High dose vitamin E therapy in amyotrophic lateral sclerosis as add-on therapy to riluzole: results of a placebo-controlled double-blind study.

UNLABELLED: Increasing evidence has suggested that oxidative stress may be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). The antioxidant vitamin E (alpha-tocopherol) has been shown to slow down the onset and progression of the paralysis in transgenic mice expressing a mutation in the superoxide dismutase gene found in certain forms of familial ALS. The current study, a double blind, placebo-controlled, randomised, stratified, parallel-group clinical trial, was designed to determine whether vitamin E (5000 mg per day) may be efficacious in slowing down disease progression when added to riluzole. METHODS: 160 patients in 6 German centres with either probable or definite ALS (according to the El Escorial Criteria) and a disease duration of less than 5 years, treated with riluzole, were included in this study and were randomly assigned to receive either alpha-tocopherol (5000 mg per day) or placebo for 18 months. The Primary outcome measure was survival, calculating time to death, tracheostomy or permanent assisted ventilation, according to the WFN-Criteria of clinical trials. Secondary outcome measures were the rate of deterioration of function assessed by the modified Norris limb and bulbar scales, manual muscle testing (BMRC), spasticity scale, ventilatory function and the Sickness Impact Profile (SIP ALS/19). Patients were assessed at entry and every 4 months thereafter during the study period until month 16 and at a final visit at month 18. Vitamin E samples were taken for compliance check and Quality Control of the trial. For Safety, a physical examination was performed at baseline and then every visit until the treatment discontinuation at month 18. Height and weight were recorded at baseline and weight alone at the follow-up visits. A neurological examination as well as vital signs (heart rate and blood pressure), an ECG and VEP's were recorded at each visit. Furthermore, spontaneously reported adverse experiences and serious adverse events were documented and standard laboratory tests including liver function tests performed. For Statistical Analysis, the population to be considered for the primary outcome measure was an "intent-to-treat" (ITT) population which included all randomised patients who had received at least one treatment dose (n = 160 patients). For the secondary outcome measures, a two way analysis of variance was performed on a patient population that included all randomised patients who had at least one assessment after inclusion. RESULTS: Concerning the primary endpoint, no significant difference between placebo and treatment group could be detected either with the stratified Logrank or the Wilcoxon test. The functional assessments showed a marginal trend in favour of vitamin E, without reaching significance. CONCLUSION: Neither the primary nor the secondary outcome measures could determine whether a megadose of vitamin E is efficacious in slowing disease progression in ALS as an add-on therapy to riluzol. Larger or longer studies might be needed. However, administration of this megadose does not seem to have any significant side effects in this patient population.

Coenzyme Q10 serum levels in Huntington's disease.

Mitochondrial dysfunction contributes to the neurodegenerative process in Huntington's disease (HD). Coenzyme Q10 (CoQ10) enhances mitochondrial complex I activity and may therefore provide a therapeutic benefit in HD. We compared serum CoQ10 levels of previously untreated-and treated HD patients with those of healthy controls. CoQ10 did not significantly (ANCOVA F(dF 2, dF 55) = 2.57; p=0.086) differ between all three groups. However, the post hoc analysis showed no significant (p = 0.4) difference between treated HD patients ([CoQ10]: 88.12 [mean]+/-24.44 [SD], [range] 48.75-146.32 [pg/million platelets]) and controls (93.71+/-20.72, 65.31-157.94), however previously untreated HD patients (70.10+/-21.12, 38.67-106.14) had marked (p = 0.051) lower CoQ10 results than treated HD patients and controls (p = 0.017). Our results support that CoQ10 supplementation in HD patients may reduce impaired mitochondrial function in HD.

The relevance of preclinical studies for the treatment of Parkinson's disease.

An essential element of pharmaceutical development, defined as the period between the discovery of a new agent and its market release, is provided by the "preclinical studies". They consist of the in vitro and in vivo studies performed before examination of the agent in human subjects. Regulatory authorities prescribe specific requirements regarding the nature and number of preclinical studies. In the present paper, we discuss the relevance of these studies for the treatment of Parkinson's disease (PD) on the basis of three examples: the L-DOPA ( L-3,4-dihydroxyphenylalanine, levodopa) story; the development of selegiline as a palliative and neuroprotective drug; and the safety concerns regarding tolcapone, an inhibitor of central and peripheral catechol-O-methyltransferase (COMT).

[Current preclinical findings on substances against Parkinson's disease]. / Aktuelle präklinische Befunde zu Anti-Parkinson-Mitteln.

Striatal dopamine loss provides the premise for dopamine substitution in palliative therapy for Parkinson's disease (PD). This includes firstly L-dopa (L-3,4-dihydroxyphenylalanine, levodopa) and dopamine receptor agonists. Although this therapy has been demonstrated to induce marked clinical improvement in the early stages of PD, its use is limited in the long term by a loss of efficacy. In addition, most patients develop the "long-term L-dopa syndrome," which is characterized by a decrease in the control of Parkinsonian symptoms (decrease in the drug's effect) and the appearance of certain motor disturbances including episodes of akinetic freezing, debilitating dyskinesias, and on-off periods. The aim in developing new drugs is to achieve better therapeutic approaches. In the case of PD, the main strategies are to develop (1) alternatives to L-dopa therapy for alleviating the striatal dopamine deficit while avoiding or retarding the long-term L-dopa syndrome, (2) antidyskinetic approaches, and (3) neuroprotective drugs aimed at causal treatment of PD which is able to preserve the remaining dopaminergic neurones and to halt or at least retard the disease process. This article reviews new approaches for the treatment of PD and presents findings from our studies using a new experimental in vivo model of PD.

A highly sensitive method for the determination of protein bound 3,4-dihydroxyphenylalanine as a marker for post-translational protein hydroxylation in human tissues ex vivo.

A highly sensitive, specific and tissue-independent method is described to evaluate oxidative stress-mediated protein hydroxylation in red blood cells, frontal cortex, and liver by HPLC separation and electrochemical detection of protein-bound 3,4-dihydroxyphenylalanine (DOPA) following gas-phase amino acid hydrolysis of tissue protein extracts containing exclusively proteins larger than 3 kDa. Simultaneous measurement of protein tyrosine (Tyr) content using fluorescence detection results in a tissue specific DOPA/Tyr ratio that may reflect oxidative stress-mediated protein modifications in disease, or following the exposure to oxidative stress-inducing agents.

Is there neuroprotection in Parkinson syndrome?

Parkinson's disease (PD) is a neurodegenerative disorder of the aging population with unknown etiopathogenesis. It is assumed that the underlying pathobiochemical processes comprise multifactorial and multigenetic disturbances leading to a progressive and devastating disorder without remission. Subtypes exist suggesting that "PD" is a spectrum disorder with variations in the cascade of pathobiochemical and genetic events. Neuroprotective endogenous processes are lost at the very beginning of PD. Supplementation of substances with neuroprotective and/or neurorescue capacity is eminent for future therapeutic strategies. MAO-B inhibitors, NMDA-receptor antagonists and dopamine receptor agonists fulfill such a criterion in preclinical studies while there is no clear evidence for clinical neuroprotection. However, PET-controlled studies comparing L-DOPA-treated and ropinirol-treated PD patients give evidence for the "concept of neuroprotective treatment strategies".

Intraoperative microdialysis and tissue-pO2 measurement in human glioma.

The amino acid glutamate is one of the major neurotoxins in the pathogenesis of neuronal death after ischemia or trauma. Microdialysis studies in both man and animal have shown elevated extracellular levels after primary lesions. Monitoring of cerebral tissue oxygenation (p(ti)O2) has been used in recent years to detect and prevent episodes of low cerebral oxygenation, e.g. after trauma or subarachnoid hemorrhage. Intraoperative monitoring of p(ti)O2 combined with microdialysis in the peritumoral edema has been chosen to study the responses of glutamate and oxygen levels during resection. In 7/9 patients p(ti)O2 was below "critical" 10 mm Hg. Elevating inspiratory oxygen concentration to 100% led to an increase of p(ti)O2 by 2.5-4 fold and a decrease of glutamate and aspartate by 50-80%. A close correlation between p(ti)O2 and microdialysis glutamate levels was not clearly shown due to frequent intraoperative manipulations.

Nitric oxide inhibits tissue factor synthesis, expression and activity in human monocytes by prior formation of peroxynitrite.

OBJECTIVE: Nitric oxide (NO) has antithrombotic properties by regulating platelet function, whereas direct effects on plasmatic coagulation are rarely described. In sepsis and inflammation, when synthesis of NO, oxygen radicals and toxic metabolites is crucial, the expression of tissue factor (TF) on monocytes stimulated by lipopolysaccharides (LPS) induces intravascular coagulation. This study was performed to examine the influence of NO and the NO-dependent metabolite peroxynitrite on LPS-induced TF expression and activity in human monocytes. DESIGN: Experimental study. SETTING: Laboratory for cell biology. METHODS: Human peripheral blood mononuclear cells were isolated from buffy coats by gradient centrifugation. The NO-releasing compounds SIN1 and NOC18 were used under different conditions. TF antigen was assayed by flow cytometry, and its activity by a clotting assay. TF-mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR-ELISA). MEASUREMENTS AND RESULTS: Whereas NOC18, a pure NO donor, had no effect, SIN1, releasing both NO and superoxide (O2-), reduced TF expression and activity in a dose- and time-dependent manner; superoxide dismutase (SOD) reversed the SIN1-mediated effect. Adding the O2(-)-deliberating system hypoxanthin/xanthin oxidase (which had no significant effect per se) to NOC18, or using the NO and O2- reaction product peroxynitrite resulted in a reduction of TF expression. RT-PCR-ELISA indicated upregulation of TF-mRNA by SIN1 with a peak at 500 microM; higher doses had less effect. CONCLUSION: These data demonstrate an influence of NO on LPS-induced TF expression in monocytes by prior formation of peroxynitrite; furthermore, the balance between NO and O2- seems to play a crucial role.

A post mortem study on neurochemical markers of dopaminergic, GABA-ergic and glutamatergic neurons in basal ganglia-thalamocortical circuits in Parkinson syndrome.

Functional models of the circuitry of the basal ganglia have recently been proposed to account for the vast spectrum of motor disorders associated with the loss of anatomical or neurochemical integrity within the basal ganglia. On the basis of these hypothetical models, hypokinetic disorders such as Parkinson's disease, are thought to be associated with excessive tonic and phasic inhibition of the output from the basal ganglia to the thalamus. In the present study we have attempted to determine the validity of the proposed model by measuring neurochemical markers of inhibitory and excitatory neurotransmission in post mortem human brain tissue. We have determined the concentrations of the excitatory neurotransmitters aspartate/glutamate and of the inhibitory neurotransmitter GABA in 18 relevant regions of the thalamocortical circuits of the basal ganglia of patients who had manifested Parkinsonian symptoms, and compared them with controls of individuals who had died without any history of neurological or psychiatric disorders and had no neuropathological abnormalities. Additionally, the receptor subtype for the excitatory amino acid N-methyl-D-aspartate (NMDA) was studied in the same brain tissue in which neurotransmitter concentrations had been analysed as neurochemical markers of post-synaptic excitatory neurotransmission. In patients who had manifested Parkinsonian symptoms, glutamate and aspartate levels were found to be unchanged in all examined brain regions. In contrast, the binding of [3H]MK-801, which identifies the NMDA receptor, was reduced in the head (-42%) and body (-38%) of the caudate nucleus. In parkinsonian patients, GABA levels were diminished by 36% in the centromedial thalamus, compared to control values. These results do not confirm the changes in neurotransmitter concentrations predicted according to the model, although we cannot rule out that the predicted changes might have been observed if the Parkinsonian group had been further subdivided into groups diagnosed on the basis of the patients' clinical picture (akinetic-rigid, tremor-dominant, equivalent type) and compared with the control group.

Injectable selenium: effect on the primary response of mice (38472).

Sodium selenite administered to mice ip (ca.5 mug Se) enhances the primary immune response to the sheep red blood cell angigen. Enhancement of the primary immune response is greatest when Se is administered prior to or simultaneously with the sheep red blood cell antigen.

Enhanced immunoglobulin M and immunoglobulin G antibody titers in mice fed selenium.

Mice fed diets supplemented with selenium (sodium selenite) immunologically respond to the sheep red blood cell antigen by producing enhanced immunoglobulin M and immunoglobulin G antibody titers.