Claus G Haase

University of Cologne, Köln, North Rhine-Westphalia, Germany

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Publications (43)138.85 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Glutamate and its specific ionotropic receptors, including N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors, are supposed to play an important role in neurodegeneration as well as neuronal regeneration. Although autoantibodies (aab) to glutamate receptors (GluR) have been identified in several neurologic diseases, including paraneoplastic encephalitis and Rasmussen's encephalitis (RE) with an increasing prevalence, the presence and role of anti-GluR aab in multiple sclerosis (MS) have not been studied yet. Objectives and methods: In this study, we tested the serum samples of 56 subjects, including patients with relapsing-remitting MS (n = 25), patients with RE (n = 8), and healthy donors (HD; n = 23), for anti-GluR aab by immunoblot analysis of a panel of recombinantly expressed GluR proteins, including GluN1, GluN2C, GluA3, GluK2, and GluD2. Results: aab were mainly found directed against GluN1 and, except for one aab positive to GluK2 in 1 MS patient and 2 HD controls positive for GluA3, no other anti-GluR aab were detected. In the sera of RE patients, no anti-GluR aab were found. In patients with MS, 8 of the 25 sera (32%) tested positive for GluN1. Compared to the HD (6/23; 26%), this difference was not statistically significant (p = 0.28). Conclusions: Our study showed that if anti-GluR aab were detectable in HD and MS patients, they were mainly directed against GluN1 (in particular to oligomeric protein complexes) and were not found in RE. Those antibodies may have low titers and low affinities and might be considered an immune epiphenomenon. Hence, further studies will have to clarify their potential role as a surrogate marker for the extent of neuronal destruction or regeneration, respectively.
    NeuroImmunoModulation 02/2014; 21(4):189-194. DOI:10.1159/000356519 · 1.88 Impact Factor
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    ABSTRACT: The contribution of glial cells, mainly astrocytes and microglia, to the pathophysiology of epilepsy is increasingly appreciated. Glia play a pivotal role in the initiation and maintenance of the central nervous system (CNS) immune response and neuronal metabolic and trophic supply. Recent clinical and experimental evidence suggests a direct relationship between epileptic activity and CNS inflammation, which is characterized by accumulation, activation, and proliferation of microglia and astrocytes. Concomitant glia-mediated mechanisms of action of several antiepileptic drugs (AEDs) have been proposed. However, their direct effects on glial cells have been rarely investigated. We aimed to investigate the effect of commonly used AEDs on glial viability, the gap junctional network, the microglial activation, and cytokine expression in an in vitro astroglia/microglia co-culture model. Primary astrocytic cultures were prepared from brains of postnatal (P0-P2) Wistar rats and co-cultured with a physiologic amount of 5%, as well as 30% microglia in order to mimic inflammatory conditions. Co-cultures were treated with valproic acid (VPA), carbamazepine (CBZ), phenytoin (PHE), and gabapentin (GBT). Viability and proliferation were measured using the tetrazolium (MTT) assay. The microglial activation state was determined by immunocytochemical labeling. The astroglial connexin 43 (Cx43) expression was measured by Western blot analysis. The transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) cytokine levels were measured by the quantitative sandwich enzyme immunosorbent assay (ELISA). Astrocytes, co-cultured with 5% microglia (M5 co-cultures), showed a dose-dependent, significant reduction in glial viability after incubation with PHE and CBZ. Furthermore, VPA led to highly significant microglial activation at all doses examined. The antiinflammatory cytokine TGF-β1 release was induced by high doses of GBT and PHE. Astrocytes co-cultured with 30% microglia (M30 co-cultures) revealed a dose-dependent significant reduction in glial viability after incubation with PHE, accompanied by increased TGF-β1 and TNF-α levels. However, CBZ significantly reduced the amount of activated microglial cells and increased the total number of inactivated microglia. Finally, CBZ resulted in reduced viability at all doses examined. CNS inflammation is characterized by a disturbance of glial cell functions. Strong microglial activation, a typical hallmark of inflammation, was induced by VPA in M5 and continued in M30 co-cultures. With regard to the direct relation between CNS inflammation and seizures, VPA seems to be unsuitable for reducing inflammatory conditions. The reverse effect was achieved after CBZ. We noticed significant microglial inactivation, after incubation of the M30 co-cultures. In conclusion, we suggest that AEDs with antiinflammatory glial features are beneficial for seizures caused by persistent brain inflammation.
    Epilepsia 12/2013; 55(1). DOI:10.1111/epi.12473 · 4.57 Impact Factor
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    ABSTRACT: We analyzed the effect of dexamethasone on gram-negative bacteria derived lipopolysaccharide (LPS) induced inflammation in astroglial/microglial co-cultures. At the cellular level the microglial phenotype converted to an activated type after LPS incubation. Furthermore, LPS compromised functional astroglial properties like membrane resting potential, intracellular coupling and connexin 43 (Cx43) expression. This change in Cx43 expression was not due to a downregulation of Cx43 mRNA expression. Morphological and functional changes were accompanied by a time-dependent release of inflammation related cytokines. Co-incubation of dexamethasone with LPS prevented these LPS-induced changes within our glial co-culture model. The ability of dexamethasone to reconstitute astrocytic properties and to decrease microglial activation in vitro could be one possible explanation for the beneficial effects of dexamethasone in the treatment of acute bacterial meningitis in vivo.
    Brain research 03/2010; 1329:45-54. DOI:10.1016/j.brainres.2010.03.012 · 2.84 Impact Factor
  • Claus G Haase · Benjamin Hopmann
    Journal of Neurology 04/2009; 256(6):1020-1. DOI:10.1007/s00415-009-5043-4 · 3.38 Impact Factor
  • A Brenk · K Laun · Claus G. Haase
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    ABSTRACT: The aim of this study was to evaluate a short-term non-specific home-based 6-week cognitive training for its effect on neuropsychological deficits and depression. Cognitive and affective abilities of patients with MS were compared with healthy controls using an identical neuropsychological test battery. Re-testing was performed after 6 weeks of cognitive home-based training. Patients already showed cognitive deficits at baseline. Cognitive training resulted in a significant improvement in several skills, in particular with respect to visuoconstructive and figural long-term memory. In addition, prior depressed mood and quality of life improved in MS patients during the training period and remained up to 6 months. Our study corroborated the early appearance of neuropsychological deficits in MS. Mental training, although unspecific, lead to improvements with respect to attention and memory functions in patients, and to some degree in control subjects, which may last for more than 6 months.
    European Neurology 10/2008; 60(6):304-9. DOI:10.1159/000157885 · 1.36 Impact Factor
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    ABSTRACT: The goal of this study was to examine the influence of seizure freedom on executive function in outpatients with generalized epilepsy and extrafrontal partial epilepsy. Recent investigations of cognitive function in epilepsy have revealed executive deficits in persons with focal temporal as well as generalized epilepsies. Additional studies have suggested an influence of seizure freedom on cognitive function. Thirty-five consecutive outpatients were divided into seizure free <or= 3 months (n=18) and seizure free >3 months (n=17). The neuropsychological tests administered included: verbal fluency tasks, the Cognitive Estimation Test, the Hayling and Brixton Test, and the Behavioural Assessment of the Dysexecutive Syndrome (BADS) battery. Both patient groups were compared with matched healthy controls (n=16). The extensive testing revealed significant differences between patients with shorter seizure-free periods and healthy controls with respect to overall errors and phonemic verbal fluency, response suppression, and BADS overall profile scores. Subjects seizure free >3 months exhibited a trend toward impairment in the phonemic fluency task only. The results suggest that deficits in executive function were present in patients with extrafrontal partial epilepsy and generalized epilepsy, indicating the potential influence of epileptic activity on the ability to focus on relevant information and switch attention to other relevant information, to plan tasks and subtasks, and to check on and encode working memory content. The results also suggest that those deficits may be more pronounced in patients with relatively short seizure-free periods.
    Epilepsy & Behavior 08/2008; 14(1):66-70. DOI:10.1016/j.yebeh.2008.08.005 · 2.26 Impact Factor
  • C. G. Haase · P. M. Faustmann · H.-C. Diener
    Aktuelle Neurologie 04/2008; 26(02):68-71. DOI:10.1055/s-2007-1017611 · 0.32 Impact Factor
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    ABSTRACT: Human gliomas are the most common class of brain neoplasm. In order to better characterize their response to inflammation, we evaluated the influence of tumor necrosis factor alpha (TNF-alpha) on the coupling behaviour and the membrane resting potential (MRP) of glioma cells (F98 glioma cell line) compared to primary astrocytes. In contrast to cultured primary astrocytes which exhibited a profound inhibition of gap junction mediated intercellular communication (GJIC), extracellular exposure of TNF-alpha to F98 glioma cells gained no effect on the functional coupling. Whereas, intracellular application of TNF-alpha into the glioma cells elicited similar effects as those found in primary astrocytes indicating a compromised accessibility of the TNF-alpha receptor in F98 cells. Western blotting, immunocytochemical staining and real time RT PCR analysis revealed a differential expression and distribution of TNF-alpha receptor 1 (TNFR1) in the glioma cells. Connexin 43 (Cx43) is the major astrocytic gap junction protein which when phosphorylated has been shown to reveal altered gating properties. Here we show that TNF-alpha increases the level of phosphorylated Cx43 in primary astrocytes but not in the F98 glioma cells. Our observations could account for the decreased regulatory effects of TNF-alpha on GJIC of F98 glioma cells.
    Journal of Neuro-Oncology 02/2008; 86(2):143-52. DOI:10.1007/s11060-007-9462-8 · 3.07 Impact Factor
  • Claus G Haase · Marc Lienemann · Pedro M Faustmann
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    ABSTRACT: Detailed neuropsychological assessment was performed in 86 women (48 patients with stable relapsing-remitting multiple sclerosis (MS) and 38 matched healthy controls (HC)). Patients were categorized into patients without (EDSS < or =1, n = 26) and with physical disability (EDSS > or =2, n = 22). Patients with EDSS > or =2 scored significantly (P < 0.05) higher in Beck's depression inventory (BDI) and depression scores (DS) compared to HC and patients with EDSS < or =1. No significant differences were found with respect to the use of specific coping strategies between the patient groups, who preferred active (EDSS < or =1) or distracting (EDSS > or =2) strategies. Cognitive deficits were significantly increased in MS with EDSS > or =2 with regard to visuo-construction and visual memory, in particular with respect to geometric figures, compared to MS with EDSS < or =1. Significant positive correlations of depression variables (BDI, DS and BL) and depressive as well as denying coping strategies were found. Our results showed increased depression scores and increased cognitive deficits in advanced physically disabled patients, without selection of specific coping strategies. This supports an individual MS-specific neuropsychological therapeutic approach in order to improve disease related deficits together with social functioning.
    European Archives of Psychiatry and Clinical Neuroscience 02/2008; 258(1):35-9. DOI:10.1007/s00406-007-0759-6 · 3.53 Impact Factor
  • Aktuelle Neurologie 02/2008; 35(1):2-7. DOI:10.1055/s-2007-971018 · 0.32 Impact Factor
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    ABSTRACT: BAY 63-9044 is a new full 5-HT(1A)-agonist with functional dopamine agonist properties aimed for the treatment of Parkinson's disease. This first-in-man study investigated the pharmacodynamics, safety and tolerability as well as the pharmacokinetics of BAY 63-9044 in a randomized, single-blind, placebo-controlled group-comparison dose escalation study. 45 healthy men received BAY 63-9044 as an oral solution in single doses of 0.25 mg, 0.5 mg, 1.2 mg, 2.5 mg and 5.0 mg. Pupil reaction (baseline pupil diameter (DIAM), constriction amplitude (CA)), body temperature, electroencephalography (EEG) and prolactin, cortisol and adrenocorticotrophic hormone (ACTH) served as pharmacodynamic measures and were monitored up to 24 h after drug intake. Safety, tolerability and plasma samples for determination of BAY 63-9044 were followed up to 72 h. Up to a dose of 2.5 mg, BAY 63-9044 was safe and well tolerated. Dose-limiting adverse events (nausea, vomiting, and dizziness) occurred in 5 out of 6 volunteers at the 5 mg dose. Adverse events resolved spontaneously in all but one volunteers who was treated with an antihistaminergic for vomiting. Dose-dependent changes of DIAM and CA were observed at doses higher than 0.5 mg and 1.2 mg, respectively. Body temperature showed a trend for reduction starting at C(max) in the highest two doses only. No clear effect was found on prolactin, cortisol and ACTH levels. The pharmacokinetics of BAY 63-9044 showed a dose-dependent increase with maximum plasma concentrations reached within 1 h. Plasma concentrations declined in a bi-phased manner with an apparent terminal half-life of 5.2-8.1 h. Up to the maximum tolerated dose (MTD) of 2.5 mg BAY 63-9044 was safe and well tolerated and showed predictable linear pharmacokinetics. Pupil reaction may serve as a non-invasive biomarker for pharmacodynamic effects of 5-HT(1A)-compounds with DIAM being the most sensitive parameter.
    European Journal of Clinical Pharmacology 01/2008; 63(12):1123-8. DOI:10.1007/s00228-007-0372-7 · 2.97 Impact Factor
  • Pedro M. Faustmann · Claus G. Haase
    Blood-Brain Barriers: From Ontogeny to Artificial Interfaces, Volume 1, 05/2007: pages 601 - 618; , ISBN: 9783527611225
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    ABSTRACT: Cytokines play an important role in the onset, regulation, and propagation of immune and inflammatory responses within the central nervous system (CNS). The main source of cytokines in the CNS are microglial cells. Under inflammatory conditions, microglial cells are capable of producing pro- and antiinflammatory cytokines, which convey essential impact on the glial and neuronal environment. One paramount functional feature of astrocytes is their ability to form a functionally coupled syncytium. The structural link, which is responsible for the syncytial behavior of astrocytes, is provided by gap junctions. The present study was performed to evaluate the influence of inflammation related cytokines on an astroglial/microglial inflammatory model. Primary astrocytic cultures of newborn rats were cocultured with either 5% (M5) or 30% (M30) microglial cells and were incubated with the following proinflammatory cytokines: tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and the antiinflammatory cytokines transforming growth factor-beta1 (TGF-beta1) and IFN-beta. Under these conditions, i.e., incubation with the inflammatory cytokines and the high fraction of microglia (M30), microglial cells revealed a significant increase of activated round phagocytotic cells accompanied by a reduction of astroglial connexin 43 (Cx43) expression, a reduced functional coupling together with depolarization of the membrane resting potential (MRP). When the antiinflammatory mediator TGF-beta1 was added to proinflammatory altered M30 cocultures, a reversion of microglial activation and reconstitution of functional coupling together with recovery of the astroglial MRP was achieved. Finally IFN-beta, added to M5 cocultures was able to prevent the effects of the proinflammatory cytokines TNF-alpha, IL-1beta, and IFN-gamma.
    Glia 11/2005; 52(2):85-97. DOI:10.1002/glia.20223 · 6.03 Impact Factor
  • Aktuelle Neurologie 10/2005; 32(S 4). DOI:10.1055/s-2005-919399 · 0.32 Impact Factor
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    ABSTRACT: This study investigated the relationship between clinical symptoms and cognitive dysfunction in multiple sclerosis. Cognitive dysfunction and visual evoked potentials (VEPs) were studied in patients free of physical disability and mildly to moderately disabled patients with multiple sclerosis (MS). Disability-free patients (EDSS < or = 1.5; n = 13), mildly to moderately disabled patients (EDSS ranging from 2 to 6; n = 13) and a healthy matched control group (n = 16) were examined with respect to attention, verbal and nonverbal memory and early visual processing (VEPs). Disability-free patients showed mild impairments on phasic alertness and divided attention. Deficits were more pronounced in mildly to moderately disabled patients who were additionally impaired with respect to non-verbal memory. Despite adequate visual acuity, one half of all patients showed abnormal VEP latencies for both eyes at the same time. The findings suggest that cognitive deficits are already present in multiple sclerosis even in the absence of physical disability. Even with normal visual acuity, perceptual impairments should be considered as part of the CNS affection.
    European Archives of Psychiatry and Clinical Neuroscience 10/2005; 255(5):319-26. DOI:10.1007/s00406-005-0565-y · 3.53 Impact Factor
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    ABSTRACT: Assessment of cerebral blood flow velocities (CBFV) can be used as a non-invasive tool to evaluate specific drug effects, like caffeine (CAF), acetazolamide (AA) as well as cognition. Their influences on each others CBFV were evaluated in detail, using a randomized, double-blind, double-dummy, placebo-controlled three-fold cross-over study design in 18 right-handed healthy male volunteers. CBFV (maximal, mean, minimal) and pulsatility index of both middle cerebral arteries were recorded by transcranial Doppler ultrasound simultaneously, during a verbal memory test, oral CAF, intravenous AA or placebo. AA led to increase in CBFV of 25-32%. Caffeine resulted in decreased V(mean) and V(min) of 10-13%. Cognitive stimulation resulted in a slight increase of CBVF of about 4%, but was overruled by effects of AA and CAF. We conclude that pharmacological effects can easily be assessed by TCD during clinical pharmacological studies of vasoactive drugs. However intraindividual variability and effects of neuropsychological stimulation needs to be taken into account.
    Progress in Neuro-Psychopharmacology and Biological Psychiatry 06/2005; 29(4):549-56. DOI:10.1016/j.pnpbp.2005.01.006 · 3.69 Impact Factor
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    ABSTRACT: BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor (VEGFR) inhibitor that targets tumour cell proliferation and tumour angiogenesis. This Phase I study was undertaken to determine the safety profile, maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, and tumour response profile of oral BAY 43-9006 in patients with advanced, refractory solid tumours. BAY 43-9006 was administered daily for repeated cycles of 21 days on/7 days off. A total of 44 patients were enrolled at doses from 50 to 800 mg b.i.d. Pharmacokinetic profiles of BAY 43-9006 in plasma were determined during the first treatment cycle. The most frequently reported adverse events over multiple cycles were gastrointestinal (75%), dermatologic (71%), constitutional (68%), pain (64%), or hepatic (61%) related. A MTD of 400 mg b.i.d. BAY 43-9006 was defined. BAY 43-9006 was absorbed rapidly; steady-state conditions were reached within 7 days. BAY 43-9006 exposure increased nonproportionally with increasing dose. In all, 32 patients were evaluated for tumour response: 15 patients showed tumour progression, 16 patients experienced stable disease (>6 months in eight patients), and one patient with renal cell carcinoma achieved a partial response. BAY 43-9006 given for 21 days with 7 days off treatment was safe, well tolerated, and showed antitumour activity.
    British Journal of Cancer 05/2005; 92(10):1855-61. DOI:10.1038/sj.bjc.6602584 · 4.84 Impact Factor
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    ABSTRACT: BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor inhibitor that inhibits tumor cell proliferation and angiogenesis. This study established the safety and pharmacokinetics of BAY 43-9006 in 69 patients with advanced refractory solid tumors. BAY 43-9006 (50 to 800 mg) was administered once or twice daily on a varying weekly schedule. Pharmacokinetic sampling was performed in all patients; preliminary tumor response was also assessed. The effect of BAY 43-9006 on phorbol myristate acetate-stimulated ERK phosphorylation in peripheral blood lymphocytes was studied using flow cytometry. Mild to moderate diarrhea was the most common (55%) treatment-related adverse event. The maximum-tolerated dose was 400 mg bid continuous. Dose-limiting toxicities were grade 3 diarrhea and fatigue at 800 mg bid, and grade 3 skin toxicity at 600 mg bid. BAY 43-9006 pharmacokinetics were highly variable for single and multiple dosing, and toxicity did not appear to be dose dependent. Significant decreases of phorbol myristate acetate-stimulated ERK phosphorylation (P < .01) were identified at doses >/= 200 mg bid continuous. Forty-five patients were assessable for efficacy; one patient had a partial response (hepatocellular carcinoma at 400 mg bid continuous), 25 patients had stable disease, with eight lasting > 6 months and five for >12 months. Eighteen patients had progressive disease, and tumor response could not be evaluated in one patient. Oral BAY 43-9006 was well tolerated and appeared to provide some clinical benefits. Based on the results of this study, BAY 43-9006 at 400 mg bid continuous is recommended for ongoing and future studies.
    Journal of Clinical Oncology 03/2005; 23(5):965-72. DOI:10.1200/JCO.2005.06.124 · 18.43 Impact Factor
  • International journal of clinical pharmacology and therapeutics 12/2004; 42(11):650-1. DOI:10.5414/CPP42650 · 1.22 Impact Factor
  • EJC Supplements 09/2004; 2(8):114-114. DOI:10.1016/S1359-6349(04)80388-4 · 9.39 Impact Factor

Publication Stats

1k Citations
138.85 Total Impact Points


  • 2014
    • University of Cologne
      Köln, North Rhine-Westphalia, Germany
  • 2003–2010
    • Ruhr-Universität Bochum
      Bochum, North Rhine-Westphalia, Germany
  • 2007–2009
    • Prosper-Hospital Recklinghausen
      Recklinghausen, North Rhine-Westphalia, Germany
  • 2004–2005
    • Bayer HealthCare
      Leverkusen, North Rhine-Westphalia, Germany
  • 1998–2005
    • University Hospital Essen
      • Institute of Immunology
      Essen, North Rhine-Westphalia, Germany
  • 2001–2003
    • University of Duisburg-Essen
      Essen, North Rhine-Westphalia, Germany
    • University of Rostock
      Rostock, Mecklenburg-Vorpommern, Germany
    • Max Planck Institute of Neurobiology
      München, Bavaria, Germany