Size-classified aerosol-bound heavy metals and their effects on human health risks in industrial and remote areas in Japan

Airborne aerosols were collected in six size classes (PM<0.1, PM0.1-0.5, PM0.5-1, PM1-2.5, PM2.5-10 and PM>10) to investigate aerosol health risks in remote and industrial areas in Japan. We focused on heavy metals and their water-dispersed fractions. The average concentration of heavy metals was 18 ± 25-86 ± 48 ngm-3 for PM<0.1, 46 ± 19-154 ± 80 for PM0.5-1 ngm-3, 98 ± 49-422 ± 186 ngm-3 for PM1-2.5, 321 ± 305-1288 ± 727 ngm-3 for PM2.5-10 and 65 ± 52-914 ± 339 ngm-3 or PM>10, and these concentrations were higher in industrial areas. Heavy metals emitted from domestic anthropogenic sources were added to the long-range transport component of the aerosols. The water-dispersed fraction of heavy metals contained 3.3-40.1% of the total heavy metals in each size class. The relative contribution of Zn and other species (As, Cd, Cr, Ni, Pb, Mn, V and Cu) increased in the water-dispersed fraction. Smaller particles contained greater proportions of the water-dispersed heavy metal fraction. Carcinogenic risk (CR) and the hazard index (HI) were estimated for each size class. The CR of carcinogens was at acceptable levels (<1 ×10-6) for five particle size fractions. The HI values for carcinogens and noncarcinogens were also below acceptable levels (<1) for the same five size fractions. The estimated CR and HI values were dominated by contributions from the inhalation process.

Copper in airborne fine particulate matter (PM2.5) from urban sites causes the upregulation of pro-inflammatory cytokine IL-8 in human lung epithelial A549 cells

Fine atmospheric particles, such as PM2.5, are strongly related to the onset and exacerbation of inflammatory responses leading to the development of respiratory and cardiovascular diseases. PM2.5 is a complex mixture of tiny particles with different properties (i.e., size, morphology, and chemical components). Moreover, the mechanism by which PM2.5 induces inflammatory responses has not been fully elucidated. Therefore, it is necessary to determine the composition of PM2.5 to identify the main factors causing PM2.5-associated inflammation and diseases. In the present study, we investigated PM2.5 from two sites (Fukue, a remote monitoring site, and Kawasaki, an urban monitoring site) with greatly different environments and PM2.5 compositions. The results of ICP-MS and EDX-SEM indicated that PM2.5 from Kawasaki contained more metals and significantly induced the expression of the pro-inflammatory cytokine gene IL-8 compared to the PM2.5 from Fukue. We also verified the increased secretion of IL-8 protein from exposure to PM2.5 from Kawasaki. We further investigated their effects on inflammatory response and cytotoxicity using metal nanoparticles (Cu, Zn, and Ni) and ions and found that the Cu nanoparticles caused a dose-dependent increase in IL-8 expression together with significant cell death. We also found that Cu nanoparticles enhanced the secretion of IL-8 protein. These results suggest that Cu in PM2.5 is involved in lung inflammation.

Benzo[a]pyrene induces NLRP1 expression and promotes prolonged inflammasome signaling

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon in the air, triggers pulmonary inflammation. This study focused on BaP-induced inflammation in the alveolar epithelium. A549 cells were stimulated with BaP for four days. BaP treatment markedly increased NLRP1 expression but slightly decreased NLRP3. Furthermore, aryl hydrocarbon receptor (AhR) knockdown displayed no increase in BaP-induced NLRP1 expression. Similar results were also observed by blocking reactive oxygen species (ROS), which is mediated through AhR, suggesting that the AhR-ROS axis operates in BaP-induced NLRP1 expression. p53 involvement in ROS-mediated NLRP1 induction has also been implied. When we confirmed inflammasome activation in cells treated with BaP for four days, while BaP transiently activated NLRP3, it predominantly activated the NLRP1 inflammasome. These findings have led to the conclusion that BaP could be a potential ligand for the NLRP1 inflammasome persistently observed in the lung epithelium. Our study may provide additional evidence for the sustained pulmonary inflammation caused by environmental air pollution.

Origin of surface water in the Southern Ocean: Implications of soluble radionuclide distributions

Concentration data of soluble radionuclides in the southern South Indian Ocean and Southern Ocean transition zone are rare or insufficient for the study of its current system. We examined the lateral surface variations in soluble natural (²²⁶Ra and ²²⁸Ra) and anthropogenic (¹³⁴Cs and ¹³⁷Cs) radionuclide activity concentrations in the surface waters in this area from November 2021 to March 2022. The surface distributions of ²²⁶Ra and ¹³⁷Cs concentrations were classified into Subantarctic Mode Water-, Antarctic Intermediate Water-, and Upper Circumpolar Deep Water (UCDW)-dominated areas along latitudinal band (40°S-65°S, 110°E-120°E). Notably, the highest ²²⁶Ra concentrations occurred along the longitudinal band (60°S-65°S, 40°E-120°E). Significantly lower ¹³⁷Cs concentrations in the Southern Ocean than those in surface waters in other global oceans were observed along with depletion of ²²⁸Ra. Additionally, ²²⁶Ra and ¹³⁷Cs concentrations appeared to show small variations between eastern and western areas (2.5-3.0 mBq/L and 0.06-0.03 mBq/L, respectively). Lateral profiles in the Southern Ocean are governed by a large contribution from deep/old waters (e.g., UCDW), with a small effect from southward transport of Subantarctic Mode Water.

Calculating source contributions to urban atmospheric polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons using 1-nitropyrene and pyrene: An application to an Asian dust event

A method to calculate source contributions to atmospheric polycyclic aromatic hydrocarbons (PAHs) and their nitrated congeners (NPAHs) is proposed, using pyrene (Pyr) and 1-nitropyrene (1-NP), as respective representatives of PAHs and NPAHs. This is based on the known increases in NPAH to PAH ratios as combustion temperatures increase. The fractions of 1-NP and Pyr from high temperature combustion sources in total 1-NP and Pyr are respectively calculated as a (0 < a <1) and b (0 < b < 1). By using atmospheric concentrations of Pyr and 1-NP obtained at monitoring sites, contributions of high and low temperature combustion sources were calculated. Using this method, the contributions of automobiles and coal combustion facilities/industries to atmospheric Pyr and 1-NP concentrations were calculated for atmospheric samples collected in Kanazawa, Japan during a seasonal Asian dust event. The results show that Pyr was almost entirely emitted from industries in China and transported long-range to Japan. By contrast, 1-NP was emitted primarily from automobiles in Kanazawa and its surrounding areas, with a small amount of 1-NP possibly transported from China. The proposed method can provide greater clarity on source identification compared to the typically used PAH isomer pairs.

Ki67 expression at Kasai portoenterostomy as a prognostic factor in patients with biliary atresia

Background

Biliary atresia is a rare paediatric biliary obliteration disease with unknown aetiology, and is the most common indication for paediatric liver transplantation (LT). However, no consensus for predicting Kasai portoenterostomy (KP) outcomes using liver histological findings exists. Ki67 is a popular biomarker for measuring and monitoring cellular proliferation.

Methods

Ki67 (clone, MIB‐1) liver parenchyma expression was measured by immunohistochemical staining of samples from living donors and patients with biliary atresia to assess its value in predicting outcomes after KP.

Results

Of 35 children with biliary atresia, 13 were native liver survivors (NLS), 17 were non‐NLS, and five had primary LT. The median proportion of Ki67 immunostained areas in donors and patients with biliary atresia at KP was 0·06 and 0·99 per cent respectively. Univariable analysis identified a high proportion of Ki67 areas, high Ki67 cell numbers and high Ki67‐positive/leucocyte common antigen‐positive cell numbers at KP as significant predictors of poor native liver survival after KP (hazard ratio 9·29, 3·37 and 12·17 respectively). The proportion of Ki67 areas in the non‐NLS group was significantly higher than that in the NLS group (1·29 versus 0·72 per cent respectively; P = 0·001), and then decreased at LT (0·32 per cent versus 1·29 per cent at KP; P < 0·001).

Conclusion

This study has demonstrated the clinical data and time course of Ki67 expression in patients with biliary atresia. High Ki67 expression at KP may be an important predictor of native liver survival following the procedure.

Mass balance and latest fluxes of radiocesium derived from the fukushima accident in the western North Pacific Ocean and coastal regions of Japan

This article summarizes and discusses mass balance calculations of the activities of Fukushima-derived ¹³⁷Cs released to the atmosphere and ocean prior to 2018 as well as the ¹³⁷Cs inventories on land and in the ocean, biota, and sediment. We propose that the consensus value of the total amount of ¹³⁷Cs released to the atmosphere was 15-21 PBq; atmospheric deposition of ¹³⁷Cs on land was 3-6 PBq; atmospheric deposition of ¹³⁷Cs on the North Pacific was 12-15 PBq; and direct discharge of ¹³⁷Cs to the ocean was 3-6 PBq. We also evaluated the movement of ¹³⁷Cs from one domain to another for several years after the accident. We calculated that the amount of ¹³⁷Cs transported by rivers might be 40 TBq. The annual deposition of ¹³⁷Cs due to resuspension at Okuma during the period 2014-2018 was 4-10 TBq year^-1. The ¹³⁷Cs discharged to the ocean was 0.73-1.0 TBq year^-1 in 2016-2018. The integrated amount of FNPP1-derived ¹³⁷Cs that entered the Sea of Japan from the Pacific Ocean from 2011 until 2017 was 270 ± 20 TBq, 6.4% of the estimated amount of FNPP1-derived ¹³⁷Cs in Subtropical Mode Water in the North Pacific. The integrated amount of FNPP1-derived ¹³⁷Cs that returned to the North Pacific Ocean through the Tsugaru Strait from the Sea of Japan was 110 ± 10 TBq. Decontamination efforts removed 134 TBq of ¹³⁷Cs from surface soil prior to February 2019, an amount that corresponded to 4% of the¹³⁷Cs deposited on land in Japan.

Estimating transboundary transported anthropogenic sulfate deposition in Japan using the sulfur isotopic ratio

High emissions of air pollutants from Northeast Asia are strongly influenced by air quality as well as by ecosystems. This study investigated the spatiotemporal variations in the sulfur isotopic ratio (δ³⁴S) in atmospheric deposition at eleven monitoring stations in Japan from 2011 to 2016 and estimated the amount of transboundary transported anthropogenic sulfate (TRB) deposition using mass balance calculations. The δ³⁴S of sulfate in precipitation ranged from -0.42 to +22.7‰. Sea salt (SS), TRB, and domestic anthropogenic sources (DOM) were the dominant sources of sulfate deposition in Japan. TRB sulfate deposition was largest on the Sea of Japan side, with an annual average value of 1.5 ± 0.3-6.9 ± 0.5 mg m^-2 d^-1 (36-44%), followed by Mt. Happo (4.5 ± 0.1 mg m^-2 d^-1; 88%), the Pacific Ocean side (1.5 ± 0.8, 4.3 ± 0.9 mg m^-2 d^-1; 24-50%), and the remote islands in the North Pacific Ocean (1.1 ± 0.2, 2.0 ± 0.8 mg m^-2 d^-1; 19-32%). TRB sulfate deposition on the Sea of Japan side was 2-12 times higher in winter and 1-2 times higher in summer than that of DOM. In contrast, TRB sulfate deposition on the Pacific Ocean side was 1.5-3 times higher in summer than in winter due to high precipitation levels. In Tokyo, the annual contribution from DOM sulfate deposition is approximately three times higher than that from TRB. Annual TRB sulfate deposition is lowest at Ogasawara at 1.1 ± 0.2 mg m^-2 d^-1, and the annual oceanic DMS contribution to sulfate deposition is high, accounting for 1.3 mg m^-2 d^-1 (20 ± 6%). The contribution of Asian dust was estimated to be 1-5.2 mg m^-2 d^-1(3-6%), which occurred in a single Asian dust event on the Sea of Japan side.

Estimate of Fukushima-derived radiocaesium in the North Pacific Ocean in summer 2012

Distributions of radiocaesium (134Cs and 137Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-134Cs and mass balance analysis as the first approach. The inventory of the 134Cs in the surface layer in the North Pacific Ocean in August-December 2012 was estimated at 5.1 ± 0.9 PBq on 1 October 2012, which corresponds to 8.6 ± 1.5 PBq when it was decay corrected to the date of the FNPP1 accident, 11 March 2011. It was revealed that 56 ± 10% of the released 134Cs into the North Pacific Ocean, which was estimated at 15.3 ± 2.6 PBq, transported eastward in the surface layer in 2012. The amount of 134Cs subducted in the CMW was estimated to be 2.5 ± 0.9 PBq based on the mass balance among the three domains of the surface layer, subtropical mode water, and CMW.

Radiocaesium derived from the TEPCO Fukushima accident in the North Pacific Ocean: Surface transport processes until 2017

We report temporal variations of ¹³⁷Cs activity concentrations in surface waters of six regions of the western and central North Pacific Ocean during 2011-2017 using a combination of 1264 previously published data and 42 new data. In the western and central North Pacific Ocean at latitudes of 30-42°N and longitudes of 140°E to 160°W, eastward transport of radiocaesium was clearly apparent. ¹³⁷Cs activity concentrations in surface water decreased rapidly to ∼2-3 Bq m^-3 in 2015/2016, still a bit higher than ¹³⁷Cs activity concentrations before the FNPP1 accident (1.5-2 Bq m^-3). ¹³⁴Cs/¹³⁷Cs activity ratios decay-corrected to 11 March 2011 were ∼0.5-0.8. To the south of 30°N and between 130°E and 160°W in the western and central Pacific Ocean, ¹³⁷Cs activity concentrations were around 1-7 Bq m^-3 in 2011/2012 but then stabilized at a few Bq m^-3 up to 2017.¹³⁴Cs activity concentrations were detected at levels of 0.1-0.9 Bq m^-3, and ¹³⁴Cs/¹³⁷Cs activity ratios decay-corrected to 11 March 2011 were ∼0.3-0.5. Temporal variations of model-simulated ¹³⁷Cs activity concentrations in surface water in the region of interest showed good agreement with observations, except in the southwestern North Pacific Ocean.

Living Donor Liver Transplantation for Progressive Familial Intrahepatic Cholestasis Type 1: Two Reported Cases

BACKGROUND

Progressive familial intrahepatic cholestasis type 1 (PFIC1) is an inherited disease characterized by cholestatic features. We report two patients with PFIC1 who underwent liver retransplantation.

CASE REPORT

One patient was a 3-year-old female who underwent liver transplantation for PFIC1. She presented with severe diarrhea and fatty liver, and went into liver failure. She therefore underwent liver retransplantation and external biliary diversion 8 years after the initial liver transplantation. The explanted liver was histologically diagnosed with chronic rejection. Her intractable diarrhea stopped after the retransplantation. She was diagnosed with a fatty liver 8 months after the retransplantation and died 4 years after retransplantation due to bleeding from an ileostomy. The other patient was a 3-year-old male. This patient underwent liver retransplantation due to liver cirrhosis caused by steatohepatitis 9 years after the initial liver transplantation. The biliary tract was not diverted. He also experienced severe diarrhea after the retransplantation and requires home parenteral nutrition due to an eating disorder.

CONCLUSIONS

Liver transplantation is the only treatment to resolve life-threatening issues due to PFIC1, but requires further improvement as a therapeutic modality.

Source-Receptor Relationship Analysis of the Atmospheric Deposition of PAHs Subject to Long-Range Transport in Northeast Asia

The source-receptor relationship analysis of PAH deposition in Northeast Asia was investigated using an Eulerian regional-scale aerosol chemical transport model. Dry deposition (DD) of PAH was controlled by wind flow patterns, whereas wet deposition (WD) depended on precipitation in addition to wind flow patterns. The contribution of WD was approximately 50-90% of the total deposition, except during winter in Northern China (NCHN) and Eastern Russia (ERUS) because of the low amount of precipitation. The amount of PAH deposition showed clear seasonal variation and was high in winter and low in summer in downwind (South Korea, Japan) and oceanic-receptor regions. In the downwind region, the contributions from NCHN (WD 28-52%; DD 54-55%) and Central China (CCHN) (WD 43-65%; DD 33-38%) were large in winter, whereas self-contributions (WD 20-51%; DD 79-81%) were relatively high in summer. In the oceanic-receptor region, the deposition amount decreased with distance from the Asian continent. The amount of DD was strongly influenced by emissions from neighboring domains. The contributions of WD from NCHN (16-20%) and CCHN (28-35%) were large. The large contributions from China in summer to the downwind region were linked to vertical transport of PAHs over the Asian continent associated with convection.

Transboundary transport of anthropogenic sulfur in PM2.5 at a coastal site in the Sea of Japan as studied by sulfur isotopic ratio measurement

Sulfur isotopic ratios (δ(34)S) in size separated aerosol particles (PM2.5 and coarse particles) were measured at Niigata-Maki facing the Sea of Japan. Non-sea salt δ(34)S (δ(34)Snss) in PM2.5 showed seasonal variations with relatively high values in winter (1.0-3.9‰ in spring, 2.8-4.5‰ in summer, 1.3-4.5‰ in autumn, 3.7-5.7‰ in winter). Taking into consideration air mass transport routes, δ(34)Snss in the air masses which originated in the Asian continent and were transported over the Sea of Japan to the monitoring sites were higher than those values for air masses which were transported over the Japanese islands after leaving the Asian continent for each season. Considering that the δ(34)Snss in sulfuric acid derived from domestic emissions in Japan are lower than those of δ(34)Snss in coal, the lower δ(34)Snss for the air mass transported over the Japanese islands suggest that sulfuric acid in PM2.5 modified the δ(34)Snss due to aerosol mixing with sulfuric acid in Japan. Material balance calculations suggested that the relative contribution of transboundary transport in winter was also higher than for other seasons (40-75% in spring, 51-63% in summer, 45-73% in autumn, and 53-81% in winter). In particular, the contribution to the air masses which were transported directly from the Asian continent was relatively large (75% in spring, 59% in autumn, 78% in winter) in comparison with that for the air masses which were transported over Japan.

Spatial and temporal distributions of (134)Cs and (137)Cs derived from the TEPCO Fukushima Daiichi Nuclear Power Plant accident in the North Pacific Ocean by using optimal interpolation analysis

Optimal interpolation (OI) analysis was used to investigate the oceanic distributions of (134)Cs and (137)Cs released from the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant (FNPP1) accident. From the end of March to early April 2011, extremely high activities were observed in the coastal surface seawater near the FNPP1. The high activities spread to a region near 165°E in the western North Pacific Ocean, with a latitudinal center of 40°N. Atmospheric deposition also caused high activities in the region between 180° and 130°W in the North Pacific Ocean. The inventory of FNPP1-released (134)Cs in the North Pacific Ocean was estimated to be 15.3 ± 2.6 PBq. About half of this activity (8.4 ± 2.6 PBq) was found in the coastal region near the FNPP1. After 6 April 2011, when major direct releases ceased, the FNPP1-released (134)Cs in the coastal region decreased exponentially with an apparent half-time of about 4.2 ± 0.5 days and declined to about 2 ± 0.4 PBq by the middle of May 2011. Taking into account that the (134)Cs/(137)Cs activity ratio was about 1 just after release and was extremely uniform during the first month after the accident, the amount of (137)Cs released by the FNPP1 accident increased the North Pacific inventory of (137)Cs due to bomb testing during the 1950s and early 1960s by 20%.

LPA signaling initiates schizophrenia-like brain and behavioral changes in a mouse model of prenatal brain hemorrhage

Genetic, environmental and neurodevelopmental factors are thought to underlie the onset of neuropsychiatric disorders such as schizophrenia. How these risk factors collectively contribute to pathology is unclear. Here, we present a mouse model of prenatal intracerebral hemorrhage--an identified risk factor for schizophrenia--using a serum-exposure paradigm. This model exhibits behavioral, neurochemical and schizophrenia-related gene expression alterations in adult females. Behavioral alterations in amphetamine-induced locomotion, prepulse inhibition, thigmotaxis and social interaction--in addition to increases in tyrosine hydroxylase-positive dopaminergic cells in the substantia nigra and ventral tegmental area and decreases in parvalbumin-positive cells in the prefrontal cortex--were induced upon prenatal serum exposure. Lysophosphatidic acid (LPA), a lipid component of serum, was identified as a key molecular initiator of schizophrenia-like sequelae induced by serum. Prenatal exposure to LPA alone phenocopied many of the schizophrenia-like alterations seen in the serum model, whereas pretreatment with an antagonist against the LPA receptor subtype LPA1 prevented many of the behavioral and neurochemical alterations. In addition, both prenatal serum and LPA exposure altered the expression of many genes and pathways related to schizophrenia, including the expression of Grin2b, Slc17a7 and Grid1. These findings demonstrate that aberrant LPA receptor signaling associated with fetal brain hemorrhage may contribute to the development of some neuropsychiatric disorders.

Source contribution analysis of surface particulate polycyclic aromatic hydrocarbon concentrations in northeastern Asia by source-receptor relationships

We analyzed the source-receptor relationships for particulate polycyclic aromatic hydrocarbon (PAH) concentrations in northeastern Asia using an aerosol chemical transport model. The model successfully simulated the observed concentrations. In Beijing (China) benzo[a]pyren (BaP) concentrations are due to emissions from its own domain. In Noto, Oki and Tsushima (Japan), transboundary transport from northern China (>40 °N, 40-60%) and central China (30-40 °N, 10-40%) largely influences BaP concentrations from winter to spring, whereas the relative contribution from central China is dominant (90%) in Hedo. In the summer, the contribution from Japanese domestic sources increases (40-80%) at the 4 sites. Contributions from Japan and Russia are additional source of BaP over the northwestern Pacific Ocean in summer. The contribution rates for the concentrations from each domain are different among PAH species depending on their particulate phase oxidation rates. Reaction with O3 on particulate surfaces may be an important component of the PAH oxidation processes.

Long-term outcomes of pediatric living donor liver transplantation in Japan: an analysis of more than 2200 cases listed in the registry of the Japanese Liver Transplantation Society

The Japanese Liver Transplantation Society (JLTS) was established in 1980 in order to characterize and follow trends in patient characteristics and graft survival among all liver transplant patients in Japan. This study analyzed the comprehensive factors that may influence the outcomes of pediatric patients who undergo living donor liver transplantation (LDLT) by evaluating the largest cohort in the world. Between November 1989 and December 2010, 2224 pediatric patients underwent LDLT in Japan. There were 998 male (44.9%) and 1226 female donors (55.1%) without donor mortalities related to transplant surgery. There were 946 male (42.5%) and 1278 female (57.5%) recipients with a median age of 4.0 years (range: 13 days to 17.9 years). Cholestatic liver disease was the leading indication for LDLT (n = 1649; 76.2%), followed by metabolic disorders (n = 194; 8.7%), acute liver failure (n = 192; 8.6%) and neoplastic liver disease (n = 66; 3.0%). The 1-, 5-, 10- and 20-year patient survival rates were 88.3%, 85.4%, 82.8% and 79.6%, respectively. Blood-type incompatibility, recipient age, etiology of liver disease and transplant era were found to be significant predictors of overall survival. We are able to achieve satisfactory long-term pediatric patient survival outcomes in the JLTS series without compromising the living donors.

Optimum interpolation analysis of basin-scale ¹³⁷Cs transport in surface seawater in the North Pacific Ocean

¹³⁷Cs is one of the conservative tracers applied to the study of oceanic circulation processes on decadal time scales. To investigate the spatial distribution and the temporal variation of ¹³⁷Cs concentrations in surface seawater in the North Pacific Ocean after 1957, a technique for optimum interpolation (OI) was applied to understand the behaviour of ¹³⁷Cs that revealed the basin-scale circulation of Cs ¹³⁷Cs in surface seawater in the North Pacific Ocean: ¹³⁷Cs deposited in the western North Pacific Ocean from global fallout (late 1950s and early 1960s) and from local fallout (transported from the Bikini and Enewetak Atolls during the late 1950s) was further transported eastward with the Kuroshio and North Pacific Currents within several years of deposition and was accumulated in the eastern North Pacific Ocean until 1967. Subsequently, ¹³⁷Cs concentrations in the eastern North Pacific Ocean decreased due to southward transport. Less radioactively contaminated seawater was also transported northward, upstream of the North Equatorial Current in the western North Pacific Ocean in the 1970s, indicating seawater re-circulation in the North Pacific Gyre.

Emission and atmospheric transport of particulate PAHs in Northeast Asia

The emission, concentration levels, and transboundary transport of particulate polycyclic aromatic hydrocarbons (PAHs) in Northeast Asia were investigated using particulate PAH measurements, the newly developed emission inventory (Regional Emission inventory in ASia for Persistent Organic Pollutants version, REAS-POP), and the chemical transport model (Regional Air Quality Model ver2 for POPs version, RAQM2-POP). The simulated concentrations of the nine particulate PAHs agreed well with the measured concentrations, and the results firmly established the efficacy of REAS/RAQM2-POP. It was found that the PAH concentrations in Beijing (China, source region), which were emitted predominantly from domestic coal, domestic biofuel, and other transformations of coal (including coke production), were approximately 2 orders of magnitude greater than those monitored at Noto (Japan, leeward region). In Noto, the PAH concentrations showed seasonal variations; the PAH concentrations were high from winter to spring due to contributions from domestic coal, domestic biofuel, and other transformations of coal, and low in summer. In summer, these contribution were decrease, instead, other sources, such as the on-road mobile source, were relatively increased compared with those in winter. These seasonal variations were due to seasonal variations in emissions from China, as well as transboundary transport across the Asian continent associated with meteorological conditions.

Depositional behaviors of plutonium and thorium isotopes at Tsukuba and Mt. Haruna in Japan indicate the sources of atmospheric dust

Monthly plutonium and thorium depositions at Tsukuba (28m asl) and Mt. Haruna (1370m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly (239,240)Pu depositions ranged from 0.044 to 2.67mBq m(-2) at Tsukuba and from 0.05 to 0.9mBq m(-2) at Mt. Haruna during the measurement periods. Monthly (239,240)Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly (239,240)Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. (230)Th/(232)Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total (239,240)Pu and Th deposits are derived from remote sources, especially in spring.

Return period of enhanced gamma ray dose rates: regional differences observed in Japan

We estimated the return period of an increased gamma ray dose rate (Delta gamma) derived from (222)Rn progeny deposited with precipitation. The approximate probability distribution for Delta gamma followed a Hazen plot, which is an empirical plotting equation, indicating that the distribution of Delta gamma was approximated by a nearly double-exponential. The distribution of Delta gamma was well represented by the Gumbel distribution, and the return period for Delta gamma was estimated theoretically. There was a notable regional difference in the return period between the coast of the Japan Sea and the inland or Pacific coast areas: the return period for a given Delta gamma at monitoring sites on the Sea of Japan coast was 1.5 to 2.5 times shorter than that in the inland or Pacific coast areas. This variation with locality suggests that the rate of wet-deposition of (222)Rn progeny is larger at sites on the Sea of Japan coast than inland or on the Pacific coast areas. The expected return period for the maximum Delta gamma at each site was about 10 years. This estimation of the return period of Delta gamma is a novel approach to the study of environmental science in fields such as radioactivity.

Trans-Tenon's retrobulbar triamcinolone acetonide injection for macular oedema related to branch retinal vein occlusion

BACKGROUND

The aim of the study was to evaluate the safety and effectiveness of trans-Tenon's retrobulbar triamcinolone acetonide (TA) injection for macular oedema associated with branch retinal vein occlusion (BRVO).

METHODS

We reviewed the medical records of 50 consecutive patients with macular oedema associated with BRVO who were treated with trans-Tenon's retrobulbar TA injection (20 mg) as initial treatment for a follow-up period of at least 12 months. Foveal thickness determined by optical coherence tomography, visual acuity, intraocular pressure (IOP) and cataract progression were measured.

RESULTS

The mean duration between oedema onset and TA injection was 4.9 months. Foveal thickness decreased significantly at 3 months after injection (p<0.0001). Furthermore, the percentage reduction in foveal thickness in eyes with posterior vitreous detachment (PVD; n = 23) was significantly greater than that without PVD (n = 27, p = 0.003). Improved visual acuity by at least 0.20 log minimum angle of resolution (logMAR) was seen in 22 eyes (44%; 11 eyes with PVD and 11 eyes without PVD). After completion of the 3-month follow-up, 29 eyes (58%) needed additional treatment including TA injections or pars plana vitrectomy (PPV). PPV seemed to be effective for macular oedema resistant to TA. IOP elevation and cataract progression occurred in less than 10% of all patients.

CONCLUSIONS

Trans-Tenon's retrobulbar TA injection appeared safe and relatively effective for macular oedema associated with BRVO. In eyes resistant to TA injection, PPV may be effective as an adjunctive treatment.

The prevalence of Helicobacter pylori infection and the status of gastric acid secretion in patients with gastroesophageal junction adenocarcinoma in Japan

We have previously reported that H. pylori infection prevents reflux esophagitis (RE) and Barrett's esophagus (BE) by decreasing gastric acid secretion. Gastroesophageal (GE) junction adenocarcinoma, including Barrett's adenocarcinoma, has been thought to be a complication of gastroesophageal reflux disease. However, the relationship between H. pylori infection, gastric acid secretion and GE junction adenocarcinoma had not yet been investigated in Japan. We demonstrated that the status of gastric acid secretion was higher in patients with GE junction adenocarcinoma than in patients with early gastric cancer (EGC), and that the level was the same in patients with RE and those with BE. We also found that the prevalence of H. pylori infection in patients with GE junction adenocarcinoma was significantly lower than that in patients with EGC, although not as low as that in patients with RE and BE, suggesting that preservation of gastric acid secretion may be important for the development of GE junction adenocarcinoma in Japanese people, regardless of the presence of H. pylori infection.

Whole-liver graft without the retrohepatic inferior vena cava for sequential (domino) living donor liver transplantation

Grafts used in Domino liver transplantation (LT) obtained from living donor liver transplantation (LDLT) for familial amyloid polyneuropathy (FAP) patients have been mainly used as reduced grafts. Because of small-for-size problems seen in LDLT, using whole liver grafts could improve post-LT outcome. Eight consecutive Domino LDLT using whole livers without retrohepatic inferior vena cava (IVC) from FAP patients were retrospectively analyzed. The graft weight/recipient's body weight ratio (GWRW) in the domino recipients ranged from 1.28% to 2.4% (mean: 1.52). Multiple vascular reconstructions in the whole-liver domino LT resulted in longer than usual warm ischemia time (mean: 64 min); however immediate post-operative recovery of hepatic function was uneventful. At 8-40 months after the transplant, all the FAP patients are well and all of the domino recipients are alive. Domino LT using a whole FAP liver from a LDLT for a FAP patient presents satisfactory results, even though the transplant procedure is technically complicated.

Iatrogenic amyloid neuropathy in a Japanese patient after sequential liver transplantation

A 57-year-old woman in Japan, the first recipient of part of a liver from a 58-year-old man with familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin Val30Met who had had sensorimotor polyneuropathy in the lower limbs for 3 years, started to develop sensory neuropathy 7 years after transplantation. Before the July 1998 sequential transplantation, she had been in a hepatic coma at the terminal stage of primary biliary cirrhosis and waiting for deceased donor liver transplantation. In September 2004, biopsy samples of her duodenum first showed amyloid deposition. Although biopsy materials in 2005 and 2006 showed no changes in amyloid deposition, decreased temperature sensation and pain in fingertips and toes were detected at a neurologic examination in March 2006. Thus, clinical symptoms of FAP appeared about 2 years after amyloid deposition started. Nerve conduction velocity studies revealed mild to moderate axonal sensory polyneuropathy without demyelination. Our findings confirmed iatrogenic sensory neuropathy induced by amyloid deposition 7 years after sequential liver transplantation.

Long-term outcome of adult-to-adult living donor liver transplantation for post-Kasai biliary atresia

Our objective was to analyze problems in the perioperative management and long-term outcome of living donor liver transplantation (LDLT) for biliary atresia (BA). Many reports have described the effectiveness of liver transplantation (LT) for BA, particularly in pediatric cases, but little information is available regarding LT in adults (> or =16 years old). Between June 1990 and December 2004, 464 patients with BA underwent LDLT at Kyoto University Hospital, of whom 47 (10.1%) were older than 16 years. In this study, we compared the outcomes between adult (> or =16 years old) and pediatric (<16 years old) patients. The incidence of post-transplant intestinal perforation, intra-abdominal bleeding necessitating repeat laparotomy and biliary leakage was significantly higher (p < 0.0001, <0.001 and <0.001, respectively) in adults. Overall cumulative 1-, 5- and 10-year survival rates in pediatric patients were significantly higher (p < 0.005) than in adults. Two independent prognostic determinants of survival were identified: a MELD score over 20 and post-transplant complications requiring repeat laparotomy. Outcome of LDLT in adult BA patients was poorer than in pediatric patients. It seems likely that LT will be the radical treatment of choice for BA and that LDLT should be considered proactively at the earliest possible stage.

Clinical characteristics and the prognosis of rhabdomyosarcoma - a report from the Study Group for Pediatric Solid Malignant Tumors in the Kyushu Area, Japan

AIM

There have been no nationwide group studies for patients with rhabdomyosarcoma in Japan. This study aims to assess the actual state of treatments and their outcome.

PATIENTS AND METHODS

From 1982 to 1996, 79 rhabdomyosarcomas were registered by the Study Group for Pediatric Solid Malignant Tumors in the Kyushu Area. The prognostic factors and treatments were assessed based on the 5-year survival rate. The staging was done according to the Intergroup Rhabdomyosarcoma Study (IRS) Clinical Grouping Classification.

RESULTS

The 5-year survival rate for all patients was 39.1 %. The survival rates for each factor were as follows, according to 1) group; 77.8 % for Group I, 51.9 % for Group II, 33.7 % for Group III, and 20.2 % for Group IV; 2) primary site: 56.3 % for the head and neck, 43.8 % for the parameningeal region, 12.5 % for the extremity, 58.3 % for the genitourinary region, and 30.5 % for the others; 3) histology: 35.8 % for the embryonal type, 36.8 % for the alveolar type.

CONCLUSIONS

Altogether, the outcome of this study was poor. To improve outcomes, a new nationwide group study for rhabdomyosarcoma, which we belong to, has just started in Japan.

Improved survival outcome for hepatoblastoma based on an optimal chemotherapeutic regimen--a report from the study group for pediatric solid malignant tumors in the Kyushu area

BACKGROUND/PURPOSE

The survival outcome for patients with hepatoblastoma normally depends on the resectability of the tumor. In Japan, the pre and/or postoperative chemotherapy protocol using a combination of cisplatin (CDDP) and tetrahydropyranyl-Adriamycin (THP-ADR) has been the standard treatment since 1991. This study aims to assess exactly what influence the establishment of this chemotherapy protocol has had on both the tumor resectability and the outcome of patients with hepatoblastoma.

METHODS

From 1982 to 1997, 60 patients with hepatoblatoma were treated in the Kyushu area, Japan. Based on the pretreatment extent of disease (PRETEXT), the outcome and tumor resectability were compared between group A (1982 to 1990, n = 27, PRETEXT I:5, II:8, III:6, IV:8) and group B (1991 to 1997, n = 33, PRETEXT I:9, II:9, III:5, IV:10).

RESULTS

The 5-year survival rates (group A and group B) were 33% and 73% for all cases (P <.01), 100% and 89% for PRETEXT I, 38% and 89% for II (P <.05), 17% and 80% for III (P <.01), and 0% and 40% for IV (P <.01), respectively. The 5-year survival rates for patients with metastases were 0% for group A (n = 5) and 57% for group B (n = 7; P <.01). The rates of a complete resection of primary tumor were 48% for group A and 67% for group B. In particular, a significant difference was found regarding the complete resection rate between groups A and B in the patients with PRETEXT III (17% for group A and 80% for group B; P <.01). In the patients with an incomplete tumor resection (14 for group A, 11 for group B), the 5-year survival rates were 0% for group A and 45% for group B (P <.01).

CONCLUSIONS

The optimal chemotherapeutic regimen of CDDP and THP-ADR was thus found to greatly contribute to the improved survival rate of hepatoblastoma patients. Preoperative chemotherapy resulted in an increased resectability of the tumor, whereas postoperative chemotherapy played an important role in the increased cure rate of cases with either an incomplete tumor resection or metastasis. However, refractory cases with PRETEXT IV or metastasis may still require the development of an even more effective treatment modality, including the use of blood stem cell transplantation.

Living donor liver transplantation: Eastern experiences

The techniques of living donor liver transplantation (LDLT) developed rapidly in the 1990s to compensate for a severe deficiency in the availability of liver grafts from cadaveric donors for the treatment of patients with end-stage liver disease. This tendency was particularly prominent in East Asia, as brain-death donors have remained largely unavailable for a variety of reasons. Thanks to refinements in surgical technique and postoperative management for LDLT, the cumulative total of LDLTs in East Asian countries has exceeded 2000 and, importantly, donor mortality has yet to be encountered. Moreover, indications for LDLT have been successfully expanded from paediatric to adult cases, following the introduction of right lobe graft. The significance of LDLT under conditions of limited opportunities for cadaveric liver transplantation, as experienced in these countries, differs significantly from that seen with the numerous opportunities for cadaveric donors in Europe and the USA. This review describes not only the experiences of East Asia, but also the specific differences from Western countries, such as indications, graft size issues and ABO blood type combinations, to shed light on the future of liver transplantation.

Malignant germ cell tumors: clinical characteristics, treatment, and outcome. A report from the study group for Pediatric Solid Malignant Tumors in the Kyushu Area, Japan

PURPOSE

This study aims to assess the prognostic factors and optimal treatments for malignant germ cell tumors (MGCT) in childhood.

METHODS

Among 117 MGCT, the clinical features were analyzed. Regarding the histology, there were 89 embryonal carcinomas, 13 dysgerminomas, 4 choriocarcinomas, and 11 others. The prognostic factors and treatments were assessed based on the 5-year survival rate.

RESULTS

(1) Stage: 100% for stage I (n = 54), 75.0% for stage II (n = 4), 67.3% for stage III (n = 14), and 54.8% for stage IV (n = 33); Unknown: n = 12. (2) Primary site: 93.4% for the testis (n = 52), 86.7% for the ovary (n = 31), 56.9% for the sacrococcygeal (n = 21), and 60.6% for others (n = 12); unknown: n = 1. (3) Surgical intervention for primary tumor: 100% for stage I with a complete resection (n = 53), 78.4% for stage III, IV with a complete resection (n = 26), and 33.3% for stage III, IV with an incomplete resection (n = 21). (4) Type of chemotherapy for the stage III and IV: 83.9% for the PVB (cisplatin, vinblastin, bleomycin; n = 13), 66.7% for the VAC (vincristine, actinomycin D, cyclophosphamide; n = 6), and 47.1% for other regimens (n = 25).

CONCLUSIONS

An early stage, a diagnosis under 1 year of age and a primary site in the gonads were favorable prognosis factors, whereas histologic findings of choriocarcinoma and liver or lung metastasis were unfavorable. Radical complete resection alone is a sufficient treatment for localized MGCT. The PVB regimen is optimal chemotherapy for advanced MGCT; however, high-risk cases still may require more aggressive treatment.

The efficacy of prevascularization by basic FGF for hepatocyte transplantation using polymer devices in rats

This study used polymer devices implanted in rats to investigate the effect of prevascularization by basic fibroblast growth factor (bFGF) on hepatocyte transplantation (HTx). Lewis rats served as both donors and recipients. Polyvinyl alcohol (PVA) sponges with either hydrogel containing bFGF (bFGF group) or distilled water (control group) were implanted between the mesenteric leaves of recipient rats. Hepatotrophic stimulation was induced by a portacaval shunt and a 70% partial hepatectomy. After 1 week of prevascularization, hepatocytes harvested from the donor Lewis rats using a collagenase digestive method were injected into the sponges. Specimens were harvested at 2 weeks, 1 month, and 2 months after HTx. Histologic examination revealed that the control groups contained small numbers of hepatocytes restricted to the peripheral areas of the sponges. However, a large number of hepatocytes, including clusters, was found distributed uniformly in the bFGF group. In the bFGF group at 2 weeks, 1 month, and 2 months, the percentage of the sponge occupied by hepatocytes was 7.21+/-2.64%, 6.98+/-2.59%, and 5.58+/-3.77%, respectively. The corresponding ratios for the control group were 0.40+/-0.39%, 0.40+/-0.40%, and 0.87+/-1.51%. In addition, the mean number of new blood vessels in the bFGF group was significantly greater than that in the control group at 0 days, 2 weeks, and 1 month after HTx. These results suggest that bFGF strongly induced vascularization, which enabled a large number of hepatocytes to survive in the polymer devices.

Pathogenesis and treatment of bile duct loss after liver transplantation

The bile duct is one of the main targets of immune reaction after liver transplantation. Bile duct loss, termed ductopenia or vanishing bile duct syndrome, is a typical pathological finding of chronic rejection (CR). The mechanism of bile duct loss in allograft rejection is twofold: T-cell mediated cytotoxicity and ischemic sequelae caused by obliterative arteriopathy. Whether or not CR is reversible remains controversial. Accumulating data show the reversibility of bile duct injury caused by immunoreaction, but not the reversibility of injuries caused by ischemia. In our living-related liver transplantation program at Kyoto University Hospital, the incidence of ductopenia, which indicates the incidence of CR, was 14 of 423 patients (3.3%), comparable to the result for cadaveric liver transplantation. The onset was within 1 year, except in 2 patients. Of the 14 patients with ductopenia, 2 recovered without re-transplantation, and of the remaining 12 patients, 7 underwent re-transplantation, and the other 5 died without a chance of re-transplantation. The diagnosis of ductopenia was based on the pathological findings, which specify that more than 50% of the portal triad does not contain visible bile ducts. Recently, staging criteria of CR were proposed by an international panel, who recommended splitting CR into an early stage and a late stage. At present, no specific immunosuppressive regimen for CR has been developed; however, early diagnosis based on these new criteria, and the earlier implementation of enforced immunosuppression, with conventional drugs, may be beneficial for a further reduction in CR.

Determination of hydrogen peroxide by iron(III) complex of thiacalix[4]arenetetrasulfonate on a modified ion-exchanger with peroxidase-like catalytic activity

An iron(III) complex of thiacalix[4]arenetetrasulfonate on a modified anion-exchanger (Fe3+-TCAS(A-500)) has shown high peroxidase-like activity at pH 5 - 6 for the reaction of quinoid-dye formation between 3-methyl-2-benzothiazolinone hydrazone and N-(3-sulfopropyl)aniline in the presence of hydrogen peroxide. Utilizing the peroxidase-like activity of Fe3+-TCAS(A-500) for this reaction, a method using Fe3+-TCAS(A-500) was applied for the spectrophotometric determination of hydrogen peroxide. The calibration curve by the method using Fe3+-TCAS(A-500) was linear over the range from 1 to 10 microg of hydrogen peroxide in a 1 ml sample solution. The apparent molar absorptivity for hydrogen peroxide was 2.4 x 10(4) l mol(-1) cm(-1). which was about 80% of that by peroxidase under the same conditions. This determination method of hydrogen peroxide using Fe3+-TCAS(A-500) was applied for the determination of glucose in diluted normal and abnormal control serum I and II.

Living-donor liver transplantation for Caroli's disease with intrahepatic adenocarcinoma

A 36-year-old woman who had Caroli's disease with refractory cholangitis and complicated intrahepatic cholangiocarcinoma was successfully treated with living-donor liver transplantation. Preoperative computed tomography and ultrasonography showed a small nodule in the dilated intrahepatic bile duct. In the resected liver specimen, a small papillary tumor was located in the dilated intrahepatic bile duct of the right lobe. The pathological finding revealed a well differentiated papillary adenocarcinoma without invasion to the parenchyma. The patient is currently doing well 2.5 years after transplantation, with no signs of recurrence of the disease. For Caroli's disease, we believe we can achieve good results with liver transplantation, not only for cholangitis but also for the carcinoma when it is localized in the liver and the patient is carefully followed up.

Biliary anastomotic complications in 400 living related liver transplantations

The purpose of this study was to evaluate the cause and outcome of biliary anastomotic complications occurring after living related liver transplantation (LRLT). A database of 391 patients undergoing 400 LRLT from June 1990 to August 1998 was reviewed. The overall incidence of biliary anastomotic complications was 18.2% (71 patients). There were 45 bile leaks, 35 anastomotic strictures, and the bile duct was ligated inadvertently in 3 cases. Univariative analysis revealed that the manner of stent usage, intrapulmonary shunting, and gender of recipients were significant risk factors for leakage. Anastomotic leaks, cytomegalovirus infection, hepatic artery complications, and gender of recipients were significant risk factors for stricture. In pediatric patients older than 2 years old, ABO blood type compatibility was another risk factor for leakage and stricture. Choice of stent usage and earlier transplantation for patients with intrapulmonary shunting should reduce the rate of biliary leaks, and prophylaxis of leaks for patients with intrapulmonary shunting, and minimizing hepatic artery complications should reduce the rate of biliary stricture after LRLT. Avoidance of ABO-incompatible donors or innovative immunosuppression in ABO-incompatible transplantation should be considered in children.

Clinical implications of flow cytometry crossmatch with T or B cells in living donor liver transplantation

BACKGROUND

Acute allograft rejection (AR) in solid organ transplantation is generally regarded to develop through cell-mediated immune response following activation of helper T cells. Since production of antibodies is also mediated by helper T cells, humoral immunity may play some roles in AR. Although flow cytometry crossmatch (FCXM) is reported as a useful method for the detection of antibodies against donor antigen, specific role of T- or B-cell FCXM and its sensitivity for AR is controversial.

METHODS

T- and B-cell FCXM using fresh donor peripheral lymphocytes were performed before and after blood-type compatible living donor liver transplantation in 47 patients. IgM and IgG anti-donor antibodies were analyzed in relation to clinical AR.

RESULTS

Positive pre-transplant T-cell FCXM was associated with a high incidence of positive post-transplant T-cell FCXM (p=0.017). Four of five cases (80%) with positive pre-transplant T-cell FCXM experienced earlier AR (day 8.0+/-4.4, mean+/-SD) than 16 of 42 cases (31%) with negative pre-transplant T-cell FCXM (17.3+/-6.8; p=0.016). In addition, higher dose of steroids was given to treat AR episodes in cases with positive pre-transplant T-cell FCXM (79.9+/-10.3 mg/kg/month) than in those with negative pre-transplant T-cell FCXM (47.1+/-26.6; p=0.039). In the first month after transplantation, 13 episodes of positive post-transplant T-cell FCXM were all concomitant with or preceded clinical AR compared with seven ARs in T-cell FCXM-negative cases (p<0.0001). T-cell FCXM between positive sera and third parties revealed some crossreactions. In contrast, detection of antibodies by B-cell FCXM in pre- and post-transplant phases was scarcely associated with AR, and no correlation was found between T- and B-cell FCXM before and after transplantation.

CONCLUSIONS

Positive T-cell FCXM is closely related with AR and that before transplantation is a predictor of early and refractory AR as well as post-transplant FCXM. In contrast, not a few detections of antibodies irrelevant to AR are observed in B-cell FCXM, suggesting its low specificity.