Mechanisms of radiocesium depuration in Sebastes cheni derived by simulation analysis of measured 137Cs concentrations off southern Fukushima 2014-2016.

The cesium depuration mechanisms were studied in Japanese rockfish Sebastes cheni off Fukushima, in which the radiocesium level remains higher than in other teleost. Samples were collected approximately 5 km south from the nuclear power plant during 2014-2016, and the 137Cs concentrations in fish, stomach content and prey species were measured. The stable cesium content in fish was also analyzed and compared with fish age which was determined by annual ring analysis in otoliths. The 137Cs concentrations in the dominant prey species, mysids and brown shrimp, were several Bq kg-w.w.-1; indicating that transfer via the food chain was substantial compared to that from seawater during the study period. The 137Cs concentrations in S. cheni decreased from 2014 to 2016 due to the metabolic excretion and the rate of decrease in its diet. Biokinetic model analyses confirmed the slower turnover of stable cesium in S. cheni, represented as a biological half-life (Tb1/2) of 140-215 d, and was associated with stable Cs levels in food of 5-7 ng g-w.w.-1. The 137Cs levels in S. cheni were also simulated, which showed that the 137Cs depuration in fish exposed to the initial contaminated plume in 2011 resulted from slower metabolic excretion, while the 137Cs levels in fish born after 2012 could be regarded as equilibrated with the environmental levels of 137Cs. Furthermore, the simulation results suggest that 137Cs depuration in S. cheni population was also caused by the alternation of generation, which can be substantial by the addition of new year class population hatched after 2012 that were not contaminated by the initial contaminated plume from the 2011 accident.

Radioactive cesium concentrations in coastal suspended matter after the Fukushima nuclear accident.

Radioactive cesium concentrations in the suspended matter of the coastal waters around the Fukushima Daiichi Nuclear Power Plant (FDNPP) were investigated between January 2014 and August 2015. The concentrations of radioactive cesium in the suspended matter were two orders higher in magnitude than those determined in the sediment. In addition, we discovered highly radioactive Cs particles in the suspended matter using autoradiography. The geometrical average radioactivity of particles was estimated to be 0.6 Bq at maximum and 0.2 Bq on average. The contribution ratio of highly radioactive Cs particles to each sample ranged from 13 to 54%, and was 36% on average. A major part of the radioactive Cs concentration in the suspended matter around the FDNPP was strongly influenced by the highly radioactive particles. The subsequent resuspension of highly radioactive Cs particles has been suggested as a possible reason for the delay in radioactive Cs depuration from benthic biota.

The effects of sediment transport on temporal variation in radiocesium concentrations in very shallow water off the southern coast of Fukushima, Japan.

We studied the very shallow coastal water off Iwaki City, Fukushima Prefecture, and investigated: (1) temporal variation in 137Cs concentrations; (2) particle-size distribution of sediments; and (3) the effect on variation by waves, component-fractionated concentration of radiocesium and mineral composition at three sampling stations (Yotsukura, Ena rocky reef and Ena sandy station). There was a decline in 137Cs concentrations in sediment samples at all sampling stations between 425 and 1173 days after the accident. All stations had fluctuations in 137Cs concentrations between 425 and 800 days. At Ena sandy station and Ena rocky reef stations the declines in 137Cs concentrations slowed from about 800 days after the accident. Fluctuations in particle median diameters were seen, as well as in 137Cs concentrations. At Yotsukura, where the fluctuation in median diameter was small, a constant decrease in 137Cs concentrations was observed. We considered that bioturbation may contribute the constant decrease. At Ena sandy station, where the fluctuation of the median diameter was large, the fluctuation in 137Cs concentrations was also large. The movement of sediments was evaluated by the Shields parameter, and results indicated that at any station where the sediment was moved more frequently, the fluctuation in 137Cs concentrations was also large. The highly contaminated small particles moved from our stations due to wave action between 425 and 800 days after the accident. The remaining relatively large particles might contribute to the slowing down in reduction of 137Cs concentrations from 800 days after the accident. However, the 137Cs concentrations in sediments in very shallow water off the southern coast of Fukushima may continue to decline over time.

Effects of the nuclear disaster on marine products in Fukushima: An update after five years.

Original data (134Cs and 137Cs, and sampling location) of marine products in Fukushima Prefecture monitored during 2011-2015 (n = 32,492) were analyzed to present an updated detailed description of radiocesium contamination after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident and to examine taxon/habitat-specific decreasing trends in different areas. Furthermore, marine species data presented by the Tokyo Electric Power Company (TEPCO) during 2012-2015 (n = 5458) were analyzed to evaluate the decreasing trends of 137Cs inside and outside (within a 20 km radius) of the FDNPP port. Monitoring results by Fukushima Prefecture show that percentages of samples higher than the Japanese regulatory limit of 100 Bq kg-1-wet (>RL%) were higher, whereas those below the detection limit (RL% and

[FIRST CASES OF ANTEROPOSTERIOR DISSECTION TUEB (TRANSURETHRAL ENUCLEATION WITH BIPOLAR)].

PURPOSE: We examined the efficacy of anteroposterior dissection transurethral enucleation with bipolar (TUEB) for benign prostate hyperplasia (BPH). PATIENTS AND METHODS: We performed anteroposterior dissection TUEB on 21 patients with BPH between October 2012 and June 2013. In anteroposterior dissection TUEB, the lateral lobes are anteroposteriorly dissected from the 12 o'clock position to the 6 o'clock position after enucleation of the middle lobe. Mean age was 73 years, mean estimated prostate volume was 62.8 ml, mean estimated transition zone volume was 44.5 ml, mean International Prostate Symptom Score (IPSS) score was 15.5, mean quality of life (QOL) score was 4.1, peak flow rate (Qmax) was 8.6 ml/s, and mean residual urine volume was 42.4 ml. RESULTS: The mean operation time was 69 min, the mean weight of removed prostate tissue was 27.3 g, and the mean decrease in hemoglobin level was 1.8 g/dl. Three months after surgery, mean IPSS score was 5.9, mean QOL score was 1.9, mean Qmax was 28 ml/s, and mean residual urine volume was 1.0 ml, values which were significantly improved over pre-surgery data. No complications such as perforation or bladder injury occurred during surgery, but 1 case (4.7%) of stress urinary incontinence and 1 case (4.7%) of urethral stricture were reported after surgery. Of note, urethral stricture was determined using a flexible cytoscope at 1 week, 1 month, and 3 months post-surgery. CONCLUSION: Anteroposterior dissection TUEB can be conducted safely and may be useful in reducing frequency of urethral stricture post-surgery.

Biological half-life of radioactive cesium in Japanese rockfish Sebastes cheni contaminated by the Fukushima Daiichi nuclear power plant accident.

Since the Fukushima accident in March 2011 the concentration of radioactive cesium in Japanese rockfish (Sebastes cheni) has been decreasing slower than other fish species. The aim of this study was therefore to investigate the possibility of slow elimination rate (i.e., relatively longer Tb) as one of the reasons for the slow decrease in (137)Cs concentrations in Japanese rockfish (S. cheni). To do this, we reared twenty-three individuals of this species for a period of about 1 year, during which time we measured the (137)Cs concentrations and γ-ray spectra 14 times by using a high-efficiency NaI(Tl) scintillator. We then examined the relationship between the (137)Cs concentrations and the total length of each individual. We estimated the biological half-life (Tb, day) for each individual using the total number of (137)Cs counts in the energy region, and examined the effects of total length and (137)Cs concentration on Tb by generalized linear model (GLM). We also examined the effect of sex, total length, seawater temperature, and the (137)Cs concentration of seawater on temporal changes in the (137)Cs count reduction rate by GLM. There was no clear relationship between the corrected whole-body (137)Cs concentrations and the total length in females, however there was a significant positive correlation between these two variables in males. The difference between males and females may be attributable to variation in the degree of dilution because of variable growth of individuals, and suggests that the (137)Cs concentrations of small individuals may be greatly diluted because of faster growth. However, there was no significant difference in Tb between sexes. The mean Tb (±SD) in all individuals was 269 (±39) days; this Tb value is 2.7-5.4 times longer than past Tb values (marine fish: 50-100 days), and is thought to be one of the reasons for the slower decrease in (137)Cs concentrations in this species than other fish species on the coast of Fukushima. The GLM showed significant effects of both total length and (137)Cs concentration on Tb, which may reflect a reduction in the metabolic rate with increased body size (i.e., aging) and gradient of concentration against seawater. The GLM also showed a significant positive effect of seawater temperature on the reduction rate of the (137)Cs counts (D, day(-1)). Therefore, D was clearly related to seasonal variations in the temperature of seawater, and this relationship may be attributable to changes in the metabolic rate that are controlled by variations in the seawater temperature. From these measurements, we examined the processes that control reductions in (137)Cs radioactivity.

Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web.

Radioactive cesium ((134)Cs and (137)Cs) concentrations in invertebrates of benthic food web (10 taxonomic classes with 46 identified families) collected from wide areas off Fukushima Prefecture (3-500 m depth) were inspected from July 2011, four months after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, to August 2013 to elucidate time-series trends among taxa and areas. Cesium-137 was detected in seven classes (77% of 592 specimens). Higher (137)Cs concentrations within detected data were often found in areas near or south of the FDNPP, which is consistent with the reported spatial distribution of (137)Cs concentrations in highly contaminated seawater and sediments after the FDNPP accident. Overall (137)Cs concentrations in invertebrates, the maxima of which (290 Bq kg(-1)-wet in the sea urchin Glyptocidaris crenularis) were lower than in many demersal fishes, had decreased exponentially with time, and exhibited taxon-specific decreasing trends. Concentrations in Bivalvia and Gastropoda decreased clearly with respective ecological half-lives of 188 d and 102 d. In contrast, decreasing trends in Malacostraca and Polychaeta were more gradual, with longer respective ecological half-lives of 208 d and 487 d. Echinoidea showed no consistent trend, presumably because of effects of contaminated sediments taken into their digestive tract. Comparison of (137)Cs concentrations in the invertebrates and those in seawater and sediments suggest that contaminated sediments are the major source of continuing contamination in benthic invertebrates, especially in Malacostraca and Polychaeta.

Effects of the nuclear disaster on marine products in Fukushima.

After the release of huge amounts of radionuclides into the ocean from the devastated Fukushima Dai-ichi Nuclear Power Plant (FDNPP), safety concerns have arisen for marine products in Fukushima Prefecture. As of October 2012, we had inspected the radionuclide ((131)I, (134)Cs and (137)Cs) concentrations in 6462 specimens within 169 marine species collected off the coast of Fukushima Prefecture from April 2011. Only two species exceeded the Japanese provisional regulatory limit for (131)I (2000 Bq/kg-wet) immediately after the FDNPP accident. In 2011 and 2012, 63 and 41 species respectively exceeded the Japanese regulatory limit for radioactive Cs (100 Bq/kg-wet). The overall radioactive Cs concentrations of the total marine products have decreased significantly. However, the time-series trends of radioactive Cs concentrations have differed greatly among taxa, habitats (pelagic/demersal), and spatial distributions. Higher concentrations were observed in shallower waters south of the FDNPP. Radioactive Cs concentrations decreased quickly or were below detection limits in pelagic fishes and some invertebrates, and decreased constantly in seaweed, surf clams, and other organisms. However, in some coastal demersal fishes, the declining trend was much more gradual, and concentrations above the regulatory limit have been detected frequently, indicating continued uptake of radioactive Cs through the benthic food web. The main continuing source of radioactive Cs to the benthic food web is expected to be the radioactive Cs-containing detritus in sediment. Trial fishing operations for several selected species without radioactive Cs contamination were commenced in Soma area, 50 km north of the FDNPP, from June 2012. Long-term and careful monitoring of marine products in the waters off Fukushima Prefecture, especially around the FDNPP, is necessary to restart the coastal fishery reliably and to prevent harmful rumors in the future.

Expression and functional role of ß3 -adrenoceptors in the human ureter.

OBJECTIVES: To investigate the presence of ß-adrenoceptor subtypes in the human ureter, and to examine whether ß(3) -adrenoceptors modulate relaxation of the human ureter. METHODS: Expression of messenger ribonucleic acid of ß-adrenoceptors in the human ureter was determined by reverse transcription polymerase chain reaction, and distribution of ß-adrenoceptors was examined by immunohistochemistry. In functional studies, the relaxant effects of isoproterenol, procaterol, TRK-380, salbutamol and BRL 37344 on KCl-induced contraction of the human ureter were evaluated, and the inhibitory effects of isoproterenol, procaterol and TRK-380 on electrical field stimulation-induced contractions were determined. RESULTS: Expression of ß(1) -, ß(2) - and ß(3) -adrenoceptor messenger ribonucleic acid in the human ureter was confirmed by reverse transcription polymerase chain reaction. Positive staining for ß(1) -, ß(2) - and ß(3) -adrenoceptor was identified not only in smooth muscle, but also in the urothelium of the human ureter. All ß-adrenoceptor agonists decreased the tone of KCl-induced contractions of the human ureter with a rank order of relaxant effects of isoproterenol > procaterol > TRK-380 > salbutamol > BRL 37344. Furthermore, isoproterenol, procaterol and TRK-380 significantly decreased the amplitude of electrical field stimulation-induced contractions with a rank order of inhibitory effects of isoproterenol > procaterol > TRK-380. CONCLUSIONS: Human ureteral relaxation is mediated by both ß(2) - and ß(3) -adrenoceptor stimulation. ß(3) -Adrenoceptor agonists have the potential to relax the human ureter, and their clinical application in the treatment of ureteral stones is expected.

Characteristics of aggressive variants in T1a renal cell carcinoma.

PURPOSE: To explore factors associated with metastasis and prognosis in T1a renal cell carcinoma (RCC). METHODS: We retrospectively reviewed 451 cases of sporadic T1aRCC among 1,060 patients admitted to the Department of Urology at Hamamatsu University Hospital and affiliated hospitals between 1978 and 2007. Clinicopathological factors were analyzed for metastatic and prognostic risks. RESULTS: We identified 32 RCC patients with metastatic disease, 22 with synchronous and 10 with metachronous metastatic RCC. Patients with metastatic disease had a significantly higher incidence of symptomatic cancer, as well as greater tumor size, C-reactive protein (CRP) level, sarcomatoid component ratio, histological grade 3 and microvascular invasion than those without metastasis. Among the 32 patients with metastasis, there is no significant difference in clinicopathological factors. The most common site of metastasis was bone. Among patients with metastatic T1aRCC, findings at diagnosis of a symptomatic cancer, CRP level of 0.4 mg/dL or more, tumor size of 3.0 cm or greater, histological grade 3, a sarcomatoid component and microvascular invasion appeared to be significant and independent risk factors. Significant independent risk factors with metachronous metastatic RCC were a symptomatic cancer and a sarcomatoid component at diagnosis. A CRP level of 0.4 mg/dL or more was also an independent prognostic factor for overall survival. CONCLUSION: RCC patients with findings at diagnosis of a symptomatic cancer, a sarcomatoid component and CRP level of 0.4 mg/dL or more require intensive follow-up.

Analyses in transfected cells and in vitro of a putative peroxisomal targeting signal of rat liver serine:pyruvate aminotransferase.

Serine:pyruvate aminotransferase (SPT; EC 2.6.1.51) of rat liver is a unique enzyme in that it is located in both mitochondria and peroxisomes. To analyze a peroxisomal targeting signal (PTS) of SPT, we constructed in this study various peroxisomal SPT clones having mutations at the C-terminal 20-amino acid region in which a putative PTS is located, and we examined subcellular localization of mutated products expressed in transfected COS-1 cells. When the mutant SPTs were unstable in transfected COS-1 cells, their translocation into peroxisomes was examined using an in vitro peroxisomal import system. Deletion of the C-terminal tripeptide, NKL, and amino acid substitution of K2 (the second lysine from the C-terminus), K4, or E15 abolished or impaired the peroxisomal import of the translated product, resulting in cytosolic accumulation in the cell. In the cases of mutation of R18G, D19A, or K2Q and the conversion to proline of L9, L13, V17, or A20, no products were detected in transfected cells. However, the results of an in vitro peroxisomal import experiment showed that the mutation of L9P, L13P, V17P, and A20P caused loss of the PTS function. When serine was introduced instead of N3 to generate a typical PTS1, the SKL motif, at the C-terminus, all of the proteins having mutations at P5, E11, R12, or E15 showed extensive localization in peroxisomes. These results suggest that the putative C-terminal PTS of SPT is not equivalent to the typical PTS1 shown in acyl-CoA oxidase and urate oxidase, because the PTS of SPT is not restricted to the C-terminal tripeptide. The results also suggest that the alpha-helical structure of the C-terminal region of SPT is important for the stable conformation of the enzyme and the peroxisomal targeting function of its PTS.