Dermal Real-Time Quaking-Induced Conversion Is a Sensitive Marker to Confirm Isolated Rapid Eye Movement Sleep Behavior Disorder as an Early α-Synucleinopathy.

BACKGROUND: Skin biopsy is a potential tool for the premortem confirmation of an α-synucleinopathy. OBJECTIVE: The aim was to assess the aggregation assay real-time quaking-induced conversion (RT-QuIC) of skin biopsy lysates to confirm isolated rapid eye movement sleep behavior disorder (iRBD) as an α-synucleinopathy. METHODS: Skin biopsies of patients with iRBD, Parkinson's disease (PD), and controls were analyzed using RT-QuIC and immunohistochemical detection of phospho-α-synuclein. RESULTS: α-Synuclein aggregation was detected in 97.4% of iRBD patients (78.4% of iRBD biopsies), 87.2% of PD patients (70% of PD biopsies), and 13% of controls (7.9% of control biopsies), with a higher seeding activity in iRBD compared to PD. RT-QuIC was more sensitive but less specific than immunohistochemistry. CONCLUSIONS: Dermal RT-QuIC is a sensitive method to detect α-synuclein aggregation in iRBD, and high seeding activity may indicate a strong involvement of dermal nerve fibers in these patients. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

α-Synuclein pathology disrupts mitochondrial function in dopaminergic and cholinergic neurons at-risk in Parkinson's disease.

Background: Pathological accumulation of aggregated α-synuclein (aSYN) is a common feature of Parkinson's disease (PD). However, the mechanisms by which intracellular aSYN pathology contributes to dysfunction and degeneration of neurons in the brain are still unclear. A potentially relevant target of aSYN is the mitochondrion. To test this hypothesis, genetic and physiological methods were used to monitor mitochondrial function in substantia nigra pars compacta (SNc) dopaminergic and pedunculopontine nucleus (PPN) cholinergic neurons after stereotaxic injection of aSYN pre-formed fibrils (PFFs) into the mouse brain. Methods: aSYN PPFs were stereotaxically injected into the SNc or PPN of mice. Twelve weeks later, mice were studied using a combination of approaches, including immunocytochemical analysis, cell- type specific transcriptomic profiling, electron microscopy, electrophysiology and two-photon-laser- scanning microscopy of genetically encoded sensors for bioenergetic and redox status. Results: In addition to inducing a significant neuronal loss, SNc injection of PFFs induced the formation of intracellular, phosphorylated aSYN aggregates selectively in dopaminergic neurons. In these neurons, PFF-exposure decreased mitochondrial gene expression, reduced the number of mitochondria, increased oxidant stress, and profoundly disrupted mitochondrial adenosine triphosphate production. Consistent with an aSYN-induced bioenergetic deficit, the autonomous spiking of dopaminergic neurons slowed or stopped. PFFs also up-regulated lysosomal gene expression and increased lysosomal abundance, leading to the formation of Lewy-like inclusions. Similar changes were observed in PPN cholinergic neurons following aSYN PFF exposure. Conclusions: Taken together, our findings suggest that disruption of mitochondrial function, and the subsequent bioenergetic deficit, is a proximal step in the cascade of events induced by aSYN pathology leading to dysfunction and degeneration of neurons at-risk in PD.

Transdermal Nicotine Treatment and Progression of Early Parkinson's Disease.

BACKGROUND: Epidemiologic studies show that smokers have a lower incidence of Parkinson's disease. Nicotine has been hypothesized to slow progression in early Parkinson's disease. METHODS: In a double-blind, placebo-controlled multicenter trial, we randomly assigned patients with Parkinson's disease, diagnosed within 18 months, who were in Hoehn and Yahr disease stage less than or equal to 2 (range from 0 to 5; higher scores indicate greater impairment), who were therapy naïve (except for stable monoamine-oxidase-B inhibition), and not requiring dopaminergic therapy, to transdermal nicotine or placebo. The primary end point was change in Unified Parkinson's Disease Rating Scale parts I­III (Total UPDRS) score (range from 0 to 172; higher scores indicate greater impairment) between baseline and 60 weeks (52 weeks of trial therapy, 8 weeks of washout). The first secondary end point was change in Total UPDRS from baseline to 52 weeks. Differences between groups were estimated using the Hodges­Lehmann (HL) method and tested with the exact two-sided stratified Mann­Whitney­Wilcoxon test according to the intention-to-treat principle. RESULTS: Among 163 participants, 101 were assessed for the primary end point. Mean worsening of Total UPDRS was 3.5 in the placebo versus 6.0 in the nicotine group (HL-difference with 95% CI: ­3 [­6 to 0], P=0.06). For the first secondary end point, analysis of 138 participants showed a mean worsening of 5.4 in the placebo versus 9.1 in the nicotine group (HL-difference with 95% CI: ­4 [­7 to ­1]). Dropout was mainly because of early treatment discontinuation or adverse events. Cutaneous adverse effects at the patch application site were common. In all, 34.6% of participants initiated dopaminergic therapy during participation. CONCLUSIONS: One-year transdermal nicotine treatment did not slow progression in early Parkinson's disease. (Funded by the Michael J. Fox Foundation for Parkinson's Research and others; ClinicalTrials.gov number, NCT01560754; EudraCT number, 2010-020299-42.)

Mitochondrial damage by α-synuclein causes cell death in human dopaminergic neurons.

Evolving concepts on Parkinson's disease (PD) pathology suggest that α-synuclein (aSYN) promote dopaminergic neuron dysfunction and death through accumulating in the mitochondria. However, the consequence of mitochondrial aSYN localisation on mitochondrial structure and bioenergetic functions in neuronal cells are poorly understood. Therefore, we investigated deleterious effects of mitochondria-targeted aSYN in differentiated human dopaminergic neurons in comparison with wild-type (WT) aSYN overexpression and corresponding EGFP (enhanced green fluorescent protein)-expressing controls. Mitochondria-targeted aSYN enhanced mitochondrial reactive oxygen species (ROS) formation, reduced ATP levels and showed severely disrupted structure and function of the dendritic neural network, preceding neuronal death. Transmission electron microscopy illustrated distorted cristae and many fragmented mitochondria in response to WT-aSYN overexpression, and a complete loss of cristae structure and massively swollen mitochondria in neurons expressing mitochondria-targeted aSYN. Further, the analysis of mitochondrial bioenergetics in differentiated dopaminergic neurons, expressing WT or mitochondria-targeted aSYN, elicited a pronounced impairment of mitochondrial respiration. In a pharmacological compound screening, we found that the pan-caspase inhibitors QVD and zVAD-FMK, and a specific caspase-1 inhibitor significantly prevented aSYN-induced cell death. In addition, the caspase inhibitor QVD preserved mitochondrial function and neuronal network activity in the human dopaminergic neurons overexpressing aSYN. Overall, our findings indicated therapeutic effects by caspase-1 inhibition despite aSYN-mediated alterations in mitochondrial morphology and function.

Safety and efficacy of epigallocatechin gallate in multiple system atrophy (PROMESA): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Multiple system atrophy is a rare neurodegenerative disease characterised by aggregation of α-synuclein in oligodendrocytes and neurons. The polyphenol epigallocatechin gallate inhibits α-synuclein aggregation and reduces associated toxicity. We aimed to establish if epigallocatechin gallate could safely slow disease progression in patients with multiple system atrophy. METHODS: We did a randomised, double-blind, parallel group, placebo-controlled clinical trial at 12 specialist centres in Germany. Eligible participants were older than 30 years; met consensus criteria for possible or probable multiple system atrophy and could ambulate independently (ie, were at Hoehn and Yahr stages 1-3); and were on stable anti-Parkinson's, anti-dysautonomia, anti-dementia, and anti-depressant regimens (if necessary) for at least 1 month. Participants were randomly assigned (1:1) to epigallocatechin gallate or placebo (mannitol) via a web-generated permuted blockwise randomisation list (block size=2) that was stratified by disease subtype (parkinsonism-predominant disease vs cerebellar-ataxia-predominant disease). All participants and study personnel were masked to treatment assignment. Participants were given one hard gelatin capsule (containing either 400 mg epigallocatechin gallate or mannitol) orally once daily for 4 weeks, then one capsule twice daily for 4 weeks, and then one capsule three times daily for 40 weeks. After 48 weeks, all patients underwent a 4-week wash-out period. The primary endpoint was change in motor examination score of the Unified Multiple System Atrophy Rating Scale (UMSARS) from baseline to 52 weeks. Efficacy analyses were done in all people who received at least one dose of study medication. Safety was analysed in all people who received at least one dose of the study medication to which they had been randomly assigned. This trial is registered with ClinicalTrials.gov (NCT02008721) and EudraCT (2012-000928-18), and is completed. FINDINGS: Between April 23, 2014, and Sept 3, 2015, 127 participants were screened and 92 were randomly assigned-47 to epigallocatechin gallate and 45 to placebo. Of these, 67 completed treatment and 64 completed the study (altough one of these patients had a major protocol violation). There was no evidence of a difference in the mean change from baseline to week 52 in motor examination scores on UMSARS between the epigallocatechin gallate (5·66 [SE 1·01]) and placebo (6·60 [0·99]) groups (mean difference -0·94 [SE 1·41; 95% CI -3·71 to 1·83]; p=0·51). Four patients in the epigallocatechin gallate group and two in the placebo group died. Two patients in the epigallocatechin gallate group had to stop treatment because of hepatotoxicity. INTERPRETATION: 48 weeks of epigallocatechin gallate treatment did not modify disease progression in patients with multiple system atrophy. Epigallocatechin gallate was overall well tolerated but was associated with hepatotoxic effects in some patients, and thus doses of more than 1200 mg should not be used. FUNDING: ParkinsonFonds Deutschland, German Parkinson Society, German Neurology Foundation, Lüneburg Foundation, Bischof Dr Karl Golser Foundation, and Dr Arthur Arnstein Foundation.

Dermal Phospho-Alpha-Synuclein Deposition in Patients With Parkinson's Disease and Mutation of the Glucocerebrosidase Gene.

Heterozygous mutations in the glucocerebrosidase gene (GBA1) represent the most common genetic risk factor for Parkinson's disease (PD) and are histopathologically associated with a widespread load of alpha-synuclein in the brain. Therefore, PD patients with GBA1 mutations are a cohort of high interest for clinical trials on disease-modifying therapies targeting alpha-synuclein. There is evidence that detection of phospho-alpha-synuclein (p-syn) in dermal nerve fibers might be a biomarker for the histopathological identification of PD patients even at premotor or very early stages of disease. It is so far unknown whether dermal p-syn deposition can also be found in PD patients with GBA1 mutations and may serve as a biomarker for PD in these patients. Skin biopsies of 10 PD patients with different GBA1 mutations (six N370S, three E326K, one L444P) were analyzed by double-immunofluorescence labeling with anti-p-syn and anti-protein gene product 9.5 (PGP9.5, axonal marker) to detect intraaxonal p-syn deposition. Four biopsy sites (distal, proximal leg, paravertebral Th10, and C7) per patient were studied. P-syn was found in six patients (three N370S, three E326K). P-syn deposition was mainly detected in autonomic nerve fibers, but also in somatosensory fibers and was not restricted to a certain GBA1 mutation. In summary, dermal p-syn in PD patients with GBA1 mutations seems to offer a similar distribution and frequency as observed in patients without a known mutation. Skin biopsy may be suitable to study p-syn deposition in these patients or even to identify premotor patients with GBA1 mutations.

Drug Safety Analysis in a Real-Life Cohort of Parkinson's Disease Patients with Polypharmacy.

BACKGROUND: Polypharmacy is common in geriatric Parkinson's disease (PD) patients in advanced disease stages with multiple comorbidities, bearing multiple risks for drug safety in theory. OBJECTIVE: The aim of this study was to empirically identify the most frequent and relevant contraindications and drug interactions actually occurring and compromising drug safety in PD in real life. METHODS: We conducted a prospective observational study in a multimorbid cohort of PD patients with polypharmacy admitted to a specialized hospital. Inclusion criteria were the presence of at least one comorbidity requiring pharmacotherapy and at least five different drugs in the discharge prescription. Hoehn and Yahr stage during the 'on' state, therapeutic problems related to motor and non-motor PD symptoms, comorbidities, and drug regimens on admission and discharge were analyzed for contraindications and interactions. RESULTS: Overall, 127 patients were included (medium Hoehn and Yahr stage = IV, range II-V). Interactions with the anti-PD medication were mainly caused by other central nervous system (CNS)-active substances, cytochrome P450-metabolized substances, and QT-time prolonging substances. Contraindications against the anti-PD medication mainly occurred from internal, haematopoietic, neurologic and psychiatric diseases, and QT-time prolonging drugs. The highest frequency of interactions and contraindications were identified with levodopa (n = 119 at admission/n = 126 at discharge), entacapone (n = 46/42), pramipexole (n = 44/24), and amantadine (n = 32/30). CONCLUSIONS: Several medically relevant risk factors (interactions and contraindications) frequently occurred in advanced PD patients. These findings provide a basis for developing programmes for awareness, education, monitoring, and preventive interventions to avoid adverse incidents. Future studies will need to evaluate preventive efficacy of structured drug safety programmes.

Acylated and unacylated ghrelin confer neuroprotection to mesencephalic neurons.

The polypeptide ghrelin is an endogenous ligand at the growth hormone secretagogue receptor 1a. To ghrelin multiple functions have been ascribed including promotion of gastrointestinal motility. Postprandial ghrelin levels have been reported to be reduced in patients suffering from Parkinson disease (PD). Experimental studies revealed neuroprotective effects of ghrelin in different PD models. The purpose of the present study was (i) to further elucidate the mechanism underlying the neuroprotective action of ghrelin and (ii) to determine whether these effects occur with both the acylated and the unacylated form. The study was conducted in primary mesencephalic cultures treated with mitochondrial complex I and complex II inhibitors. We show that protective effects of ghrelin against complex I inhibition with MPP+ were independent of the acylation status of ghrelin, although acylated ghrelin appeared to be more potent. Protection by both forms was also observed when neurons were exposed to the complex II inhibitor 3-NP. Both forms led to higher oxygen consumption rates upon electron transport chain uncoupling, indicating that the two peptides may exert uncoupling effects themselves. We demonstrate that the rescue provided by ghrelin required calcium influx through L-type voltage-gated calcium channels. Whereas the protective effects of acylated ghrelin required receptor binding, effects of the unacylated form remained unaffected by treatment with a ghrelin receptor antagonist. Importantly, inhibition of ghrelin O-acyltransferase failed to reduce the activity of unacylated ghrelin. Overall, our data suggest that both acylated and unacylated ghrelin afford protection to dopamine neurons but through mechanisms that only partially overlap.

Dermal phospho-alpha-synuclein deposits confirm REM sleep behaviour disorder as prodromal Parkinson's disease.

Phosphorylated alpha-synuclein (p-alpha-syn) deposits, one of the neuropathological hallmarks of Parkinson's disease (PD), have recently been detected in dermal nerve fibres in PD patients with good specificity and sensitivity. Here, we studied whether p-alpha-syn may serve as a biomarker in patients with a high risk of developing PD, such as those with REM sleep behaviour disorder (RBD). We compared the presence and distribution of p-alpha-syn deposits in dermal nerve fibres in 18 patients with RBD, 25 patients with early PD and 20 normal controls. Skin biopsy was taken at C7, Th10, and the upper and lower leg. Presynaptic dopamine transporter imaging using FP-CIT-SPECT was performed in all patients with RBD and in 11 patients with PD. All RBD patients underwent olfactory function testing. The likelihood ratio (LR) for prodromal PD was calculated for each patient based on published research criteria. Skin serial sections were assessed by double-immunofluorescence labelling with antibodies to pSer129-alpha-syn under blinded conditions. P-alpha-syn was visualized in 10/18 patients with RBD (sensitivity of 55.6%) and in 20/25 early PD patients (sensitivity of 80%) but in none of the controls (specificity of 100%). The percentage of dermal structures innervated by p-alpha-syn-positive fibres was negatively correlated with dopamine transporter binding in the FP-CIT-SPECT (ρ = -0.377, p = 0.048), with olfactory function (ρ = -0.668, p = 0.002), and positively correlated with the total LR for RBD to present prodromal PD (ρ = 0.531, p = 0.023). Dermal p-alpha-syn can be considered a peripheral histopathological marker of synucleinopathy and can be detected in a subgroup of RBD patients presumably representing prodromal PD. Dermal p-alpha-syn is detectable in RBD patients without PD motor symptoms, thereby stratifying a patient group that is of great interest for clinical trials testing disease-modifying drugs.

Reduced intraepidermal nerve fiber density in patients with REM sleep behavior disorder.

BACKGROUND: Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) has been increasingly acknowledged to be an initial specific manifestation of alpha-synucleinopathies such as Parkinson's disease (PD), multiple system atrophy (MSA) and dementia with Lewy bodies (DLB). Recent findings suggest that cutaneous abnormalities like small fiber neuropathy and alpha-synuclein deposition might reflect brain pathology and might function as early biomarkers in PD. This is the first study to elucidate whether iRBD patients already suffer from distinctive cutaneous features. METHODS: We examined skin punch biopsies from the distal leg of 18 iRBD patients and 22 age- and sex-matched controls using immunohistochemistry and microscopy. Further clinical evaluation included structured interviews, clinical motor and non-motor questionnaires and rating scales (e.g. Unified Parkinson's disease rating scale [UPDRS], non-motor symptoms questionnaire [NMS-Quest] and Beck Depression Inventory, Epworth Sleepiness Scale, evaluation of cognitive and olfactory functioning as well as blood samples. RESULTS: Intraepidermal nerve fiber density (IEFND) was reduced in iRBD patients compared to controls (p = 0.037), whereas the axon swelling ratio did not differ between groups. Patients with iRBD reported non-motor symptoms more frequently than controls (UPDRS I, NMS-Quest). Olfaction and daytime sleepiness differed between both groups, whereas there were no differences regarding cognition. CONCLUSIONS: These in vivo findings demonstrate small fiber neuropathy in iRBD patients that are associated with non-motor symptoms indicating that peripheral abnormalities may occur early in iRBD. However, the prognostic value has to be further investigated in longitudinal studies.

Biceps electromyography in dialeptic and automotor seizures with and without secondary generalization.

OBJECTIVE: Localization of seizure onset during presurgical video-EEG monitoring is indispensable for successful epilepsy surgery. Sometimes analysis of ictal EEG and video fails to identify this zone. Therefore, this study explored the hypothesis that ictal EMG recordings contribute to the lateralization or localization of focal epilepsy. METHODS: All patients with automotor or dialeptic seizures with or without secondary generalization were prospectively included during presurgical video-EEG monitoring over a 5years study period. We analyzed characteristics of ictal biceps EMG and compared the results to EEG and video findings. RESULTS: 79 patients with 185 seizures were included (51.9% male; 73.5% automotor and 26.5% dialeptic seizures; 24.3% seizures secondarily generalized). Even in dialeptic seizures, muscle tone increased bilaterally within seconds after EEG seizure onset (66.7%) without clinical movements. Bilateral "spindle-shaped" EMG activity during the automotor phase predicted secondary generalization in 88.7%. Increase of muscle activity in the contralateral side of the body in the beginning of the secondarily generalized tonic-clonic phase was detected in 78.1% after automotor seizures whereas this phenomenon was less pronounced after dialeptic seizures (69.2%). 38.5% of dialeptic seizures evolved into generalized tonic-unilateral clonic seizures. CONCLUSION: Ictal EMG recordings provide lateralizing signs especially in secondarily generalized automotor seizures. In addition, the study suggested that secondary generalization in automotor seizures is determined early already during the automotor phase. Dialeptic seizures can evolve only unilaterally into a tonic-clonic seizure while the other side of the body remains tonic. SIGNIFICANCE: Ictal biceps EMG can provide further information regarding lateralization of epileptic seizures.

Systemically administered neuregulin-1ß1 rescues nigral dopaminergic neurons via the ErbB4 receptor tyrosine kinase in MPTP mouse models of Parkinson's disease.

Previously, we demonstrated that systemically injected extracellular domain of neuregulin-1ß1 (Nrg1ß1), a nerve growth and differentiation factor, passes the blood-brain barrier and rescues dopaminergic neurons of substantia nigra in the 6-hydroxydopamine-mouse model of Parkinson's disease (PD). Here, we studied the effects of peripherally administered Nrg1ß1 in another toxin-based mouse model of PD. For this purpose, (i) nigrostriatal pathway injury was induced by treatment of adult wild-type mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in acute and subchronic paradigms; and (ii) Nrg1ß1 or saline (control) were administered 1 h before each MPTP injection. We found that Nrg1ß1 significantly reduced the loss of nigral dopaminergic neurons in both intoxication paradigms (7 days post-injection). However, Nrg1ß1 did not reverse MPTP-induced decrease in dopamine levels and dopaminergic fibers in the striatum. We also show that MPTP conversion to its toxic metabolite 1-methyl-4-phenylpyridinium as well as levels of dopamine transporter, mediating intracellular uptake of 1-methyl-4-phenylpyridinium, are unaffected by Nrg1ß1. Finally, neuroprotective properties of Nrg1ß1 on nigral dopaminergic neurons are specifically mediated by ErbB4 as revealed through the study of ErbB4 knockout mice. In conclusion, systemically administered Nrg1ß1 protects midbrain dopaminergic neurons against this PD-related toxic insult. Thus, Nrg1ß1 may have a benefit in the treatment of PD patients. Previously, we demonstrated that systemically administered neuregulin-1ß1 (Nrg1ß1) passes the blood-brain barrier, phosphorylates ErbB4 receptors and elevates dopamine (DA) levels in the nigrostriatal system of healthy mice. Nrg1ß1 protects nigral DAergic neurons in the 6-hydroxydopamine (6-OHDA) mouse model of Parkinson's disease (PD). Here, we show that Nrg1ß1 rescues nigral DAergic neurons also against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced cell death. ErbB4 expression is essential for the neuroprotective effect of Nrg1ß1 on midbrain DAergic neurons. Nrg1ß1 might be beneficial in PD treatment.

Targeted resequencing and systematic in vivo functional testing identifies rare variants in MEIS1 as significant contributors to restless legs syndrome.

Restless legs syndrome (RLS) is a common neurologic condition characterized by nocturnal dysesthesias and an urge to move, affecting the legs. RLS is a complex trait, for which genome-wide association studies (GWASs) have identified common susceptibility alleles of modest (OR 1.2-1.7) risk at six genomic loci. Among these, variants in MEIS1 have emerged as the largest risk factors for RLS, suggesting that perturbations in this transcription factor might be causally related to RLS susceptibility. To establish this causality, direction of effect, and total genetic burden of MEIS1, we interrogated 188 case subjects and 182 control subjects for rare alleles not captured by previous GWASs, followed by genotyping of ∼3,000 case subjects and 3,000 control subjects, and concluded with systematic functionalization of all discovered variants using a previously established in vivo model of neurogenesis. We observed a significant excess of rare MEIS1 variants in individuals with RLS. Subsequent assessment of all nonsynonymous variants by in vivo complementation revealed an excess of loss-of-function alleles in individuals with RLS. Strikingly, these alleles compromised the function of the canonical MEIS1 splice isoform but were irrelevant to an isoform known to utilize an alternative 3' sequence. Our data link MEIS1 loss of function to the etiopathology of RLS, highlight how combined sequencing and systematic functional annotation of rare variation at GWAS loci can detect risk burden, and offer a plausible explanation for the specificity of phenotypic expressivity of loss-of-function alleles at a locus broadly necessary for neurogenesis and neurodevelopment.

Diesterified derivatives of 5-iodo-2'-deoxyuridine as cerebral tumor tracers.

With the aim to develop beneficial tracers for cerebral tumors, we tested two novel 5-iodo-2'-deoxyuridine (IUdR) derivatives, diesterified at the deoxyribose residue. The substances were designed to enhance the uptake into brain tumor tissue and to prolong the availability in the organism. We synthesized carrier added 5-[125I]iodo-3',5'-di-O-acetyl-2'-deoxyuridine (Ac2[125I]IUdR), 5-[125I]iodo-3',5'-di-O-pivaloyl-2'-deoxyuridine (Piv2[125I]IUdR) and their respective precursor molecules for the first time. HPLC was used for purification and to determine the specific activities. The iodonucleoside tracer were tested for their stability against human thymidine phosphorylase. DNA integration of each tracer was determined in 2 glioma cell lines (Gl261, CRL2397) and in PC12 cells in vitro. In mice, we measured the relative biodistribution and the tracer uptake in grafted brain tumors. Ac2[125I]IUdR, Piv2[125I]IUdR and [125I]IUdR (control) were prepared with labeling yields of 31-47% and radiochemical purities of >99% (HPLC). Both diesterified iodonucleoside tracers showed a nearly 100% resistance against degradation by thymidine phosphorylase. Ac2[125I]IUdR and Piv2[125I]IUdR were specifically integrated into the DNA of all tested tumor cell lines but to a less extend than the control [125I]IUdR. In mice, 24 h after i.p. injection, brain radioactivity uptakes were in the following order Piv2[125I]IUdR>Ac2[125I]IUdR>[125I]IUdR. For Ac2[125I]IUdR we detected lower amounts of radioactivities in the thyroid and stomach, suggesting a higher stability toward deiodination. In mice bearing unilateral graft-induced brain tumors, the uptake ratios of tumor-bearing to healthy hemisphere were 51, 68 and 6 for [125I]IUdR, Ac2[125I]IUdR and Piv2[125I]IUdR, respectively. Esterifications of both deoxyribosyl hydroxyl groups of the tumor tracer IUdR lead to advantageous properties regarding uptake into brain tumor tissue and metabolic stability.

Intravenous immunoglobulin maintenance treatment in myasthenia gravis: a randomized, controlled trial sample size simulation.

INTRODUCTION: In cases of exacerbation or crisis, myasthenia gravis (MG) patients can be treated with intravenous immunoglobulin (IVIg), plasmapheresis, or immunoadsorption. However, IVIg efficacy data in maintenance treatment are sparse. METHODS: We prospectively observed 16 index patients with chronic and insufficiently controlled MG under standard immunosuppressant therapy and symptomatic treatment. The IVIg treatment response was measured using changes in quantitative myasthenia gravis (QMG) score and surrogates. Based on these results, a sample size calculation for a future randomized, controlled trial (RCT) was simulated. RESULTS: There was an enduring decline in QMG score and other parameters of about 50% under IVIg maintenance treatment. RCT sample size calculation results in 73 or 33 patients per arm to detect at least a 20% vs. 30% clinical difference in QMG score. CONCLUSION: We recommend using the QMG score as a primary endpoint for an RCT of IVIg maintenance for chronic MG.

Intravenous iron sucrose for restless legs syndrome in pregnant women with low serum ferritin.

We report on two pregnant women who either had de novo restless legs syndrome (RLS) or had marked enhancement of preexisting RLS symptoms during pregnancy. Both patients had ferritin values <50 µg/L at baseline. The patients had relevant sleep disorders and daytime symptoms caused by RLS. The women were treated in an open paradigm with intravenous iron sucrose. A few weeks after therapy, both patients experienced a significant reduction or even remission of RLS symptoms. Their quality of life and sleep substantially improved and no treatment-related adverse effects were observed. According to our initial experience, intravenous iron sucrose administration appears to be an effective therapy in RLS patients with low ferritin values during pregnancy.

Early detection of bone metabolism changes under different antiepileptic drugs (ED-BoM-AED)--a prospective multicenter study.

PURPOSE: To determine early changes in bone turnover markers induced by treatment with oxcarbazepine or valproate. METHODS: In this prospective study, 31 adults with newly diagnosed epilepsy were included who were started on therapy with either oxcarbazepine (OXC, n=16, mean age 45.6 years, 37.5% female) or valproate (VPA, n=15, mean age 42.2 years, 33.3% female). Clinical characteristics were obtained at baseline, after 2 weeks and 3 months. In addition, blood samples were drawn at each visit. Calcium, phosphate, alkaline phosphatase (AP), receptor activator of NF-κB ligand (RANKL), osteoprotegerin (OPG), osteocalcin (OC) and cathepsin K were determined. RESULTS: In OXC treated patients, OPG increased by 0.06 pmol/L (p=0.0004) after 2 weeks and remained elevated by 0.05 pmol/L (p=0.02) after 3 months. Between 2 weeks and 3 months of OXC treatment, OC increased by 1.98 ng/mL (p=0.02). During the first 3 months of OXC treatment, total serum AP increased by 11%±9% (p=0.02). Compared to baseline, serum calcium raised by 0.06 mmol/L (p=0.04) after 2 weeks and by 0.07 mmol/L (p=0.004) after 3 months of OXC treatment. In VPA treated patients, a late OPG increase by 0.07 pmol/L (p=0.007) occurred after 3 months. During the first 3 months of OXC treatment, total serum AP decreased by by 7%±15% (p=0.03). No changes in OC or calcium were seen. RANKL was below detection limit in 16 out of 31 patients (52%) and did not change significantly during treatment. Cathepsin K was below detection limit at baseline in 27 out of 31 patients (87%) and was therefore not further evaluated. Phosphate did not change during treatment. CONCLUSION: Increased bone turnover can be measured within few weeks of newly started treatment with OXC, while significant changes under VPA treatment occurred only after 3 months. Our data suggest distinct mechanisms of increased bone turnover in different anticonvulsants. These variable mechanisms may require individual prevention and treatment strategies.

Bee venom and its component apamin as neuroprotective agents in a Parkinson disease mouse model.

Bee venom has recently been suggested to possess beneficial effects in the treatment of Parkinson disease (PD). For instance, it has been observed that bilateral acupoint stimulation of lower hind limbs with bee venom was protective in the acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. In particular, a specific component of bee venom, apamin, has previously been shown to have protective effects on dopaminergic neurons in vitro. However, no information regarding a potential protective action of apamin in animal models of PD is available to date. The specific goals of the present study were to (i) establish that the protective effect of bee venom for dopaminergic neurons is not restricted to acupoint stimulation, but can also be observed using a more conventional mode of administration and to (ii) demonstrate that apamin can mimic the protective effects of a bee venom treatment on dopaminergic neurons. Using the chronic mouse model of MPTP/probenecid, we show that bee venom provides sustained protection in an animal model that mimics the chronic degenerative process of PD. Apamin, however, reproduced these protective effects only partially, suggesting that other components of bee venom enhance the protective action of the peptide.

Cost-effectiveness of deep brain stimulation in patients with Parkinson's disease.

In addition to medical treatment, deep brain stimulation has become an alternative therapeutic option in advanced Parkinson's disease. High initial costs of surgery have to be weighted against long-term gains in health-related quality of life. The objective of this study was to assess the cost-effectiveness of deep brain stimulation compared with long-term medical treatment. We performed a cost-utility analysis using a lifetime Markov model for Parkinson's disease. Health utilities were evaluated using the EQ-5D generic health status measure. Data on effectiveness and adverse events were obtained from clinical studies, published reports, or meta-analyses. Costs were assessed from the German health care provider perspective. Both were discounted at 3% per year. Key assumptions affecting costs and health status were investigated using one-way and two-way sensitivity analyses. The lifetime incremental cost-utility ratio for deep brain stimulation was €6700 per quality-adjusted life year (QALY) and €9800 and €2500 per United Parkinson's Disease Rating Scale part II (motor experiences of daily living) and part III (motor examination) score point gained, respectively. Deep brain stimulation costs were mainly driven by the cost of surgery and of battery exchange. Health status was improved and motor complications were reduced by DBS. Sensitivity analysis revealed that battery life time was the most influential parameter, with the incremental cost-utility ratio ranging from €20,000 per QALY to deep brain stimulation dominating medical treatment. Deep brain stimulation can be considered cost-effective, offering a value-for-money profile comparable to other well accepted health care technologies. Our data support adopting and reimbursing deep brain stimulation within the German health care system.

Myasthenia gravis: analysis of serum autoantibody reactivities to 1827 potential human autoantigens by protein macroarrays.

BACKGROUND: Myasthenia gravis is a disorder of neuromuscular transmission associated with autoantibodies against the nicotinic acetylcholine receptor. We have previously developed a customized protein macroarray comprising 1827 potential human autoantigens, which permitted to discriminate sera of patients with different cancers from sera of healthy controls, but has not yet been evaluated in antibody-mediated autoimmune diseases. OBJECTIVE: To determine whether autoantibody signatures obtained by protein macroarray separate sera of patients with myasthenia gravis from healthy controls. METHODS: Sera of patients with acetylcholine receptor antibody-positive myasthenia gravis (n = 25) and healthy controls (n = 32) were analyzed by protein macroarrays comprising 1827 peptide clones. RESULTS: Autoantibody signatures did not separate patients with myasthenia gravis from controls with sufficient sensitivity, specificity, and accuracy. Intensity values of one antigen (poly A binding protein cytoplasmic 1, p = 0.0045) were higher in patients with myasthenia gravis, but the relevance of this and two further antigens, 40S ribosomal protein S13 (20.8% vs. 0%, p = 0.011) and proteasome subunit alpha type 1 (25% vs. 3.1%, p = 0.035), which were detected more frequently by myasthenia gravis than by control sera, currently remains uncertain. CONCLUSION: Seroreactivity profiles of patients with myasthenia gravis detected by a customized protein macroarray did not allow discrimination from healthy controls, compatible with the notion that the autoantibody response in myasthenia gravis is highly focussed against the acetylcholine receptor.