Kazuaki Shinomiya

Effects of short-acting hypnotics on sleep latency in rats placed on grid suspended over water.

The present study was performed to develop a new sleep disturbance model for evaluating hypnotic potencies by placing rats on a grid suspended over water up to 1 cm under the grid surface. When rats were placed on the grid, significant increases in sleep latency and amount of wakefulness were observed compared with those of rats placed on sawdust. However, the amounts of non-rapid eye movement (non-REM) sleep and rapid eye movement (REM) sleep of rats placed on the grid were significantly decreased compared with those of rats placed on sawdust. Four short-acting hypnotics (triazolam, zopiclone, brotizolam, lormetazepam) caused significant decreases in sleep latency, and the effects of hypnotics in rats placed on the grid were more potent than those in rats placed on sawdust. In conclusion, the present model can serve as a new sleep disturbance model and may also be useful for evaluating the sleep-inducing effects of short-acting hypnotics.

Effects of bupropion on the forced swim test and release of dopamine in the nucleus accumbens in ACTH-treated rats

The dopamine reuptake inhibitor bupropion has clinically been proven to improve depression and treatment-resistant depression. We examined its influence on the duration of immobility during the forced swim test in adrenocorticotropic hormone (ACTH)-treated rats and further analyzed the possible role of dopamine receptors in this effect. Additionally, the mechanism by which bupropion acts in this model was explored specifically in relation to the site of action through the use of microinjections into the medial prefrontal cortex and nucleus accumbens. Bupropion significantly decreased the duration of immobility in normal and ACTH-treated rats. This effect was blocked by D2 and D3 receptor antagonists in normal rats. Furthermore, infusions of bupropion into the nucleus accumbens, but not medial prefrontal cortex, decreased the immobility of normal and ACTH-treated rats during the forced swim test. Bupropion treatment plus repeated ACTH treatment significantly increased the extracellular dopamine concentration. These findings suggest the antidepressant-like effect of bupropion to be related to levels of dopamine in the rat nucleus accumbens.

Participation of histaminergic H1 and noradrenergic α1 receptors in orexin A-induced wakefulness in rats

The participation of histaminergic H(1) and noradrenergic alpha(1) receptors in orexin A-induced wakefulness was studied by examining the sleep-wakefulness cycle in rats. Intracerebroventricular infusion of orexin A (1 nmol) caused an increase in the wakefulness state, while non-rapid eye movement sleep (NREM sleep) and rapid eye movement sleep (REM sleep) states were decreased. Prazosin (150 nmol) showed no significant antagonistic effect on the orexin A-induced increase in the wakefulness state and decrease in NREM and REM sleep. On the contrary, pyrilamine (150 nmol) was effective in antagonizing orexin A-induced increase in wakefulness and decrease in NREM sleep. When prazosin (150 nmol) and pyrilamine (150 nmol) were simultaneously perfused into the lateral ventricle, an almost complete antagonistic effect was observed with the increase in the wakefulness state and decrease in NREM sleep. Orexin A (1 nmol) caused a significant decrease in the histamine contents of the cortex, hippocampus and hypothalamus, whereas noradrenaline contents were decreased only in the hypothalamus. From these results, we concluded that the arousal effect induced by orexin A occurs through histaminergic H(1) and noradrenergic alpha(1) receptors, although participation of the H(1) receptor was more important than the alpha(1) receptor.

Inhibitory effect of iodophenpropit, a selective histamine H3 antagonist, on amygdaloid kindled seizures

The effect of histamine H(3) antagonist, iodophenpropit on amygdaloid kindled seizures in rats was studied in comparison with those of other H(3) antagonists. Under pentobarbital anesthesia, the rats were fixed to a stereotaxic apparatus and bipolar electrodes were implanted into the amygdala. Electrodes were connected to a miniature receptacle, which was embedded in the skull with dental cement. To cause kindled seizures, electrical stimulation was applied to the amygdala bipolarly every day by a constant current stimulator, and electroencephalogram and convulsive behavior were observed. Drug effects were estimated in rats showing generalized kindled seizures. Intraperitoneal injection of H(3) antagonists, iodophenpropit, thioperamide, AQ0145 and clobenpropit, resulted in a dose-related inhibition of amygdaloid kindled seizures. The effect of iodophenpropit on amygdaloid kindled seizures was more potent than those of thioperamide, AQ0145 and clobenpropit. In conclusion, iodophenpropit may be useful for the treatment of partial epilepsy and/or secondary generalized seizures in humans.

Effects of chlorogenic acid and its metabolites on spontaneous locomotor activity in mice.

Chlorogenic acid possessed a weak caffeine-like psychostimulant property when assessed for its effect on spontaneous locomotor activity in mice. In the evaluation of the effects for the major metabolites of chlorogenic acid which were detected upon incubation with rat feces and/or excreted in urine after oral administration to rats, caffeic and m-coumaric acids were found to be the principal active metabolites, while the others contributed little to this caffeine-like psychostimulant activity.

Effect of seed coat extract from black soybeans on radial maze performance in rats

1. In the present study, we tested the effect of seed coat extract from black soybeans on eight‐arm radial maze performance in rats.

Clinical risk factors associated with postoperative delirium and evaluation of delirium management and assessment team in lung and esophageal cancer patients

BackgroundDelirium is an acute change in cognition and concentration that complicates the postoperative course. Patients who suffer delirium after surgery have an increased risk of persistent cognitive impairment, functional decline, and death. Postoperative delirium is also associated with an increased length of hospital stay and higher costs. With the goal of preventing delirium in postoperative patients, we organized a medical team from the Delirium Management and Assessment Center (D-mac) at Okayama University Hospital in January 2012. The team members consisted of physicians, pharmacists, nurses, and clinical psychologists.MethodsWe retrospectively reviewed the medical records of patients with delirium to examine risk factors related to the patients’ background.ResultsFifty-nine postoperative patients with lung or esophageal cancer were investigated; 25% exhibited delirium during hospitalization. Multiple logistic regression analysis showed significant associations between the presence of delirium and a past history of delirium (odds ratio, 4.22; 95% CI, 1.10-16.2; p = 0.09) and use of benzodiazepine receptor agonists (odds ratio, 3.97; 95% CI, 1.09-14.5; p = 0.03). Intervention by the D-mac significantly reduced the rate of delirium episodes in lung cancer patients (p =0.01). Notably, prior to intervention, the incidence of delirium was 100% when three high-risk factors for delirium were present. In contrast, the incidence of delirium in patients with three high-risk factors decreased following implementation of the D-mac intervention.ConclusionsThese findings suggest that active participation by various staff in the medical team managing delirium had a marked therapeutic impact.

Effects of the 5-HT1A Receptor Agonist Tandospirone on ACTH-Induced Sleep Disturbance in Rats

The aim of this study was to compare the effect of the serotonin (5-HT)1A receptor agonist tandospirone versus that of the benzodiazepine hypnotic flunitrazepam in a rat model of long-term adrenocorticotropic hormone (ACTH)-induced sleep disturbance. Rats implanted with electrodes for recording electroencephalogram and electromyogram were injected with ACTH once daily at a dose of 100 µg/rat. Administration of ACTH for 10 d caused a significant increase in sleep latency, decrease in non-rapid eye movement (non-REM) sleep time, and increase in wake time. Tandospirone caused a significant decrease in sleep latency and increase in non-REM sleep time in rats treated with ACTH. The effect of tandospirone on sleep patterns was antagonized by the 5-HT1A receptor antagonist WAY-100635. In contrast, flunitrazepam had no significant effect on sleep parameters in ACTH-treated rats. These results clearly indicate that long-term administration of ACTH causes sleep disturbance, and stimulating the 5-HT1A receptor by tandospirone may be efficacious for improving sleep in cases in which benzodiazepine hypnotics are ineffective.

Trends in the medication reviews of community pharmacies in Japan: a nationwide retrospective study

Background The trends in medication reviews made by community pharmacies in Japan are currently unknown. Objective We aimed to comprehensively describe the national trends in medication reviews in Japan’s community pharmacies in the backdrop of the country’s ageing population. Setting Community pharmacies in Japan. Methods We analysed national health insurance claims data for 2010–2015. These data were provided by the Ministry of Health, Labour and Welfare as part of the Survey of Medical Care Activities in Public Health Insurance. Main outcome measures The national trends in community pharmacy visits involving medicine dispensing and medication reviews that involve consultations with a physician. Results Among the 365 million pharmacy visits for 2010–2015, we identified 373,429 medication reviews accompanied by consultations with a physician. The pharmacy visit rate per 1000 population increased from 427.2 in 2010 to 483.7 in 2015. Medication reviews also increased from 407 per million pharmacy visits in 2010 to 1445 in 2015. Among the 373,429 medication reviews during the study period, the prescription was changed through collaboration with a physician 338,982 times (90.4%). The proportion of medication review acceptance increased from 80.6% in 2010 to 94.8% in 2015. The prescription change rate was higher among older patients than among younger ones. Conclusions Medication reviews by community pharmacists involving consultations with a physician increased in Japan from 2010 to 2015, as did prescription changes following these reviews.

Pattern of antibiotic prescriptions for outpatients with acute respiratory tract infections in Japan, 2013–15: a retrospective observational study

Background In this age of antimicrobial resistance, unnecessary use of antibiotics to treat non-bacterial acute respiratory tract infections (ARTIs) and inappropriate use of antibiotics in treating bacterial ARTIs are public health concerns. Purpose Our aim is to identify the pattern of oral antibiotic prescriptions for outpatients with ARTIs in Japan. Methods We analysed health insurance claims data of patients (aged ≤74 years) from 2013 to 2015, to determine the pattern of antibiotic prescriptions for outpatient ARTIs and calculated the proportion of each antibiotic. Results Data on 4.6 million antibiotic prescriptions among 1559394 outpatients with ARTIs were analysed. The most commonly prescribed classes of antibiotics included cephalosporins (41.9%), macrolides (32.8%) and fluoroquinolones (14.7%). The proportion of first-, second- and third-generation cephalosporins was 1.0%, 1.7% and 97.3%, respectively. Fluoroquinolones accounted for a quarter of the prescriptions for ARTIs in patients aged >20 years. In contrast, penicillins accounted for just 8.0% of the total number of antibiotic prescriptions for ARTIs. Conclusions According to clinical guidelines, penicillins are first-line antibiotics against ARTIs. However, third-generation cephalosporins, macrolides and fluoroquinolones are more frequently prescribed in Japan. Although we could not assess the extent to which appropriate antibiotics are selected, our results support the necessity of improving antibiotic choices in the treatment of ARTIs.