Mentally stimulating activities associate with better cognitive performance in Parkinson disease.

Subjects at risk of dementia benefit from participation in mentally stimulating activities, but no prior studies have investigated similar associations in Parkinson disease (PD). The aim of this study was to investigate the relationship between times spent engaging in mentally stimulating activities and cognitive functions in PD while accounting for the degree of primary neurodegenerations. PD patients (N = 41, 33 males; age 68.5 ± 7.2; Hoehn and Yahr stage 2.6 ± 0.6) completed the Community Health Activities Model Program for Seniors questionnaire, mini-mental state examination (MMSE), and [11C]dihydrotetrabenazine dopaminergic and [11C]piperidinyl propionate acetylcholinesterase PET imaging. The subset of mentally stimulating activity items of the Community Health Activities Model Program for Seniors questionnaire was used to develop a rating scale as primary outcome variable in this study. Findings showed that mean rating scale score of time spent in mentally stimulating activities over a 4-week timespan was 20.0 ± 8.3 h and mean MMSE score was 28.4 ± 1.9. Regression analysis showed that duration of participation in mentally stimulating activities was a significant predictor of MMSE scores (standardized ß = 0.39, t = 2.8, p = 0.009; total model: F (6,34) = 3.5, p = 0.005) independent from significant effects for cortical cholinergic activity (ß = 0.35, t = 2.4, p = 0.024). Caudate nucleus dopaminergic activity, age, education, or duration of disease were not significant regressors. Post hoc analysis did not show significant effects of motor disease severity or level of physical activities. We conclude that engagement in mentally stimulating activities is associated with better cognitive abilities in PD, independent of education, severity of motor disease, nigrostriatal dopaminergic and cortical cholinergic degenerations.

Prevalence of impaired odor identification in Parkinson disease with imaging evidence of nigrostriatal denervation.

There is wide variability in the reported prevalence rates of abnormal smell in Parkinson disease (PD). This study assessed the prevalence of abnormal smell, using the University of Pennsylvania Smell Identification Test (UPSIT), in 183 patients with PD with confirmed PET imaging evidence of nigrostriatal denervation. Impaired olfaction in this sample was nearly universal (97.8 %). Wide-ranging prior olfactory impairment estimates may reflect not only uncertainty regarding diagnostic classification, but also the use of inaccurate normative data and differences in olfactory tests used.

Mapping Nucleosome Location Using FS-Seq.

The organization of nucleosomes in eukaryotic chromatin is thought to play a critical role in the regulation of the biological function of the chromatin. Because of this potential role in regulation, a number of techniques have been developed, which combine chromatin fragmentation around nucleosomes with next-generation sequencing to map the location of nucleosomes in chromatin. In this section, a procedure using a kit from New England Biolabs (NEB NEXT Ultra II FS DNA library prep Kit) to fragment chromatin in preparation for next-generation sequencing is described and compared to other available procedures for mapping nucleosome location.

Early in an SV40 infection, histone modifications correlate with the presence or absence of RNAPII and direction of transcription.

Since epigenetic regulation seemed likely to be involved in SV40 early transcription following infection, we have analyzed the organization of nucleosomes carrying histone modifications (acetyl-H3, acetyl-H4, H3K9me1, H3K9me3, H3K4me1, H3K4me3, H3K27me3, H4K20me1) at 30 min and 2 h post infection in SV40 minichromosomes prepared in the absence or presence of the transcription inhibitor dichloro-1-beta-d-ribofuranosyl benzimidazole. The former condition was used to determine how SV40 chromatin structure changed during early transcription, and the latter was used to determine the role of active transcription. The location of RNAPII was used as a marker to identify where histone modifications were most likely to be involved in regulation. Acetyl-H3 acted like epigenetic memory by being present at sites subsequently bound by RNAPII, while H3K9me1 and H3K27me3 were reorganized to the late side of the SV40 regulatory region apparently to repress late transcription. The organization of acetyl-H3 and H3K9me1 but not H3K27me3 required active transcription.

Comparing a new method for mapping nucleosomes in simian virus 40 chromatin to standard procedures.

The location of nucleosomes in chromatin significantly impacts many biological processes including DNA replication, repair, and gene expression. A number of techniques have been developed for mapping nucleosome locations in chromatin including MN-Seq (micrococcal nuclease digestion followed by next-generation sequencing), ATAC-Seq (Assay for Transposase-Accessible Chromatin followed by next-generation sequencing), and ChIP-Seq (chromatin immunoprecipitation and fragmentation followed by next-generation sequencing). All of these techniques have been successfully used, but each with its own limitations. Recently, New England Biolabs has marketed a new kit, the NEBNext Ultra II FS Library Prep kit, for preparing libraries for next-generation sequencing from purified genomic DNA. This kit is based on a novel proprietary DNA fragmentation procedure which appears to cleave DNA that is not bound by proteins. Because DNA is fragmented directly in the FS kit, we tested whether the kit might also be useful for mapping the location of nucleosomes in chromatin. Using simian virus 40 (SV40) chromatin isolated at different times in an infection, we have compared nucleosome mapping using the NEB FS kit (referred to as FS-Seq) to MN-Seq, ATAC-Seq, and ChIP-Seq. Mapping nucleosomes using FS-Seq generated nucleosome profiles similar to those generated by ATAC-Seq and ChIP-Seq in regulatory regions of the SV40 genome. We conclude that FS-Seq is a simple, robust, cost-effective procedure for mapping nucleosomes in SV40 chromatin that should be useful for other forms of chromatin as well. We also present evidence that FS-Seq may be useful for mapping transcription factors.

Differential SP1 interactions in SV40 chromatin from virions and minichromosomes.

SP1 binding in SV40 chromatin in vitro and in vivo was characterized in order to better understand its role during the initiation of early transcription. We observed that chromatin from disrupted virions, but not minichromosomes, was efficiently bound by HIS-tagged SP1 in vitro, while the opposite was true for the presence of endogenous SP1 introduced in vivo. Using ChIP-Seq to compare the location of SP1 to nucleosomes carrying modified histones, we found that SP1 could occupy its whole binding site in virion chromatin but only the early side of its binding site in most of the minichromosomes carrying modified histones due to the presence of overlapping nucleosomes. The results suggest that during the initiation of an SV40 infection, SP1 binds to an open region in SV40 virion chromatin but quickly triggers chromatin reorganization and its own removal.

Color discrimination errors associate with axial motor impairments in Parkinson's disease.

BACKGROUND: Visual function deficits are more common in imbalance-predominant compared to tremor-predominant PD suggesting a pathophysiological role of impaired visual functions in axial motor impairments. OBJECTIVE: To investigate the relationship between changes in color discrimination and motor impairments in PD while accounting for cognitive or other confounder factors. METHODS: PD subjects (n=49, age 66.7±8.3 years; Hoehn & Yahr stage 2.6±0.6) completed color discrimination assessment using the Farnsworth-Munsell 100 Hue Color Vision Test, neuropsychological, motor assessments and [11C]dihydrotetrabenazine vesicular monoamine transporter type 2 PET imaging. MDS-UPDRS sub-scores for cardinal motor features were computed. Timed up and go mobility and walking tests were assessed in 48 subjects. RESULTS: Bivariate correlation coefficients between color discrimination and motor variables were significant only for the Timed up and go (RS=0.44, P=0.0018) and the MDS-UPDRS axial motor scores (RS=0.38, P=0.0068). Multiple regression confounder analysis using the Timed up and go as outcome parameter showed a significant total model (F(5,43)= 7.3, P<0.0001) with significant regressor effects for color discrimination (standardized ß=0.32, t=2.6, P=0.012), global cognitive Z-score (ß=-0.33, t=-2.5, P=0.018), duration of disease (ß=0.26, t=1.8, P=0.038), but not for age or striatal dopaminergic binding. The color discrimination test was also a significant independent regressor in the MDS-UPDRS axial motor model (standardized ß=0.29, t=2.4, P=0.022; total model t(5,43)= 6.4, P=0.0002). CONCLUSIONS: Color discrimination errors associate with axial motor features in PD independent of cognitive deficits, nigrostriatal dopaminergic denervation, and other confounder variables. These findings may reflect shared pathophysiology between color discrimination visual impairments and axial motor burden in PD.

Motor Speech Apraxia in a 70-Year-Old Man with Left Dorsolateral Frontal Arachnoid Cyst: A [18F]FDG PET-CT Study.

Motor speech apraxia is a speech disorder of impaired syllable sequencing which, when seen with advancing age, is suggestive of a neurodegenerative process affecting cortical structures in the left frontal lobe. Arachnoid cysts can be associated with neurologic symptoms due to compression of underlying brain structures though indications for surgical intervention are unclear. We present the case of a 70-year-old man who presented with a two-year history of speech changes along with decreased initiation and talkativeness, shorter utterances, and dysnomia. [18F]Fluorodeoxyglucose (FDG) Positron Emission and Computed Tomography (PET-CT) and magnetic resonance imaging (MRI) showed very focal left frontal cortical hypometabolism immediately adjacent to an arachnoid cyst but no specific evidence of a neurodegenerative process.