Re-assessing acalculia: Distinguishing spatial and purely arithmetical deficits in right-hemisphere damaged patients.

Arithmetical deficits in right-hemisphere damaged patients have been traditionally considered secondary to visuo-spatial impairments, although the exact relationship between the two deficits has rarely been assessed. The present study implemented a voxelwise lesion analysis among 30 right-hemisphere damaged patients and a controlled, matched-sample, cross-sectional analysis with 35 cognitively normal controls regressing three composite cognitive measures on standardized numerical measures. The results showed that patients and controls significantly differ in Number comprehension, Transcoding, and Written operations, particularly subtractions and multiplications. The percentage of patients performing below the cutoffs ranged between 27% and 47% across these tasks. Spatial errors were associated with extensive lesions in fronto-temporo-parietal regions -which frequently lead to neglect- whereas pure arithmetical errors appeared related to more confined lesions in the right angular gyrus and its proximity. Stepwise regression models consistently revealed that spatial errors were primarily predicted by composite measures of visuo-spatial attention/neglect and representational abilities. Conversely, specific errors of arithmetic nature linked to representational abilities only. Crucially, the proportion of arithmetical errors (ranging from 65% to 100% across tasks) was higher than that of spatial ones. These findings thus suggest that unilateral right hemisphere lesions can directly affect core numerical/arithmetical processes, and that right-hemisphere acalculia is not only ascribable to visuo-spatial deficits as traditionally thought.

BICUVOX.1-matrix composite electrolyte with yttria-stabilized zirconia as an inert phase: SEM evaluation of the chemical stability under hydrogen atmosphere.

The purpose of this study is to evaluate the efficacy of yttria-stabilized zirconia (3Y-TZP) as an inert phase to prevent the decomposition of Bi2 V0.9 Cu0.1 O5.5 -δ (BICUVOX.1) electrolyte under reducing atmosphere. A post-mortem scanning electron microscopy (SEM) study was performed after chemical stability tests under hydrogen-rich atmosphere using a Sieverts-type apparatus. SEM results showed that BICUVOX.1 decomposition starts under a hydrogen pressure of 19.7 atm at 300°C, even in the case of the composite containing 3Y-TZP. The microstructure of BICUVOX.1 after decomposition was observed to be composed of microspheres ranging from 10 to 100 µm formed primarily of metallic bismuth. In the composite, in addition to microspheres, the microstructure contained bismuth fibers growth from the grain area of the BICUVOX.1 matrix. Despite significant surface morphological modifications, the grain-boundary-arranged 3Y-TZP particles in a BICUVOX.1-matrix composite did not result in enhanced chemical stability.

[Nurse's role in the processes of hospital humanization and procedural pain relief in children]. / L'umanizzazione dell'ospedale: il ruolo dell'infermiere nella riduzione della paura e dello stress nel bambino, con particolare riferimento alla procedura del prelievo venoso periferico.

In childhood, hospital admission is frequently seen as something unexplanable and close to a "punishment". Involving parents/caretakers in the process of care is critical for the child to cope with the distress arising from hospital contacts and medical procedures. However, some grey zone remains for common procedures as venipuncture in hospital and ambulatory settings. We have conducted a literature review, searching for articles focused on procedural distress reduction/control in children. Several studies show that communication play a critical role and that children as young as 5 are able to "read" the way nurses and doctors interact with them and their approach is very important in reducing procedural distress. However, children attitude toward communication of health information may not be so linear, because they tend to continuously shift from a position of "passive bystander" to a "active participant" one, and viceversa. Nurse's role is crucial for the reduction of procedural distress because of her/his frequent contact with the young patients, but often she/he does not have the skills to help children to cope with procedural distress. Several approaches to this issue are discussed.

Visuomotor imagery and rehabilitation of neglect.

OBJECTIVE: To assess the effectiveness of visuomotor imagery training in the rehabilitation of unilateral neglect. DESIGN: Before-after trial. Behavioral analysis of single cases. SETTING: Neurologic rehabilitation unit of a university hospital. PATIENTS: Two patients with acquired brain injury who were suffering from severe and long-lasting unilateral neglect consequent to large lesions of cortical and subcortical right-brain. INTERVENTION: A behavioral training program consisting of visual and movement imagery exercises. Forty experimental sessions, each lasting 50 minutes, were delivered. MAIN OUTCOME MEASURES: Six neuropsychological tests evaluating unilateral neglect: seven "functional" tests assessing neglect behavior under daily life conditions; a questionnaire (filled out by the patients' relatives) concerning the patients' disability in the family context attributable to neglect. All the outcome measures were recorded at three different times: before, soon after, and 6 months after the end of the experimental training. RESULTS: The visuomotor "imagery training" ameliorated the deficit in performance related to neglect in both patients. All the outcome measures (neuropsychological and functional tests and the questionnaire) were positively influenced by the treatment. Moreover, the improvement was stable over a 6-month period, suggesting that the treatment had a long-term effect. CONCLUSIONS: The results show the possible effectiveness of a training method based on visuomotor imagery in diminishing impairment and functional disability associated with contralateral neglect.

Effects of hypercarbia on autoregulation of brain blood flow and cerebral metabolism in newborn piglets.

We tested the hypothesis that, in newborn piglets, hypercarbia impairs autoregulation of total and regional brain blood flow at the lower limb of the autoregulatory curve. Cerebral oxygen metabolism was measured in the same piglets to relate changes in metabolism to blood flow. Instrumented hypercarbic (n = 9) and normocarbic (n = 8) newborn piglets exposed to phlebotomy were studied during normotension and graded hypotension with mean arterial blood pressures of 55-41, 40-31 and < 30 mmHg. In the hypercarbic piglets, total brain blood flow decreased (P < 0.01) from the hypercarbic-normotensive value of 187 +/- 15 mliter min-1 100 g-1 to 139 +/- 18, 66 +/- 11 and 34 +/- 6 at mean arterial blood pressures of 55-41, 40-31 and < 30 mmHg, respectively; in the normocarbic piglets, total brain blood flow did not change from the normotensive value (70 +/- 11 mliter min-1 100 g-1) until the mean arterial blood pressure was < 30 mmHg, when brain blood flow had decreased (P < 0.01) to 49 +/- 8 mliter min-1 100 g-1. In the hypercarbic piglets, all brain regions (cerebrum, caudate nucleus, cerebellum, brainstem and medulla) demonstrated similar response patterns to that of total brain blood flow during hypotension. Thus, during hypercarbia, none of the brain regions demonstrated autoregulation. In the normocarbic piglets, cerebral blood flow decreased (P < 0.01) from the normocarbic-normotensive value of 74 +/- 6 mloter min-1 100 g-1 to 51 +/- 8 and 37 +/- 7 at mean arterial blood pressures of 40-31 and < 30 mmHg, respectively, and blood flow to the caudate nucleus, cerebellum and brainstem did not decrease significantly, and in fact increased (P < 0.01) to the medulla during hypotension. Although cerebral oxygen metabolism was compromised in the hypercarbic and normocarbic piglets, the relationship between metabolism and blood flow was altered such that the cerebral metabolic rate of oxygen per unit of blood flow was lower in the hypercarbic than the normocarbic piglets. We conclude that hypercarbia impairs total and regional brain blood flow autoregulation in newborn piglets.

Chemical sorbents: official guidelines and experimental approach.

To evaluate the biocompatibility of an anionic exchange resin with active group trimethylammonium and charged with chloride ions an experimental study was performed with different tests to determine cytocompatibility, acute systemic toxicity, intracutaneous reactivity, allergic sensibilization, haemocompatibility and release of acetone, dichloromethane, quaternary amines and heavy metals (Pb, Cu, Cd) in eluate. Thus an anionic exchange resin can link all anionic substances; an ex vivo study on the participation of the dissociated sodic heparin in the anionic exchange was also conducted. In fact every time an extracorporeal circuit is made an anticoagulant must be administered to the patient and the removal of the drug could cause serious haemocoagulative problems. The results of the study showed a high biocompatibility of the resin that did not cause different significant reactions in comparison with negative control substances. The coating of the resin with poly-hydroxy-ethyl methacrilate with a separation phase technique avoided heparin removal from blood. Therefore adjustment of the dosage may not be necessary during further in vivo experiments. Future researches aiming to evaluate the the effectiveness and the biocompatibility of the sorbent in a living being will be performed in the next steps of the study.

Postprandial gastrointestinal blood flow and oxygen consumption during environmental cold stress.

We studied the independent and combined effects of feeding and environmental cold stress by measuring pre- and postprandial gastrointestinal blood flow (QGI), oxygen consumption (GIVO2), and oxygen extraction (GIO2ex) in seven awake 3- to 4-day-old piglets while in a thermoneutral environment (control phase, 31 degrees C) and during environmental cold stress (experimental phase, 20.5 degrees C). Each animal consecutively completed both the control and experimental phases. In the control phase, measurements were made before and 30 min after feeding. In the experimental phase, measurements were made before and 30 min after induction of cold stress. A feeding was then given and measurements repeated 30 min later during continued cold stress. QGI (ml.100 g-1.min-1) increased postprandially while in a thermoneutral environment (130 +/- 11 to 152 +/- 12) but not while in a cold environment (126 +/- 15 to 121 +/- 8). Postprandial GIVO2 (ml O2.100 g-1.min-1) increased from 2.1 +/- 0.2 to 3.7 +/- 0.5 while in a warm environment. During preprandial cold stress, an unexpected increase in GIVO2 was observed (1.7 +/- 0.2 to 3.1 +/- 0.5). Feeding while in a cold environment provoked a further significant increase in GIVO2 (3.1 +/- 0.5 to 4.2 +/- 0.4). All increases in GIVO2 were associated with increased GIO2ex. This study has demonstrated that 1) postprandial GIVO2 is appropriately increased during cold stress as a function of GIO2ex and 2) that fasting GIVO2 is increased during cold stress, demonstrating an intestinal metabolic contribution to cold-induced systemic thermogenesis.