Phylogenetic relationships of species of Raymunida (Decapoda: Galatheidae) based on morphology and mitochondrial cytochrome oxidase sequences, with the recognition of four new species

19 pages.-- RECEIVED: 10 April 2000, ACCEPTED: 8 November 2000.The species of the genus Raymunida from the Pacific and Indian oceans are revised using morphological characters and the mitochondrial cytochrome oxidase subunit I sequences. Four new species are described (R. confundens, R. dextralis, R. erythrina, and R. insulata), and the status of R. bellior and R. elegantissima are revised. The species of Raymunida can be identified by subtle morphological characters, which match differences in mitochondrial nucleotide sequences. Therefore, the sequence divergences confirm the specific and phylogenetic value of some morphological characters (e.g., length of the mesial spine on the basal antennal segment, length of the walking legs). Furthermore, they confirm the importance of the color pattern as a diagnostic character. The widespread species (R. elegantissima), known from the Philippines to Fiji, shows minimal divergence between specimens from different localities (maximum of 3 nucleotide differences or 0.2% mean divergence). The phylogenetic reconstruction agreed with the monophyletic condition of Raymunida and its differentiation with respect to the genus Munida (in which Raymunida species had previously been included) and Agononida.Peer reviewe

The sensitivity of 18-fluorodopa positron emission tomography and magnetic resonance imaging in Parkinson's disease

© 2004 European Federation of Neurological Societie

Monosymptomatic resting tremor and Parkinson's disease: A multitracer positron emission tomographic study

We sought to elucidate the relationship between monosymptomatic resting tremor (mRT) and Parkinson's disease (PD). We studied eight mRT patient,, (mean Hoehn and Yahr [HY], 1.1 +/- 0.4), eight patients with PD (mean HY, 1.5 +/- 0.8), who showed all three classic parkinsonian symptoms, and seven age-matched healthy subjects. Subjects underwent cerebral magnetic resonance imaging (MRI) and multitracer positron emission tomography (PET) with 6-[F-18]fluoro-L-dopa (F-dopa), [F-18]fluorodeoxyglucose (FDG), and [C-11]raclopride (RACLO). PD and mRT patients did not show significant differences in F-dopa-, RACLO-, or FDG-PET scans. In F-dopa- and RACLO-PET, significant differences between the pooled patient data and control subjects were found for the following regions: anterior and posterior putamen ipsilateral and contralateral to the more affected body side, and ipsilateral and contralateral putaminal gradients of the K-i values. Furthermore. we found a difference for the normalized glucose values of the whole cerebellum between the control group (0.94 +/- 0.06) and PD patients (1.01 +/- 0.04 P < 0.05) but not for the mRT group (0.97 +/- 0.03). Our findings indicate that monosymptomatic resting tremor represents a phenotype of Parkinson's disease, with a nearly identical striatal dopaminergic deficit and postsynaptic D2-receptor upregulation in both patient groups. We suggest that the cerebellar metabolic hyperactivity in PD is closer related to akinesia and rigidity rather than to tremo

Deep brain stimulation of the subthalamic nucleus versus levodopa challenge in Parkinson's disease: measuring the on- and off-conditions with FDG-PET

In order to compare the effects of high-frequency stimulation of the subthalamic nucleus (STN-DBS) and a levodopa-challenge on cerebral metabolic activity, we conducted PET scans with [F- 18]2-fluoro-2-deoxyglucose (FDG) in the drug- and stimulation- on- and off-condition in a single patient suffering from advanced PD. Our data revealed evidence for improved thalamocortical processing released from inhibition by overactive basal ganglia output nuclei in both on-conditions. While levodopa also led to a reduction of lentiform hyperactivity, effective STN stimulation seemed to interfere with distinct cerebellar and limbic circuits

[F-18]fluorodopa uptake in the upper brainstem measured with positron emission tomography correlates with decreased REM sleep duration in early Parkinson's disease

Copyright 2003 ELSEVIER SCIENC

The antiparkinsonian effects of deep brain stimulation in the subthalamic nucleus are not mediated by an increase of tonic striatal dopamine receptor stimulation: evidence from serial [11C]raclopride-PET in parkinsonian humans

Copyright Elsevier Science 200

Decisionmaking impairments in patients with pathological gambling

Abstract. A high percentage of Parkinson&apos;s disease (PD) patients show cognitive impairments in addition to the cardinal motor symptoms. These deficits primarily concern executive functions most probably linked to dysfunctions in prefrontal regions due to decreased dopaminergic transmission in fronto-striatal loops. To investigate possible associations between decision-making and executive functions in PD, we examined 20 non-demented PD patients and 20 healthy control subjects with a neuropsychological test battery and the Game of Dice Task. In this computerised decision-making task, the rules for gains and losses and the winning probabilities are obvious and stable. Thus, strategic components besides feedback processing might influence decisionmaking in this task. We found that PD patients were impaired in the Game of Dice task performance and that the frequency of disadvantageous choices correlated with both executive functions and feedback processing. We suggest that decision-making deficits of PD patients in explicit gambling situations might be associated with dysfunctions in two different fronto-striatal loops: the limbic-orbitofrontal-striatal loop, involved in feedback processing, and the dorsolateral prefrontal-striatal loop, involved in executive functions