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Introduction: Etanercept (ETN) has been shown to slow radiographic progression of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) in clinical trials. This real-world, non-interventional study assessed radiographic progression in patients with RA or PsA treated with ETN for ≤ 36 months in outpatient care in Germany (NCT01623752)., Methods: Patients with RA or PsA attended ≤ 10 visits across two study phases (phase 1: seven visits, baseline to month 18; phase 2: three visits until month 36). Radiographs were taken at baseline (Rx1), months 12-18 (Rx2), and/or months 30-36 (Rx3). Historic radiographs (Rx0) taken 12-48 months pre-baseline were also evaluated (if available). The primary endpoint was the change in modified total Sharp score (mTSS). The erosion score (ES) and joint space narrowing score (JSN) were also evaluated., Results: Overall, 1821 patients were enrolled (RA: n = 1378; PsA: n = 440). In patients with Rx1 and Rx2 (RA: n = 511; PsA: n = 167), the mean mTSS remained stable for both disease groups, and the annualized median change in mTSS was 0. In patients with Rx0, Rx1, and Rx2 (RA: n = 180; PsA: n = 47), annualized radiographic progression in mTSS, ES, and JSN was larger in the pre-ETN treatment phase than during ETN treatment in both disease groups. The percentage of patients with radiographic non-progression was higher during ETN treatment versus pre-ETN. Improvement in clinical disease activity and patient-reported outcomes was also observed., Conclusions: This was the first real-world, non-interventional study to report systematically collected radiographic data in a large cohort of patients with RA or PsA under treatment with a biologic. In patients with available radiographic data, mean radiographic progression was lower and the proportion of patients without progression was greater during ETN treatment than in the pre-ETN period., (© 2022. The Author(s).)

Background: For rheumatoid arthritis (RA), the treat-to-target concept suggests attaining remission or at least low disease activity (LDA) after 12 weeks., Objectives: This German, prospective, multicenter, non-interventional study aimed to determine the proportion of patients with RA who achieved their treat-to-target aim after 12 and 24 weeks of etanercept (ETN) treatment in a real-life setting, as opposed to patients achieving their therapeutic target at a later timepoint (week 36 or 52)., Methods: A total of 824 adults with a confirmed diagnosis of RA without prior ETN treatment were included. Remission and LDA were defined as DAS28 < 2.6 and DAS28 ≤ 3.2, respectively., Results: The proportion of patients achieving remission was 24% at week 12 and 31% at week 24. The proportion of patients achieving LDA was 39% at week 12 and 45% at week 24. The proportion of patients achieving remission or LDA further increased beyond week 24 up to week 52. Improvement in pain and reduction in concomitant glucocorticoid treatment were observed. Improvements in patient-reported outcomes were also seen in patients who did not reach remission or LDA. No new safety signals were detected., Conclusions: A considerable proportion of patients with RA attained the target of remission or LDA after 12 weeks of ETN treatment. Even beyond that timepoint, the proportion of patients achieving treatment targets continued to increase up to week 52., Trial Registration: ClinicalTrials.gov Identifier: NCT02486302., (© 2022. The Author(s).)

Background: The efficacy and safety of the TNF‑α inhibitor etanercept (ETA) as a treatment for rheumatoid arthritis (RA) is well established by randomized controlled trials. The purpose of this study was to evaluate the benefit yielded by ETA within the regular outpatient care., Patients and Methods: This prospective non-interventional trial included patients being treated with ETA. Data concerning efficacy, safety and life quality were collected over a period of 52 weeks. Statistical evaluation was done on a solely descriptive level., Results: From 329 specialized medical centres, 4945 patients were enrolled. Of all patients, 94.4% received a co-medication for RA, additionally to their treatment with ETA. At baseline, 22.1% of all patients fulfilled the criteria for functional remission according to the Funktionsfragebogen Hannover (FFbH) questionnaire (95% CI: 21.0-23.3%); at 52 weeks, functional remission rate accounted for 41.1% (last observation carried forward [LOCF], 95% CI: 39.4-42.9%). The disease activity score (DAS) DAS28 declined from 5.4 ± 1.3 (N = 4304) to 3.3 ± 1.4 (as observed; N = 2608). EuroQol EQ-5D, a measurement of health-related life quality issues, indicated an improvement on the visual analogue scale (VAS) from 53.1 ± 21.3 mm (N = 4718) at baseline to 70.0 ± 20.5 mm (as observed; N = 3036). Generally, ETA has been tolerated well. With regard to the safety profile specified by previous studies, no meaningful deviations concerning the nature, frequency or severity of adverse events were detected., Conclusion: Based on a large number of patients and in a treatment context that is representative of routine outpatient care in Germany, it was confirmed that patients with RA may benefit from a treatment with ETA.

The pioneering work of Arvid Carlsson has laid the foundation for a number of innovative therapies for severe central nervous system (CNS) diseases. He was awarded the Nobel Price for the discovery of the crucial role of dopamine (DA) as a neurotransmitter in the CNS, thereby forming the basis for the symptomatic therapy of Parkinson's disease (PD) with L-DOPA and subsequently dopaminergic drugs. Parenteral apomorphine has a short lasting effect in PD, bromocriptine can be administered orally and has a long-lasting effects but is poorly tolerated. Lisuride on the other hand has a high affinity to DA receptors and can be administered orally, parenterally or via the transdermal route of administration. Last but not least Carlsson developed the concepts of presynaptic effects of DA agonists as well as DA partial agonism potentially innovative mechanisms for treatment of PD and schizophrenia.

Competing Interests: Der Erstautor ist Mitarbeiter der Firma Pfizer Pharma GmbH, dem Hersteller von Genotropin® und Enbrel®

Objective: To evaluate patients with psoriatic arthritis (PsA) receiving etanercept (ETN) monotherapy or ETN plus conventional synthetic disease-modifying antirheumatic drugs (csDMARD) to determine the proportion achieving a clinically meaningful response in arthritis, psoriasis, and quality of life simultaneously., Methods: A prospective, multicenter, 52-week observational study in patients with active PsA evaluated treatment with ETN in clinical practice (ClinicalTrials.gov: NCT00293722). This analysis assessed simultaneous achievement of 3 treatment targets: low disease activity (LDA) based on 28-joint count Disease Activity Score (DAS28); body surface area (BSA) involvement ≤ 3%; and a score > 45 on the Medical Outcomes Study Short Form-12 (SF-12) physical component summary., Results: Of 579 patients, 380 received ETN monotherapy and 199 received combination ETN plus csDMARD. At 52 weeks, data for all 3 disease domains were available for 251 patients receiving monotherapy and 151 receiving combination therapy. In the monotherapy and combination therapy groups, 61 (24.3%) and 37 (24.5%) patients, respectively, achieved all 3 treatment targets simultaneously. A significantly greater proportion of patients receiving monotherapy versus combination therapy achieved SF-12 > 45 (43.0% vs 31.8%; p < 0.05) and DAS28 LDA (72.5% vs 62.3%; p < 0.05). Conversely, BSA ≤ 3% was reached by a significantly greater proportion receiving combination therapy (75.5% vs 56.6%; p < 0.001). However, baseline BSA involvement was higher for the monotherapy group., Conclusion: While nearly half the patients achieved arthritis and psoriasis treatment targets simultaneously and one-fourth reached all 3 treatment targets, combining ETN and csDMARD did not substantially improve clinical response compared with ETN monotherapy in this real-world PsA patient population.

Over the past few decades, research on Alzheimer's disease (AD) has focused on pathomechanisms linked to two of the major pathological hallmarks of extracellular deposition of beta-amyloid peptides and intra-neuronal formation of neurofibrils. Recently, a third disease component, the neuroinflammatory reaction mediated by cerebral innate immune cells, has entered the spotlight, prompted by findings from genetic, pre-clinical, and clinical studies. Various proteins that arise during neurodegeneration, including beta-amyloid, tau, heat shock proteins, and chromogranin, among others, act as danger-associated molecular patterns, that-upon engagement of pattern recognition receptors-induce inflammatory signaling pathways and ultimately lead to the production and release of immune mediators. These may have beneficial effects but ultimately compromise neuronal function and cause cell death. The current review, assembled by participants of the Chiclana Summer School on Neuroinflammation 2016, provides an overview of our current understanding of AD-related immune processes. We describe the principal cellular and molecular players in inflammation as they pertain to AD, examine modifying factors, and discuss potential future therapeutic targets.

Approximately 30% of patients with rheumatoid arthritis receiving biological disease-modifying antirheumatic drugs (bDMARDs) take them as monotherapy. Although etanercept (ETN) monotherapy has been evaluated in clinical trials, data in the real-world setting are sparse. We compared the efficacy and safety of ETN, given alone or in combination with methotrexate (MTX), in routine clinical practice. This was a subanalysis of patients who received either ETN alone or ETN + MTX during a 52-week prospective, observational study conducted at 329 German centers. The primary endpoint was "Funktionsfragebogen Hannover" (Hannover Functional Ability Questionnaire [FFbH]; low FFbH = worse function) functional remission at week 26 and week 52. Secondary endpoints included the 28-joint count Disease Activity Score (DAS28), DAS28 remission (DAS28 < 2.6), and adverse events (AEs). Participating centers applied ETN monotherapy in 43.1% of patients and ETN + MTX in 56.9%. A smaller proportion of patients achieved FFbH functional remission with ETN vs ETN + MTX (31.9%, 95% confidence interval [CI] 29.1-34.9% vs 39.8%, 37.2-42.5%, respectively; p < 0.001) at 26 weeks and at 52 weeks (38.4%, 35.1-41.7% vs 44.3%, 41.5-47.2%, respectively; p = 0.007). After 52 weeks, the mean DAS28 (±SD) decreased from 5.5 ± 1.3 to 3.4 ± 1.4 (ETN) vs 5.3 ± 1.3 to 3.2 ± 1.3 (ETN + MTX) and DAS28 remission was achieved by 32.5% (95% CI 29.0-36.1%) of patients with ETN vs 38.8% (35.8-41.9%; p = 0.007) with ETN + MTX. Overall, 20.6 (ETN) and 19.7% (ETN + MTX) of patients reported treatment-related AEs. Patients received ETN monotherapy almost as often as ETN + MTX. ETN + MTX appeared marginally more effective than ETN monotherapy in some, but not all, outcomes measured.

Background: There is an unmet need for long-term, real-life data on the effect of a drug-free interval between treatment cycles in patients with plaque psoriasis being treated with etanercept, which is licensed for intermittent and continuous treatment., Objective: The aim of this study was to determine the average duration of the drug-free interval between etanercept treatment cycles in patients with plaque psoriasis., Methods: This was a non-interventional, open-label, multicentre, prospective study in patients for whom the decision had already been made to initiate treatment with etanercept during routine practice in German centres. Clinical outcomes were documented over 36 months with study visits every 12 weeks. The primary endpoint was the duration of the treatment-free interval between etanercept treatment cycles (24 weeks/cycle). Secondary endpoints assessed efficacy [Psoriasis Area and Severity Index (PASI), Body Surface Area (BSA), static Physician's Global Assessment (sPGA)], health-related outcomes [EuroQol-5 Dimensions (EQ-5D), Dermatology Life Quality Index (DLQI)] and safety., Results: A total of 955 patients were enrolled from 224 centres; 926 of these were included in the safety analyses and 720 patients from the safety population were included in the efficacy analysis. The mean duration of drug-free intervals was 12.9 ± 12.8 weeks. Efficacy and health-related quality of life outcomes measures showed consistent improvement that occurred within 12 weeks of treatment with etanercept. There was a descriptive difference between the continuous and intermittent treatment subgroups, as subjects in the latter showed a deterioration at the first visit following an interval. However, retreatment with etanercept resulted in a clinical efficacy identical to the initial effect. The incidence of physician-assessed, drug-related adverse events and serious adverse events was 13.1% and 1.9%, respectively., Conclusion: The mean duration of drug-free intervals was relatively short, most patients experienced improvements in disease activity and health-related quality of life within 12 weeks of either continuous or intermittent treatment with etanercept, and there were no new safety signals. ClinicalTrials.gov identifier: NCT00708708., (© 2016 European Academy of Dermatology and Venereology.)

Introduction: Tigecycline is an established treatment option for infections with multiresistant bacteria (MRB). It retains activity against many strains with limited susceptibility to other antibiotics. Efficacy and safety of tigecycline as monotherapy or in combination regimens were investigated in a prospective noninterventional study involving 1,025 severely ill patients in clinical routine at 137 German hospitals., Materials and Methods: Data on the full population have been published; our present analysis focuses on infections caused by MRB. The study population included patients with complicated infections, high disease severity (APACHE II > 15: 65 %) and high MRB prevalence. Most patients had comorbidities, including cardiovascular disease, renal insufficiency, and/or diabetes mellitus. Treatment success was defined as cure/improvement without requirement of further antibiotic therapy., Results: Pathogens isolated from 215 evaluable patients with documented MRB infections included 132 methicillin-resistant Staphylococcus aureus (MRSA), 42 vancomycin-resistant Enterococci (VRE) and 67 Gram-negative extended beta-lactamase (ESBL) producers. Of the MRB subpopulation, 140 patients received tigecycline monotherapy, 75 were treated with combination regimens. High overall clinical success rates were recorded for MRB infections treated with tigecycline alone (94 %) or in combinations (88 %); in detail intraabdominal infections (monotherapy: 90 %; combinations: 93 %), skin/soft tissue infections (93; 100 %), community-acquired pneumonia (100; 100 %), hospital-acquired pneumonia (94,7; 72,7 %), diabetic foot infections (89; 33 %), blood stream infections (100; 100 %) and multiple-site infections (92; 71 %)., Conclusions: Tigecycline achieved high clinical success rates in patients with documented infections involving MRB strains despite high disease severity. These results add to the evidence indicating that tigecycline is a valuable therapeutic option for complicated infections in severely ill patients with a high likelihood of multidrug-resistant pathogen involvement.

This large prospective non-interventional study investigated the effects of tigecycline either as single agent or in combination with other antimicrobial agents in 1,025 patients treated in clinical routine at German hospitals. Sixty-five percent of the patients had APACHE II scores > 15, indicating high overall disease severity. Complicated intra-abdominal infections (cIAI) or complicated skin and skin tissue infections (cSSTI) were the most common indications, with Staphylococcus aureus, Enterococcus faecium and Escherichia coli being the most frequently isolated pathogens. Clinical success was reported at the end of tigecycline therapy in 74.2% of the total population, in 75.4% of the cIAI and in 82.2% of the cSSTI patients. The subpopulation (28.0% of the patients) infected with multidrug-resistant pathogens (methicillin-resistant S. aureus, extended-spectrum β-lactamase producers and vancomycin-resistant enterococci) were treated with similar success rates as the overall population. Tigecycline was generally well tolerated. Drug-related adverse events (AEs) were reported in 7.7% of the total population; 2.5% had serious AEs mostly attributable to inefficacy of therapy or deterioration of the disease. Mortality rates were consistent with the types of infection and severity of illness. There was no indication of excessive mortality associated with tigecycline as had been suggested in previously performed meta-analyses. In this large non-interventional study performed in the clinical routine setting, tigecycline achieved favorable clinical success rates in a patient population with high severity of illness and a high prevalence of multidrug-resistant pathogens and showed a good safety and tolerability profile., (Copyright © 2012 S. Karger AG, Basel.)

To document the development of resistance to tigecycline in comparison with 17 other antimicrobials, the susceptibilities of 2,741 isolates comprising 16 bacterial species recovered from hospitalised patients in 15 German centres in 2009 were assessed. The results were compared with those of previous trials (German Tigecycline Evaluation Surveillance Trial, G-TEST I and II, performed in 2005 and 2007, respectively) conducted prior to and shortly after the introduction of tigecycline in Germany. Moreover, the in vitro activities of tigecycline against the subset of multidrug-resistant (MDR) pathogens recovered within all three sampling periods (n = 4,988) were evaluated in comparison to the corresponding non-MDR isolates. All susceptibility tests were performed by broth microdilution. Between 2005 and 2009, tigecycline retained its high activity against Gram-positive and Gram-negative organisms, including MDR pathogens. By contrast, an in part marked increase in resistance to broad-spectrum beta-lactams and fluoroquinolones was observed for many Enterobacteriaceae and for non-fermenting Gram-negative bacteria. Against a background of a steadily increasing number of multiresistant pathogens, the activity of tigecycline remained unaltered. With the exception of Acinetobacter isolates with decreased susceptibility to carbapenems, tigecycline's activity profile was not notably affected by organisms resistant to other drug classes and, thus, holds promise as an important therapeutic agent, particularly for situations in which MDR organisms are suspected.

N-methyl-D-aspartate (NMDA) receptor antagonists have antiakinetic and antidyskinetic effects in animals models of Parkinson's disease (PD). However, non-selective inhibition of NMDA receptors throughout the central nervous system may result in undesired effects such as ataxia and psychosis. We therefore studied Ro 25-6981, an activity-dependent antagonist of NMDA receptors containing the NR2B subunit which are predominantly expressed in the striatum. Ro 25-6981 induced contraversive rotations in 6-hydroxydopamine (6-OHDA)-lesioned rats without stimulating locomotion in normal rats and reversed parkinsonian symptoms in 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP)-treated common marmosets. Due to the small number of marmosets, there were no significant differences between Ro 25-6981 and vehicle though there was a significant trend toward differences, as shown by the Page test. Furthermore, Ro 25-6981 potentiated the action of levodopa in both species and attenuated the maximal levodopa response in 6-OHDA-lesioned rats chronically treated with levodopa without reducing the overall response. Ro 25-6981 also potentiated the action of the dopamine receptor agonists apomorphine, A68930 and quinpirole in 6-OHDA-lesioned rats. The present observations suggest a therapeutic potential of NR2B-selective NMDA receptor antagonists in the management of PD.

Using the rat model of Parkinson's disease described by Ungerstedt the release of [3H]acetylcholine ([3H]ACh) in the caudatoputamen was investigated to assess possible long-term effects of unilateral dopaminergic denervation on the modulation of cholinergic interneurons. This seemed of interest since rats with 6-hydroxydopamine (6-OHDA) lesions of the left substantia nigra showed an increase in the behavioural susceptibility to small doses of dopamine (DA) D2 receptor agonists 30 months after the lesion. Electrical field stimulation with 3 Hz elicited release of [3H]ACh in slices of both the lesioned and the intact striatum. The DA reuptake blocker nomifensine was ineffective on the lesioned side but diminished the release of [3H]ACh in the intact striatum. This inhibition was reversed by the D2 receptor antagonist domperidone and hence probably due to the effect of endogenously released DA. Single electrical pulses at 0.05 Hz, which neither induced autoinhibition of [3H]ACh release nor heteroinhibition by endogenous DA, elicited a higher release of [3H]ACh on the intact side. Under this stimulation paradigm activation of the D2 heteroreceptor with quinpirole depressed the release of [3H]ACh to a similar extent on both sides, irrespective of the absence or presence of the competitive NMDA receptor antagonist D-CPPene. Also blockade of the NMDA receptor channel by dizocilpine, or of AMPA receptors by NBQX, was ineffective on either side. The NMDA-evoked release of [3H]ACh was higher on the lesioned side. It was equally depressed by quinpirole and by ethanol on both sides. Thus, single electrical pulses and NMDA stimulation per se had opposite effects on the lesioned and the intact side, whereas the modulation of release was similar. Since the lesioned striata were considerably smaller, measurements of mRNA levels of choline acetyltransferase (ChAT) were used to assess the density of cholinergic interneurons and their content of ChAT mRNA. This analysis did not reveal any side difference. In conclusion, the function of D2 heteroreceptors on, and the density and ChAT mRNA content of, cholinergic interneurons are not or no longer altered after long-term DA denervation. Most probably, cholinergic interneurons are not involved in the increased behavioural susceptibility of 6-OHDA-lesioned rats to DA agonists.

In a hamster model (genetic symbol dt(sz)) of primary paroxysmal non-kinesiogenic dystonic choreoathetosis, recent studies have shown beneficial effects of glutamate and dopamine receptor antagonists. Nitric oxide (NO), synthesized from L-arginine by NO synthase in response to glutamate receptor activation, elicits cyclic GMP and modulates glutamate-mediated processes and striatal dopamine release. Therefore, the effects of NO synthase inhibitors and of L-arginine on severity of dystonia were investigated in dt(sz) hamsters in which dystonic attacks, characterized by twisting movements and postures, can be induced by stress. The NO synthase inhibitors N(G)-nitro-L-arginine (L-NNA), N(G)-nitro-L-arginine methyl ester (L-NAME) and 7-nitroindazole significantly reduced the severity of dystonia. At antidystonic effective doses neither L-NNA nor L-NAME caused observable side effects, whereas 7-nitroindazole exerted moderate reduction of locomotor activity. The antidystonic effect of L-NAME was reversed by co-administration of the NO precursor L-arginine. However, L-arginine administered alone did not exert any effect on severity of dystonia. Cerebellar cyclic GMP levels in brains of mutant hamsters in comparison to non-dystonic control hamsters did not significantly differ, but the cerebellar cyclic GMP levels tended to be increased in dt(sz) hamsters during a dystonic attack. L-NAME significantly decreased the cerebellar cyclic GMP levels in both dt(sz) and control hamsters. Although an overproduction of NO is probably not critically involved in the pathogenesis of paroxysmal dystonia, it may contribute to the manifestation of dystonic attacks, as indicated by the antidystonic effects of NO synthase inhibitors. Peripheral side effects may limit the clinical use of NO synthase inhibitors, but more selective inhibitors of the neuronal NO synthase should be considered as interesting candidates for the treatment of paroxysmal dystonia.

Here we study expression of the inducible isoform of nitric oxide synthases after intrastriatal microinjection of interferon-gamma and bacterial lipopolysaccharide in the rat at different time points to detect time- and localisation-dependent changes of iNOS expression. Three different areas in the striatum and the corpus callosum were evaluated. Antibodies against the glial fibrillary acidic protein and the microglia/brain macrophage epitope ED1 were used to detect colocalization of inducible nitric oxide synthase with astrocytes or activated microglia/brain macrophages, respectively. Inducible nitric oxide synthase-positive cells occurred first in intravascular and perivascular cells at 4 h. Perivascular and parenchymal inducible nitric oxide synthase expression increased up to 24 h in the striatum, whereas in the corpus callosum inducible nitric oxide synthase expression was maximal after 16 h. Inducible nitric oxide synthase was still present in perivascular cells 7 days after immunostimulation. At all time points, inducible nitric oxide synthase was predominantly detected in ED1-positive microglia/brain. Nitrotyrosine immunohistochemistry was performed to detect NO-mediated nitration of proteins at all time points. Nitrotyrosine-positive neurons and microglial cells were detected from 24 h until 7 days after immunostimulation and were absent in controls. Detailed knowledge of the changes in the time course and cellular source of inducible nitric oxide synthase expression following brain immunostimulation provide a basis for establishing treatment strategies and windows of therapeutic intervention during neuroinflammation.

We studied the substantia nigra of three Parkinson's disease (PD) patients and three age-matched individuals by in situ DNA-end labeling (ISEL) and immunohistochemistry for the apoptosis regulating proteins Bcl-2, Bax and Bcl-x on 50 consecutive sections per patient. No melanin-containing cell was identified with typical apoptotic changes in either patient or control substantia nigra. With prolonged reaction-time the terminal transferase-mediated DNA-end labeling revealed a signal in 2.0 +/-1.2% melanin-containing cells in PD compared to 1.3 +/-1.1% in control. This difference did nor reach statistical significance and no condensation or margination of the chromatin was evident. No significant changes of any of the apoptosis regulating proteins were apparent in PD substantia nigra. These findings do not support the hypothesis that apoptosis plays a central role in the pathogenesis of PD.

Studies in rats have shown that the polysynaptic flexor reflex (FR) but not the monosynaptic reflexes are affected by N-methyl-D-aspartate (NMDA) receptor antagonists. Theoretically, the suppression of FR might be caused by an alteration of the spinal nociceptive neurons. To investigate, whether the non-competitive NMDA receptor antagonist memantine interferes with nociception in man, we studied both its effect on pain perception and on FR. In a double-blind study 14 male subjects were randomly assigned to either placebo or memantine (30 mg p.o.) treatment. H-reflex (HR) and FR as well as pain and tolerance threshold were determined prior to and 6 h after drug intake. Contrary to expectations, there were no differential treatment effects either on FR threshold and magnitude or on pain and tolerance thresholds or the HR amplitude.

Nitric oxide (NO) is thought to play an important role in neurotransmission, inflammation, and regulation of cell death in the mammalian brain. Here, we examined the synthesis and biological effects of NO in human malignant glioma cells. Exposure to cytokines such as interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha or interleukin (IL)-1beta and lipopolysaccharide (LPS) induced NO synthesis in rat C6 and A172 human glioma cells, but not in LN-229, T98G or LN-18 human malignant glioma cells. Induced release of NO involved enhanced expression of inducible NO synthase (iNOS). Failure to detect NO release in the latter cell lines was not overcome by neutralization of endogenous TGF-beta or by coexposure to cytokines, LPS, and antioxidants. Apoptosis induced by CD95 ligand (CD95L) did not involve NO formation. Neither NOS inhibitors nor NO donators modulated CD95L-induced apoptosis. Dexamethasone (DEX)-mediated protection of glioma cells from CD95L-induced apoptosis was also independent of DEX effects on NO metabolism. DEX inhibited not only cytokine/LPS-evoked NO release but also attenuated the toxicity of NO in three of five cell lines. Forced expression of temperature-sensitive p53 val135 in C6 cells in either mutant or wild-type conformation inhibited cytokine/LPS-induced NO synthesis. Further, accumulation of p53 in both mutant or wild-type conformation protected glioma cells from the toxicity of exogenous NO, consistent with a gain of p53 function associated with p53 accumulation. We conclude that resistance to NO-dependent immune defense mechanisms may contribute to the malignant progression of human cancers with p53 alterations, notably those associated with the accumulation of mutant p53 protein.

In rats, striatal histotoxic hypoxic lesions produced by the mitochondrial toxin malonate resemble those of focal cerebral ischemia. Intrastriatal injections of malonate induced cleavage of caspase-2 beginning at 6 h, and caspase-3-like activity as identified by DEVD biotin affinity-labeling within 12 h. DEVD affinity-labeling was prevented and lesion volume reduced in transgenic mice overexpressing BCL-2 in neuronal cells. Intrastriatal injection of the tripeptide, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk), a caspase inhibitor, at 3 h, 6 h, or 9 h after malonate injections reduced the lesion volume produced by malonate. A combination of pretreatment with the NMDA antagonist, dizocilpine (MK-801), and delayed treatment with zVAD-fmk provided synergistic protection compared with either treatment alone and extended the therapeutic window for caspase inhibition to 12 h. Treatment with cycloheximide and zVAD-fmk, but not with MK-801, blocked the malonate-induced cleavage of caspase-2. NMDA injections alone resulted in a weak caspase-2 cleavage. These results suggest that malonate toxicity induces neuronal death by more than one pathway. They strongly implicate early excitotoxicity and delayed caspase activation in neuronal loss after focal ischemic lesions and offer a new strategy for the treatment of stroke.

Exposure of neuronal PC12 cells, differentiated by nerve growth factor, to tumor necrosis factor-alpha (TNF-alpha) and bacterial lipopolysaccharide (LPS) resulted in de novo synthesis of inducible nitric oxide synthase (iNOS) mRNA and protein with an increase up to 24 h. Brain NOS expression was unaffected. The induction of iNOS in differentiated PC12 cells was associated with cell death characterized by features of apoptosis. The NOS inhibitors N-monomethylarginine, aminoguanidine, and 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine.HCl prevented TNF-alpha/LPS-induced cell death and DNA fragmentation, suggesting that the TNF-alpha/LPS-induced cell death is mediated by iNOS-derived NO. This hypothesis is supported by the finding that addition of L-arginine, which serves as a precursor and limiting factor of enzyme-derived NO production, potentiated TNF-alpha/LPS-induced loss of viability.

3-Acetylpyridine is a niacinamide antagonist with potent neurotoxic properties in vitro and in vivo. 3-Acetylpyridine neurotoxicity was associated with positive DNA end-labelling and displayed features of active cell death without the ultrastructural changes of apoptotic cell death. After systemic administration in rats (70 mg/kg), we detected labelled nuclei in the inferior olive using in situ DNA end-labelling. However, the conventional chromatin stain did not show chromatin condensation or fragmentation and electron microscopy studies failed to reveal features of apoptosis. Although areas of condensed chromatin were present in some nuclei, cytoplasmic damage with extensive organelle swelling was the most prominent finding. In vitro, 3-acetylpyridine (0.1-1 mM) induced degeneration of cerebellar granule neurons in a concentration- and time-dependent manner. The protein synthesis inhibitor cycloheximide (10 micrograms/ml) and the transcriptional inhibitor actinomycin D (10 microM) protected against 3-acetylpyridine toxicity. In contrast, neither the free radical scavenger alpha-phenyl-N-tertbutylnitron (100 microM), nor glutathione ethyl ester (10-100 microM), N-acetyl-cysteine (10-200 microM) or 3-aminobenzamide (0.1-4 mM), an inhibitor of poly(ADP-ribose) synthesis, were effective. 3-Acetylpyridine-induced neuronal death in vitro was associated with positive in situ DNA labelling. However, DNA fragmentation could not be demonstrated prior to neuronal cell loss and no DNA "laddering" was detected by DNA gel electrophoresis. Correspondingly, no apoptotic nuclei were revealed upon electron microscopy but organelle swelling and extensive vacuolization, changes similar to autophagocytosis. In conclusion, 3-acetylpyridine induces an active form of cell death that required de novo protein synthesis but is distinct from apoptosis. A loss of glutathione accompanies, but does not precede, cell death.

In the present study acute effects of ethanol on [3H]-acetylcholine ([3H]-ACh) release induced by activation of strychnine-sensitive glycine receptors in superfused slices of rat caudatoputamen were investigated. The glycine-evoked [3H]-ACh release (Ig EC50 = -4.10, CI95 = [-4.14, -4.05]) was inhibited by strychnine in a competitive manner (pA2 = 6.86, CI95 = [6.61, 7.08]). Release of [3H]-ACh could also be induced by L-serine. L-serine was less potent than glycine (Ig EC50 = -2.61, CI95 = [-2.69, -2.52]). Both glycine and L-serine showed similar maximum effects (Emax(glycine) = 1.34, CI95 = [1.24, 1.45]; Emax(L-serine) = 1.19, CI95 = [1.09, 1.32]). Ethanol at concentrations of 2%/1000 (= 34 mM) and 4%/1000 (= 68 mM) inhibited glycine-evoked [3H]-ACh release in a manner like the competitive antagonist strychnine, however with lower potency. The pA2 of ethanol was 1.19, CI95 = [0.85, 1.41], at 2%/1000 [v/v] and 1.51, CI95 = [1.19, 1.78] at 4%/1000 ethanol. Similar to its action on glycine-evoked [3H]-ACh release, ethanol at 4%/1000 [v/v] also inhibited L-serine-evoked transmitter release in a competitive-like fashion (pA2 = 0.83, CI95 = [-0.15, 1.18]). We conclude, that strychnine-sensitive glycine receptors, mediating [3H]-ACh release in the rat caudatoputamen, might represent a new site of action of ethanol.

In the present study the renal response to intravenous infusion of the catecholamine precursors L-dihydroxyphenylalanine (L-DOPA) or L-tyrosine was investigated in thiopentone sodium-anaesthetized Sprague-Dawley rats. Glomerular filtration rate (GFR) was assessed by renal clearance of inulin, urinary concentration of dopamine (U(DA)V) by HPLC and sodium excretion (U(Na)V) by flame photometry. We found that basal U(DA)V was 6.5 +/- 0.5 pmol/min per 100 g body weight (mean +/- SEM). Intravenous infusion of L-tyrosine at 0. 1-3.0 micromol/min dose dependently enhanced U(DA)V (17 +/- 3 to 144 +/- 14 pmol/min respectively) with higher doses of L-tyrosine resulting in no further increase in U(DA)V. Compared with L-tyrosine administration significantly lower doses of L-DOPA (0.07 to 35 nmol/min) caused increases in U(DA)V which were orders of magnitude higher (18 +/- 1 to 7800 +/- 470 pmol/min, respectively) and did not show saturation characteristics. GFR did not change in response to L-tyrosine or L-DOPA infusion. No variations in urinary flow rate or in U(Na)V could be observed which were significantly correlated to changes in U(DA)V. In contrast, intravenous infusion of dopamine at a dose of 6 nmol/min significantly increased GFR by 35 +/- 6.2% and urinary flow rate by over 2-fold. Immunohistochemistry with light microscopy revealed no tyrosine hydroxylase in the kidney. Therefore, dopamine synthesis in the tubular cells mainly depends on the renal supply of L-DOPA. The unchanged GFR and U(Na)V in spite of large variations of U(DA)V argue against the hypothesis that intratubular dopamine plays a functional role in the regulation of hemodynamics or sodium transport in the kidney. Renal dopamine excretion may rather represent an effective pathway for the elimination of catecholamine precursors from the plasma.

Neuronally differentiated PC12 cells undergo synchronous apoptosis when deprived of nerve growth factor (NGF). Here we show that NGF withdrawal induces actinomycin D- and cycloheximide-sensitive caspase (ICE-like) activity. The peptide inhibitor of caspase activity, N-acetyl-Asp-Glu-Val-Asp-aldehyde, was more potent than acetyl-Tyr-Val-Ala-Asp-chloromethyl ketone in preventing NGF withdrawal-induced apoptosis, suggesting an important role for caspase-3 (CPP32)-like proteases. We observed a peak of reactive oxygen species (ROS) 6 h after NGF withdrawal. ROS appear to be required for apoptosis, because cell death is prevented by the free radical spin trap, N-tert-butyl-alpha-phenylnitrone, and the antioxidant, N-acetylcysteine. ROS production was blocked by actinomycin D, cycloheximide, and caspase protease inhibitors, suggesting that ROS generation is downstream of new mRNA and protein synthesis and activation of caspases. Forced expression of either BCL-2 or the BCL-2-binding protein BAG-1 blocked NGF withdrawal-induced apoptosis, activation of caspases, and ROS generation, showing that they function upstream of caspases. Coexpression of BCL-2 and BAG-1 was more protective than expression of either protein alone.

It was recently demonstrated that selective phosphodiesterase type 4 (PDE4) inhibition suppresses the clinical manifestations of acute experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), and inhibits the production of tumor necrosis factor-alpha (TNF-alpha), a pathogenetically central cytokine. Since the most common presentation of MS in humans is a relapsing-remitting course, we investigated the therapeutic potential of PDE4 inhibition in the relapsing-remitting EAE model of the SJL mouse. Administration of rolipram, the prototypic PDE4 inhibitor, reduced the clinical signs of EAE during both the initial episode of disease and subsequent relapses. In parallel, there was marked reduction of demyelination and also less inflammation throughout the central nervous system (CNS) of rolipram-treated animals. Gene expression of proinflammatory cytokines in the CNS was reduced in most of the rolipram-treated animals. Additional experiments demonstrated that PDE4 inhibition acted principally by inhibiting the secretion of Th1 cytokines, however, the encephalitogenic potential of myelin basic protein-specific T cells was not impaired. Our findings suggest that PDE4 inhibitors are a promising cytokine-directed therapy in chronic demyelinating disease.

Earlier results obtained in one of our laboratories showed that microinjection into the dorsal raphe nucleus (DRN) of the excitatory amino acid kainic acid, the benzodiazepine (BZD) inverse agonist FG 7142, and the 5-HT1A receptor agonist 8-OHDPAT changed the behavior of rats in the elevated T-maze, an animal model of anxiety. The present study investigates biochemical correlates of these results in awake rats by measuring 5-HT release with in vivo microdialysis in two brain structures innervated by the DRN-the amygdala (Am) and the dorsal periaqueductal gray matter (DPAG)-that have been implicated in anxiety. Microinjection of kainic acid (60 pmol) into the DRN significantly increased 5-HT release in both the Am and the DPAG. In the DPAG, the increase was 14-fold higher with respect to the baseline and occurred only at the first sample, which was collected 30 min after the injection. In the Am, the increase was less pronounced (nearly fourfold) but persistent, lasting until the fourth sample, which was collected 120 min from the injection. FG 7142 (40 pmol) and 8-OH-DPAT (8 nmol) were ineffective. Because only intra-DRN kainate both increased inhibitory avoidance and decreased one-way escape in the elevated T-maze, the present behavioral results support the suggestion that 5-HT facilitates conditioned fear in the Am and inhibits unconditioned fear in the DPAG.

Stimulation of the dopamine (DA) D-2 and D-1 receptors results in behavioural activation (i.e., induction of contralateral rotations) in 6-hydroxydopamine (6-OHDA) substantia nigra lesioned rats. Competitive N-methyl-D-aspartate (NMDA) antagonists as well as alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) antagonists potentiate the stimulatory responses to threshold doses of L-DOPA or the mixed dopamine D-1/D-2 agonist apomorphine in this model, indicating the potential of such combinations for the management of Parkinson's disease. Neuroanatomic and electrophysiologic data indicate a differential distribution of DA D-1 and DA D-2 receptors within motor loops of the basal ganglia. DA D-1 receptors are preferentially located on GABAergic neurones projecting to the substantia nigra compacta (SNc) and to the substantia nigra reticulata (SNr), whereas DA D-2 receptors are preferentially located on neurones that innervate the external pallidum. NMDA receptors are present in high densities within the striatum, whereas AMPA receptors are enriched in the entopeduncular nucleus/internal pallidum and the SNr. To further characterise the functional interaction between DA and glutamate receptors, we tested the competitive NMDA antagonist 3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) and the AMPA antagonist 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f] quinoxaline (NBQX) following systemic administration in combination with the DA D-2 selective agonist quinpirole or the DAD-1 selective agonist A 68 930 (1R,3S)-1-aminomethyl-5,6-dihydroxy-3-phenylisochroman) in rats with chronic 6-OHDA lesions of the SNc. CPP potentiated quinpirole-induced rotations and did not affect those induced by the D-1 agonist A 68930. By contrast, NBQX had no effect on quinpirole-induced rotations, whereas synergism was seen with A 68930. These results suggest that rotations induced by combined treatment with glutamate antagonists and DA agonists are mediated by different pathways within the basal ganglia, depending on which subtype of receptor is involved. AMPA antagonists could act preferentially by activating the direct motor pathway, whereas NMDA antagonists could modulate the indirect loop.

The intracellular content of glutathione in astroglia-rich primary cultures derived from the brains of newborn rats was used as an indicator for the ability of these cells to use dipeptides for glutathione synthesis. For restoration of the glutathione level, after a 24-h starvation period in the absence of glucose and amino acids, glucose, glutamate, cysteine, and glycine have to be present in the incubation buffer. The dipeptides CysGly and gammaGluCys were able to substitute for cysteine plus glycine and glutamate plus cysteine, respectively. Half-maximal contents of glutathione were found at 20 microM CysGly and 3 mM gammaGluCys. In addition, the oxidized forms of the dipeptides CysGly and GlyCys could replace cysteine plus glycine for glutathione restoration, and the glycine-containing dipeptides GlyGly, GlyLeu, GlyGlu, GlyGln, and gammaGluGly could partially substitute for the glycine necessary for the replenishment of glutathione. The glutathione resynthesis in the presence of CysGly plus glutamate was totally inhibited in the presence of buthionine sulfoximine, an inhibitor of gamma-glutamylcysteine synthetase. In contrast, glutathione restoration from gammaGluCys at a concentration of 10 mM in the presence of glycine was not influenced by the inhibitor. The use of CysGly or gammaGluCys was not affected by the presence of the dipeptidase inhibitors cilastatin or bestatin. In addition, carnosine and several other dipeptides applied in a 50-fold excess only slightly prevented the use of CysGly, hinting at the existence in astroglial cells of a transport system specific for CysGly. The results demonstrate that astroglial cells can use dipeptides for intracellular glutathione synthesis and that the dipeptides most likely are taken up as intact molecules into astroglial cells before intracellular hydrolysis occurs.

The present study investigated the effects of a single oral dose (30 mg) of the non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist memantine on memory and learning in human subjects. Sixteen male healthy volunteers participated in a double blind placebo controlled study. There were no significant effects of memantine on mood, attention or immediate and delayed verbal and visuospatial memory. Memantine did, however, delay the acquisition of classical eyeblink conditioning and reduced the overall frequency of conditioned responses without affecting reflex or spontaneous eyeblinks. These findings are compatible with the higher affinity of memantine to cerebellar as compared to forebrain tissue and demonstrate the dissociability of different memory systems by pharmacological tools.

Sepsis and its complications, hypotension, shock, and multiorgan failure continue to represent a significant cause of mortality among hospitalized patients, affecting approximately 200,000 patients per year in the US and 100,000 in Europe (Dal Nogare, A.R. 1991. Am. J. Med. Sci. 302:50-65.). Incidence rates appear to be increasing, probably due to an increase in the population with risk factors such as diabetes or invasive procedures. Activation of cytokines by endotoxins and subsequent formation of nitric oxide is of central pathogeneic importance in sepsis. In this study we show that polymerized bovine hemoglobin (Biopure 2) restores both cardiovascular and renal functions in an endotoxin-induced shock model in rats. These effects are compared to those of the nitric oxide synthase inhibitor N(G)-nitro-L-arginine, and hydroxyethyl starch, the latter currently in clinical use for intravenous volume replacement. Our results clearly indicate that polymerized hemoglobin but not nitric oxide synthase inhibition or volume replacement normalize cardiovascular and kidney function in acute septic shock. This new therapeutic approach is readily applicable to controlled clinical trials because polymerized hemoglobin has been tested in humans and is therefore available for such studies.

Apoptotic neuronal death is a key mechanism that regulates the elimination of neuronal precursor cells during the development of the mammalian brain. The principal action of neurotrophins such as nerve growth factor is probably the suppression of the preexistent machinery of programmed cell death that is readily activated in neurons deprived of neurotrophins. Potassium-mediated neuronal depolarization prolongs neuronal survival in vitro and has become a major model of examining neuronal apoptosis. Apoptosis induced by potassium deprivation triggers a lethal cascade of events that includes specific RNA and protein synthesis, induction of interleukin 1-converting enzyme-like protease activity, and generation of free radicals. Neuronal susceptibility to apoptosis is also regulated by the expression of bcl-2 family proteins. Current research focuses on the significance of these findings for the premature death of adult neurons in human neurodegenerative diseases.

Budipine is a novel antiparkinsonian drug which is particularly beneficial in the treatment of parkinsonian tremor. The mechanism of action of budipine is not fully understood. To study whether budipine has dopaminergic activity in vivo, we used the 6-hydroxydopamine rotational model of Parkinson's disease. Budipine (0.78-12.5 mg/kg i.p.) did not induce ipsilateral or contralateral rotations, suggesting that it does not possess direct or indirect dopaminergic activity. This conclusion is further supported by the observation that budipine (10 mg/kg) i.v. did not facilitate striatal dopamine release measured in vivo by brain microdialysis. To investigatate possible antimuscarinic and N-methyl-D-aspartic acid (NMDA) antagonistic properties of budipine, we compared budipine with the antimuscarinic antiparkinsonian drug biperiden and the NMDA receptor antagonist 3-[(+/-)-2-carboxypiperazine-4-yl]-propyl-1-phosphonic acid (CPP). In receptor-binding assays, budipine inhibited thienylcyclohexylpiperidyl-3,4-[3H](n) ([I3H]TCP) (2.5 nM)-binding with an IC50 of 36 microM and [3H]3-quinuclidinol benzilate-binding with an IC50 of 1.1 microM. The respective values for biperiden were 170 and 0.053 microM. In line with these findings, budipine and CPP increased the threshold for NMDA-induced seizures in mice with an ED50 of 10.2 and 4.4 mg/kg, respectively, whereas biperiden was not effective. In 6-hydroxydopamine-lesioned rats, budipine (3.13-12.5 mg/kg) and CPP (0.1-0.39 mg/kg) increased the number of contralateral rotations induced by apomorphine, whereas biperiden was not effective. The present data suggest that budipine acts by blocking muscarinic and NMDA transmission while facilitation of dopaminergic transmission does not appear to contribute to its in vivo action. In comparison to biperiden, which has also antimuscarinic and NMDA receptor antagonistic properties, the anti-NMDA action of budipine is more prominent.

The present behavioral study was undertaken to investigate whether neuronal nitric oxide (NO) synthase mediates the abnormal consequences of increased NMDA receptor-mediated synaptic transmission in models of postural tremor, Parkinson's disease and epilepsy. We used 7-nitroindazole, a selective inhibitor of neuronal NO synthase, and NG-nitro-L-arginine (L-NAME), an unspecific NO synthase inhibitor, and compared their action with that of the competitive NMDA receptor antagonist 3-[(R)-2-carboxypiperazin-4-yl]-prop-2-enyl-1-phosphonic acid (D-CPPene). In both mice and rats, 7-nitroindazole, L-NAME and D-CPPene dose dependently reversed the harmaline-induced increase of cerebellar cyclic guanosine-5'-monophosphate (cGMP) levels. For subsequent behavioral experiments we used doses of 7-nitroindazole, L-NAME and D-CPPene which were equipotent in preventing harmaline-induced cGMP increase. Harmaline-induced tremor in mice and rats was suppressed by D-CPPene, but not by 7-nitroindazole or by L-NAME. This effect of D-CPPene was not due to unspecific suppression of motor activity, since D-CPPene did not affect locomotor activity at doses which reduced tremor. D-CPPene, but not 7-nitroindazole and L-NAME potentiated the antiparkinsonian action of the dopamine agonist lisuride in rats with unilateral 6-hydroxydopamine lesions of the substantia nigra. D-CPPene antagonized seizures induced by intracerebroventricular injection of NMDA in mice. In contrast, 7-nitroindazole and L-NAME had only a tendency to prevent seizures and to delay the latency to onset of seizures. We conclude from these results that neuronal NO synthase does not serve as a major mediator of increased NMDA receptor-mediated synaptic transmission in animal models of Parkinson's disease, postural tremor and epilepsy. The novel observation that D-CPPene suppresses harmaline-induced tremor leads us to suggest that NMDA receptor antagonists should be considered as novel therapeutics for postural tremor.

Glutathione levels are decreased in the substantia nigra of patients with Parkinson's disease. We studied whether glutathione depletion contributes to dopaminergic cell death using a specific inhibitor of glutathione biosynthesis, L-buthionine sulfoximine (BSO). We found no significant reduction of tyrosine hydroxylase-positive cells in the substantia nigra pars compacta (SNpc) when BSO was administered systemically to preweanling mice or locally to the SNpc of adult rats. However, the combination of BSO with MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) in preweanling mice and the combination of nigral injections of BSO with intrastriatal injections of MPP+ (1-methyl-4-phenylpyridinium), the active metabolite of MPTP in adult rats, potentiated the toxic effects of MPTP and MPP+ on nigral neurones. Our data show that glutathione depletion can result in cell death if the nigrostriatal system is metabolically compromised.

Apoptosis in the central nervous system of mutant weave (wv) and lurcher (lc) mice was studied using in situ DNA end-labeling. The number of apoptotic cells in the external granule cell layer of weaver (wv/+) mice at postnatal day 9 was increased six- to eight-fold compared to (+/+) littermates. Purkinje cells and Bergmann glia cells were not affected. No labeled cells were found in the substantia nigra. In lurcher (lc/+) mice, labeled nuclei of large cells were found in the Purkinje cell layer, suggesting that Purkinje cells of mutant lurcher mice undergo apoptosis. Apoptotic granule cell nuclei were found in the internal granule cell layer. In contrast to weaver (wv/+) mice, the number of apoptotic cells in the external granule cell layer was not increased. Apoptosis appears to be the common pathway of cell death in the degenerative processes induced by the weaver and the lurcher gene, respectively. These mutant mice offer the opportunity to study the mechanisms that underlie inappropriate apoptotic cell death in vivo.

In rodent models of Parkinson's disease such as reserpinized or 6-hydroxydopamine substantia nigra lesioned rats, blockade of glutamate receptors of the NMDA (N-methyl-D-aspartate) or the AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate) receptor subtypes and concomitant treatment with L-DOPA (L-3,4-dihydroxyphenylalanine) or direct dopamine agonists restores locomotor activity and induces rotations. An alternative approach to interfere with glutamatergic transmission would involve the inhibition of glutamate release resulting in functional glutamate antagonism. The novel antiepileptic drug lamotrigine blocks the veratridine-evoked release of the excitatory transmitters L-glutamate and L-aspartate. Due to its presumed antiglutamatergic action it has been suggested that lamotrigine may be useful in the treatment of Parkinson's disease. In a preliminary open-label study in patients with Parkinson's disease some favourable effects were reported. The present study was undertaken to systematically investigate the effects of lamotrigine in rat models of Parkinson's disease. However, lamotrigine failed to exert antiparkinsonian activity in reserpinized rats when administered alone or in combination with the dopamine receptor agonist apomorphine. In rats bearing 6-hydroxydopamine lesions of the substantia nigra lamotrigine did not induce rotations when given alone and did not modify rotations induced by apomorphine or the preferential dopamine D2 receptor agonist lisuride. On the basis of these negative results it is predicted that lamotrigine will not have significant favourable effects on akinesia and rigidity in Parkinson's disease patients.

In multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) the cytokines tumour necrosis factor-alpha (TNF), lymphotoxin-alpha (LT), and interferon-gamma (IFN-gamma) are of central pathogenetic importance. A therapy capable of stopping neurological deterioration in MS patients is not yet available. Here, we report that rolipram, a selective type IV phosphodiesterase inhibitor, stereospecifically suppresses the production of TNF/LT and less strongly also IFN-gamma in human and rat auto-reactive T cells. Moreover, we show that rolipram is an effective treatment for EAE. Rolipram has extensively been studied in humans for the treatment of depression, but has not yet been marketed. The data presented here identify rolipram as potential therapy for multiple sclerosis and provoke the immediate initiation of clinical trials.