Prenatal folate deficiency impairs sociability and memory/recognition in mice offspring.

Folate is essential for the normal growth and development of the fetus. Folic acid supplementation during the fetal period affects postnatal brain development and reduces the incidence of mental disorders in animal and human studies. However, the association between folate deficiency (FD) during pregnancy and developmental disorders in children remains poorly understood. In this study, we investigated whether prenatal FD is associated with neurodevelopmental disorders in offspring. ICR mice were fed a control diet (2 mg folic acid/kg diet) or a folate-deficient diet (0.3 mg folic acid/kg diet) from embryonic day 1 until parturition. We evaluated locomotor activity, anxiety, grooming, sociability and learning memory in male offspring at 7-10 weeks of age. No differences were found in locomotor activity or anxiety in the open field test, nor in grooming time in the self-grooming test. However, sociability, spatial memory, and novel object recognition were impaired in the FD mice compared with control offspring. Furthermore, we measured protein expression levels of the NMDA and AMPA receptors, as well as PSD-95 and the GABA-synthesizing enzymes GAD65/67 in the frontal cortex and hippocampus. In FD mice, expression levels of AMPA receptor 1 and PSD-95 in both regions were reduced compared with control mice. Moreover, NMDA receptor subunit 2B and GAD65/67 were significantly downregulated in the frontal cortex of prenatal FD mice compared with the controls. Collectively, these findings suggest that prenatal FD causes behavioral deficits together with a reduction in synaptic protein levels in the frontal cortex and hippocampus.

5-Fluorouracil exacerbates cefepime-induced convulsions in pentylenetetrazol-kindled mice.

OBJECTIVE: The antibiotics cefepime and meropenem are recommended for the treatment of neutropenia. However, cefepime has been found to be associated with both peripheral and central adverse events such as renal impairment and seizures, respectively. Previous studies showed that cefepime exacerbated convulsions in corneal kindled mouse models of epilepsy. However, its involvement in chemotherapy-induced side effects is unknown. METHODS: In this study, we examined the convulsive potential of cefepime (500 mg/kg) and meropenem (500 mg/kg) in pentylenetetrazol (PTZ)-kindled mice using an electroconvulsive shock test with low-intensity stimulus currents. Then, the effects of 5-fluorouracil (5-FU, 200 and 400 mg/kg, i.p.) treatment, a model of chemotherapy-induced side effects, were investigated in the PTZ-kindled mouse model. RESULTS: In fully PTZ-kindled mice, intravenous administration of cefepime (500 mg/kg) or meropenem (500 mg/kg) did not elicit any convulsions in the electroconvulsive shock test with low-intensity stimulus currents. In the PTZ-kindled mice treated with 5-FU (200 mg/kg), intravenous administration of cefepime (500 mg/kg) exacerbated the convulsions that occurred within 1 min in the electroconvulsive shock test, and the mice subsequently developed convulsive status epilepticus. However, intravenous administration of meropenem (500 mg/kg) did not produce such effects. CONCLUSION: These findings suggest that the combination of 5-FU and cefepime exacerbates early-onset convulsive seizures and elicits delayed-onset convulsive status epilepticus. Additionally, 5-FU treatment increases the risk of induction of neurotoxic side effects by cefepime.

Change in mutation frequency at a TP53 hotspot during culture of ENU-mutagenised human lymphoblastoid cells.

Mutations in oncogenes or tumour suppressor genes cause increases in cell growth capacity. In some cases, fully malignant cancer cells develop after additional mutations occur in initially mutated cells. In such instances, the risk of cancer would increase in response to growth of these initially mutated cells. To ascertain whether such a situation might occur in cultured cells, three independent cultures of human lymphoblastoid GM00130 cells were treated with N-ethyl-N-nitrosourea to induce mutations, and the cells were maintained for 12 weeks. Mutant frequencies and spectra of the cells at the MspI and HaeIII restriction sites located at codons 247-250 of the TP53 gene were examined. Mutant frequencies at both sites in the gene exhibited a declining trend during cell culture and reached background levels after 12 weeks; this was also supported by mutation spectra findings. These results indicate that the mutations detected under our assay conditions are disadvantageous to cell growth.

TRPV1 mediates the anticonvulsant effects of acetaminophen in mice.

OBJECTIVE: Acetaminophen is one of the most commonly used analgesic and antipyretic drugs. It has been reported that acetaminophen has anticonvulsant effects in several animal models of seizure. An active metabolite of acetaminophen, AM404, inhibits the uptake of the endocannabinoid anandamide. However, the mechanism of the anticonvulsant effect of acetaminophen is unknown. METHODS: This study was performed to examine whether or not acetaminophen can protect against pentylenetetrazol-induced kindling in mice and to investigate the precise mechanisms of the anticonvulsant effect of acetaminophen using the fully kindled mouse models. RESULTS: Repeated administration of acetaminophen significantly delayed the progression of seizure severity induced by pentylenetetrazol. Additionally, acetaminophen showed a dose-dependent anticonvulsant activity against fully pentylenetetrazol-kindled seizures. AM404 also exhibited a dose-dependent anticonvulsant activity in fully kindled animals. The anticonvulsant activity of acetaminophen was antagonized by capsazepine and AMG9810, two transient receptor potential vanilloid-1 (TRPV1) antagonists. However, the transient receptor potential ankyrin 1 (TRPA1) antagonist HC030031 and CB1 receptor antagonist AM251 had no effect. CONCLUSION: These findings suggest that acetaminophen has an anticonvulsant effect in pentylenetetrazol-kindled mouse models and TRPV1 mediates the anticonvulsant action.

Environmental enrichment alleviates cognitive and behavioral impairments in EL mice.

Epilepsy in children is occasionally associated with comorbidities, such as cognitive impairment, behavioral disturbances, and social deficits. These neurobehavioral comorbidities are closely related to environmental factors and the severity of the seizures. Previous studies show that environmental enrichment has a beneficial effect in animal models of temporal lobe epilepsy following systemic chemoconvulsant administration. However, the effect of environmental enrichment on behavioral impairments in the EL mouse, a genetic model of human idiopathic epilepsy, remains unknown. In the present study, we examined the effect of environmental enrichment on cognitive and behavioral impairments in this murine model. The EL mice, under standard laboratory conditions, exhibited impairments in spatial memory in the Morris water maze test, hyperactivity and impaired habituation in the open-field test, and a deficit in social novelty preference in the three-chamber social approach test, compared with control DDY mice, a genetically related nonepileptic strain. These impairments in EL mice were ameliorated by exposure to an enriched environment. These findings suggest that environmental enrichment effectively ameliorates cognitive and behavioral deficits in EL mice.

Anticonvulsant effects of acetaminophen in mice: Comparison with the effects of nonsteroidal anti-inflammatory drugs.

OBJECTIVE: The appropriate use of analgesic drugs based on their degree of analgesia and adverse effects is important for pain management. Although it has been reported that AM404, a metabolite of acetaminophen, has anticonvulsant effects in several animal seizure models, little is known about the relation between acetaminophen and seizures. We therefore investigated the effects of acetaminophen on seizure susceptibility in several mouse seizure and epilepsy models and compared the effects with those of nonsteroidal anti-inflammatory drugs (NSAIDs). METHODS: Anticonvulsant activity was evaluated in ICR mice using maximum electroshock-induced seizure tests and acute pentylenetetrazol-induced seizure tests. Electrical kindling via corneal stimulation and pentylenetetrazol administration were used to establish animal kindling epilepsy models. Proconvulsive activity was examined using an electroconvulsive shock test with low-stimulus currents. RESULTS: Acetaminophen showed slight, but not statistically significant, anticonvulsant activity in both the maximum electroshock-induced seizure test (300-600mg/kg i.p.) and acute pentylenetetrazol-induced seizure test (100-600mg/kg i.p.). In contrast, acetaminophen exhibited significant anticonvulsant effects in corneal electroshock-kindled and pentylenetetrazol-kindled mice (ED50 values: 251 and 310mg/kg i.p., respectively). When the proconvulsive effects of NSAIDs were examined in the low-current electroconvulsive shock-induced seizure model, the nonselective cyclooxygenase (COX)-1 and COX-2 inhibitors indomethacin, diclofenac, and loxoprofen induced dose-dependent proconvulsant activity. Celecoxib, a COX-2 selective inhibitor, had no proconvulsant activity. CONCLUSION: These findings suggest that acetaminophen has a significant anticonvulsant effect and that its profile is completely different from that of NSAIDs.

The α4ß2 nicotinic acetylcholine receptor modulates autism-like behavioral and motor abnormalities in pentylenetetrazol-kindled mice.

Epilepsy is associated with several psychiatric disorders, including cognitive impairment, autism and attention deficit/hyperactivity disorder (ADHD). However, the psychopathology of epilepsy is frequently unrecognized and untreated in patients. In the present study, we investigated the effects of ABT-418, a neuronal nicotinic acetylcholine receptor agonist, on pentylenetetrazol (PTZ)-kindled mice with behavioral and motor abnormalities. PTZ-kindled mice displayed impaired motor coordination (in the rotarod test), anxiety (in the elevated plus maze test) and social approach impairment (in the three-chamber social test) compared with control mice. ABT-418 treatment (0.05 mg/kg, intraperitoneally) alleviated these behavioral abnormalities in PTZ-kindled mice. Immunolabeling of tissue sections demonstrated that expression of the α4 nicotinic acetylcholine receptor subunit in the medial habenula was similar in control and PTZ-kindled mice. However, expression was significantly decreased in the piriform cortex in PTZ-kindled mice. In addition, we examined the expression of the synaptic adhesion molecule neuroligin 3 (NLG3). NLG3 expression in the piriform cortex was significantly higher in PTZ-kindled mice compared with control mice. Collectively, our findings suggest that ADHD-like or autistic-like behavioral abnormalities associated with epilepsy are closely related to the downregulation of the α4 nicotinic receptor and the upregulation of NLG3 in the piriform cortex. In summary, this study indicates that ABT-418 might have therapeutic potential for attentional impairment in epileptic patients with psychiatric disorders such as autism and ADHD.

Involvement of stimulation of α7 nicotinic acetylcholine receptors in the suppressive effect of tropisetron on dextran sulfate sodium-induced colitis in mice.

Ulcerative colitis (UC) involves chronic inflammation of the large intestine. Several agents are used to treat UC, but adverse side effects are remaining problems. We examined the effect of tropisetron as a new type of drug for UC using a dextran sulfate sodium (DSS)-induced model of colitis in mice. We developed a DSS-induced model of colitis and calculated the Disease Activity Index and colon length. We measured myeloperoxidase activity and determined the protein level and mRNA level of cytokines in the colon. DSS-induced colitis was ameliorated by administration of tropisetron and PNU282987. Pre-administration of methyllycaconitine diminished the suppressive effect of tropisetron upon DSS-induced colitis. These findings suggested that α7 nicotinic acetylcholine receptors (α7 nAChRs) were related to the suppressive effect of tropisetron on DSS-induced colitis. Additionally, stimulation of α7 nAChRs decreased the colon level of interleukin-6 and interferon-γ upon DSS administration. Furthermore, stimulation of α7 nAChRs decreased macrophage infiltration, with expression of α7 nAChR increased by DSS administration. These results suggest that the underlying mechanism of this suppressive effect on DSS-induced colitis is via stimulation of α7 nAChRs and involves suppression of expression of pro-inflammatory cytokines. Tropisetron could be a new type of therapeutic agent for UC.

Evaluation of edaravone against radiation-induced oral mucositis in mice.

Oral mucositis induced by radiotherapy for cancers of the head and neck reduce the quality of life of patients. However, effective therapeutic agents are lacking. Symptomatic treatment involves local anesthesia and analgesia. We focused on the antioxidant effects of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; Radicut(®)). Oral mucositis was induced on the tongue tips of mice using a single dose of X-rays (20 Gy). To evaluate the protective effect of edaravone (30 and 300 mg/kg), administration was carried out 30 min before irradiation. Survival, oral mucositis score, myeloperoxidase activity, and levels of 2-Thiobarbituric acid reactive substances were measured, and all were improved compared with those of control mice. A significant difference was not found in terms of survival due to edaravone. Histopathologic findings also highlighted the beneficial features of edaravone. Edaravone reduced the production of reactive oxygen species. These findings suggest that the protective effect of edaravone against radiation-induced oral mucositis is through an antioxidant effect.

Assessment of the hamster cheek pouch as a model for radiation-induced oral mucositis, and evaluation of the protective effects of keratinocyte growth factor using this model.

PURPOSE: Oral mucositis induced by radiotherapy impacts quality of life. Previous studies have reported on the use of the hamster as a model for radiation-induced oral mucositis; however, details regarding factors such as radiation dose response, effects on myeloperoxidase (MPO) activity and related histopathological changes remain unclear. In the present study using the hamster, we evaluated the dose dependency of radiation-induced oral mucositis and the effects of keratinocyte growth factor (palifermin). METHODS: Oral mucositis was induced in the cheek pouch by X-irradiation using single doses in the range 20-50 Gy. To evaluate the protective effect of palifermin, administration was carried out (5 mg/kg) on days 1, 2 and 3 or on days 9, 10 and 11 after single irradiation at a dose of 40 Gy. RESULTS: The oral mucositis score, MPO activity and histopathological findings of inflammation increased in a dose dependent manner. Palifermin treatment stimulated the proliferation of mucosal epithelial cells. Additionally, palifermin when administered on days 1, 2 and 3 after irradiation (40 Gy) reduced the severity of oral mucositis. CONCLUSIONS: The hamster was found to be a suitable model for radiation-induced oral mucositis, with excellent results regarding the evaluation of radiation dose response and drug reactivity.

Convulsive liability of cefepime and meropenem in normal and corneal kindled mice.

We have reported significantly higher convulsion prevalence in patients treated with cefepime than in those treated with meropenem. Additionally, cefepime-associated convulsions were found only in patients with brain disorders, not renal failure. Here, we compared the convulsive liability of cefepime and meropenem administered intravenously in normal and corneal kindled mice with low seizure thresholds. We used the proconvulsive test in normal mice following pentylenetetrazol (PTZ) injection and electroconvulsive shock at low-stimulus currents and in corneal kindled mice. We also measured electroencephalogram (EEG) activity 1 min after antibiotic injections. Intravenous injection of cefepime and meropenem at 250 or 500 mg/kg of body weight had no effect on PTZ-induced convulsions in normal mice. However, in convulsions induced by electroconvulsive shock at low-stimulus currents, mean seizure stage following cefepime administration at 500 mg/kg was significantly higher than that following saline injection. Additionally, EEG spikes were recorded for mice that were given cefepime (500 mg/kg). In corneal kindled mice following cefepime injection, mean seizure stage was significantly higher than that following meropenem injection. The convulsive liability of cefepime is significantly higher than that of meropenem in normal and corneal kindled mice. In patients with low seizure thresholds, convulsive liability of cefepime may be assumed.

Imipramine-induced c-Fos expression in the medial prefrontal cortex is decreased in the ACTH-treated rats.

Previous studies have shown that the antidepressive-like effect of tricyclic antidepressants is blocked by repeated treatments with adrenocorticotropic hormone (ACTH). However, little is known about the neuroanatomy underlying the mechanism of the imipramine treatment-resistant depression model. In the present study, first experimental evidence showed no significant difference of the serum imipramine concentrations between the saline and ACTH-treated rats. In further study, imipramine produced significant increases in the c-Fos expression in the medial prefrontal cortex (mPFC), the dentate gyrus of the hippocampus (DGH), and the central nucleus of the amygdala (CeA), in rats repeatedly treated with saline. The imipramine-increased c-Fos immunoreactivity was suppressed in the mPFC of rats repeatedly treated with ACTH. However, there was no significant difference in c-Fos expression in the DGH and CeA between ACTH- and saline-treated rats. These results suggest that the mPFC is maybe involved in effects of the imipramine in the ACTH-treated rats.

Comparison of the prevalence of convulsions associated with the use of cefepime and meropenem.

BACKGROUND: The US Food and Drug Administration reported seizures associated with the use of cefepime (primarily in patients with renal impairment who did not receive appropriate dose adjustments of cefepime). OBJECTIVE: The maximum dose of cefepime in the USA (6 g per day) is higher than that in Japan (4 g per day). We investigated the prevalence of convulsions associated with the use of cefepime by comparing it with that of meropenem. METHODS: A retrospective study was undertaken in 183 patients treated with cefepime and 745 patients treated with meropenem over 2 years at Ehime University Hospital. Cefepime or meropenem-associated convulsions were defined according to the following criteria: (1) administration or dose escalation of diazepam, phenytoin, phenobarbital and thiamylal given via the intravenous route (2) convulsions recorded in medical records during administration of cefepime or meropenem. RESULTS: The prevalence of convulsions was significantly greater in the cefepime treated group than in the meropenem-treated group. Among the patients who had cefepime-associated convulsions, none had renal failure. Cefepime-associated convulsions occurred only in patients with brain disorders. CONCLUSION: Cefepime-associated convulsions should be recognized as potential complications even in patients with normal renal function. Brain disorders may increase the risk of cefepime-associated convulsions.

Treatment with linezolid in a neonate with meningitis caused by methicillin-resistant Staphylococcus epidermidis.

UNLABELLED: Recent findings have focused on the possible role of linezolid (LZD) as a suitable candidate for the treatment of central nervous system infections. LZD treatment for meningitis has been sporadically reported in adults, but there are no reports in neonates or infants. We report a case of meningitis caused by methicillin-resistant Staphylococcus epidermidis (MRSE) in a neonatal girl. The patient had intraventricular hemorrhage on postnatal day 1 and was treated with ventricular drainage. Twenty-two days after drainage, the patient developed a fever and seizure. Although ampicillin and ceftriaxone were given empirically for meningitis, an increased cell count and protein were observed in cerebrospinal fluid (CSF). Vancomycin (VCM) was administered intravenously because MRSE was detected from CSF 2 days after the administration of ampicillin and ceftriaxone. However, intravenous administration of VCM did not show any effect. Subsequent treatment of LZD successfully reduced the cell count and protein in CSF. CONCLUSION: LZD may be a treatment option for neonates and infants for drain-associated meningitis caused by MRSE.

Oral mucosal adhesive films containing royal jelly accelerate recovery from 5-fluorouracil-induced oral mucositis.

Oral mucositis induced by chemotherapy or radiotherapy has an impact upon quality-of-life, is dose-limiting for chemotherapy, and causes considerable morbidity. We evaluated the effect of royal jelly (RJ) on 5-fluorouracil (5-FU)-induced oral mucositis in hamsters. Oral mucositis was induced in hamsters through a combination of 5-FU treatment and mild abrasion of the cheek pouch. RJ was contained in chitosan-sodium alginate film (RJ film). Films were attached to the oral mucosa and the healing process examined by measuring the area of mucositis, myeloperoxidase (MPO) activity, microscopic aspects, and RT-PCR for detection of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1ß). Furthermore, we evaluated the radical-scavenging activity of RJ and generation of keratinocyte growth factor from human periodontal ligament fibroblasts. RJ films (10%, 30%) significantly improved recovery from 5-FU-induced damage, reduced MPO activity and the production of pro-inflammatory cytokines. Additionally, RJ showed radical-scavenging activity. These data suggest that topical application of films that contain RJ had a healing effect on the severe oral mucositis induced by 5-FU and that the effect was caused by the anti-inflammatory or anti-oxidative activities of RJ.

Involvement of α4ß2 nicotinic acetylcholine receptors in working memory impairment induced by repeated electroconvulsive seizures in rats.

A role of cholinergic nervous system in the behavioral impairments induced by repeated ECS is not understood. The α4ß2 nicotinic acetylcholine receptor (nAChR) agonist ABT-418, but not the α7 nAChR agonist, significantly ameliorated the impairment of spontaneous alternation behavior in the Y-maze test. And, repeated ECS caused a reduction of α4 nAChR-positive cells in the prefrontal cortex and hippocampus. Thus, the α4ß2 nAChR is related to ECS-induced deficits in rats.

The assessment of risk for gastrointestinal injury with anticoagulant and antiplatelet drugs: the possible beneficial effect of eicosapentaenoic Acid for the risk of gastrointestinal injury.

Antithrombotic drugs have been increasingly used for treating ischemic cardiovascular diseases among the elderly in Japan. However, antithrombotic drugs are known to be risk factors for gastrointestinal injury. Therefore, we conducted a pharmacoepidemiologic study on patients receiving antithrombotic drugs to identify the risk factors for gastrointestinal injury. This retrospective case-control study included patients who were prescribed antithrombotic drugs at the Ehime University Hospital between April and September 2010. Of the 3271 patients who received antithrombotic drug therapy, 172 (5.3%) developed gastrointestinal injuries, including gastric ulcers, duodenal ulcers, and hemorrhagic gastrointestinal injuries. Further, the incidence of gastrointestinal injury was higher in patients with hypertension than in those without (p<0.0001). Multivariate adjusted odds ratios and 95% confidence intervals were calculated using stepwise logistic regression. The adjusted odds ratios for gastrointestinal injury were 1.56 (95% confidence interval 1.07-2.36) for hypertension, 1.70 (1.17-2.50) for low-dose aspirin, 2.77 (1.70-4.49) for clopidogrel, 1.95 (1.23-3.08) for warfarin, and 4.13 (2.88-5.95) for nonsteroidal anti-inflammatory drugs. On the other hand, the non-adjusted odds ratio for drug-associated gastrointestinal injury was 0.43 (0.20-0.84) for eicosapentaenoic acid (EPA). In addition, we found that patients aged 70 years or older were at increased risk of drug-associated gastrointestinal injury. These findings suggest that while many antithrombotic drugs are risk factors for gastrointestinal injury, EPA may be a safe option for suppressing or preventing gastrointestinal injury.

Concurrent administration of rituximab and CHOP chemotherapeutic agents for outpatients with CD20-positive lymphoma.

R (rituximab)-CHOP (cyclophosphamide, adriamycin, vincristin, and prednisone) is given to outpatients with CD20-positive lymphoma as a standard treatment. However, this regimen requires long-term infusion because of the necessity for monitoring the infusion reaction (IR) during R administration. In this study, pharmacological changes in anti-tumor agents were examined after the joint use of R and CHOP, and the possibility of concurrent administration of R and CHOP for outpatients was discussed. After combining antitumor agents with R, the binding capacity of R to the CD20 peptide and molecular changes in anti-tumor agents were measured by ELISA and LC/MS/MS-based analysis. At the same time, a pilot study involving concurrent administration of R and CHOP to patients with diffuse large B-cell lymphoma (DLBCL) was carried out after the first course of R-CHOP. After combining with either adriamycin or cyclophosphamide, the binding capacity of R to the CD20 antigen was equivalent to controls, and no molecular changes in adriamycin and cyclophosphamide were detected after combination with R. Twenty-one cases of DLBCL were treated safely with concurrent administration of R and CHOP. Twenty patients achieved complete remission after a full course of R-CHOP. The results indicated that long-term medication might not be necessary for outpatients treated with R-CHOP.

[Impaired memory following repeated pentylenetetrazol treatments in kindled mice].

Epilepsy is characterized by recurrent seizures, which are caused by excessive discharges from cerebral neurons. Currently, antiepileptic drugs that possess sodium channel blocking activities and also mediate GABA-ergic systems are primarily used to prevent epileptic seizure. However, approximately 40% of patients with epilepsy suffer from interictal psychiatric comorbidities in clinical practice. Furthermore, it is unclear whether epilepsy is associated with psychic function. The aim of the present study was to clarify the effects of kindling-induced epileptic seizures on psychic functioning using behavioral pharmacological tests. Pentylenetetrazol (PTZ)-kindled mice demonstrated no significant differences in locomotor activity and muscle relaxation compared with naïve mice. PTZ-kindled mice also demonstrated cognitive impairment in the objective location test, but no significant effects of PTZ-kindling were observed in the Y-maze test. These findings suggested that PTZ-kindling impairs reference memory, but not working memory. These results suggest that, with respect to their psychic functioning, PTZ-kindled mice have specific characteristics.