Clinical Characteristics with an Impact on ADL Functions of PD Patients with Cognitive Impairment Indicative of Dementia

Background

Dementia in Parkinson’s disease (PD) is defined as cognitive decline severe enough to affect activities of daily living function (ADL). The aim of our exploratory study was to compare two groups of PD patients. Both groups had cognitive deficits severe enough to justify diagnosis of dementia, but they differed according to caregivers’ rating on ADL dysfunction. Parameters which differed between the two groups were interpreted to affect the caregivers’ perception of ADL dysfunction in PD patients with cognitive impairment indicative of Parkinson’s disease dementia.

Methodology/Principal Findings

Thirty of 131 Parkinson’s disease patients fulfilled the Movement Disorders Society Task Force – recommended, cognitive Level-I-criteria for dementia. According to standardized caregiver ratings, volunteers were grouped into 18 patients with (ADL-) and 12 without instrumental activities of daily living dysfunction (ADL+). Caregiver activities of daily living function ratings closely correlated with self-estimates of patients and those of physician (p<0.001). ADL- patients performed worse on tests assessing visual-construction (p<0.05) and attention (p=0.03) than ADL+ patients. Moreover, the postural instability and gait disorder subtype was more frequent in ADL- patients (p=0.009). ADL- patients tended to have more communication problems (p=0.05), more anxiety (p=0.05) and showed a tendency to be treated more often with neuroleptics (p=0.049) than ADL+.

Conclusions/Significance

Results indicate that worse attention, visual-construction abilities, the postural instability and gait disorder subtype, communication problems, medication and presence of anxiety are related to activities of daily living dysfunctions in Parkinson’s disease patients with cognitive decline indicative of dementia. Our data suggests that not only cognitive factors but also non-cognitive factors seem to be linked to the diagnosis of Parkinson’s disease dementia associated with significant impact on instrumental activities of daily living function. Further studies with larger sample sizes are needed to verify our results.     

NIKEI: A New Inexpensive and Non-Invasive Scoring System to Exclude Advanced Fibrosis in Patients with NAFLD

Aims

To develop, validate and compare a non-invasive fibrosis scoring system for non-alcoholic fatty liver disease (NAFLD) derived from routinely obtained clinical and biochemical parameters.

Methods

267 consecutive patients with biopsy proven fatty liver or non-alcoholic steatohepatitis were randomly assigned to the estimation (2/3) or validation (1/3) group to develop a model for the prediction of advanced fibrosis. Univariate statistics were performed to compare patients with and without advanced fibrosis, and following a multivariate logistic regression analysis a new scoring system was constructed. This non-invasive Koeln-Essen-index (NIKEI) was validated and compared to the FIB-4 index by calculating the area under the receiver operating characteristic curve (AUC). We evaluated a stepwise combination of both scoring systems for the precise prediction of advanced fibrosis. To set in contrast, we additionally tested the diagnostic accuracy of the AST/ALT ratio, BARD score and the NAFLD fibrosis score in our cohort.

Results

Age, AST, AST/ALT ratio, and total bilirubin were identified as significant predictors of advanced fibrosis and used to construct the NIKEI with an AUC of 0.968 [0.937; 0.998] compared to 0.929 [0.869; 0.989] for the FIB-4 index. The absence of advanced fibrosis could be confirmed with excellent accuracy (99–100%). The positive predictive value of the FIB-4 index was higher (100% vs. 60%), however, the false negative rate was also high (33%). With a stepwise combination of both indices 82%–84% of biopsies would have been avoidable without a single misclassification. The AUROC for AST/ALT ratio, the NAFLD fibrosis score, and the BARD score were 0.81 (95% CI, 0.72–0.90), 0.96 (95% CI 0.92–0.99), and 0.67 (95% CI 0.55–0.78), respectively.

Conclusion

The NIKEI can reliably exclude advanced fibrosis in subjects with NAFLD. In combination with the FIB-4 index misclassification with inadequate clinical management can be avoided while the need for liver biopsies can be reduced.     

Early Detection of Abnormal Prion Protein in Genetic Human Prion Diseases Now Possible Using Real-Time QUIC Assay

Introduction

The definitive diagnosis of genetic prion diseases (gPrD) requires pathological confirmation. To date, diagnosis has relied upon the finding of the biomarkers 14-3-3 protein and total tau (t-tau) protein in the cerebrospinal fluid (CSF), but many researchers have reported that these markers are not sufficiently elevated in gPrD, especially in Gerstmann-Sträussler-Scheinker syndrome (GSS). We recently developed a new in vitro amplification technology, designated “real-time quaking-induced conversion (RT-QUIC)”, to detect the abnormal form of prion protein in CSF from sporadic Creutzfeldt-Jakob disease (sCJD) patients. In the present study, we aimed to investigate the presence of biomarkers and evaluate RT-QUIC assay in patients with gPrD, as the utility of RT-QUIC as a diagnostic tool in gPrD has yet to be determined.

Method/Principal Findings

56 CSF samples were obtained from gPrD patients, including 20 cases of GSS with P102L mutation, 12 cases of fatal familial insomnia (FFI; D178N), and 24 cases of genetic CJD (gCJD), comprising 22 cases with E200K mutation and 2 with V203I mutation. We subjected all CSF samples to RT-QUIC assay, analyzed 14-3-3 protein by Western blotting, and measured t-tau protein using an ELISA kit. The detection sensitivities of RT-QUIC were as follows: GSS (78%), FFI (100%), gCJD E200K (87%), and gCJD V203I (100%). On the other hand the detection sensitivities of biomarkers were considerably lower: GSS (11%), FFI (0%), gCJD E200K (73%), and gCJD V203I (67%). Thus, RT-QUIC had a much higher detection sensitivity compared with testing for biomarkers, especially in patients with GSS and FFI.

Conclusion/Significance

RT-QUIC assay is more sensitive than testing for biomarkers in gPrD patients. RT-QUIC method would thus be useful as a diagnostic tool when the patient or the patient''s family does not agree to genetic testing, or to confirm the diagnosis in the presence of a positive result for genetic testing.     

Posttranslational modifications in human plasma MBL and human recombinant MBL

Mannan-binding lectin (MBL) is a complex serum protein that plays an important role in innate immunity. In addition to assuming several different oligomeric forms, the polypeptide itself is highly heterogeneous. This heterogeneity is due to post-translational modifications, which help to stabilize the intact protein in its active conformation. For the first time, positions and occupation frequency of partial hydroxylations and partial glycosylations are reported in MBL. Hydroxylation and glycosylation patterns of both recombinant and plasma derived MBL were determined, using a combination of mass spectrometry on reduced MBL and on enzyme cleaved MBL. Variations in the degree of hydroxylation and glycosylation seem to be an indigenous characteristic of collectins. In addition to these already known modifications, a new post-translational modification was identified. Cys(216) (and occasionally also Cys(202)) was modified in trace amounts to dehydroalanine, as detected by a 34 Da mass loss. This impairs the formation of a disulphide bond in the carbohydrate recognition domain. The dehydroalanine was identified in similar small amounts in both recombinant and plasma-derived MBL.     

Protein chemical characterization of Gc globulin (vitamin D-binding protein) isoforms; Gc-1f, Gc-1s and Gc-2

Gc globulin, also called vitamin D-binding protein, is a plasma protein involved in the extracellular actin-scavenger system, vitamin D transport and possibly also other biological activities. Low levels of Gc globulin have been found to correlate with multiple organ failure and non-survival of patients with fulminant hepatic failure and trauma. Here, we characterize the dominant isoforms of plasma-derived Gc globulin from Cohn fraction IV paste with respect to amino acid sequence and posttranslational modifications. Gc globulin was purified in large scale and the isoforms separated by ion exchange chromatography. The separated isoforms and several commercial preparations of individual isoforms were characterized by mass spectrometry. This revealed that the major isoforms were non-glycosylated. Compared to the Gc-1f isoform the other dominating isoforms represented an Asp/Glu substitution (Gc-1s) and a Thr/Lys substitution (Gc-2) in agreement with DNA sequencing studies. The commercial preparations were found to represent mainly one or two isoforms. An O-linked glycan with a mass of 656 Da and terminating with a sialic acid residue was detected on a minor proportion of Gc globulin molecules.     

Antioxidant and antiplatelet effects of rosuvastatin in a hamster model of prediabetes

The objectives of this study were to determine the relationships among Type II diabetes (T2DM)-dependent elevations in platelet-derived reactive oxygen species (ROS), platelet-surface protein disulfide isomerase (psPDI) NO-releasing activity, and platelet aggregation and to evaluate the efficacy of rosuvastatin in normalizing these parameters in primary cells derived from a hamster model of prediabetic insulin resistance induced by fructose feeding. Platelets from rosuvastatin-treated non-fructose-fed (NFF) and fructose-fed (FF) hamsters were analyzed for aggregability and psPDI-denitrosation activity. Platelets from NFF animals treated with xanthine/xanthine oxidase (X/XO) were assessed for the same parameters and primary aortic endothelial cells (AEC) cultivated with a range of [rosuvastatin] +/- mevalonate were analyzed for ROS production. Platelets from FF hamsters displayed statistically significant enhanced ROS production, diminished psPDI-mediated NO-releasing activity, and hyperaggregability. Suggestively, platelets from NFF animals treated with X/XO displayed characteristics similar to platelets from FF animals. Rosuvastatin elicited a normalizing effect on all parameters measured in platelets from FF animals. Further, ROS production in primary AEC from FF animals could be blunted to that of NFF animals by concentrations of rosuvastatin in the range of those achieved in the bloodstream. Diminished psPDI-dependent NO-releasing activity and increased initial aggregation rates of FF platelets may result from elevated vascular ROS production under conditions of insulin resistance. Normalization of ROS production and platelet aggregation by rosuvastatin indicates its potential use as a vasculoprotective agent.     

Genome Wide Meta-analysis Highlights the Role of Genetic Variation in RARRES2 in the Regulation of Circulating Serum Chemerin

Chemerin is an adipokine proposed to link obesity and chronic inflammation of adipose tissue. Genetic factors determining chemerin release from adipose tissue are yet unknown. We conducted a meta-analysis of genome-wide association studies (GWAS) for serum chemerin in three independent cohorts from Europe: Sorbs and KORA from Germany and PPP-Botnia from Finland (total N = 2,791). In addition, we measured mRNA expression of genes within the associated loci in peripheral mononuclear cells by micro-arrays, and within adipose tissue by quantitative RT-PCR and performed mRNA expression quantitative trait and expression-chemerin association studies to functionally substantiate our loci. Heritability estimate of circulating chemerin levels was 16.2% in the Sorbs cohort. Thirty single nucleotide polymorphisms (SNPs) at chromosome 7 within the retinoic acid receptor responder 2 (RARRES2)/Leucine Rich Repeat Containing (LRRC61) locus reached genome-wide significance (p<5.0×10⁻⁸) in the meta-analysis (the strongest evidence for association at rs7806429 with p = 7.8×10⁻¹⁴, beta = −0.067, explained variance 2.0%). All other SNPs within the cluster were in linkage disequilibrium with rs7806429 (minimum r² = 0.43 in the Sorbs cohort). The results of the subgroup analyses of males and females were consistent with the results found in the total cohort. No significant SNP-sex interaction was observed. rs7806429 was associated with mRNA expression of RARRES2 in visceral adipose tissue in women (p<0.05 after adjusting for age and body mass index). In conclusion, the present meta-GWAS combined with mRNA expression studies highlights the role of genetic variation in the RARRES2 locus in the regulation of circulating chemerin concentrations.     

GoIFISH: a system for the quantification of single cell heterogeneity from IFISH images

Molecular analysis has revealed extensive intra-tumor heterogeneity in human cancer samples, but cannot identify cell-to-cell variations within the tissue microenvironment. In contrast, in situ analysis can identify genetic aberrations in phenotypically defined cell subpopulations while preserving tissue-context specificity. GoIFISH is a widely applicable, user-friendly system tailored for the objective and semi-automated visualization, detection and quantification of genomic alterations and protein expression obtained from fluorescence in situ analysis. In a sample set of HER2-positive breast cancers GoIFISH is highly robust in visual analysis and its accuracy compares favorably to other leading image analysis methods. GoIFISH is freely available at www.sourceforge.net/projects/goifish/.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-014-0442-y) contains supplementary material, which is available to authorized users.     

Development of a liquid chromatography tandem mass spectrometry method for the simultaneous determination of zearalenone,deoxynivalenol and their metabolites in pig serum

A sensitive and selective liquid chromatography tandem mass spectrometry method using negative electrospray ionisation (LC-ESI-MS/MS) was developed for the simultaneous determination of zearalenone (ZEN), deoxynivalenol (DON) and their metabolites α-zearalenol, β-zearalenol, zearalanone, α-zearalanol, β-zearalanol and de-epoxy-deoxynivalenol in pig serum. For method development, different sample preparation columns were tested for their suitability for extraction and clean up. Finally, preparation of serum samples was carried out using Oasis? HLB solid-phase extraction (SPE) columns. The analyte concentrations were determined by the use of isotopically labelled internal standards (IS). The method was in-house validated for all analytes. Calibration graphs (0.3–480 ng/ml) were prepared and high degree of linearity was achieved (r?≥?0.99). Results for method precision ranged between 2.7 and 21.5 % for inter-day and between 1.1 and 11.1 % for intra-day. The recoveries were in the range of 82–131 %. Limits of detection and quantification ranged 0.03–0.71 and 0.08–2.37 ng/ml, respectively. The method has been successfully used for quantitative determination of ZEN, DON and their metabolites in pig serum from a feeding trial with practically relevant ZEN and DON concentrations. This method is precise and reproducible and can be used as a multi-biomarker method to assess animal exposure to these mycotoxins and for diagnosis of intoxications.