TNFα-induced DLK activation contributes to apoptosis in the beta-cell line HIT.

Reduction in beta-cell mass and function contributes to the pathogenesis of diabetes mellitus type 2. The proinflammatory cytokines tumor necrosis factor (TNF)α and interleukin (IL)-1β have been implicated in the pathogenesis of this disease. Overexpression of the dual leucine zipper kinase (DLK) inhibits beta-cell function and induces apoptosis in the beta-cell line HIT.

The influence of object height on maximum grip aperture in empirical and modeled data.

During a grasping movement, the maximum grip aperture (MGA) is almost linearly scaled to the dimension of the target along which it is grasped. There is still a surprising uncertainty concerning the influence of the other target dimensions on the MGA. We asked healthy participants to grasp cuboids always along the object's width with their thumb and index finger.

Routine clinical testing underestimates proprioceptive deficits in Friedreich's ataxia.

Friedreich's ataxia (FA) is the most common recessive ataxia in the Western world with degeneration of dorsal root ganglia neurons as its major neuropathological hallmark. The sensitivity of clinical tools commonly used for the assessment of the proprioceptive component of FA is currently unknown. We hypothesised that current clinical testing underestimates proprioceptive deficits in FA patients.

Guidelines and quality measures for the diagnosis of optic ataxia.

Since the first description of a systematic mis-reaching by Bálint in 1909, a reasonable number of patients showing a similar phenomenology, later termed optic ataxia (OA), has been described. However, there is surprising inconsistency regarding the behavioral measures that are used to detect OA in experimental and clinical reports, if the respective measures are reported at all. A typical screening method that was presumably used by most researchers and clinicians, reaching for a target object in the peripheral visual space, has never been evaluated.

Effects of pictorial cues on reaching depend on the distinctiveness of target objects.

There is an ongoing debate under what conditions learned object sizes influence visuomotor control under preserved stereovision. Using meaningful objects (matchboxes of locally well-known brands in the UK) a previous study has nicely shown that the recognition of these objects influences action programming by means of reach amplitude and grasp pre-shaping even under binocular vision. Using the same paradigm, we demonstrated that short-term learning of colour-size associations was not sufficient to induce any visuomotor effects under binocular viewing conditions.

Limb apraxia in acute ischemic stroke: a neglected clinical challenge?

Symptoms of limb apraxia and executive dysfunctions are currently not explicitly considered by the National Institutes of Health Stroke Scale and, thus, not routinely tested by clinicians in the acute care of patients with suspected stroke. Neuropsychological testing, clinical examination, MRI, and functional magnetic resonance imaging (fMRI) were performed in a right-handed patient with acute onset of left-sided sensorimotor hemiparesis due to a right hemisphere ischemic stroke. Deficits in the execution of meaningless and meaningful gestures were not detected properly on initial clinical examination but were revealed later on through neuropsychological testing.

The recognition of everyday objects changes grasp scaling.

Current concepts of action and perception emphasise a dissociation between conscious visual recognition and visual action control. These models do not expect an effect of the recognisable identity of an object on the kinematic parameterisation of grasping movements under binocular viewing conditions without pre-test learning periods. We performed two experiments presenting participants with familiar everyday objects or neutral geometrical objects.

Eye proprioception used for visual localization only if in conflict with the oculomotor plan.

Both the corollary discharge of the oculomotor command and eye muscle proprioception provide eye position information to the brain. Two contradictory models have been suggested about how these two sources contribute to visual localization: (1) only the efference copy is used whereas proprioception is a slow recalibrator of the forward model, and (2) both signals are used together as a weighted average. We had the opportunity to test these hypotheses in a patient (R.

Direct electrical stimulation of human cortex - the gold standard for mapping brain functions?

Despite its clinical relevance, direct electrical stimulation (DES) of the human brain is surprisingly poorly understood. Although we understand several aspects of electrical stimulation at the cellular level, surface DES evokes a complex summation effect in a large volume of brain tissue, and the effect is difficult to predict as it depends on many local and remote physiological and morphological factors. The complex stimulation effects are reflected in the heterogeneity of behavioural effects that are induced by DES, which range from evocation to inhibition of responses - sometimes even when DES is applied at the same cortical site.

Bilateral hand representations in human primary proprioceptive areas.

Sensory representations in the postcentral gyrus are supposed to be strictly lateralised and to provide spatially unbiased representations of limb positions. However, electrophysiological and behavioural measurements in humans and non-human primates tentatively suggested some degree of bilateral processing even in early somatosensory areas. We report a patient who suffered a small and confined lesion of the hand area in the postcentral gyrus that resulted in a proprioceptive deficit without any concomitant primary motor impairment.

Visual action control does not rely on strangers--effects of pictorial cues under monocular and binocular vision.

Fast goal-directed actions are supposed to be controlled almost exclusively by bottom-up visual control. This mode of processing has been identified with the so-called dorsal visual stream. It is generally accepted that object recognition, mediated by the ventral stream, must be important for deciding what action to execute depending on the specific object to be grasped and the particular purpose.

Comment on "Movement intention after parietal cortex stimulation in humans".

Desmurget et al. (Reports, 8 May 2009, p. 811) applied direct electrical stimulation (DES) to the human cortex to study the origin of movement intention.

Activation of the dual-leucine-zipper-bearing kinase and induction of beta-cell apoptosis by the immunosuppressive drug cyclosporin A.

Post-transplant diabetes is an untoward effect often observed under immunosuppressive therapy with cyclosporin A. Besides the development of peripheral insulin resistance and a decrease in insulin gene transcription, a beta-cell toxic effect has been described. However, its molecular mechanism remains unknown.