Evaluation of arene ruthenium(II) N-heterocyclic carbene complexes as organometallics interacting with thiol and selenol containing biomolecules

Metal complexes with N-heterocyclic carbene (NHC) ligands have been widely used in catalytic chemistry and are now increasingly considered for the development of new chemical tools and metal based drugs. Ruthenium complexes of the type (p-cymene)(NHC)RuCl(2) interacted with biologically relevant thiols and selenols, which resulted in the inhibition of enzymes such as thioredoxin reductase or cathepsin B. Pronounced antiproliferative effects could be obtained provided that an appropriate cellular uptake was achieved. Inhibition of tumor cell growth was accompanied by a perturbation of metabolic parameters such as cellular respiration.

Investigation of serotonin-1A receptor function in the human psychopharmacology of MDMA

Serotonin (5-HT) release is the primary pharmacological mechanism of 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') action in the primate brain. Dopamine release and direct stimulation of dopamine D2 and serotonin 5-HT2A receptors also contributes to the overall action of MDMA. The role of 5-HT1A receptors in the human psychopharmacology of MDMA, however, has not yet been elucidated. In order to reveal the consequences of manipulation at the 5-HT1A receptor system on cognitive and subjective effects of MDMA, a receptor blocking study using the mixed beta-adrenoreceptor blocker/5-HT1A antagonist pindolol was performed. Using a double-blind, placebo-controlled within-subject design, 15 healthy male subjects were examined under placebo (PL), 20 mg pindolol (PIN), MDMA (1.6 mg/kg b.wt.), MDMA following pre-treatment with pindolol (PIN-MDMA). Tasks from the Cambridge Neuropsychological Test Automated Battery were used for the assessment of cognitive performance. Psychometric questionnaires were applied to measure effects of treatment on core dimensions of Altered States of Consciousness, mood and state anxiety. Compared with PL, MDMA significantly impaired sustained attention and visual-spatial memory, but did not affect executive functions. Pre-treatment with PIN did not significantly alter MDMA-induced impairment of cognitive performance and only exerted a minor modulating effect on two psychometric scales affected by MDMA treatment ('positive derealization' and 'dreaminess'). Our findings suggest that MDMA differentially affects higher cognitive functions, but does not support the hypothesis from animal studies, that some of the MDMA effects are causally mediated through action at the 5-HT1A receptor system.

Warum rauchen Schizophreniepatienten?

Patients suffering from schizophrenia are known to show an increased prevalence of nicotine addiction. The aim of this paper is to elucidate the relationship between schizophrenia and (chronic) use of nicotine. Nicotine seems to improve cognitive functions critically affected in schizophrenia, in particular sustained attention, focused attention, working memory, short-term memory, and recognition memory. Furthermore, several studies using evoked potentials (P50 paradigm) and prepulse inhibition of the acoustic startle reflex suggest that deficient preattentive information processing, a core feature of schizophrenia illness, is improved following treatment with nicotine. Smoking can also improve extrapyramidal secondary effects of antipsychotic medication and it induces cytochrome P4501A2, an enzyme system involved in the metabolism of several antipsychotics. There is substantial evidence that nicotine could be used by patients with schizophrenia as a "self-medication" to improve deficits in attention, cognition, and information processing and to reduce side effects of antipsychotic medication. Possible pharmacotherapeutic approaches for the regulation of abnormal neurotransmission at nicotinic acetylcholine receptors are discussed.

Crescentic glomerulonephritis associated with myeloperoxidase-antineutrophil-cytoplasmic antibodies: first report on the efficacy of primary anti-TNF-alpha treatment

We report on successful induction of remission in a patient with necrotizing crescentic glomerulonephritis associated with myeloperoxidase-antineutrophil-cytoplasm antibodies by primary use of the anti-tumor necrosis factor (TNF)-alpha chimeric monoclonal antibody infliximab in combination with corticosteroids only. The standard treatment containing cyclophosphamide has reduced the former high mortality from systemic vasculitides. However, the toxicity of this alkylating agent limits its long-term use. As TNF-alpha has been shown to play a central pathogenic role in vasculitis as well as in crescentic glomerulonephritis, anti-TNF-alpha treatment in combination with cyclophosphamide has been found to be effective in therapy-resistant vasculitis. Previous reports on TNF-alpha-blocking therapies without additional cyclophosphamide did not include patients with active and severe crescentic glomerulonephritis. As our patient refused cyclophosphamide, he was given four infusions of infliximab (4 mg/kg on weeks 0, 2, 6 and 10) and methylprednisolone pulses (1 g on days 1-3), followed by daily oral prednisolone (starting with 2 mg/kg and tapering down to 5 mg daily within 3 months). After 12 weeks, control biopsy demonstrated lack of active glomerular inflammation while initially reduced renal function (creatinine 271 versus 172 mol/l, clearance 26 versus 62 ml/min) and proteinuria (2.4 versus 1.0 g/d) improved. Under remission maintenance therapy with azathioprine and prednisolone, the patient showed no relapses during a 1-year follow-up. Finally we demonstrate that there might be patients with crescentic glomerulonephritis who do not require therapy with alkylating substances and that less toxic agents such as the TNF-alpha-blocking monoclonal antibody infliximab could play a role in future primary treatment of crescentic glomerulonephritis.

Prepulse inhibition deficits in patients with panic disorder

Prepulse inhibition (PPI) is an operational measure of sensorimotor gating that is reduced in several neuropsychiatric disorders that are characterized by deficits in inhibition or gating of intrusive or irrelevant stimuli. Clinically, panic disorder (PD) patients have been described as having difficulties in inhibition of responding to sensory and cognitive events. Because such difficulties may be due to failures in early stages of information processing, we examined PPI in patients with PD. Acoustic startle reactivity, habituation, and PPI (30-, 60-, 120-, 240-, and 2,000-ms interstimulus intervals) were assessed in patients with panic disorder (m/f = 10, 10) and age- and gender-matched healthy controls (m/f = 11, 10). PD patients were assessed with structured clinical interview for DSM-IV criteria with benzodiazepine treatment as an exclusion criterion. Panic disorder patients exhibited normal startle reactivity, reduced habituation, and significantly reduced PPI in the 30-, 60-, and 240-ms prepulse conditions. Within the PD group, the patients with high trait and state anxiety exhibited less PPI than patients with low trait and state anxiety. Furthermore, in PD patients, decreased PPI correlated significantly with high trait but not state anxiety. These data indicate that early stages of sensory information processing are abnormal in patients with PD. These observed deficits in PPI could reflect a more generalized difficulty in suppressing or gating information in panic disorder. The correlation between high trait anxiety and deficient PPI supports the hypothesis that sensorimotor gating abnormalities are an enduring feature of subjects with PD.

[Toxicity of polychlorinated biphenyls (PCB)--indoor air pollution by PCB-containing durable elastic sealants]

The widespread use of the persistent and lipophilic polychlorinated biphenyls (PCB) e.g. in electrical engineering, hydraulics and chemistry of the polymers, caused their ubiquitous distribution and accumulation in food chains. Chronic toxicity in humans is known from several incidents of PCB contaminated food. Dose-response experiences, however, remain uncertain due to the technical grade of PCB as a complex mixture of about 150 congeners and many impurities, like polychlorinated dibenzodurans. Some information on the toxicity of a few PCB congeners is available from animal experiments. Large differences in enzyme-inductive efficacy between the PCB congeners rendered the use of toxicity equivalent factors (related to 2,3,7,8-TCDD, "Seveso-Dioxin") necessary. For risk assessment, the use of "sum of PCB", calculated from questionable determinations of 6 minor toxic congeners, is insufficient. Serious problems arise from evaporation of PCB e.g. in technical rooms of telephone companies (in Germany: Telekom) and generally, from sealing materials in buildings. The German Federal Health Administration, BGA, recommends 300 ng total PCB/m3 indoor air as "precautionary value". Since neither the extreme differences in toxicity of the congeners nor bioaccumulation are taken into account, this recommendation of BGA can not be justified any longer.