A Phase 1 Study to Assess the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Single Oral Doses of DS-3801b, a Motilin Receptor Agonist, in Healthy Subjects.

DS-3801b is an orally active, nonmacrolide, selective motilin receptor agonist. The aim of this 2-part first-in-human study was to assess the safety, tolerability, pharmacokinetics, and pharmacodynamic effects on proximal and distal gastrointestinal (GI) motility of single oral doses of DS-3801b in healthy subjects. The C-octanoate breath test was used to assess gastric emptying (GE), a measure of proximal GI motility.

Evaluation of a repeated-dose liver micronucleus assay with 2,6-dinitrotoluene using young adult rats.

As part of a collaborative study by the Mammalian Mutagenicity Study Group of the Environmental Mutagen Society of Japan, we examined micronucleus induction in hepatocytes following oral administration of 2,6-dinitrotoluene (2,6-DNT) at 30, 40, and 50mg/kg/day for 14 days or at 20, 30, and 40mg/kg/day for 28 days to young adult male rats. This compound is known to be a rat liver carcinogen. The formation of micronucleated hepatocytes was confirmed to be dose-dependent with statistically significant increases observed in both treatments.

Evaluation of the therapeutic index of a novel phosphodiesterase 4B-selective inhibitor over phosphodiesterase 4D in mice.

Phosphodiesterase 4 (PDE4) inhibitors have been developed for the treatment of pulmonary inflammatory diseases, but their clinical use was dose-limited by mainly gastric adverse effects. Recent studies suggested PDE4B-selective inhibitors over PDE4D are supposed to display a wider therapeutic index than subtype non-selective PDE4 inhibitors such as roflumilast. Compound A was identified as an orally active PDE4B-selective inhibitor over PDE4D both in humans (80-fold selective) and mice (29-fold selective).

Genotoxicity studies of 2,6-dinitrotoluene (2,6-DNT).

The potential genotoxicity of the rodent liver carcinogen 2,6-dinitrotoluene (2,6-DNT) was evaluated in compliance with the guidelines for genotoxicity studies of drugs (Notification No. 1604, Nov. 1, 1999, Ministry of Health and Welfare, Japan) and the OECD guidelines for the testing of chemicals by performing the bacterial reverse mutation (Ames) assay, the in vitro chromosomal aberration assay, and the in vivo comet assay (alkaline single cell gel electrophoresis) in rat liver.

Adenovirus E1A regulates lung epithelial ICAM-1 expression by interacting with transcriptional regulators at its promoter.

We focused on the regulation of inflammatory mediator expression by adenovirus E1A in lung epithelial cells and the role of this viral protein in the pathogenesis of chronic obstructive pulmonary disease (COPD). We previously reported that E1A, a well-known regulator of host genes, increased ICAM-1 expression in human bronchial epithelial (HBE) and A549 cells in response to LPS stimulation. In this report, we clarified the mechanism of this regulation.

Novel triple neurokinin receptor antagonist CS-003 inhibits respiratory disease models in guinea pigs.

Neurokinins are known to induce neurogenic inflammation related to respiratory diseases. The effects of CS-003 ([1-{2-[(2R)-(3,4-dichlorophenyl)-4-(3,4,5-trimethoxybenzoyl)morpholin-2-yl]ethyl}spiro[benzo[c]thiophene-1(3H),4'-piperidine]-(2S)-oxide hydrochloride]), a novel triple neurokinin receptor antagonist, on several respiratory disease models were evaluated in guinea pigs. As we have already shown that CS-003 is intravenously effective, we first determined if CS-003 was orally effective.

Particulate matter exposure induces persistent lung inflammation and endothelial dysfunction.

Epidemiologic and animal studies have shown that exposure to particulate matter air pollution (PM) is a risk factor for the development of atherosclerosis. Whether PM-induced lung and systemic inflammation is involved in this process is not clear. We hypothesized that PM exposure causes lung and systemic inflammation, which in turn leads to vascular endothelial dysfunction, a key step in the initiation and progression of atherosclerosis.

Novel triple neurokinin receptor antagonist CS-003 strongly inhibits neurokinin related responses.

Neurokinins are known to induce neurogenic inflammation related to respiratory diseases, though there is little information on triple neurokinin receptor antagonists. The pharmacological properties of the novel triple neurokinin 1, 2 and 3 receptor antagonist [1-(2-[(2R)-(3,4-dichlorophenyl)-4-(3,4,5-trimethoxybenzoyl)morpholin-2-yl]ethyl)spiro[benzo[c]thiophene-1(3H),4'-piperidine]-(2S)-oxide hydrochloride] (CS-003) were evaluated in this study. The binding affinities of CS-003 were evaluated with human and guinea pig neurokinin receptors.

Central-type benzodiazepine receptors and epileptogenesis: basic mechanisms and clinical validity.

Purpose: Gamma-aminobutyric acid (GABA)-A/benzodiazepine receptors (BZRs) play an important inhibitory role in epileptogenesis. [123I]Iomazenil (123I-IMZ) is a specific ligand for central-type (or neuronal-type) BNRs and is available for single-photon emission computed tomography (SPECT) in brain disorders. We demonstrated alterations of central-type BZRs in human focal epilepsies and their experimental models.

Epilepsy and driving in Japan.

Purpose: The driving regulations in Japan were amended in 2002, which lifted the absolute ban on driving by persons with epilepsy (PWE) and granted licenses to PWE after a 2-year seizure-free period.

Methods: To survey the effect of the new driving regulations, we sent questionnaires both to the driving authorities (DAs) and to doctors of the Japan Epilepsy Society (JES).

Results: Around 1,400 PWE legally obtained a driving license within 1 year after the amendment, licenses were rejected in 157, and 61 had the license withheld for <6 months.

Quantitative evaluation of central-type benzodiazepine receptors with [(125)I]Iomazenil in experimental epileptogenesis: II. The rat cortical dysplasia model.

[(123)I]Iomazenil (IMZ) is a specific ligand for central-type benzodiazepine receptors (BZRs) and is available for single photon emission computed tomography (SPECT) to detect epileptogenic foci. We have recently demonstrated time-dependent alterations of [(125)I]IMZ binding in the rat kainate model of temporal lobe epilepsy. Quantitative evaluation of central-type benzodiazepine receptors with [(125)I]Iomazenil in experimental epileptogenesis.

Quantitative evaluation of central-type benzodiazepine receptors with [(125)I] Iomazenil in experimental epileptogenesis. I. The rat kainate model of temporal lobe epilepsy.

This study aimed at quantitatively evaluating hippocampal central-type benzodiazepine receptors (BZRs) in the kainate model of temporal lobe epilepsy (TLE) by in vitro autoradiography (ARG) using [(125)I] Iomazenil (IMZ) specific ligand for central-type BZRs. Kainate (1 microg/0.5 microl) was injected into the left amygdala to induce limbic status epilepticus.

Involvement of enhanced neurokinin NK3 receptor expression in the severe asthma guinea pig model.

In this study, we investigated the involvement of neurokinin NK3 receptors in a severe asthma model prepared by administering ovalbumin via inhalation three times to systemically sensitized guinea pigs. [3H]senktide, a neurokinin NK3 receptor ligand, showed significant specific binding to the lungs from the model animals, but not to those from negative control animals. The airway responsiveness to intravenous neurokinin B, a neurokinin NK3 receptor agonist, was increased in the model, indicating an increase in functional NK3 receptors.

Greater involvement of neurokinins found in Guinea pig models of severe asthma compared with mild asthma.

Background: Involvement of neurokinins in asthma has been previously pointed out by several reports. However, the relationship between neurokinins and the severity of asthma has remained unclear. We developed a model of mild asthma (model I) and severe asthma (model II) in guinea pigs, and investigated the function of neurokinins in both models.

Kindling and status epilepticus models of epilepsy: rewiring the brain.

This review focuses on the remodeling of brain circuitry associated with epilepsy, particularly in excitatory glutamate and inhibitory GABA systems, including alterations in synaptic efficacy, growth of new connections, and loss of existing connections. From recent studies on the kindling and status epilepticus models, which have been used most extensively to investigate temporal lobe epilepsy, it is now clear that the brain reorganizes itself in response to excess neural activation, such as seizure activity. The contributing factors to this reorganization include activation of glutamate receptors, second messengers, immediate early genes, transcription factors, neurotrophic factors, axon guidance molecules, protein synthesis, neurogenesis, and synaptogenesis.

Enhancement of central dopaminergic activity in the kainate model of temporal lobe epilepsy: implication for the mechanism of epileptic psychosis.

There is an increased incidence of schizophrenia-like psychosis in temporal lobe epilepsy (TLE), and several risk factors have been implicated, including the duration of epilepsy and temporal lobe neuropathology. To investigate the biological mechanism of epileptic psychosis, we examined alterations of central dopaminergic systems in the kainate model of TLE. In adult rats, kainate was microinjected into the left amygdala to induce status epilepticus.

Kindling of the ventral tegmental area induces supersensitivity in the central dopamine system.

Kindling of the ventral tegmental area (VTA), a major source of the mesolimbic dopamine pathway, was examined in rats. We applied two quantitative measurements of dopamine sensitivity before and 2 weeks after VTA kindling (20 times electrical stimulations (100 microA at 1 min intervals) delivered once per day for 14 consecutive days): behavioral responses induced by test VTA stimulation and methamphetamine (MAP)-induced locomotor activity. The total amount of MAP-induced locomotor activity was significantly increased after VTA kindling, while the responses to electrical stimulation were unchanged.

Kainate exacerbates beta-amyloid toxicity in rat hippocampus.

We have previously shown that beta-amyloid (Abeta) increased the excitotoxicity of ibotenate, an N-methyl-D-aspartate (NMDA) receptor agonist, to hippocampal neurons of rats. In this report, non-toxic amounts of kainate were co-injected with Abeta into rat hippocampus. Nissl-stained brain sections revealed that Abeta/kainate co-injection exerted synergistic neuronal degeneration in the hippocampus as well as that by Abeta/ibotenate co-injection.

Acute neuroinflammation exacerbates excitotoxicity in rat hippocampus in vivo.

Accumulating evidence suggests that inflammation may play an important part in neurodegenerative diseases such as Alzheimer's disease. Inflammation itself, however, is insufficient to produce acute neurodegeneration in vivo. In this report, we determined whether inflammation increases excitotoxicity in hippocampal neurons.

Delusional disorder: molecular genetic evidence for dopamine psychosis.

Unlabelled: Since delusional disorder is characterized by mono-symptomatic paranoid symptoms, it can be a good clinical model for investigating the dopaminergic mechanism responsible for paranoid symptoms. We examined neuroleptic responses, plasma homovanillic acid (pHVA) and genes of the dopamine receptor (DR) and its synthesizing enzyme (tyrosine hydroxylase: TH) in patients with delusional disorder and compared them with those of schizophrenic patients and healthy controls.

Results: (1) A relatively small dose of haloperidol was more effective for delusional disorder than for schizophrenia.