Dual task performance in Parkinson's disease: A sensitive predictor of impairment and disability

BackgroundDual task (DT) performance assesses the ability to perform two tasks simultaneously. Difficulty with DT performance may be a sensitive indicator of early Parkinson's disease (PD) impairment. The objective of this study was to assess what elements of a DT performance (cognition or gait) are most associated with impairment and disability in PD.MethodsPerformance in single and DT conditions was examined in 154 PD patients. The single task assessments included the time required to walk 50 feet (gait speed) and the number of words generated in a verbal fluency task (word generation). The DT comprised simultaneous performance of the single tasks. Impairment and disability were measured with the Unified Parkinson's Disease Rating Scale, Hoehn &Yahr, Berg Balance Scale, and Older Americans Resource and Services Scale. Age, education, and gender were control variables. Standardized residuals from regressions of DT upon single task performance were computed separately for word and gait, indicating the extent that the individual performed proportionally better/worse than predicted in DT considering their single task performance.ResultsMultiple regressions revealed that individuals who performed worse than expected in DT-word had greater impairment and disability. Dual task-gait was not significant in any model. Verbal fluency during DT performance is more closely associated with PD-related impairment and disability than gait speed during DT.ConclusionThis suggests that subjects prioritize gait performance at the expense of cognitive performance, and that DT word generation may be a sensitive indicator of early PD impairment and disability.     

How should risk be communicated to children: a cross-sectional study comparing different formats of probability information

Background  

Newborn screening, which identifies inherited disorders and sometimes carrier status, will increasingly involve health professionals in the provision of appropriate information and support to children and their families. The ability to understand carrier results relies on an understanding of probabilistic terms. However, little is known about how best to convey probabilistic medical information to children. Research with adult populations suggests information format significantly affects comprehension. This study aimed to explore which presentation format is most effective in conveying probabilistic information to children.     

Surgery in the Philippines

The Philippines is an archipelago of about 7000 islands, with an area about the size of England, situated just above the equator in Southeast Asia. It has a population of 70 million. The Philippines has had extensive commercial and social contact with Asian neighbors, specifically the Chinese, even before the 377 years of Spanish colonization from 1521 to 1898 and the 48 years of American rule from 1898 to 1946. More than 80% of Filipinos are Catholics; the rest are Muslims and Protestants of various denominations, including those who belong to Filipino church groups. Infectious diseases such as tuberculosis, amoebiasis, typhoid fever, and malaria are still prevalent, and arteriosclerosis, cancer, and stroke are common and on the rise.     

Vascular Closure Stapler Clip Anastomosis Decreases Aortic Cross-Clamping Time Compared to Interrupted Nonabsorbable and Running Absorbable Sutures in Growing Pigs

The latest generation in titanium clip application systems, the vascular closure staples (VCS) system avoids intimal lesions and therefore minimizes the subsequent hyperplastic reaction, while at the same time enhancing distensibility and vascular growth. Moreover, VCS clips allow the surgeon to perform vascular anastomosis easily and faster than conventional suture. This system may become the option of choice for vascular reconstruction in pediatric surgery where, as in the case of aortic and transplant surgery, decreasing vascular occlusion times may influence the outcomes. The aim of this study was to determine whether VCS metallic clips would allow shorter anastomosis times than conventional interrupted polypropylene or running Dexon suturing in end-to-end anastomosis performed in the abdominal aorta of young pigs. Twenty-four domestic swine, 45 days old, were used for this study. All animals were subjected to an end-to-end anastomosis in the abdominal aorta using VCS clips, interrupted polypropylene, or running Dexon suture. Aortic cross-clamping time was significantly shorter in the VCS clips group (4.02 ± 0.72 min), compared to interrupted polypropylene (21.89 ± 1.93 min) or running Dexon (9.82 ± 3.97 min) suture. VCS clips are easy to use, and therefore may aid surgeons to significantly decrease the time needed for performing an end-to-end anastomosis in the abdominal aorta, thus decreasing cross-clamping time when compared to interrupted polypropylene or running Dexon sutures.     

Measurement of cervical spinal cord cross-sectional area by MRI using edge detection and partial volume correction

PURPOSE: To detail a procedure to accurately measure upper cervical cord cross-sectional area (CSA), using MRI, by correcting for partial volume averaging (PVA), and to assess the usefulness of the procedure for measuring cervical cord atrophy rates in longitudinal studies. MATERIALS AND METHODS: Analysis of errors associated with measuring CSA in the presence of PVA is given. A numerical phantom image is produced, including simulated acquisition noise, to assess accuracy of the method in idealized conditions, and to verify the results of the error analysis. A phantom, consisting of 11 rods of known CSA, was scanned 10 times and measurement accuracy assessed. A total of 10 normal subjects were scanned twice to assess the reproducibility under experimental conditions. RESULTS: The measurement error for the numerical phantom increased with increased simulated acquisition noise, as predicted by the analysis. Measurement of the plastic phantom revealed a systematic overestimate in CSA due to limited scanner accuracy of 3.15%. The scan-rescan error for the CSA of the cervical spine in the 10 normal subjects was 0.55%. CONCLUSION: Correcting for PVA allows accurate measurement of the upper cervical cord CSA and accurate measurement of a standard phantom to guard against scanner drift in longitudinal studies of cord CSA.     

A piece of the human heart: variance of protein phosphorylation in left ventricular samples from end-stage primary cardiomyopathy patients

Cardiomyocyte contraction is regulated by phosphorylation of sarcomeric proteins. Throughout the heart regional and transmural differences may exist in protein phosphorylation. In addition, phosphorylation of sarcomeric proteins is altered in cardiac disease. Heterogeneity in protein phosphorylation may be larger in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) as it may be caused by multiple mutations in genes encoding different sarcomeric proteins. Moreover, HCM is characterized by asymmetric remodelling of the heart. In the present study we assessed if local differences in sarcomeric protein phosphorylation are more evident in primary HCM or DCM than in non-failing donors. Thereto, phosphorylation of the two main target proteins of the beta-adrenergic receptor pathway, troponin I (cTnI) and myosin binding protein C (cMyBP-C) was analysed in different parts in the free left ventricular wall of end–stage failing HCM and DCM patients and donors obtained during transplant surgery. Intra-patient variability in protein phosphorylation within tissue samples of approximately 2 g wet weight was comparable between donor, HCM and DCM samples and could partly be attributed to the precision of the technique. Thus, our data indicate that within the precision of the measurements small, biopsy-sized cardiac tissue samples are representative for the region of the free left ventricular wall from which they were obtained.     

Regional studies of serotonin and dopamine metabolism and quantification of serotonin uptake sites in human cerebral cortex

Summary An increasing number of studies have indicated that neuronal metabolism of serotonin (5-HT) and other monoamines may be altered in patients with affective disorders and in completed suicides. However, studies have yielded discordant results. The purpose of this study was to determine the regional variation of 5-hydroxyindolacetic acid (5-HIAA), homovanillic acid (HVA), (5-HT) and 5-HT uptake sites within the human cerebral cortex.Our sample consisted of 19 patients who died suddenly and accidently. Cortical concentrations of 5-HIAA, HVA and 5-HT were measured in six regions using an HPLC. 5-HT uptake sites in cortex were examined using [³H] Paroxetine.5-HT values within each brain were fairly constant in cortical regions studied except for the posterior parietal areas. By contrast, 5-HIAA values showed a trend towards a rostro-caudal increase, with peak values seen at sections corresponding to the post-central gyrus and the occipital pole. Using the ratio of 5-HIAA/5-HT as a crude index of 5-HT turnover, there was a progressive rostro-caudal increase of values which achieved statistical significance: the posterior superior parietal area and the occipital pole displayed a greater ratio than the other four cortical regions. HVA values were highest in the pre-central region and decreased both rostrally and caudally. 5-HIAA and HVA values were correlated positively in 5 of 6 cortical areas, while 5-HIAA and 5-HT were correlated in areas 4 and 5. Results obtaining using [³H]-Paroxetine suggest that 5-HT uptake sites in the human cortex are distributed rather uniformally and are not correlated with 5-HT levels.