The parietal role in the sense of self-ownership with temporal discrepancy between visual and proprioceptive feedbacks

One hypothesis on how we recognize an image of, for example, an arm as our own is through the co-occurrence of multiple sensory feedbacks, especially visual and proprioceptive feedbacks, in this process. It has been suggested that the parietal lobe is the region where proprioceptive and visual information of one's own body is integrated. This study investigated parietal cortical activity during a visual-proprioceptive synchrony judgment task in which visual feedback of the subjects' own passively moving hand was delayed. The subjects were required to judge whether or not there was a delay between the proprioceptive and visual feedbacks. Parietal cortical activity, which was measured using a 48-channel near-infrared spectroscopy (NIRS) apparatus, appeared to be modulated by the length of the delay between the visual and proprioceptive feedbacks. The bilateral superior/middle parietal areas were involved in experiencing the synchrony between the visual and proprioceptive feedbacks, whereas the right inferior parietal areas were strongly activated when discrepancy between the two feedbacks was detected. We postulate that the superior portion of the parietal lobe is essential for maintaining one's own body image, while the right inferior portion is involved in detecting movements of others.     

Aortic regurgitation: ventricular response after aortic valve replacement

This study was designed to evaluate the usefulness of the ratio of the preoperative regurgitant stroke volume to left ventricular end-diastolic volume (RSV/LVEDV) for assessing the left ventricular function preoperatively. In 26 patients with aortic regurgitation (AR), the percent decrease in LVEDV was compared with the preoperative RSV/LVEDV, ejection fraction (EF), LVEDV, left ventricular end-systolic volume (LVESV) or left ventricular end-diastolic pressure (LVEDP). There was a significant correlation between the percent decrease in LVEDV and RSV/LVEDV. Patients with RSV/LVEDV of more than 0.26 had a significantly smaller postoperative left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI), and a greater postoperative EF than patients with smaller RSV/LVEDV. All but one patient with RSI/LVEDVI larger than 0.0016 LVEDVI had normal postoperative LVEDVI. Based on these findings, it is concluded that the RSV/LVEDV is an useful indicator for preoperative evaluation of left ventricular functions in patients with AR. Surgical intervention for patients with AR should be recommended before the RSI/LVEDVI drops to less than 0.0016 LVEDVI, to expect good postoperative ventricular responses.     

Remarkable selectivity of the in vivo binding of [3H]Ro15‐4513 to α5 subtype of benzodiazepine receptor in the living mouse brain

To evaluate the binding characteristics of [³H]Ro15‐4513 with the central benzodiazepine (BZ) receptor, inhibition experiments of [³H]Ro15‐1788 and [³H]Ro15‐4513 were performed both in vitro and in vivo, using two BZ ligands, flunitrazepam (FNP), and ethyl‐β‐carboline‐3‐carboxylate (β‐CCE). FNP inhibited the binding of [³H]Ro15‐1788 and [³H]Ro15‐4513 in a dose‐dependent manner in the mouse cerebral cortex, hippocampus, and cerebellum, both in vitro and in vivo. β‐CCE also inhibited the binding of [³H]Ro15‐1788 and [³H]Ro15‐4513 in all the aforementioned brain regions in vitro. However, in vivo, β‐CCE inhibited the binding of [³H]Ro15‐4513 in the cerebral cortex and cerebellum, but not in the hippocampus, even at an injected dose of up to 1mg/kg. In contrast, more than 50% of the in vivo binding of [³H]Ro15‐1788 was inhibited by 1 mg/kg of β‐CCE in all regions. The time‐activity curve of [³H]Ro15‐4513 in the hippocampus also showed no alteration of the peak uptake between the control group and 0.3 mg/kg of β‐CCE coinjected group. These results indicated that the binding characteristics of [³H]Ro15‐4513 with the BZ receptor differed markedly between the in vitro and in vivo condition, and the selectivity of [³H]Ro15‐4513 binding to α5 subtype of BZ receptor in the mouse brain seemed to be remarkable under the in vivo condition. Synapse 64:928–936, 2010. © 2010 Wiley‐Liss, Inc.     

Antitumor effects of vaccination with dendritic cells transfected with modified receptor for hyaluronan-mediated motility mRNA in a mouse glioma model

OBJECT: The receptor for hyaluronan-mediated motility (RHAMM) is frequently overexpressed in brain tumors and was recently identified as an immunogenic antigen by using serological screening of cDNA expression libraries. In this study, which was conducted using a mouse glioma model, the authors tested the hypothesis that vaccination with dendritic cells transfected with RHAMM mRNA induces strong immunological antitumor effects. METHODS: The authors constructed a plasmid for transduction of the mRNAs transcribed in vitro into dendritic cells, which were then used to transport the intracellular protein RHAMM efficiently into major histocompatibility complex class II compartments by adding a late endosomal-lysosomal sorting signal to the RHAMM gene. The dendritic cells transfected with this RHAMM mRNA were injected intraperitoneally into the mouse glioma model 3 and 10 days after tumor cell implantation. The antitumor effects of the vaccine were estimated by the survival rate, histological analysis, and immunohistochemical findings for immune cells. Mice in the group treated by vaccination therapy with dendritic cells transfected with RHAMM mRNA survived significantly longer than those in the control groups. Immunohistochemical analysis revealed that greater numbers of T lymphocytes containing T cells activated by CD4+, CD8+, and CD25+ were found in the group vaccinated with dendritic cells transfected with RHAMM mRNA. CONCLUSIONS: These results demonstrate the therapeutic potential of vaccination with dendritic cells transfected with RHAMM mRNA for the treatment of malignant glioma.     

Inhibitory effect of methyl ethyl ketone upon the enhancement of cerebral blood flow during status epilepticus induced by lithium-pilocarpine

Significant increases in local cerebral blood flow during lithium-pilocarpine (Li-P) induced seizure have been reported. We recently found that both acetone and methyl ethyl ketone (MEK) showed anticonvulsive effects in status epilepticus induced by Li-P in rats. In this study, we examined whether MEK also suppressed the enhancement of local cerebral blood flow induced by Li-P with a simplified autoradiographic method using [¹⁴C]-para-iodo-N-isopropyl amphetamine ([¹⁴C]-IMP). Significant increases in local cerebral blood flow in the thalamus, hypothalamus, hippocampus and cerebellum were observed in Li-P induced status epilepticus rats. Pretreatment with MEK (8 mmol/kg) completely suppressed the enhancement of local cerebral blood flow to or below the control level in all regions.     

Generation of co-speech gestures based on spatial imagery from the right-hemisphere: evidence from split-brain patients

It has been claimed that the linguistically dominant (left) hemisphere is obligatorily involved in production of spontaneous speech-accompanying gestures (Kimura, 1973a, 1973b; Lavergne and Kimura, 1987). We examined this claim for the gestures that are based on spatial imagery: iconic gestures with observer viewpoint (McNeill, 1992) and abstract deictic gestures (McNeill, et al. 1993). We observed gesture production in three patients with complete section of the corpus callosum in commissurotomy or callosotomy (two with left-hemisphere language, and one with bilaterally represented language) and nine healthy control participants. All three patients produced spatial-imagery gestures with the left-hand as well as with the right-hand. However, unlike healthy controls and the split-brain patient with bilaterally represented language, the two patients with left-hemispheric language dominance coordinated speech and spatial-imagery gestures more poorly in the left-hand than in the right-hand. It is concluded that the linguistically non-dominant (right) hemisphere alone can generate co-speech gestures based on spatial imagery, just as the left-hemisphere can.     

An effective vacuum-assisted closure treatment for mediastinitis with aortic arch replacement

Little experience exists with the vacuum-assisted closure (VAC) therapy in the high-risk group of patients with perigraft abscess containing a large amount of prosthetic vascular grafts. We report our experience in the VAC therapy for patients with mediastinitis after aortic arch replacement. Between February 2003 and December 2006, five patients with a mean age of 72.2 years developed postoperative mediastinitis after aortic arch replacement, and were treated with the VAC system. In all the patients the mediastinal fluid and tissue examinations turned out to be negative for microbiological cultures, and successful closure of the midline incision was achieved with concomitant omental transfer after a mean duration of 22.6 days of VAC treatment. Four of the five patients survived to discharge and have been free from recurrent sign of mediastinal or graft infection at long-term follow-up. Our study indicates that the VAC treatment may reduce early mortality of life-threatening deep sternal wound infection complicated by a prior aortic arch replacement and become a preferred therapeutic option for the patients to whom another replacement is too risky.     

Risk of surgical failure and hemorrhagic complications associated with antithrombotic medication in glaucoma surgery

Graefe's Archive for Clinical and Experimental Ophthalmology - The purpose of this retrospective study was to determine the extent to which the use of antithrombotic drugs during glaucoma...