Mirror star‐tracing performance in HIV‐1 infection: an assessment of visuoconstructive skills?

This study examines the visuoconstructive skills of HIV‐1+ individuals using an alpha‐adrenergic challenge, mirror star‐tracing. Participants were HIV‐1+ and HIV‐1? non‐drug injecting men and women involved in a study examining endocrine functioning in relation to HIV infection under challenge conditions. Performance on the star‐tracing task was based on the amount of errors committed when outlining a double‐lined star with a pencil while looking only at its reflection in a mirror. Chi‐square analysis indicated that significantly more HIV‐1+ participants were in the high error group on the mirror star‐tracing task than HIV‐1? participants. This finding provides a potential novel approach for examining visuoconstructive skills in HIV‐1+ individuals and warrants further research to better understand the meaning of such findings. Preliminary data from mirror star‐tracing performances of HIV‐1? injecting drug users (IDUs) a trend toward significantly more HIV‐1? IDUs in the high error group. Copyright © 2001 John Wiley & Sons, Ltd.     

Self‐recognition in live videos by young children: does video training help?

The overall aim of the experiment reported here was to establish whether self‐recognition in live video can be facilitated when live video training is provided to children aged 2–2.5 years. While the majority of children failed the test of live self‐recognition prior to video training, more than half exhibited live self‐recognition post video training. Children who failed the live video self‐recognition tasks passed the test of mirror self‐recognition. The findings are discussed in light of a video deficit and the potential role of pre‐test training in facilitating self‐recognition in live video by young children.     

Expertise with pathological actions modulates a viewer's motor system

Brain mechanisms for action understanding rely on matching the observed actions into the viewer's motor system. Health professionals, who treat patients affected by movement disorders as dystonia, frequently see hyperkinetic action patterns characterized by an overflow of muscle co-contractions. To avert an overload of the motor system during observation of those actions, they might need to look at dystonic motor symptoms in a cool, detached way. To investigate whether visual expertise about atypical movement kinematics influences the viewer's motor system, we applied transcranial magnetic stimulation to clinicians and to naive subjects, while they observed handwriting actions performed with two different kinematics: fluent and non-fluent. Crucially, the latter movement pattern was easily recognized by the clinicians as a typical expression of writer's cramp, whereas it was unknown to the naive subjects. Results showed that clinicians had similar corticospinal activation during observation of dystonic and healthy writings, whereas naive subjects were hyper-activated during observation of dystonic movements. Hyper-activation was selective for the muscles directly involved in the dystonic co-contractions and inversely correlated with subjective movement fluency scores, hinting at a fine-tuned association between the breakdown of observed movement fluency and corticospinal activation. These findings suggest that observation of unusual pathological actions differently modulates the viewer's motor system, depending on knowledge, visual expertise, and ability in recognizing suboptimal movement kinematics.     

Prenatal cardiac magnetic resonance imaging of right aortic arch with mirror image branching and retroesophageal left ductus arteriosus

Objective: To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) in diagnosing right aortic arch with mirror image branching and retroesophageal left ductus arteriosus (RLDA).

Methods: This retrospective study included six infants diagnosed with right aortic arch with mirror image branching and RLDA postnatally by cardiac computed tomography (CT) that had fetal echocardiography (echo) and MRI initially performed. The six fetal MRI cases were examined using 1.5 T MRI unit. Steady-state free precession (SSFP) sequence and single-shot turbo spin echo (SSTSE) sequence were used to evaluate the fetal great vessels and airway. The gestational age of six fetuses at time of fetal MRI ranged from 23 to 35 weeks (mean, 26.7 weeks).

Results: Of six cases with mirror image right aortic arch and RLDA confirmed by postnatal CT, 4/6 were correctly diagnosed by fetal cardiac MRI and 3/6 were correctly diagnosed by prenatal echo. All six cases were not associated with other congenital heart defect. All ductus arteriosus were closed after birth.

Conclusions: Fetal cardiac MRI can be a useful adjunct for evaluating fetal right aortic arch with mirror-image and RLDA.     

Hippocampal and medial prefrontal cortical volume is associated with overnight declarative memory consolidation independent of specific sleep oscillations

The current study was designed to further clarify the influence of brain morphology, sleep oscillatory activity and age on memory consolidation. Specifically, we hypothesized, that a smaller volume of hippocampus, parahippocampal and medial prefrontal cortex negatively impacts declarative, but not procedural, memory consolidation. Explorative analyses were conducted to demonstrate whether a decrease in slow‐wave activity negatively impacts declarative memory consolidation, and whether these factors mediate age effects on memory consolidation. Thirty‐eight healthy participants underwent an acquisition session in the evening and a retrieval session in the morning after night‐time sleep with polysomnographic monitoring. Declarative memory was assessed with the paired‐associate word list task, while procedural memory was tested using the mirror‐tracing task. All participants underwent high‐resolution magnetic resonance imaging. Participants with smaller hippocampal, parahippocampal and medial prefrontal cortex volumes displayed a reduced overnight declarative, but not procedural memory consolidation. Mediation analyses showed significant age effects on overnight declarative memory consolidation, but no significant mediation effects of brain morphology on this association. Further mediation analyses showed that the effects of age and brain morphology on overnight declarative memory consolidation were not mediated by polysomnographic variables or sleep electroencephalogram spectral power variables. Thus, the results suggest that the association between age, specific brain area volume and overnight memory consolidation is highly relevant, but does not necessarily depend on slow‐wave sleep as previously conceptualized.     

Kinetic analysis of interactions between bispecific monoclonal antibodies and immobilized antigens using a resonant mirror biosensor

A resonant mirror biosensor (IAsys) protocol is described for the comparative kinetic analysis of the ability of monoclonal antibodies (Mabs) and bispecific antibodies (Babs) to bind immobilized antigens. The protocol has been optimized and validated using the panel of affinity-purified antibodies, including two parental Mabs, one specific to human immunoglobulin G (hIgG) and another specific to horseradish peroxidase (HRP), and a Bab derived thereof by cell fusion (anti-hIgG/HRP Bab). The real-time kinetic analysis of antigen–antibody interactions using this protocol allows to demonstrate the differences in the avidity of bivalently binding Mabs and monovalent Babs. As shown in our previous study [J. Immunol. Methods 261 (2002) 103], the observed equilibrium association constants (K_ass) determined by IAsys using this protocol yield figures almost overlapping with those obtained by solid-phase radioimmunoassay (RIA). The described protocol is suited for the investigation of the effects of valency on the binding properties of antibodies. It also may be applied for the selection of Mabs and Babs with desired features, for different fields of application.     

3种眼科镜检溶液临床效果比较

对3种供眼科三面镜等检查用的滴眼溶液进行临床效果对比观察,各组观察107只眼,l次成功率分别为2％羟丙基甲基纤维素104只眼,占97.2％,5％聚乙烯醇滴眼溶液5l只眼,占47.7％;0.25％氯霉素滴眼溶液12只眼,占11.2％,此结果表明2％羟丙基甲基纤维索滴眼溶液优于其它二种滴眼溶液,而且它安全、无刺激、配制方便,因而认为2％羟丙基甲基纤维素是眼科三面镜等检查用的首选滴眼溶液.     

Mirror Image from a Left Atrial Line Mimicking a Catheter in the Left Ventricle During Transesophageal Echocardiography

We describe a case report where a left atrial catheter inserted intraoperatively produced an artifact, which mimicked a catheter in the left ventricle during transesophageal echocardiographic examination.