Altered functional neuroanatomy of response inhibition in adolescent males who were born very preterm.

Event-related functional magnetic resonance imaging (fMRI) was used to investigate the hypothesis that males who were born very preterm may show differences in relative strength of blood oxygen level dependent (BOLD) signals in selective brain areas during performance of a simple response inhibition task compared with term-born controls. Participants were eight males (mean gestational age at birth 28wks, [SD 2]; mean age at testing 16y, [SD 1] and 14 controls matched for sex, age (mean age 17y, [SD 1]), and IQ. A 'go-no-go' task was used to assess response selection and motor response inhibition in response to a visual stimulus.

Acute effects of iron-particle radiation on immunity. Part I: Population distributions.

Health risks due to exposure to high-linear energy transfer (LET) charged particles remain unclear. The major goal of this study was to confirm and further characterize the acute effects of high-LET radiation ((56)Fe(26)) on erythrocyte, thrombocyte and leukocyte populations in three body compartments after total-body exposure. Adult female C57BL/6 mice were irradiated with total doses of 0, 0.

Pharmacokinetics of clarithromycin extended-release (ER) tablets in patients with AIDS.

Background: Clarithromycin is a key agent in effective antimycobacterial therapy and prophylaxis for AIDS-related disseminated Mycobacterium avium complex (dMAC) infection. Immediate-release (IR) clarithromycin tablets are dosed at 500 mg bid for these indications. A new extended-release (ER) tablet of clarithromycin has been developed and approved at a dosing interval of once every 24 hours for treatment of respiratory tract bacterial infections.

Neural correlates of executive function in autistic spectrum disorders.

Background: Some clinical characteristics of high-functioning individuals with autistic spectrum disorder (ASD) such as repetitive stereotyped behaviors, perseveration, and obsessionality have been related to executive function (EF) deficits, more specifically to deficits in inhibitory control and set shifting and mediating frontostriatal neural pathways. However, to date, no functional imaging study on ASD has investigated inhibition and cognitive flexibility and no one has related EF brain activation to brain structure.

Methods: We compared brain activation (using functional magnetic resonance imaging) in 10 normal intelligence adults with ASD and 12 healthy control subjects during three different EF tasks: 1) motor-inhibition (GO/NO-GO); 2) cognitive interference-inhibition (spatial STROOP); and 3) set shifting (SWITCH).

[Diagnostics methods for sleep disorders].

The aim of this manuscript is to describe the procedures, recommendations, findings and value of the diagnostic methods used in Sleep Disorders including questionnaires, Actigraph, Polysomnography and Multiple sleep latency test. Specific questionnaires including evaluation of sleep quality , hyper somnolence, Respiratory Sleep Disorders and Sleep-Wake rhythm are in general, used as a screening for the Sleep Disorders and indication of sleep studies. Polysomnogram and Multiple sleep latency test are considered the gold standard methods for the diagnosis of majority of sleep disorders and Narcolepsy respectively.

Abnormal brain activation during inhibition and error detection in medication-naive adolescents with ADHD.

Objective: Patients with attention deficit hyperactivity disorder (ADHD) and a medication history have shown abnormal brain activation in prefrontal and striatal brain regions during cognitive challenge. Previous findings have been confounded, however, by potential long-term effects of stimulant medication exposure and group discrepancies in task performance. The aim of this study was to investigate whether medication-naive adolescents with ADHD would still show abnormal brain activation in prefrontal brain regions during motor response inhibition in a task designed to control for intergroup performance discrepancies.

[Rh(CO)2Cl]2-catalyzed domino reactions involving allylic substitution and subsequent carbocyclization reactions.

[reaction: see text] Three novel domino reaction processes have been discovered and developed that employ the regioselective and stereoselective [Rh(CO)(2)Cl](2)-catalyzed alkylations of allylic trifluoroacetates with alpha-substituted sodiomalonates followed by an intramolecular Pauson-Khand annulation, a [5 + 2] cycloaddition, or a cycloisomerization. A unique aspect of the methodology is that a single catalyst is used to effect sequential transformations simply by increasing the temperature for the second reaction.

Enhanced photosynthetic performance and growth as a consequence of decreasing mitochondrial malate dehydrogenase activity in transgenic tomato plants.

Transgenic tomato (Solanum lycopersicum) plants expressing a fragment of the mitochondrial malate dehydrogenase gene in the antisense orientation and exhibiting reduced activity of this isoform of malate dehydrogenase show enhanced photosynthetic activity and aerial growth under atmospheric conditions (360 ppm CO2). In comparison to wild-type plants, carbon dioxide assimilation rates and total plant dry matter were up to 11% and 19% enhanced in the transgenics, when assessed on a whole-plant basis. Accumulation of carbohydrates and redox-related compounds such as ascorbate was also markedly elevated in the transgenics.

Activation and function of mitochondrial uncoupling protein in plants.

Plant mitochondrial uncoupling protein (UCP) is activated by superoxide suggesting that it may function to minimize mitochondrial reactive oxygen species (ROS) formation. However, the precise mechanism of superoxide activation and the exact function of UCP in plants are not known. We demonstrate that 4-hydroxy-2-nonenal (HNE), a product of lipid peroxidation, and a structurally related compound, trans-retinal, stimulate a proton conductance in potato mitochondria that is inhibitable by GTP (a characteristic of UCP).

The neural correlates of cognitive time management: a review.

Cognitive time management is an important aspect of human behaviour and cognition that has so far been understudied. Functional imaging studies in recent years have tried to identify the neural correlates of several timing functions, ranging from simple motor tapping to higher cognitive time estimation functions. Several regions of the frontal lobes, in particular dorsolateral prefrontal cortex (DLPFC), inferior prefrontal cortex (IFC), anterior cingulate gyrus (ACG) and the supplementary motor area (SMA), alongside non-frontal brain regions such as the inferior parietal lobes, the cerebellum and the basal ganglia have been found to be involved in tasks of motor timing and time estimation.

Expression and DNA-binding activity of MYCN/Max and Mnt/Max during induced differentiation of human neuroblastoma cells.

Amplification of MYCN is one of the most important prognostic markers for neuroblastoma and is correlated with rapid tumor progression and poor prognosis. MYCN belongs to the Myc/Max/Mad/Mnt network of proteins that regulate proliferation, apoptosis, and differentiation. It is well established that MYCN is downregulated during induced differentiation of neuroblastoma cells carrying an amplified MYCN gene, but very little is known about other components of the network, i.

Trials of teaching methods in basic life support (4): comparison of simulated CPR performance at unannounced home testing after conventional or staged training.

This study compares the retention of basic life support (BLS) skills after 6 and 12 months by lay persons trained either in a conventional manner, or using a staged approach. Three classes, each of 2h, were offered to volunteers over a period of 4 months. For the conventional group, the second and third classes consisted of review of skills.

Neural correlates of switching set as measured in fast, event-related functional magnetic resonance imaging.

Attentional switching has shown to involve several prefrontal and parietal brain regions. Most cognitive paradigms used to measure cognitive switching such as the Wisconsin Card Sorting Task (WCST) involve additional cognitive processes besides switching, in particular working memory (WM). It is, therefore, questionable whether prefrontal brain regions activated in these conditions, especially dorsolateral prefrontal cortex (DLPFC), are involved in cognitive switching per se, or are related to WM components involved in switching tasks.

Skill acquisition and retention in automated external defibrillator (AED) use and CPR by lay responders: a prospective study.

This prospective study evaluated the acquisition and retention of skills in cardio-pulmonary resuscitation (CPR) and the use of the automated external defibrillator (AED) by lay volunteers involved in the Department of Health, England National Defibrillator Programme. One hundred and twelve trainees were tested immediately before and after and initial 4-h class; 76 were similarly reassessed at refresher training 6 months later. A standardised test scenario that required assessment of the casualty, CPR and the use of on AED was evaluated using recording manikin data and video recordings.

To blow or not to blow: a randomised controlled trial of compression-only and standard telephone CPR instructions in simulated cardiac arrest.

This randomised controlled trial used a manikin model of cardiac arrest to compare skill performance in untrained lay persons randomised to receive either compression-only telephone CPR (Compression-only tel., n=29) or standard telephone CPR instructions (Standard tel., n=30).

Right inferior prefrontal cortex mediates response inhibition while mesial prefrontal cortex is responsible for error detection.

Inhibitory control and error detection are among the highest evolved human self-monitoring functions. Attempts in functional neuroimaging to effectively isolate inhibitory motor control from other cognitive functions have met with limited success. Different brain regions in inferior, mesial, and dorsolateral prefrontal cortices and parietal and temporal lobes have been related to inhibitory control in go/no-go and stop tasks.

A right hemispheric frontocerebellar network for time discrimination of several hundreds of milliseconds.

Debate still surrounds the nature of the role of the dorsolateral prefrontal gyrus (DLPFC) in time perception. This region is frequently associated with working memory and is thus implicated as a so-called "accumulator" within a hypothesized internal clock model. However, we hypothesized that this region may have a more primary role in time perception.

Motor timing deficits in community and clinical boys with hyperactive behavior: the effect of methylphenidate on motor timing.

In a previous paper we showed that community children with hyperactive behavior were more inconsistent than controls in the temporal organization of their motor output. In this study we investigated: (1) various aspects of motor timing processes in 13 clinically diagnosed boys with attention deficit hyperactivity disorder (ADHD) who were compared to 11 community boys with hyperactive behavior and to a control group and (2) the effect of methylphenidate on the motor timing processes in the clinical group with ADHD in a double blind, cross-over, medication-placebo design, including 4 weeks of medication. The clinical group with ADHD, like the community group with hyperactivity, showed greater variability in sensorimotor synchronization and in sensorimotor anticipation relative to controls.

Behavioral consequences of radiation exposure to simulated space radiation in the C57BL/6 mouse: open field, rotorod, and acoustic startle.

Two experiments were carried out to investigate the consequences of exposure to proton radiation, such as might occur for astronauts during space flight. C57BL/6 mice were exposed, either with or without 15-g/cm2 aluminum shielding, to 0-, 3-, or 4-Gy proton irradiation mimicking features of a solar particle event. Irradiation produced transient direct deficits in open-field exploratory behavior and acoustic startle habituation.

Evidence for a pure time perception deficit in children with ADHD.

Background: Deficits have been found previously in children with ADHD on tasks of time reproduction, time production and motor timing, implicating a deficit in temporal processing abilities, which has been interpreted as either secondary or primary to core executive dysfunctions. The aim of this study was to explore further the abilities of hyperactive children in skills of time estimation, using a range of time perception tasks in different temporal domains.

Method: Time estimation was tested in a verbal estimation task of 10 seconds.

Trials of teaching methods in basic life support (3): comparison of simulated CPR performance after first training and at 6 months, with a note on the value of re-training.

A randomised controlled trial comparing staged teaching of cardiopulmonary resuscitation (CPR) with conventional training provided the additional opportunity to investigate skill acquisition and retention in those attending conventional CPR classes. All subjects were tested immediately after their first instruction period and again at 6-9 months at an unheralded home visit. We were able to assess how far performance was related to poor acquisition of skills and how far it was related to skill decay.

Dose and dose rate effects of whole-body proton-irradiation on lymphocyte blastogenesis and hematological variables: part II.

The goal of part II of this study was to evaluate functional characteristics of leukocytes and circulating blood cell parameters after whole-body proton irradiation at varying doses and at low- and high-dose-rates (LDR and HDR, respectively). C57BL/6 mice (n=51) were irradiated and euthanized at 4 days post-exposure for assay. Significant radiation dose- (but not dose-rate-) dependent decreases were observed in splenocyte responses to T and B cell mitogens when compared to sham-irradiated controls (P<0.