Daytime impulsiveness, attention, and learning in the restless legs syndrome.

INTRODUCTION: Restless legs syndrome (RLS) is a sensorimotor condition characterized by disturbing sensations and the desire to move, often localized in the legs. Cognitive changes and impulsivity can be present in RLS, although the potential effect of commonly co-occurring attention-deficit/hyperactivity disorders (ADHD) or dopamine agonist (DA) use on these are unclear. METHOD: Twenty-three RLS patients and 22 healthy controls were included. Rey Auditory Verbal Learning Test (RAVLT), Continuous Performance Test (CPT), Beck Depression Inventory (BDI), Epworth Sleepiness Scale (ESS), State and Trait Anxiety Inventory (STAI), and Adult Attention Deficit Self-Evaluation Scale (ASRS) were administered. Performance was compared between RLS patients and controls accounting for the presence of attention-deficit/hyperactivity disorder (ADHD) and DA use. RESULTS: Age, education, BDI, ESS, STAI, and ASRS scores were similar for control and RLS groups. Control and RLS groups performed similarly on auditory verbal learning and general attention tests. In the CPT, commission error was significantly higher and response time was significantly shorter in the RLS group compared to controls (p = .014 and p = .010, respectively). These significant differences persisted after adjusting for ADHD and DA usage. CONCLUSION: In this study, RLS patients were more impulsive than the healthy individuals independent of ADHD and DA use. However, learning and attention performances of the patients are not affected.

The operational definition of epileptiform discharges significantly improves diagnostic accuracy and inter-rater agreement of trainees in EEG reading.

To assess whether trainees can learn and implement the operational definition of interictal epileptiform discharges (IEDs) of the International Federation of Clinical Neurophysiology (IFCN), based on six morphological criteria, and whether its implementation improves their diagnostic performance and inter-rater agreement (IRA). Seven trainees evaluated a balanced dataset of 70 EEG samples containing sharp transients (35 from patients with epilepsy and 35 from patients with non-epileptic paroxysmal events). The gold standard was derived from video-EEG recordings of the habitual clinical episodes. The trainees individually reviewed the EEGs, blinded to all other data, in two successive training sessions, three months apart. The second session was preceded by a teaching module about the IFCN criteria, and the trainees implemented them during the second reading session. By implementing the IFCN criteria, trainees significantly improved their specificity (94.29% vs. 77.14%; p=0.01) and overall accuracy (81.43% vs. 64.29%; p=0.01) for identifying IEDs. Sensitivity also improved but did not reach the level of statistical significance (77.14% vs. 60%; p=0.07). IRA improved significantly from fair (k=0.31; 95% CI: 0.22-0.40) to high-moderate (k=0.56; 95% CI:0.46-0.67) beyond-chance agreement. Implementing the IFCN criteria significantly improves the diagnostic performance and IRA of trainees in identifying IEDs. Teaching the IFCN criteria for IEDs will increase specificity in clinical EEG and avoid over-reading, the most common cause of misdiagnosing epilepsy.

Dose conversion ratio, comparative efficacy, and adverse events after switching from onabotulinum toxin A to abobotulinum toxin A for neurological conditions.

OBJECTIVES: Onabotulinum toxin A (ONA, Botox®) and abobotulinum toxin A (ABO, Dysport®) are most frequently used in the treatment of movement disorders. The aim of this study was to identify the dose conversion ratio (ABO dose:ONA dose), comparative efficacy, and adverse events in patients who switched from ONA to ABO. METHODS: There were 64 patients with cervical dystonia (39), hemifacial spasm (16), oromandibular dystonia (5), blepharospasm (3), and extremity dystonia (1) who switched from ONA to ABO. The efficacy, adverse events, duration of action, and severity of the adverse events after the final dose of ONA, initial dose of ABO, and second dose of ABO were investigated in these patients. RESULTS: The mean dose conversion ratio was 4.70 (2.27-9.62). The mean efficacy of the final ONA injection was 70.62%; initial ABO injection, 72.27%; and second ABO injection, 73.52%, which showed improvement on a visual analog scale (p = 0.71, p = 0.5). Incidence of adverse events after the final ONA injection was 18.8%; this increased to 39.1% after the initial ABO injection (p < 0.001) and decreased to 14.1% after the second ABO injection (p = 0.77). After the initial ABO injection, 20% of the adverse events were trivial, 36% were mild, and 32% were severe. After the second ABO injection, 7.8% of the adverse events were mild and 6.3% were severe. CONCLUSION: Although the mean dose conversion ratio was 4.70, the range was very wide (approximately 2-9). Therefore, we conclude that after the switch from Botox to Dysport, the doses should be tailored to the patients' clinical situation at treatment initiation, without using a dose conversion ratio.

Risk Factors, Biomarkers, Etiology, Outcome and Prognosis of Ischemic Stroke in Cancer Patients

Introduction: Cerebrovascular disease is the second most common complication in individuals with tumours. The aim of this study was to investigate risk factors, biomarkers, etiology and prognosis of ischemic stroke in cancer patients (ISCPs). Methods: The medical records of 619 consecutive patients who were admitted with acute ischemic stroke from January 2012 to November 2014 were retrospectively evaluated. The patients were divided into two groups (group 1, patients with an active cancer prior to the onset of ischemic stroke; group 2, patients without an active cancer history). The demographic data, risk factors, NIHSS scores, thrombocyte count, D-dimer, fibrinogen and C reactive protein (CRP) level at admission, modified Rankin Scale (mRS) scores in the follow-up period and location of lesions on DWI were recorded. The Mann-Whitney U test, chi-squared test and logistic regression was used for analyzing data, p<0.05 being considered statistically significant. Results: A total of 46 (7.4%) ISCPs were included. Hyperlipidemia was significantly lower in the ISCP group (p=0.001). Elevated thrombocyte counts, D-dimer, fibrinogen and CRP levels at admission, acute multiple ischemic lesions, other causes, mortality in hospital and worse outcome were significantly related to ISCP (p<0.05). On logistic regression analysis, follow up mRS>3, acute multiple ischemic lesions located in more than one vascular territory (AMIMCT) and other causes were significantly associated with ISCP (p<0.001). Conclusion: In our study, other causes, AMIMCT and mRS>3 were more common in the ISCP group. We consider that CCS could be more suitable for detecting other causes than TOAST. Biomarkers could be important in the ISCP group.

Assessment of voiding dysfunction in Parkinson's disease: Reliability and validity of the Turkish version of the Danish Prostate Symptom Score.

AIMS: To investigate the reliability and validity of the Turkish version of the Danish Prostate Symptom Score (Dan-PSS) questionnaire in patients with Parkinson's disease (PD) and to compare the burden of LUTS (Lower urinary tract symptoms) in men and women. METHODS: For analysis of test-retest reliability, the Turkish version of the Dan-PSS scale was developed using the back translation method, and it was administered on the day of admission and repeated 1 week after in 60 patients with PD. The OAB-q (Overactive Bladder Questionnaire) and PDQ-39 (Parkinson's Disease Questionnaire-39) were administered to 73 patients for validity analysis. RESULTS: Both the internal consistency (Cronbach's alpha coefficient: 0.99-1.00) and the test-retest reliability (intraclass correlation coefficient: 0.99-1.00) of the Dan-PSS were found to be high in patients with PD. Although weak to moderate correlations were found between the subscales of the Dan-PSS and PDQ-39 (r: 0.20-0.42; P < 0.05), a strong correlation was found with the OAB-q (r: 0.60-0.79; P < 0.05). Nocturnal urination was the most frequent (93.2%), and bothersome (54.8%) symptom. The majority of the symptom and bother responses were similar in men and women. CONCLUSIONS: Current study shows that the Turkish version of the Dan-PSS questionnaire is an internally consistent, reliable, and valid scale for patients with PD. Therefore, it can be used to evaluate frequency and severity of LUTS in PD. LUTS are commonly seen in patients with PD in both sexes. It is suggested that all patients with PD should be referred for urological assessment.

Comparative effects of cationic triarylmethane, phenoxazine and phenothiazine dyes on horse serum butyrylcholinesterase.

The kinetic effects of a selection of triarylmethane, phenoxazine and phenothiazine dyes (pararosaniline (PR), malachite green (MG), methyl green (MeG); meldola blue (MB), nile blue (NB), nile red (NR); methylene blue (MethB)) and of ethopropazine on horse serum butyrylcholinesterase were studied spectrophotometrically at 25( degrees )C in 50mM MOPS buffer, pH 8, using butyrylthiocholine as substrate. PR, MeG, MB and ethopropazine acted as linear mixed type inhibitors of the enzyme, with respective K(i) values of 4.5+/-0.50 microM, 0.41+/-0.007 microM, 0.44+/-0.086 microM and 0.050+/-0.0074 microM. MG, NB, MethB and NR caused complex, nonlinear inhibition pointing to cooperative binding at two sites. Intrinsic K' values ( identical with[I](2)(0.5) extrapolated to [S]=0) for MG, NB, NR and MethB were 0.20+/-0.096 microM, 0.0018+/-0.0015 microM, 0.92+/-0.23 microM and 0.23+/-0.08 microM. NB stood out as a potent inhibitor effective at nM levels. Comparison of inhibitory effects on horse and human serum butyrylcholinesterases suggested that the two enzymes must have distinct microstructural features.

Inhibition of electric eel acetylcholinesterase by triarylmethane dyes.

The effects of three cationic triarylmethane dyes--pararosaniline (PR), malachite green (MG), methyl green (MetG)--on electric eel AChE (eAChE) activity were tested at 25 degrees C, in 100 mM MOPS buffer (pH 8) containing 0.125 mM 5-5-dithio-bis(2-nitrobenzoic acid), 20-120 microM acetylthiocholine and 0-20 microM dye. All three dyes caused reversible, linear- or hyperbolic-mixed inhibition of esteratic activity. The respective inhibitory parameters for PR, MG and MetG were K(i)=8.4+/-0.67, 1.9+/-0.51 and 0.27+/-0.017 microM; alpha (competitive coefficient)=5.8+/-2.0, 4.8+/-1.8 and 2.7+/-0.32; beta (noncompetitive coefficient)=0, 0 and 0.20+/-0.011. The data were consistent with ligand binding at the peripheral site and a remote effect on substrate binding and turnover.

An assessment of the role of intracellular reductive capacity in the biological clearance of triarylmethane dyes.

The second-order rate constants (at pH 7, 25 degrees C) for the reduction of three cationic triarylmethane dyes [pararosaniline (PR+), malachite green (MG+), methyl green (MeG+)] by NADH were 1.4 x 10(-2) to 6.7 x 10(-2)mM(-1)min(-1). Based on these values the intracellular nonenzymatic reduction of TAM+ to TAM-H by endogenous NADH was estimated to proceed with an average half-life of 30 min. Rapid and significant adduct formation was observed with the thiol, 3-mercaptopropionic acid (MPA), suggesting that the primary intracellular form of the dyes must be a thiol adduct and that the conversion to adduct form takes place within ms-s. These time frames, when compared to the min-h time frame for microbial clearance of triarylmethanes from culture media, suggest that transport must be the rate-limiting step in non-adsorptive (chemical) clearance of the dyes and that the presence of enzymes to complement the nonenzymatic reductive and adduct-forming activities cited serves a kinetically limited purpose. It appears that a superior catalytic scavenger will be one with a superior transport capacity.

Multi-site inhibition of human plasma cholinesterase by cationic phenoxazine and phenothiazine dyes.

Two cationic phenoxazine dyes, meldola blue (MB) and nile blue (NB), and the structurally related phenothiazine, methylene blue (MethB), were found to act as complex inhibitors of human plasma cholinesterase (butyrylcholinesterase, BChE). Studied at 25 degrees C, in 100mM MOPS buffer (pH 8.0), with butyrylthiocholine as substrate, the kinetic pattern of inhibition indicated cooperative I binding at 2 sites. Intrinsic K' values ( identical with[I](0.5)(2) extrapolated to [S]=0) for MB, NB and MethB were 0.64+/-0.05, 0.085+/-0.026 and 0.42+/-0.04 microM, respectively. Under the same experimental conditions the dyes acted as single-occupancy, hyperbolic-mixed inhibitors of electric eel acetylcholinesterase (AChE), with K(i)=0.035+/-0.010, 0.026+/-0.0034 and 0.017+/-0.0063 microM (for MB, NB, MethB); alpha (coefficient of competitive interaction)=1.8-2.4 and beta (coefficient of noncompetitive interaction)=0.15-0.28. The complexity of the BChE inhibitory effect of phenoxazine/phenothiazine dyes contrasted with that of conventional ChE inhibitors which cause single-occupancy (n=1), competitive or mixed inhibition in both AChE and BChE and signaled novel modes of ligand interaction at (or remote from) the active site gorge of the latter enzyme.

Inhibition of choline oxidase by quinoid dyes.

Choline oxidase catalyzes the oxidation of choline to glycine-betaine, with betaine-aldehyde as intermediate and molecular oxygen as primary electron acceptor. This study reports on the inhibitory effects of triarylmethanes (cationic malachite green; neutral leukomalachite green), phenoxazines (cationic, meldola blue and nile blue; neutral nile red) and a structurally-related phenothiazine (methylene blue) on choline oxidase, assayed at 25 degrees C in 50 mM MOPS buffer, pH 7, using choline as substrate. Methylene B acted as a competitive inhibitor with K(i) = 74 +/- 7.2 microM, pointing to the choline-binding site of the enzyme as a target site. Nile B caused noncompetitive inhibition of enzyme activity with K(i) = 20 +/- 4.5 microM. In contrast to methylene B and nile B, malachite G and meldola B caused complex, nonlinear inhibition of choline oxidase, with estimated K(i) values in the micromolar range. The difference in kinetic pattern was ascribed to the differential ability of the dyes to interact (and interfere) with the flavin cofactor, generating different perturbations in the steady-state balance of the catalytic process.

Inhibition of human plasma cholinesterase by malachite green and related triarylmethane dyes: mechanistic implications.

The inhibitory effects of the cationic triarylmethane (TAM+) dyes, pararosaniline (PR+), malachite green (MG+), and methyl green (MeG+) on human plasma cholinesterase (BChE) were studied at 25 degrees C in 100 mM Mops, pH 8.0, with butyrylthiocholine as substrate. PR+ and MG+ caused linear mixed inhibition of enzyme activity. The respective inhibitory parameters were K(i) = 1.9 +/- 0.23 microM, alpha = 13 +/- 48, beta = 0 and K(i) = 0.28 +/- 0.037 microM, alpha = 23 +/- 7.4, beta = 0. MeG+ acted as a competitive inhibitor with K(i) = 0.12 +/- 0.017 microM (alpha, infinity, beta, not applicable). The K(i) values were within the same range reported for a number of ChE inhibitors including propidium ion, donepezil, and the phenothiazines, suggesting that TAM+s are active site ligands. On the other hand, the alpha values failed to correlate with values previously reported for a number of ChE inhibitors. It appears that mixed inhibition is the combined result of more than one type of binding and S-I interference. The impact of ligands at the choline-specific and peripheral anionic sites (or, possibly, accessory structural domains) on BChE activity needs to be studied in further detail.

Steady-state kinetic properties of sorbitol dehydrogenase from chicken liver.

The steady-state kinetic properties of partially purified chicken liver sorbitol dehydrogenase (SDH) were determined spectrophotometrically at 25 degrees C, in 50 mM 3-(N-morpholino)propanesulfonic acid (MOPS) buffer, pH 8.0. In the sorbitol-to-fructose direction, analysis was based on initial rate data obtained at [NAD(+)](o)=0.1-0.4 mM and [sorbitol](o)=1.25-10 mM. The reverse process was analyzed by recording progress curves for NADH consumption, starting with [NADH](o)=0.2 mM and [fructose](o)=66.7-267 mM. The kinetics conformed to an ordered sequential model, with the cofactors adding first. The steady-state parameters in the forward direction, K(NAD(+)), K(iNAD(+)) and K(sorbitol), were found to be 210+/-62 muM, 220+/-69 microM and 3.2+/-0.54 mM, respectively. The corresponding parameters in the reverse direction were K(NADH)=240+/-58 microM, K(iNADH)=10+/-2.8 microM and K(fructose)=1000+/-140 mM. The results indicated a close parallelism with human SDH, yet up to 40-fold differences were observed when compared to related reports on other mammalian species. The structural and adaptive bases of the variation in substrate and cofactor affinities need to be accounted for.

Adduct-forming tendencies of cationic triarylmethane dyes with proteins: metabolic and toxicological implications.

The formation of colorless adducts by four cationic triarylmethane dyes (TAM(+)s), methyl green (MeG(+)), malachite green (MG(+)), pararosaniline (PR(+)), and crystal violet (CV(+)) was studied spectrophotometrically at 25 degrees C, in 50 mM 3-(N-morpholino)propanesulfonic acid (MOPS) buffer (pH 8), by monitoring the loss in TAM(+) color in the absence and presence of human serum proteins as potential addends. Unfractionated serum caused a rapid bleaching of MeG(+) and MG(+), while PR(+) and CV(+) were unaffected. Sephacryl S200 HR chromatographic screening of the serum revealed two composite peaks of MeG(+)-bleaching activity. The major peak (M(r) range, 40,000-130,000) overlapped with and extended on either side of the albumin peak. The minor peak corresponding to ca. 10% of the total MeG(+)-bleaching capacity had M(r) > 230,000. MG(+)-bleaching activity dominated the entire chromatographic profile and implicated a multitude of minority proteins with a high capacity to form colorless MG adducts. It is concluded that highly electrophilic TAM(+)s such as MeG(+) and MG(+) must be quantitatively trapped in the form of dye-protein adducts in biological fluids and that the primary in vivo effects (e.g. toxicity) of such dyes most likely arise from ligand-type effects on multiple protein targets. Mechanisms that call for unmodified TAM(+) structure (radical-mediated redox changes, DNA intercalation) may be more relevant to the in vivo impact of dyes such as PR(+) and CV(+) that have a lower tendency to form adducts.

A comparison between SDS-PAGE and size exclusion chromatography as analytical methods for determining product composition in protein conjugation reactions.

Horseradish peroxidase (HRP) was conjugated with bovine serum albumin (BSA) or human alpha(1)-proteinase inhibitor (alpha(1)-PI). The enzyme was maleimidylated using N-succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) and then allowed to react with thiolated BSA or reduced alpha(1)-PI. The conjugation products were analysed both by SDS-PAGE and size exclusion chromatography (SEC) on Sephadex G200. The two methods of evaluating conjugative processes were compared with respect to information provided in relation to the behaviour of the products in solution. The results showed that neither SDS-PAGE nor SEC alone provides sufficient information about conjugate structure. The basic conjugate units observed in electrophoresis tend to form dimeric or higher-order aggregates under gel chromatographic conditions.