Impact of adult age and Alzheimer's disease on levels of neural noise for letter matching.

We tested healthy young and older adults as well as higher-scoring (Mini-Mental State Exam, MMSE, scores between 14-20) and lower-scoring patients diagnosed with probable Alzheimer's disease (AD) on a letter-matching task. Subjects were instructed to respond "same" if two simultaneously presented letters were identical, or "different" if the letters did not match. Healthy older adults showed a larger "fast-same" effect than healthy young adults. Also, higher-scoring AD patients showed a large "false-different" effect for errors, but lower-scoring AD patients showed a large "false-same" effect. These data indicate that older adults exhibit higher neural noise levels than younger adults. The cross-over error pattern for AD suggests that moderately demented AD patients show evidence of forming degraded visual percepts whereas more severely demented AD patients show evidence of forming incomplete percepts.     

Regurgitant Volume/Left Ventricular End-Diastolic Volume Ratio: Prognostic Value in Patients With Secondary Mitral Regurgitation

ObjectivesThe purpose of this study was to investigate the prognostic implications of the ratio of mitral regurgitant volume (RVol) to left ventricular (LV) end-diastolic volume (EDV) in patients with significant secondary mitral regurgitation (MR).BackgroundQuantification of secondary MR remains challenging, and its severity can be over- or underestimated when using the proximal isovelocity surface area method, which does not take LV volume into account. This limitation can be addressed by normalizing mitral RVol to LVEDV.MethodsA total of 379 patients (mean age 67 ± 11 years; 63% male) with significant (moderate and severe) secondary MR were divided into 2 groups according to the RVol/EDV ratio: RVol/EDV ≥20% (greater MR/smaller EDV) and <20% (smaller MR/larger EDV). The primary endpoint was all-cause mortality.ResultsDuring median (interquartile range) follow-up of 50 (26 to 94) months, 199 (52.5%) patients died. When considering patients receiving medical therapy only, patients with RVol/EDV ratio ≥20% tended to have higher mortality rates than those with RVol/EDV ratio <20% (5-year estimated rates 24.1% vs. 18.4%, respectively; p = 0.077). Conversely, when considering the entire follow-up period including mitral valve interventions, patients with a higher RVol/EDV ratio (≥20%) had lower rates of all-cause mortality compared with patients with RVol/EDV ratio <20% (5-year estimated rates 39.0% vs. 44.8%, respectively; p = 0.018). On multivariable analysis, higher RVol/EDV ratio (per 5% increment as a continuous variable) was independently associated with lower all-cause mortality (0.93; p = 0.023).ConclusionsIn patients with significant secondary MR treated medically, survival tended to be lower in those with a higher RVol/EDV ratio. Conversely, a higher RVol/EDV ratio was independently associated with reduced all-cause mortality. when mitral valve interventions were taken into consideration     

Insufficient Mitral Leaflet Remodeling in Relation to Annular Dilation and Risk of Residual Mitral Regurgitation After MitraClip Implantation

ObjectivesThe purpose of this study was to determine whether the mitral valve (MV) total leaflet area (TLA)-to-mitral annular area (MAA) (TLA/MAA) ratio measured using 3-dimensional (3D) transesophageal echocardiography (TEE) was associated with residual mitral regurgitation (MR) after MitraClip implantation in patients with secondary MR.BackgroundThe factors influencing the results of MitraClip implantation for secondary MR are controversial. This study hypothesized that insufficient remodeling of the mitral leaflets relative to the annular dilation may be associated with significant MR after MitraClip implantation.MethodsThis study included patients with secondary MR treated with MitraClips. Using 3D TEE dataset, the TLA in diastole and MAA in systole were measured with dedicated software.ResultsIn a total cohort of 119 patients (mean age 74 ± 9 years; 61% male), significant residual MR (≥2+) was present in 43 patients (36%). In patients with significant residual MR, MAA was greater than in patients without residual MR (10.7 ± 2.4 cm² vs. 9.0 ± 2.1 cm²; p < 0.001) whereas no significant difference was observed in TLA (12.2 ± 2.6 cm² vs. 12.0 ± 2.9 cm²; p = 0.836). TLA/MAA ratio was lower in patients with significant residual MR as compared to their counterparts (1.14 ± 0.15 vs. 1.34 ± 0.16; p < 0.001), suggesting insufficient leaflet remodeling relative to annular dilation. On receiver-operating characteristic curve analysis, the TLA/MAA ratio had better discriminative power to identify patients who will have significant residual MR compared to MAA alone (area under the curve [AUC]: 0.830 vs. 0.723; p = 0.049).ConclusionsIn patients with secondary MR, insufficient mitral leaflet remodeling relative to the annulus dilation, as reflected by a lower TLA/MAA ratio, is associated with significant residual MR after MitraClip implantation.     

Visual barriers to prevent ambulatory Alzheimer's patients from exiting through an emergency door

Mobility combined with impaired mental functioning presents safety risks for Alzheimer's patients and poses an ethical dilemma for staff. This study, conducted on an Alzheimer's unit, tested seven different visual barrier conditions for reducing patient exists. Findings indicate that exiting was eliminated under two conditions. The results suggest visual agnosia, the inability to interpret what the eye sees, may be utilized as a tool in managing wandering behavior of Alzheimer's patients.     

Novel use of botulinum toxin to ameliorate arthrofibrosis: an experimental study in rabbits

This study aimed to investigate the effects of intra-articular botulinum toxin in preventing arthrofibrosis. Arthrofibrosis was induced in both stifle joints of 20 rabbits by transecting the anterior cruciate ligament under intramuscular anesthesia with ketamine and xylazine. Intra-articular toxin at a dose of 0.6 ml (50 unit) and physiologic saline solution (0.6 ml) were injected into the right and left stifle joints, respectively, 3 times with a 1-week interval between each injection. The rabbits were euthanized in the 12th week via high dose anesthesia to remove the stifle joint. The severity of adhesions was assessed, applying a universal scoring system. Also the stifle joints were histologically evaluated for fibrosis. With regards to severity of adhesion a significant reduction in the adhesion score was observed in the toxin-treated group in comparison to untreated controls with mean +/- SE values of 0.2 +/- 0.1 and 2.4 +/- 0.2, respectively (p < 0.01). The histological evaluation showed no significant fibroblast in the toxin-treated group versus dense fibers with mature fibroblasts in the control group. Our results suggest that botulinum toxin demonstrated efficacy in preventing adhesion after knee surgery and all the parameters monitored showed consistent statistically significant improvement.     

<Emphasis Type="Italic">Biebersteinia multifida</Emphasis> DC a potential savior against testicular torsion-induced reperfusion injury

The study aimed to investigate the potential therapeutic effect of the methanolic extract of Biebersteinia multifida DC on ischemia–reperfusion injury induced by testicular torsion/detorsion in rats. Forty adult male Sprague-Dawley rats were randomly divided into four groups. Sham operation group, torsion/detorsion group plus saline, and torsion/detorsion groups plus 75 and 150 mg/kg doses of DC extract (administered intraperitoneally 15 min before detorsion). Testicular ischemia was induced via keeping the left testis under 720° counterclockwise torsion for 2 h; afterwards, detorsion was performed. All rats were sacrificed 4 h after detorsion and bilateral testes were removed for histological examinations. The testes in sham operation group had normal structure. Contralateral testicular tissue had mild injury in torsion/detorsion (T/D) group, while it was approximately normal in DC-treated group. In the T/D group, most of the testes demonstrated severe lesions in ipsilateral testes. In contrast, ipsilateral twisted testicular tissue in DC-treated group showed mild to moderate injuries. Similar histopathological results were obtained in both utilized therapeutic doses of DC (75 and 150 mg/kg). B. multifida is a rich source of phenolic antioxidant components that can be potentially used as a free radical scavenger in testicular damages caused by reperfusion injury, although more detailed studies are warranted.