In vivo evaluation of effects of histamine H3 receptor antagonists on methamphetamine-induced hyperlocomotion in mice.

A single administration with METH (3 mg/kg) induced a hyperlocomotion in male ICR mice. Pretreatment of mice with pitolisant, a histamine H3 receptor antagonist (5 and 10 mg/kg), for 30 min showed a significant reduction of the hyperlocomotion induced by METH, as compared with vehicle (saline)-pretreated subjects. Pretreatment of mice with the histamine H3 receptor antagonists JNJ-10181457 (5 and 10 mg/kg) or conessine (20 mg/kg), also showed similar inhibitory effects on METH-induced hyperlocomotion, similar to pitolisant. No significant change in locomotion was observed in mice pretreated with pitolisant, JNJ-10181457, or conessine alone. The pitolisant (10 mg/kg) action on METH-induced hyperlocomotion was completely abolished by the histamine H1 receptor antagonist pyrilamine (10 mg/kg), but not by the peripherally acting histamine H1 receptor antagonist fexofenadine (20 mg/kg), the brain-penetrating histamine H2 receptor antagonist zolantidine (10 mg/kg), or the brain-penetrating histamine H4 receptor antagonist JNJ-7777120 (40 mg/kg). Pretreatment with a histamine H3 receptor agonist immepip (10 mg/kg) augmented METH--induced behavior, including hyperlocomotion and stereotyped biting, and combined pretreatment with pitolisant (10 mg/kg) significantly attenuated stereotyped biting. These observations suggest that pretreatment with histamine H3 receptor antagonists attenuate METH-induced hyperlocomotion via releasing histamine after blocking H3 receptors, which then bind to the post-synaptic histamine receptor H1 (but not H2 or H4). It is likely that activation of brain histamine systems may be a good strategy for the development of agents, which treat METH abuse and dependence.

Measurements of gamma (γ)-emitting radionuclides with a high-purity germanium detector: the methods and reliability of our environmental assessments on the Fukushima 1 Nuclear Power Plant accident.

The severe accident of Fukushima 1 Nuclear Power Plant due to the Tohoku Region Pacific Coast Earthquake in 11 March 2011 caused wide contamination and pollution by radionuclides in Fukushima and surrounding prefectures. In the current JPR symposium, a group of plant scientists attempted to examine the impact of the radioactive contamination on wild and cultivated plants. Measurements of gamma (γ) radiation from radionuclides in "Fukushima samples", which we called and collected from natural and agricultural areas in Fukushima prefecture were mostly done with a high-purity Ge detector in the Graduate School of Maritime Sciences, Kobe University. In this technical note, we describe the methods of sample preparation and measurements of radioactivity of the samples and discuss the reliability of our data in regards to the International Atomic Energy Agency (IAEA) Interlaboratory comparisons and proficiency test (IAEA proficiency test).

Difference in cesium accumulation among rice cultivars grown in the paddy field in Fukushima Prefecture in 2011 and 2012.

After the accident of the Fukushima 1 Nuclear Power Plant in March 2011, radioactive cesium was released and paddy fields in a wide area including Fukushima Prefecture were contaminated. To estimate the levels of radioactive Cs accumulation in rice produced in Fukushima, it is crucial to obtain the actual data of Cs accumulation levels in rice plants grown in the actual paddy field in Fukushima City. We herein conducted a two-year survey in 2011 and 2012 of radioactive and non-radioactive Cs accumulation in rice using a number of rice cultivars grown in the paddy field in Fukushima City. Our study demonstrated a substantial variation in Cs accumulation levels among the cultivars of rice.

Radioactive pollution and accumulation of radionuclides in wild plants in Fukushima.

The radionuclide status of wild plants and soil in the Fukushima area was investigated during the period May 2011 to October 2012, using an imaging plate (autoradiograms) or a high purity germanium detector. Analyses of autoradiograms showed that wild plants grown in March 2011 were strongly polluted with fallout released from the Fukushima 1 Nuclear Power Plant. The radioactivity was mostly due to fallout adsorbed on the surface of the plants. On the other hand, a number of herbaceous plants were regularly collected in the Fukushima area and their radionuclide concentrations were measured with a high-purity germanium detector. Plants grown in March 2011 showed very high levels of ¹³4Cs and ¹³7Cs, but these radioactivity levels decreased rapidly after July 2011 and eventually became lower than that of endogenous 4°K. During this period, the radioactivity of the soil remained high. We therefore suppose that a significant proportion of the radioactivity detected from plants harvested after July 2011 was most likely derived from soil dust attached on the plant surface. Autoradiograms of rice plants were virtually identical between plants cultivated in Fukushima and Osaka area, reflecting the background radiation due to 4°K.

Radioactive cesium accumulation in seaweeds by the Fukushima 1 Nuclear Power Plant accident-two years' monitoring at Iwaki and its vicinity.

Accumulations of radionuclides in marine macroalgae (seaweeds) resulting from the Fukushima 1 Nuclear Power Plant (F1NPP) accident in March 2011 have been monitored for two years using high-purity germanium detectors. Algal specimens were collected seasonally by snorkeling at Nagasaki, Iwaki, Fukushima Prefecture (Pref.), Japan, ca. 50 km perimeter from the F1NPP. Additional collections were done at Soma, Hironocho, Hisanohama and Shioyazaki in Fukushima Pref. as well as at Chiba Pref. and Hyogo Pref. as controls. In May 2011, specimens of most macroalgal species showed ¹³7Cs levels greater than 3,000 Bq kg⁻¹ at Shioyazaki and Nagasaki. The highest ¹³7Cs level recorded 7371.20 ± 173.95 Bq kg⁻¹ in Undaria pinnatifida (Harvey) Suringar on 2 May 2011, whereas seawater collected at the same time at Shioyazaki and Nagasaki measured 8.41 ± 3.21 and 9.74 ± 3.43 Bq L⁻¹, respectively. The concentration factor of marine macroalgae was estimated to be ca. 8-50, depending on taxa and considering a weight ratio of wet/dry samples of ca. 10. ¹³7Cs level declined remarkably during the following 5-6 months. In contrast, the ¹³7Cs level remained rather stable during the following 12-16 months, and maintained the range of 10-110 Bq kg⁻¹. Contamination was still detectable in many samples in March 2013, 24 months after the most significant pollution.

Rapid increase of vacuolar volume in response to salt stress.

Suspension-cultured cells of mangrove [Bruguiera sexangula (Lour.) Poir.] showed a rapid increase in vacuolar volume under salt stress, although there was no change in the cell volume. The rapid increase in the vacuolar volume was an active process, which followed the activation of the tonoplast H(+)-ATPase and the vacuolar acid phosphatase. The same phenomenon was observed in barley (Hordeum vulgare L. cv. Doriru) root meristematic cells under salt stress but not in pea ( Pisum sativum L.). Increases in vacuolar volume could potentially protect the cytoplasm by decreasing the cytoplasmic volume during the initial phases of salt stress.