137 research outputs found

    Coarse distance from dynamically convex to convex

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    Chaidez and Edtmair have recently found the first example of dynamically convex domains in R4\mathbb R^4 that are not symplectomorphic to convex domains (called symplectically convex domains), answering a long-standing open question. In this paper, we discover new examples of such domains without referring to Chaidez-Edtmair's criterion. We also show that these domains are arbitrarily far from the set of symplectically convex domains in R4\mathbb R^4 with respect to the coarse symplectic Banach-Mazur distance by using an explicit numerical criterion for symplectic non-convexity.Comment: 18 pages, 7 figure

    Anxiety and Depression Prevalence Rates in Age-Related Macular Degeneration

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    PURPOSE. To estimate the prevalence rates of depression and anxiety in patients with wet age-related macular degeneration (AMD) and the relationship with visual acuity and to develop a simple algorithm for depression screening. METHODS. This cross-sectional, prospective, observational, multicenter study was performed in France, Germany, and Italy. Retina specialists at 10 centers per country each enrolled 12 consecutive patients with wet ARMD. Patients were stratified into four severity groups by using best eye (BE) and worst eye (WE) visual acuity (VA) thresholds (BE:VA 20/40 and WE:VA 20/200). Patients rated themselves on the Hospital Anxiety and Depression Scale (HADS). Analysis of variance was performed to estimate the effect of VA severity levels on HADS scores adjusted on age, gender, and country. RESULTS. Patients (females 609/6) were recruited, with a mean age of 77 years and 2.3 years' disease duration. Mean BE:VA at inclusion was 0.49 logMar (logarithm of the minimum angled of resolution) and NW:VA 1.0 logMar. The prevalence of severe depression increased from 0% (BE:VA >= 20/40+WE:VA >= 20/200) to 7.6% (BE:VA < 20/40+)WE:VA < 20/200), whereas anxiety was unrelated to VA loss. Moreover, total depression scores were strongly associated with VA severity (P = 0.006), but not total anxiety scores (P = 0.840). Responses to two HADS items ("I still enjoy things I used to enjoy"; "I can enjoy a good book or radio or television program") identified 95% of severely to moderately depressed patients. CONCLUSIONS. Self-rated depression in patients with AMD was associated with VA severity level. It should, therefore, be relatively easy for ophthalmologists to implement the screening procedure and refer identified patients to psychiatrists for proper assessment and treatment

    Family trios analysis of common polymorphisms in the obestatin/ghrelin, BDNF and AGRP genes in patients with Anorexia nervosa: Association with subtype, body-mass index, severity and age of onset.

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    Anorexia nervosa (AN) affects 0.3% of young girls with a mortality of 6%/decade and is strongly familial with genetic factors. Ghrelin is an upstream regulator of the orexigenic peptides NPY and AgRP and acts as a natural antagonist to leptin's effects on NPY/AgRP-expressing neurons, resulting in an increase in feeding and body weight. Obestatin which counteracts ghrelin action on feeding is derived from the same propeptide than ghrelin. BDNF has been involved in body weight regulation and its Val66Met polymorphism associated with AN. We therefore re-investigated the association between AN and the Leu72Met and Gln90Leu polymorphisms of the prepro-ghrelin/obestatin gene, the Ala67Thr polymorphism of AgRP and the Val66Met polymorphism of BDNF taking into account clinical subtypes (restrictive-ANR-and bingeing/purging-ANB-subtypes). Family trios study of these 4 single nucleotide polymorphisms were performed in 114 probands with AN and both their parents recruited in two specialized French centres. A transmission disequilibrium was observed for the Leu72Met SNP of the preproghrelin gene and for the Ala67Thr SNP of the AgRP gene. When stratified by clinical subtype, these two polymorphisms were preferentially transmitted for the trios with a bingeing/purging proband. An excess of transmission of the Gln90Leu72 preproghrelin/obestatin haplotype in patients with AN was observed. These results do not provide evidence for a preferential transmission of the 66Met allele of BDNF but support the hypothesis that ghrelin and AGRP polymorphisms confers susceptibility to AN. Further simultaneous analysis of genetic variants of the biological determinants of energy metabolism and feeding behaviour in very large populations should contribute to the understanding of the high degree of heritability of eating disorders and to the description of pathophysiological patterns leading to life-threatening conditions in a highly redundant system

    Development of neurons in the ectostriatum of normal and monocularly deprived zebra finches: a quantitative Golgi study

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    Herrmann K, Bischof H-J. Development of neurons in the ectostriatum of normal and monocularly deprived zebra finches: a quantitative Golgi study. The Journal of Comparative Neurology. 1988;277(1):141-154.The postnatal development of the main neuron type in the ectostriatum, the telencephalic station of the tectofugal pathway, was followed in normally reared and monocularly deprived zebra finches by using the Golgi method. Three parameters were investigated: dendritic field radius, branching index, and spine density. The results show that all three exhibit the same developmental trend - namely, an increase from day 5 until day 20, followed by a subsequent reduction until adulthood (>100 days). Monocular deprivation from birth until day 20, 40, or at least 100 does not seem to interfere with the development of the dendritic field radius or branching index. Clear changes in spine density result from depriving the birds for at least 40 days. In these birds, neurons in the deprived hemisphere bear significantly fewer spines than those in the nondeprived hemisphere, which is mainly due to a lack of normally occurring spine reduction in the nondeprived hemisphere rather than to spine reduction in the deprived hemisphere

    Obestatin as a key regulator of metabolism and cardiovascular function with emerging therapeutic potential for diabetes

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    Obestatin is a 23‐amino acid C‐terminally amidated gastrointestinal peptide derived from preproghrelin and which forms an α helix. Although obestatin has a short biological half‐life and is rapidly degraded, it is proposed to exert wide‐ranging pathophysiological actions. Whilst the precise nature of many of its effects is unclear, accumulating evidence supports positive actions on both metabolism and cardiovascular function. For example, obestatin has been reported to inhibit food and water intake, body weight gain and gastrointestinal motility and also to mediate promotion of cell survival and prevention of apoptosis. Obestatin‐induced increases in beta cell mass, enhanced adipogenesis and improved lipid metabolism have been noted along with up‐regulation of genes associated with beta cell regeneration, insulin production and adipogenesis. Furthermore, human circulating obestatin levels generally demonstrate an inverse association with obesity and diabetes, whilst the peptide has been shown to confer protective metabolic effects in experimental diabetes, suggesting that it may hold therapeutic potential in this setting. Obestatin also appears to be involved in blood pressure regulation and to exert beneficial effects on endothelial function, with experimental studies indicating that it may also promote cardioprotective actions against, for example, ischaemia–reperfusion injury. This review will present a critical appraisal of the expanding obestatin research area and discuss the emerging therapeutic potential of this peptide for both metabolic and cardiovascular complications of diabetes

    Differences in relatives' and patients' illness perceptions in functional neurological symptom disorders compared with neurological diseases

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    Objective: The illness perceptions of the relatives of patients with functional neurological symptom disorders (FNSDs) and their relation to the illness perceptions of the patients have been little studied. We aimed to compare illness perceptions of relatives of patients with FNSDs with those held by patients themselves. We used control pairs with neurological diseases (NDs) to examine the specificity of the findings to FNSDs. Material and methods: Patients with FNSDs (functional limb weakness and psychogenic nonepileptic seizures) and patients with NDs causing limb weakness and epilepsy, as well as their relatives, completed adapted versions of the Illness Perception Questionnaire - Revised (IPQ-R). Results: We included 112 pairs of patients with FNSDs and their relatives and 60 pairs of patients with NDs and their relatives. Relatives of patients with FNSDs were more likely to endorse psychological explanations and, in particular, stress as causal factors than patients with FNSDs (p. <.001). Relatives of patients with FNSDs were also more pessimistic about the expected duration of the disorder and perceived a greater emotional impact compared with patients themselves (p. <.001). However, the latter two differences between patients and relatives were also found in pairs of patients with NDs and their relatives. Conclusion: The main difference in illness perceptions between relatives and patients that appeared specific to FNSDs was a tendency for relatives to see psychological factors as more relevant compared with patients. Some other differences were observed between pairs of patients with FNSDs and their relatives, but the same differences were also seen in pairs of patients with NDs and their relatives. These other differences were, therefore, not specific to FNSDs. Discussion about possibly relevant psychological factors with patients suffering from FNSDs may be helped by including relatives
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