understood as a lens lending transparency to the group’s scope of action.

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Herta Schemmel Diplom-Psychologin, Weiterbildungsleiterin am Psychodrama-Institut-Münser; in freier Praxis, Hamburg     

Zur Extraktion eines unteren Schneidezahnes

Ohne ZusammenfassungMit 10 Abbildungen