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Long‐term monitoring of forest tree communities is a basis for elucidating forest structure and dynamics and for evaluating ecosystem functions such as primary production. Because global climate change is changing forest ecosystems from the local to the global scale, it is essential to document long‐term monitoring data of forests to examine the temporal and geographical trends of forest changes. We report monitoring data of 45 forest plots (average area 0.69 ha; range 0.0325–6.25 ha) at 27 sites in Japan. These plots are situated within 32.38° N to 43.36° N and at elevations ranging from 8 to 2453 m above sea level. The forest plots include both old‐growth and secondary forests, and cover various forest biomes, such as warm‐temperate evergreen forests, temperate deciduous broadleaved forests, and boreal or sub‐alpine coniferous forests. In each plot, all living trees and lianas larger than a certain minimum size (typically 15 cm stem girth at breast height) were repeatedly measured and survival and recruitment of stems were recorded over 5–40 years (average 17.3 years). The data are presented in the format used by the Monitoring Sites 1000 Project in Japan (Ishihara et al. 2011, Ecological Research, 26, 1007–1008) and in the sample‐based Darwin Core format. This dataset expands existing open monitoring data for Japanese forests and thereby facilitates further meta‐analysis of forest community structures and changes in relation to climate change and other drivers. The complete data set for this abstract is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2024-03.1/jalter-en. [ABSTRACT FROM AUTHOR]

Understanding the regeneration and succession of belowground communities, particularly in forests, is vital for maintaining ecosystem health. Despite its importance, there is limited knowledge regarding how fungal communities change over time during ecosystem development, especially under different forest restoration strategies. In this study, we focused on two restoration methods used in northern Japan: monoculture planting and natural regeneration. We examined the responses of the fungal community to monoculture plantations (active tree planting) and naturally regenerated (passive regeneration) forests over a 50-year chronosequence, using natural forests as a reference. Based on DNA metabarcoding, we assessed the richness of fungal Operational Taxonomic Units (OTUs) and their dissimilarity. Our findings revealed that soil fungal richness remained stable after natural regeneration but declined in monoculture plantations, from 354 to 247 OTUs. While the compositional dissimilarity of fungal assemblages between monoculture plantations and natural forests remained consistent regardless of the time since tree planting, it significantly decreased after natural regeneration, suggesting recovery to a state close to the reference level. Notably, the composition of key functional fungal groups—saprotrophic and ectomycorrhizal— has increasingly mirrored that of natural forests over time following passive natural regeneration. In summary, our study suggests that monoculture plantations may not be effective for long-term ecosystem function and service recovery because of their limited support for soil fungal diversity. These results underscore the importance of natural regeneration in forest restoration and management strategies. [ABSTRACT FROM AUTHOR]

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As interest in natural capital grows and society increasingly recognizes the value of biodiversity, we must discuss how ecosystem observations to detect changes in biodiversity can be sustained through collaboration across regions and sectors. However, there are many barriers to establishing and sustaining large-scale, fine-resolution ecosystem observations. First, comprehensive monitoring data on both biodiversity and possible anthropogenic factors are lacking. Second, some in situ ecosystem observations cannot be systematically established and maintained across locations. Third, equitable solutions across sectors and countries are needed to build a global network. Here, by examining individual cases and emerging frameworks, mainly from (but not limited to) Japan, we illustrate how ecological science relies on long-term data and how neglecting basic monitoring of our home planet further reduces our chances of overcoming the environmental crisis. We also discuss emerging techniques and opportunities, such as environmental DNA and citizen science as well as using the existing and forgotten sites of monitoring, that can help overcome some of the difficulties in establishing and sustaining ecosystem observations at a large scale with fine resolution. Overall, this paper presents a call to action for joint monitoring of biodiversity and anthropogenic factors, the systematic establishment and maintenance of in situ observations, and equitable solutions across sectors and countries to build a global network, beyond cultures, languages, and economic status. We hope that our proposed framework and the examples from Japan can serve as a starting point for further discussions and collaborations among stakeholders across multiple sectors of society. It is time to take the next step in detecting changes in socio-ecological systems, and if monitoring and observation can be made more equitable and feasible, they will play an even more important role in ensuring global sustainability for future generations. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'. [ABSTRACT FROM AUTHOR]

The snake Rhabdophis tigrinus sequesters cardiotonic steroids, bufadienolides (BDs), from ingested toads and stores them in the nuchal glands as defensive toxins. It has previously been shown that there are individual differences in the total quantity of BDs stored in the nuchal glands of adult R. tigrinus and that BD quantities and profiles of R. tigrinus exhibit geographic variation. However, no previous study has examined the total quantity of BDs as a percentage of body mass (relative BD quantity) and the concentration of BDs in the nuchal gland fluid (BD gland concentration). In addition, intrinsic factors that are associated with relative BD quantity and BD concentration have not been examined within a single population. We collected 158 adult snakes from an area of central Japan from May to October and analyzed their BD quantities by UV analysis. We assessed individual differences in BD quantity, relative BD quantity and BD gland concentration. We found that 1) in approximately 60% of the 158 individuals, the BD gland concentration was greater than 50%; 2) body length and body condition are positively correlated with relative BD quantity and BD gland concentration; 3) even in a single population, individual differences of BD quantity are large, and are greater in females than in males; and 4) relative BD quantity and BD gland concentration of females during the gestation season are lower than those during the non-gestation season. [ABSTRACT FROM AUTHOR]

Aim: Global flux data analyses have shown a significant positive and linear relationship between site‐scale photosynthetic optimum temperature (Topt‐s) and averaged temperature variables. However, as existing studies have not fully considered species composition, it remains unclear to what extent the change in Topt‐s is derived from intraspecific plasticity or from a difference in species with a consistent species‐specific Topt‐s. We tested these two hypotheses using the satellite‐derived enhanced vegetation index (EVI). Location: Subalpine and temperate forests in Japan. Time period: 2001–2020. Major taxa studied: Thirty‐three tree species. Methods: Based on an in situ vegetation survey dataset, we identified 1814 EVI cells (250 m × 250 m) that were characteristic of the spectral reflectance of a single dominant species. For each cell, we pooled EVIs from 2001 to 2020 and estimated the temperature at the time of EVI peak as a species‐specific Topt‐s. We tested our hypotheses by fitting linear regression models to the Topt‐s and mean annual temperature (MAT). A positive slope indicated support for the intraspecific plasticity hypothesis. Results: For 32 of the 33 tree species, the Topt‐s increased with an increase in MAT. A linear mixed‐effect model provided a good explanation of the variation in the Topt‐s based on the MAT (intercept = 14.63, slope = 0.58, marginal R2 =.78), with minimal effect of species difference (conditional R2 =.75). Main conclusions: Our results support the intraspecific plasticity hypothesis. At least in East Asian subalpine and temperate forests, the Topt‐s can be estimated from the MAT, irrespective of the dominant canopy species. The observed MAT–Topt‐s relationship is consistent with the findings of previous photosynthetic studies and has important implications for the establishment of new algorithms for estimating gross primary productivity that can account explicitly for spatial and temporal differences in temperature‐dependent photosynthetic responses. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to compare the prognostic impact of laparoscopic left hepatectomy (LLH) with that of open left hepatectomy (OLH) on patient survival after resection of left hepatocellular carcinoma (HCC). Methods: Among the 953 patients who received initial treatment for primary HCC that was resectable by either LLH or OLH from 2013 to 2017 in Japan and Korea, 146 patients underwent LLH and 807 underwent OLH. The inverse probability of treatment weighting approach based on propensity scoring was used to address the potential selection bias inherent in the recurrence and survival outcomes between the LLH and OLH groups. Results: The occurrence rate of postoperative complications and hepatic decompensation was significantly lower in the LLH group than in the OLH group. Recurrence-free survival (RFS) was better in the LLH group than in the OLH group (hazard ratio, 1.33; 95% confidence interval, 1.03–1.71; p = 0.029), whereas overall survival (OS) was not significantly different. Subgroup analyses of RFS and OS revealed an almost consistent trend in favor of LLH over OLH. In patients with tumor sizes of ≥4.0 cm or those with single tumors, both RFS and OS were significantly better in the LLH group than in the OLH group. Conclusions: LLH decreases the risk of tumor recurrence and improves OS in patients with primary HCC located in the left liver. [ABSTRACT FROM AUTHOR]

Growing interest in ecosystem restoration has recently turned the focus on tree planting, one of the most widely used restoration tools globally. Here, we study the restoration potential of tree planting in a cool‐temperate forest in Shiretoko National Park, northern Japan. We used simulation modeling to investigate the long‐term success of tree planting in restoring biodiversity and the climate change mitigation function relative to intact natural forests. Specifically, we investigated 31 different restoration scenarios, consisting of five planting densities (1,000–10,000 trees/ha) × six levels of planted tree species richness (one to six species) + one no‐planting scenario. We examined these scenarios at different distances from natural forests serving as a seed source (0–300 m) to quantify the potential for natural regeneration. In restoration areas in close proximity to a natural forest, species‐rich high‐density planting scenario performed best, reaching >50% of the reference values from intact natural forests within 33 years for both restoration goals. However, variation in restoration outcomes was small when >2,500 trees/ha of more than four species were planted, regardless of distance to seed source. In contrast, biodiversity restoration was considerably delayed in scenarios where planted species richness was low as well as in restoration areas that were far from a seed source yet relied solely on natural regeneration. We here demonstrate how forest landscape simulation can be used to identify viable restoration options for managers across multiple restoration goals as an important step to bridge the research–implementation gap in forest restoration. [ABSTRACT FROM AUTHOR]

We present the largest freely available EcoPlate dataset for Japan, comprising data collected from a network of 33 natural forest sites (77 plots) in regions of East Asia ranging from cool temperate to subtropical. EcoPlate is a 96‐well microplate that contains three repeated sets of 31 response wells with different sole carbon substrates. The utilization of each carbon substrate by the microbial community is quantified by the color density of the well during incubation. EcoPlate can provide a multifunctional index of a soil microbial community. Soil properties (water content, carbon [C] and nitrogen [N] contents, the C/N ratio, and pH) that are essential for interpreting the EcoPlate results were also measured. The network is part of the Forest and Grassland Survey of the Monitoring Sites 1000 Project established by the Ministry of the Environment. Using a standardized protocol, soil was sampled between September and December 2020. A preliminary principal component analysis was performed on the temporal integration of color density using 31 substrates. For the temporal integration, we calculated the cumulative amount of color development by integrating the color density development curve. PC1 contributed 55.6% and is thought to represent the magnitude of the overall absorbance of all substrates. The model of environmental factors including elevation and the model of soil properties, including water content and pH, were selected as the best‐fit models for variation in PC1. EcoPlate data enable the meta‐analysis of comparative studies among forest types and testing community ecology and ecosystem function hypotheses at broad spatial scales. The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP‐2022‐01.1/jalter‐en. [ABSTRACT FROM AUTHOR]

The Japanese natricine snake Rhabdophis tigrinus sequesters cardiotonic steroids, bufadienolides (BDs), from ingested toads in the nuchal glands as defensive toxins. A previous study showed that R. tigrinus in captivity converts dietary BDs when it sequesters them. However, it is unknown whether the dietary BDs are actually converted and the modified products accumulated under natural conditions. It is also unknown to what extent the BD profile of ingested toads is reflected in that of the snake. We collected 123 snakes from throughout Japan, analyzed their BD profiles by liquid chromatography/mass spectrometry, and identified 15 BDs from R. tigrinus by nuclear magnetic resonance analyses. We also compared their BD profiles using hierarchical cluster analysis (HCA). HCA exhibited two main clusters associated with their collection locations: eastern and western regions of the Japanese main islands. These results, coupled with previous findings on the BDs of Japanese toads, suggest that 1) R. tigrinus converts toad-derived BDs into other compounds under natural conditions; 2) there are both universal and regionally-specific conversions of dietary BDs by R. tigrinus; and 3) geographic variation in toad BD profiles is partially reflected in the variation of snake BD profiles. [ABSTRACT FROM AUTHOR]

Foraging tactics of predators generally include two major modes, active searching and ambushing. A colubrid snake, Lycodon semicarinatus , is a typical example of a predator, which uses both tactics to forage on sea turtles on islands of the Kerama Group in the Central Ryukyu Archipelago, Japan. To investigate factors that determine the foraging mode of this snake, we conducted a four-year field survey on its foraging behaviour on sea turtles on another island, Okinawa Island. We found that the snake performs only active searching at our study site. Snakes visited a small area exactly above the nest of sea turtles and attempted to burrow a tunnel to feed on eggs and hatchlings in the sand. Tunnels leading from the surface of the beach to the inside of the nest were formed only by large snakes. Many other snakes used the already made tunnels to capture eggs and hatchlings in the nest. When the snakes caught a hatchling, they brought the hatchling away into the nearby bush area without swallowing it above the nest (taking-away behaviour). When snakes failed to find food on a nest, they terminated the intensive search above the nest in approximately 5 minutes irrespective of snake body size, season, and the condition of the nest. Subsequently, they left the nest and resumed extensive searching for other nests. Our findings showed that L. semicarinatus has a different foraging strategy depending on populations. Two environmental traits, diversity of available prey animals other than sea turtles and characteristics of sand that beaches consist of, were considered as factors that might cause the difference in the foraging strategy. The fine sand of our study site enables snakes to form a sturdy tunnel in nests. We presume that such an environment facilitates the use of active searching by the snakes to find the nest with tunnels suitable for exploitation. The taking-away behaviour may be effective to reduce excessive contact with other conspecifics under the situation that the nest with tunnels attracts many visitors. Furthermore, the observation that the snake left the nest site after a consistent duration of unprofitable searching supports the giving-up time rule, which has been predicted by a theoretical model concerning the optimal time for predators to leave a patch. [ABSTRACT FROM AUTHOR]

Toads of the genus Bufo synthesize and accumulate bufadienolides (BDs) in their parotoid glands. BDs are cardiotonic steroids that play an important role in defense against the toads' predators. Three bufonid taxa occur in mainland Japan, Bufo japonicus formosus, B. j. japonicus, and B. torrenticola. The chemical structures of BDs isolated from B. j. formosus were studied several decades ago, but there is no further information on the toxic components of Japanese toads and their metabolism. In this study, we analyzed BDs of toads from throughout Japan and compared the BD profiles by liquid chromatography/mass spectrometry (LC/MS) and hierarchical cluster analysis (HCA). We observed BDs in three taxa of Japanese toads, and identified five of the most common BDs by nuclear magnetic resonance (NMR) analyses. Of the five BDs, only bufalin was detected in all individuals. HCA of individual BD profiles divided the three taxa into five primary clusters and several subclusters. This result indicates that BD profiles differ both among and within the taxa. The clustering pattern of BDs is generally concordant with a phylogenetic tree reconstructed from the mitochondrial cytochrome b gene of Japanese toads. Our results suggest that the BDs of Japanese toads have diversified not in response to specific selective pressures, but simply due to population structuring over evolutionary time. [ABSTRACT FROM AUTHOR]

Topography often promotes habitat heterogeneity and is a major factor in fine‐grained changes in vegetation. Especially in temperate mountainous regions of East Asia, the distribution of tree species is largely explained by topographic niche differentiation. Because species niche is at least partially a historical product through the evolution of functional traits, phylogenetic signals are expected in the topographic arrangement pattern of species, although this has not been fully investigated. Thus, we examined common temperate trees in a 306 ha watershed on Mt Tanzawa, central Japan. The topographic niche position of each species was explained with two principal component analysis (PCA) axes, which aligned with the topographic structure of the watershed. High scores on PC1 reflected lower elevations, steeper slopes and nearby valleys. Higher scores on PC2 indicated thicker soil, more south‐facing slopes, slighter slope inclinations and nearby valleys. The former indicated the species were aligned on a habitat gradient of land‐surface instability, for which the gradient is typical under the current geological conditions. The latter indicated that a niche axis for resource availability relating to water, nutrients and light or heat existed. A phylogenetic signal, identified by Pagel's λ and the Mantel test, was detected for PC2 scores. However, the species arrangement along PC1 was independent of phylogeny. Our results suggested that the topographic niche of tree species in this area is caused by both relatively recently derived traits regarding adaptation to unstable land surfaces and conservative traits derived through plant evolution. [ABSTRACT FROM AUTHOR]

Resistance of hosts to ticks has important roles in their interactions. Ticks parasitize not only mammals, but also birds, reptiles and amphibians. Thus, a better understanding of their interaction requires studies of the resistance of various host taxa. We examined the presence of ticks engorged on three species of snakes, Gloydius tsushimaensis, Lycodon rufozonatus and Elaphe climacophora, on Tsushima Islands, Japan in 2017 and 2018. The rate of G. tsushimaensis parasitized by ticks was high (87.5%), but none of those ticks were engorged, and the frequency of live ticks on each snake was low (16.1 ± 5.4%). On the other hand, engorged ticks were found on L. rufozonatus and E. climacophora, and no dead ticks were observed on them. In addition, laboratory observation revealed that two of three ticks that had attached to G. tsushimaensis died within approximately 6 days after attaching, and the third did not engorge. Our results suggest that only G. tsushimaensis among the three snake species on the Tsushima Islands possesses strong host resistance to ticks. Our study suggests that host resistance in snakes may have considerable influence on tick and host populations and on transmission dynamics between them. [ABSTRACT FROM AUTHOR]

Ungulates can greatly affect forest ecosystems' functional characteristics. However, limited information is available about their influence on litter decomposition, a major ecosystem process, despite disturbance of ungulates on vegetation through selective browsing and trampling. This study focused on effects of the presence/absence of deer herbivory on decomposition of leaves and roots of three major tree species in a Hokkaido, Japan forest. Our litterbag experiment showed that litter decomposition was significantly faster for both leaves and roots in a deer exclosure than in a control site with deer herbivory. Possible factors for this slowed decomposition because of deer presence include their physical disturbance on soil through trampling. In both sites, the remaining mass of litter was positively correlated with the C:N ratio and lignin content. When analyzed for leaf litter, species with lower C:N ratio and lignin content showed lower litter mass remaining in both sites. Deer generally prefer species with a low leaf C:N ratio and lignin content; the results suggest that leaves of palatable species were less resistant to decomposition. A similar interspecific difference in decomposition was not observed for roots, most likely resulting from the small difference in root litter quality among species. In this forest, tree species with unpalatable leaves, which are becoming predominant, likely decreases leaf litter decomposition, as leaves of palatable plants decompose more rapidly. Roots, however, are not exposed to browsing, regardless of aboveground palatability, and remain within soil as a recalcitrant slowly decomposing litter substrate. These synergetic influences could allow deer herbivory to reduce overall plant decomposition rates aboveground and belowground via changes in plant species composition. [ABSTRACT FROM AUTHOR]

Theory suggests that biodiversity might help sustain multiple ecosystem functions. To evaluate possible biodiversity-multifunctionality relationships in a natural setting, we considered different spatial scales of diversity metrics for soil fungi in the northern forests of Japan. We found that multifunctionality increased with increasing local species richness, suggesting a limited degree of multifunctional redundancy. This diversity-multifunctionality relationship was independent of the compositional uniqueness of each community. However, we still found the importance of community composition, because there was a positive correlation between community dissimilarity and multifunctional dissimilarity across the landscape. This result suggests that functional redundancy can further decrease when spatial variations in identities of both species and functions are simultaneously considered at larger spatial scales. We speculate that different scales of diversity could provide multiple levels of insurance against the loss of functioning if high-levels of local species diversity and compositional variation across locations are both maintained. Alternatively, making species assemblages depauperate may result in the loss of multifunctionality. [ABSTRACT FROM AUTHOR]

The diversity, composition, and host recurrence of endophytic fungi in the Xylariaceae were compared in subtropical (ST), cool temperate (CT), and subboreal forests (SB) in Japan based on the 28S ribosomal DNA sequences from fungal isolates. A total of 610 isolates were obtained from the leaves of 167 tree species in three sites, which were classified into 42 operational taxonomic units (OTUs) at the 99 % similarity level of the 28S rDNA sequence. ST, CT, and SB yielded 31, 13, and three OTUs, respectively. The OTU richness, diversity, and evenness of fungal communities were in the order: ST > CT > SB. The 42 OTUs were assigned to nine genera in the Xylariaceae: Xylaria, Annulohypoxylon, Anthostomella, Biscogniauxia, Nemania, Hypoxylon, Muscodor, Daldinia, and Rosellinia. Xylarioid isolates in the subfamily Xylarioideae outnumbered Hypoxyloid isolates in the subfamily Hypoxyloideae in ST and CT, whereas the opposite was found in SB. Sørensen's quotient of similarity was generally low between the three sites. Host recurrence of fungal OTUs was evaluated with the degree of specialization of interaction network between xylariaceous endophytes and plant species and compared between the three sites. We found that the networks in the three sites showed a significantly higher degree of specialization than simulated networks, where partners were associated randomly. Permutational multivariate analyses of variance indicated that plant family and leaf trait significantly affected the OTU composition in ST, which can account for the specialization of interaction network and host recurrence of xylariaceous endophytes. [ABSTRACT FROM AUTHOR]

Far less is known about the coarse woody debris (CWD) stock and decay process in temperate Asia compared with that in boreal and temperate Europe and North America. We estimated coniferous CWD stock (logs and snags), decay rate and process, and fungal species responsible for the decay process in a Japanese subalpine coniferous forest. The CWD mass was 42.4 Mg ha, which was the greatest among the previous data recorded in temperate Asia. The decay rate calculated using the annual input of CWD divided by CWD accumulation was 0.036 year, whereas the decay rate when measured chronosequentially was 0.020-0.023 year. The decay process was divided into two phases characterized by different dominant organic chemical constituents. In the first phase, both acid-unhydrolyzable residue and holocellulose decayed simultaneously, suggestive of the white-rot process. In the second phase, holocellulose was selectively decomposed and AUR accumulated, suggestive of the brown-rot process. Nutrients (N, P, K, Na, Mg, and Ca) were mineralized in the first phase but immobilized in the second phase. The fruiting bodies of 26 taxa of fungi were recorded as occurring on CWD in the study area. Trichaptum abietinum and T. fuscoviolaceum, which dominated in the first phase and are known as white-rot fungi, were assumed to be the main decomposers of lignocellulose in the first phase. Although no known strong wood decomposers dominated the second phase, Laetiporus sulphureus and Oligoporus caesius, known as brown-rot fungi, were expected to participate in the selective decomposition of holocellulose in the second phase. [ABSTRACT FROM AUTHOR]

Aim To clarify the role of disease recurrence as a cause of graft loss after living-donor liver transplantation ( LDLT) for primary biliary cirrhosis ( PBC), we investigated explant grafts, as well as the native liver and liver biopsy specimens, of patients who underwent retransplantation. Methods Of 516 patients who underwent LDLT for PBC and were registered in the Japanese Liver Transplant Registry, nine patients (1.7%) underwent retransplantation. Results Seven patients undergoing retransplantation later than 6 months after primary liver transplantation ( LT) were enrolled. All seven patients were female, with ages ranging from 34-57 years, and Model for End- Stage Liver Disease scores ranging 10-28. The right lobe was used as graft in one and the left lobe in six. The initial immunosuppression regimen was tacrolimus in six and cyclosporin in one. The period between the primary LT and retransplantation ranged 11-120 months, with a median of 36 months. Three patients survived and four patients died due to poor graft functions or complications after retransplantation. The primary causes of primary graft loss revealed by histological examination of the explant livers were chronic rejection in three, portal thrombus and/or steatohepatitis in three and outflow block in one. PBC recurrence was observed in 3 and the stage was mild in all. Conclusion PBC recurrence has a small impact as a cause of graft loss after LDLT. [ABSTRACT FROM AUTHOR]

Purpose: Tacrolimus pharmacokinetics and calcineurin activity in peripheral blood mononuclear cells (PBMCs) were investigated in adult patients undergoing primary living-donor liver transplantation (LDLT) in order to clarify the significance of monitoring the tacrolimus blood trough concentration during the early post-transplantation period. Methods: Fourteen patients were enrolled in this study, and time-course data following the oral administration of a conventional tacrolimus formulation twice daily were obtained at 1 and 3 weeks post-transplantation. The concentration of tacrolimus in whole blood and calcineurin activity in PBMCs were measured. Results: The apparent clearance of tacrolimus significantly increased at 3 weeks versus 1 week post-transplantation, although the trough concentration did not significantly differ at these time points. The concentration at each sampling time, except at 1 h post-dose, correlated well with the area under the concentration-time curve from 0 to 12 h (AUC). Neither the concentration at the trough time point nor AUC was correlated with the area under the calcineurin activity-time curve from 0 to 12 h; however, calcineurin activity at the trough time point was strongly correlated with the latter ( r > 0.92). Conclusions: Based on these results, trough concentration monitoring can be considered an appropriate procedure for routine tacrolimus dosage adjustment in adult LDLT patients. Monitoring of calcineurin activity at the trough time point was also found to be potentially useful for predicting the immunological status of the patient during the tacrolimus dosing interval. [ABSTRACT FROM AUTHOR]

Ovophis okinavensis is an endemic pitviper of the subtropical region of Japan. Based on information from various localities, the species has been considered a dietary generalist that exploits various terrestrial vertebrates. We analyzed stomach contents of O. okinavensis in a northern mountain area on Okinawa Island, based on data of a 10-years-study, to examine its trophic features at the population level. We recovered a total of 461 prey items, which were comprised of six, three, five, and three species of frogs, reptiles, birds, and mammals, respectively. Approximately 93% of dietary items consisted of frogs, the majority of which belonged to two explosively breeding species aggregating to restricted spots along the stream only during their reproductive season (winter). On the other hand, from April to November, the snake mainly depended on vertebrates other than frogs. Neither an ontogenetic dietary shift nor intersexual dietary divergence was evident although males tended to exploit one of the two explosively breeding frog species more frequently than females. There were weak positive correlations between snake size and prey size, but large snakes did not drop small prey items from their diet. Average body mass of each prey item was only 5.2% of snake body mass. Characteristics of trophic features of O. okinavensis of this population, such as extremely high dependency on frogs in winter, the absence of ontogenetic dietary shift, and utilization of small sized prey, are discussed in comparison with other viperids. [ABSTRACT FROM AUTHOR]

We infer the biogeography and colonization history of a dispersal-limited terrestrial vertebrate, the Japanese four-lined ratsnake ( Elaphe quadrivirgata), to reveal the number of times mainland populations have invaded the Izu Archipelago of Japan, the mainland sources of these colonists, and the time-scale of colonization. We compare these results with those of past studies in an attempt to uncover general biogeographical patterns. Moreover, we briefly examine the significance of colonization history when evaluating the evolution of body size and melanism of the Izu Island E. quadrivirgata populations. The Izu Islands (Oshima, Toshima, Niijima, Shikine, Kozu, Tadanae and Mikura), a volcanic archipelago off the Pacific coast of central Japan. We obtained DNA sequences of the mitochondrial cytochrome b gene (1117 base pairs) from 373 individual snakes sampled from seven of the Izu Islands and 25 mainland localities. We employed partitioned Bayesian phylogenetic analyses assuming a relaxed molecular clock to estimate phylogenetic relationships among extant haplotypes and to give an explicit temporal scale to the timing of clade divergence, colonization history and tempo of body-size evolution. Moreover, we employed model-based biogeographical analysis to calculate the minimum number of times E. quadrivirgata colonized the Izu Islands. We found evidence that three separate regions of the Izu Archipelago have been colonized independently from mainland ancestors within the past 0.58-0.20 Ma. The Izu Peninsula plus Oshima and Mikura were both colonized independently from lineages inhabiting eastern mainland Japan. The Toshima, Niijima, Shikine, Kozu and Tadanae populations all derive from a single colonization from western mainland Japan. Oshima has been subject to three or possibly four colonizations. These results support the hypothesis that the extreme body-size disparity among island populations of this ratsnake evolved in situ. Moreover, the fact that the dwarf, melanistic population inhabiting Oshima descends from multiple mainland colonization events is evidence of an extremely strong natural selection pressure resulting in the rapid evolution of this unique morphology. These results contrast with theoretical predictions that natural selection pressures should play a decreased role on islands close to the mainland and/or subject to frequent or recent immigration. [ABSTRACT FROM AUTHOR]

We investigated mature dwarf Abies mariesii trees growing in conifer thicket–meadow parklands on a snowy subalpine plateau, where these dwarf trees are buried in the accumulated snow in winter. We focused on structural variation in the needles, shoots, and branchlets within different crown positions (leader crown vs lower crown) of the dwarf trees. In the leader crown, which appears above the snow surface earlier than the lower crown, current-year shoots and branchlets had greater total biomass, and foliage was more closely packed along the stem axis than in the lower crown, whereas current-year shoots in the leader crown had a lower needle mass ratio than in the lower crown. These results suggest that current-year shoots and branchlets in the leader crown have a specific structure that allows them to harvest more light, although construction and maintenance costs would be higher. In contrast, the structural characteristics of current-year shoots and branchlets in the lower crown efficiently concentrate incoming light by avoiding mutual shading within foliage, thus leading to increased biomass of photosynthetic needles within shoot and branchlet biomass. Such within-crown variability at various hierarchical levels from needles to branches in mature, but very dwarf, A. mariesii trees maintains the crown and allows survival within conifer clumps in areas of subalpine parklands that receive heavy snowfall. [ABSTRACT FROM AUTHOR]

Abstract: We examined niche differentiation in the root foraging strategies of four late-successional species, namely, Abies mariesii, Abies veitchii, Picea jezoensis var. hondoensis, and Tsuga diversifolia, in an old-growth subalpine forest on Mt. Ontake in central Japan. Substrate type and substrate height were assessed for all the trees (H ≥2m) in a 1.0ha plot. Root architectural characteristics were assessed based on the total length and vertical depth of taproot and horizontal root extensity for the seedlings on logs with three different degrees of decay (and soil for the two Abies species). The two Abies species established on the lowest substrates, including soil, and woody substrates with higher decay classes. These seedlings effectively extended their taproots deep into the soil or well-decayed logs, where the substrate height was low. P. jezoensis var. hondoensis mainly established on substrates, including less-decayed woody substrates, that were taller than those on which the two Abies species established. Their seedlings were expected to acquire belowground resources efficiently by means of greater horizontal root extensity on less-decayed logs, where nutrients are mostly concentrated in the thinner humus layer. Of the four species, T. diversifolia established on the tallest substrates, which covered small projection areas and were difficult for the other three species to establish on. Their seedlings appear to endure poor nutrient conditions by having small root architecture both vertically and horizontally. Thus, we observed species-specific root foraging strategies closely associated with regeneration of the four conifer species. [Copyright &y& Elsevier]

Feeding performance (handling time, capture success) in numerous animal species is well known to be influenced by a variety of ecological, functional, and physiological factors. Nonetheless, few studies have tested which factors are the strongest determinants of animal feeding performance in the wild. Using a field-based experiment, we examined the relationships among a number of functionally important variables and the predatory behaviour of free-ranging pit-vipers ( Ovophis okinavensis) from Okinawa Island, Japan. Our main findings were: (1) strike latency was negatively related to snake body temperature and, hence, hotter snakes struck at frogs more readily than colder snakes; (2) initial bite position was correlated with ingestion direction (headfirst versus hindfirst) but ingestion direction was not correlated with ingestion duration; and (3) both snake head length and body temperature were negatively related with ingestion duration and, thus, snakes with longer heads and higher body temperatures had shorter ingestion durations. In O. okinavensis, head size and body temperature are therefore likely to have direct ecological consequences in terms of its feeding rate on explosively breeding frogs. More generally, however, this field-based study adds to the growing body of literature demonstrating that temperature has a pervasive influence on the feeding performance of ectotherms in general. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 53–62. [ABSTRACT FROM AUTHOR]

Structural characteristics of Abies mariesii M.T. Mast. saplings growing in sun and shade in a snowy subalpine parkland in central Japan were assessed to infer how saplings acclimate to suppression by larger individuals in a conifer clump and to extremely snowy conditions. Sun and shade saplings produced structurally different current-year shoots, and allocated biomass to needles and stem differently. Compared with sun saplings, shoots of shade saplings had lower needle mass per unit shoot size, which indicates less dense needle packing and more effective use of the limited available light by avoiding mutual shading among needles. Biomass allocation within lateral branches also differed between sun and shade saplings. Compared with sun saplings, needle mass was a smaller proportion of total branch mass in shade saplings although shade saplings retained needles for longer, thereby compensating, in part, for their lower annual production of needles. Thus shade saplings incur a high mechanical cost to support their low-light acclimated, conspicuously flattened crowns in this snowy habitat. Suppressed saplings are an important component of the persistent conifer clumps in snowy subalpine parklands. The observed structural characteristics of A. mariesii saplings, which ensure high shade- and snow-tolerance, contribute to the dominance of the species in snowy subalpine regions in Honshu, Japan. [ABSTRACT FROM PUBLISHER]

Abstract: Seasonal and substrate effects on first-year seedling establishment of major conifer species (Abies mariesii, Abies veitchii, Picea jezoensis var. hondoensis, and Tsuga diversifolia) were assessed in an old-growth subalpine forest in central Japan. Older seedlings (≥1 year) were more abundant on woody debris (WD), such as fallen logs, than on soil. It is known that this preferential seedling establishment on WD is determined by the first-year seedling establishment. The present results indicate that first-summer seedling survivorship clearly contributes to the creation of such seedling–substrate associations, because mortality during the first-summer was greater on soil than WD but that during the first-autumn/winter was not different. Although the standardized mortality rate of current-year seedlings on WD was not so different among the three seasons, that on soil significantly decreased in the winter; indicating that soil is not an unsuitable substrate for seedling survivorship during snow-covered winter. Thus, it can be concluded that biotic and abiotic factors enhancing seedling mortality on soil are most active during summer, and seedling–substrate associations seem to be determined mainly during the first-summer soon after seedling emergence. Furthermore, the first-year survivorship of P. jezoensis var. hondoensis, which has smaller-sized seeds/seedlings that are disadvantageous for early survival, decreased with progressing WD decay toward soil. This suggests that the properties of WD also affect current-year seedling survivorship, especially for species sensitive to substrate properties. In conclusion, initial survivorship affects seedling bank dynamics, and such early dynamics are greatly regulated by the highly heterogeneous substrate availability on forest floors. [Copyright &y& Elsevier]

In this study, we investigated substrate-associated seedling recruitment and establishment of major conifer species, Abies mariesii, Abies veitchii, Picea jezoensis var. hondoensis and Tsuga diversifolia, in a subalpine forest in central Japan. For all species, the abundance of currently germinated seedlings significantly reflected seed rain abundance and did not differ between substrate types, suggesting that seedlings emerge where seeds fall and that there is little difference in germination rate between substrates. This is probably because moisture-retention capacity, which is important for seedling germination, is usually adequate at the time of germination irrespective of substrate type. However, for all species, the survival rate of current seedlings was higher on woody debris (WD) than soil, and as a result older seedlings (≥1-year-old) were more abundant on WD. It is probable that several agents such as summer drought and pathogenic fungi reduced the survivorship of current seedlings on soil. Although mortality agents influence the survival of not only current seedlings but also older ones, results suggest that a relatively drastic change occurs from the current to 1-year-old seedling stage. Consequently, WD functions as safe sites, especially for first-year establishment, and thereby older seedlings are preferentially established on WD. Additionally, results suggest that the properties of WD have a significant effect on seedling survival and establishment, since older seedling densities seemed to differ among WD decay classes. Furthermore, compared to Picea and Tsuga, a relatively large proportion of 1-year-old Abies seedlings were maintained on soil due to their higher survival rate on soil substrates. This results from the large seed/seedling size of Abies, which probably provides several advantages at the time of first-year establishment. Thus, the events determining variations in safe sites for the seedlings of each conifer species in this subalpine forest specifically occur at the time of first-year establishment following germination. [Copyright &y& Elsevier]

To clarify the mechanism by which overstory trees shade understory saplings, we investigated the relationships among light conditions of the saplings (measured as indirect site factor; ISF and direct site factor; DSF), the calculated competition effects of overstory trees on the saplings (W), and relative height growth rate of the saplings (RHGR). We calculated several W values in order to find a W value which can express the light conditions as appropriately as possible, and the results indicated that W explained only 21.9%–24.7% of the total variance of light conditions in the cases where W gave the best fit. In this study, W was calculated based on the basal areas of overstory trees. However, it is known that canopy structure also affects the light regimes in the forest understory, and this might yield the possible errors even within W representing the shading effects most adequately. Therefore, although W significantly represents the shading effect from overstory trees, a great proportion of the variance remained without being explained by W. RHGR was negatively correlated with W, and the W value which had the most adequate explanation of the shading effect also showed the best negative correlation with RHGR. This provides the evidence that the competitive effect of overstory trees on sapling growth is mediated by the shading effect, indicating that competition for light clearly exists within this forest. Such competition for light may closely relate to the well-known phenomenon of gap regeneration in subalpine forests in central Japan. [ABSTRACT FROM AUTHOR]

• Larch plantations acted as windbreaks and protected native trees from wind. • Larch overstory promoted species abundance and richness of native trees. • No regenerating alien individuals (Larix kaempferi) were observed. • Alien species improved environmental conditions that limit natural regeneration. Restoring forests has recently received considerable attention in the context of sequestering carbon and supporting biodiversity. Although considering alien species as a tool for natural forest restoration still remains controversial, harnessing alien species when they are already present in an ecosystem might result in overall benefits for nature and society. In this study we evaluated whether the presence of an alien tree species supports or hinders the establishment of naturally regenerating forests in Shiretoko National Park, Japan. In particular, we focused on Larix kaempferi , which is widely present yet non-native to the region, and examined how this alien species affects two factors influencing the success of restoration: wind disturbance and deer herbivory. We examined the following effects of L. kaempferi plantations on natural regeneration: (1) the windbreak function for protecting native tree growth and (2) the nursery function to promote the regeneration of native tree saplings and seedlings under high herbivory pressure. We assessed tree height and regeneration, using large-scale remotely sensed data and terrestrial inventory data in five major vegetation types. We found that L. kaempferi plantations can protect native species from predominant winds. Additionally, L. kaempferi canopy cover promoted abundance and species richness in understory saplings and seedlings compared to other vegetation types such as primary and secondary forests, even under excessive browsing pressure. No regenerating L. kaempferi individuals were observed during the field census, suggesting the species is likely not invasive in our study system. The positive relationship between alien tree species and the regeneration of native tree assemblages emphasizes that existing alien species have the potential to act as nurse plants. Our findings imply that the presence of alien species can contribute to natural forest restoration by improving the local environmental conditions for native species in the short-term. Given the multiple ecological and social needs in our changing world, careful consideration is required to evaluate the long-term consequences of alien species. Especially in ecosystems in which alien species have already established, using their positive functions rather than swiftly eradicating them from the landscape might be beneficial for long-term restoration goals. We conclude that managers need to be aware of the context-dependency of alien species to make restoration more effective. [ABSTRACT FROM AUTHOR]

Arctic ecosystems are altered profoundly by climate changes. However, the responses of Arctic marine and terrestrial ecosystems as well as their biodiversity to global warming remain largely unknown. This article provides comprehensive insights into the results and major findings from the Arctic Challenge for Sustainability (ArCS) Project – an Arctic region research program initiated in Japan, which aims to address and advance our understanding of these uncertainties. Marine ecosystem studies have identified several biogeochemical processes that are associated with sea ice decline and northward transport and shift of marine species across multiple trophic levels over the Bering and Chukchi Sea shelves. Studies of the terrestrial ecosystem have identified factors that are important for the understanding of terrestrial biodiversity and ecosystems, including Arctic lakes, under the presence of global warming. Novel fungal species from the Arctic terrestrial ecosystem have also been isolated and described. Overall, these results could contribute to the conservation and sustainable management of the Arctic ecosystem services. • Most publications from the ArCS project were reviewed. • Biogeochemical process assciated with sea ice decline and northward shift of marine species were revealed. • Novel fungal species in the terrestrial ecosystem and notable contributions of biological interaction to ecosystem changes were discovered. [ABSTRACT FROM AUTHOR]

The article reports that the Japanese government does well in considering how the society can adapt to cope with the uncertainty and change caused by sudden disastrous natural events like tsunamis, by adapting the resilience thinking.

Objective: To clarify the short and long-term postoperative outcomes and surgical indications for patients accompanied by hepatocellular carcinoma with tumor thrombus (TT) in the inferior vena cava (IVC) or right atrium (RA)., Background: These patients are known to have an extremely poor prognosis; however, the postoperative outcomes have not been fully verified because of the rarity of this disease., Methods: We contacted 211 specialized centers in Japan and collected data on liver resection for hepatocellular carcinoma with TT in the IVC or RA from centers with experience performing surgery for such patients. The patient characteristics, operative procedures, and surgical outcomes were then analyzed., Results: A total of 119 patients from 23 institutions were enrolled; 49 patients had TT in the IVC below the diaphragm (type I), 42 had TT in the IVC above the diaphragm (type II), and 28 had TT entering the RA (type III). The severity and frequency of postoperative complications did not differ among the 3 groups. There was one surgery-related death in the type III group. The median survival times were 2.47 years in the type I group, 1.77 years in the type II group, and 1.02 years in the type III group. Multivariate analysis identified an indocyanine green retention rate at 15 minutes >15% and ≥3 tumors as prognostic factors affecting survival, whereas the use of cardiopulmonary bypass and ≥3 tumors were risk factors for recurrence., Conclusions: As the postoperative prognosis of patients with type I or type II disease and of patients with no risk factors is relatively good, surgery should be considered for these patient populations., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: A score derived from the concentrations of α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) and tumor volume (TV), called ADV score, has been shown to be prognostic of hepatocellular carcinoma (HCC) recurrence following hepatic resection (HR) or liver transplantation., Methods: This multicenter, multinational validation study included 9200 patients who underwent HR from 2010 to 2017 at 10 Korean and 73 Japanese centers, and were followed up until 2020., Results: AFP, DCP, and TV showed weak correlations (ρ ≤ .463, r ≤ .189, p < .001). Disease-free survival (DFS), overall survival (OS), and post-recurrence survival rates were dependent on 1.0 log and 2.0 log intervals of ADV scores (p < .001). Receiver operating characteristic (ROC) curve analysis showed that ADV score cutoffs of 5.0 log for DFS and OS yielded the areas under the curve ≥ .577, with both being significantly prognostic of tumor recurrence and patient mortality at 3 years. ADV score cutoffs of ADV 4.0 log and 8.0 log, derived through K-adaptive partitioning method, showed higher prognostic contrasts in DFS and OS. ROC curve analysis showed that an ADV score cutoff of 4.2 log was suggestive of microvascular invasion, with both microvascular invasion and an ADV score cutoff of 4.2 log showing similar DFS rates., Conclusions: This international validation study demonstrated that ADV score is an integrated surrogate biomarker for post-resection prognosis of HCC. Prognostic prediction using ADV score can provide reliable information that can assist in planning treatment of patients with different stages of HCC and guide individualized post-resection follow-up based on the relative risk of HCC recurrence., (© 2023 Japanese Society of Hepato-Biliary-Pancreatic Surgery.)

Newts and salamanders show remarkable diversity in antipredator behavior, developed to enhance their chemical defenses and/or aposematism. The present study reports on the antipredator behavior of newts (Cynops pyrrhogaster) in response to snakes. Newts displayed a significant amount of tail-wagging and tail-undulation in response to a contact stimulus from the snake's tongue, which is a snake-specific predator stimulus, as compared to a control stimulus (behavioral scores: tongue, 1.05 ± 0.41; control, 0.15 ± 0.15). Newts that were kept in warm temperature conditions, 20°C (at which snakes are active in nature), performed tail displays more frequently than newts kept in low-temperature conditions, 4°C (at which snakes are inactive in nature). Our results suggest that the tail displays of C. pyrrhogaster could function as an antipredator defense; they direct a snake's attention to its tail to prevent the snake from attacking more vulnerable body parts. We also discussed the reason for inter-populational variation in the tendency of newts to perform tail displays., Competing Interests: NO authors have competing interests.

Background: Post-hepatectomy portal vein thrombosis (PH-PVT) is a severe complication. The risk factors of PH-PVT after laparoscopic and open hepatectomy have not been clarified yet. We aimed to retrospectively investigate the risk factors and outcome of PH-PVT in patients with primary liver cancer., Methods: We enrolled 622 consecutive patients who underwent hepatectomy in our hospital between January 2006 and August 2016., Results: Of 21 patients (3.4%) with PH-PVT, 7 had grade I; 13, grade II; and 1, grade III. The patients with PH-PVT were significantly older than those without PH-PVT. Of the 413 patients who underwent open hepatectomy, those who underwent a major right hepatectomy (4.1%) had a slightly higher incidence of PH-PVT. Of the 209 patients who underwent laparoscopic hepatectomy, those who underwent a left lateral sectionectomy (21.2%) and major right hepatectomy (16.7%) had high incidence rates of PH-PVT. The treatment was only observation in five patients, medication with an antithrombotic drug in 15 patients, and reoperation in one patient. PH-PVT diminished in 17 patients. Cavernous transformation and/or stenosis of the portal vein developed in three patients. The patient with grade III PH-PVT after open right hemihepatectomy underwent reoperation but died of hepatic failure., Conclusion: This study demonstrated that patient age, left lateral sectionectomy were risk factors of PH-PVT. Laparoscopic left lateral sectionectomy and major right hepatectomy might bring about relatively higher risk of PH-PVT. Major right hepatectomy tends to lead to severe PH-PVT. Careful handling of the PV during hepatectomy and early treatment of PH-PVT are necessary.

Approximately 10-20% of patients with primary biliary cholangitis (PBC) progress to jaundice stage regardless of treatment with ursodeoxycholic acid and bezafibrate. In this study, we performed a GWAS and a replication study to identify genetic variants associated with jaundice-stage progression in PBC using a total of 1,375 patients (1,202 early-stage and 173 jaundice-stage) in a Japanese population. SNP rs13720, which is located in the 3'UTR of cathepsin Z (CTSZ), showed the strongest association (odds ratio [OR] = 2.15, P = 7.62 × 10 -7 ) with progression to jaundice stage in GWAS. High-density association mapping at the CTSZ and negative elongation factor complex member C/D (NELFCD) loci, which are located within a strong linkage disequilibrium (LD) block, revealed that an intronic SNP of CTSZ, rs163800, was significantly associated with jaundice-stage progression (OR = 2.16, P = 8.57 × 10 -8 ). In addition, eQTL analysis and in silico functional analysis indicated that genotypes of rs163800 or variants in strong LD with rs163800 influence expression levels of both NELFCD and CTSZ mRNA. The present novel findings will contribute to dissect the mechanism of PBC progression and also to facilitate the development of therapies for PBC patients who are resistant to current therapies.

Recently, interest in utilizing ecosystems for disaster risk reduction has increased, even though there remains considerable uncertainty regarding the role of ecosystems in buffering against natural hazards. This ecosystem role can be considered an ecosystem service. Although a strong body of evidence shows that biodiversity enhances ecosystem services, there are only a few studies of the relationship between biodiversity and the role of the ecosystem in reducing the risk of natural disasters. To explore the desired state of an ecosystem for disaster risk reduction we applied the finding that biodiversity enhances ecosystem services to evaluate the role of woody vegetation in reducing the frequency and severity of shallow landslides. Using information related to shallow landslides and woody vegetation in Japan as a case study, we compared the severity of shallow landslides (i.e., landslide volume) with tree species richness. Although we provide no direct evidence that tree species richness reduces shallow landslide volume, we found that the predictability of the model, which evaluated relationships between landslide volume and environmental variables in watersheds throughout the Japanese Archipelago, increased with tree species richness. This finding suggests that biodiversity is likely associated with shallow landslide risk reduction, emphasizing a possible reduction of spatial and temporal uncertainty in the roles of woody vegetation. Our study identifies a need for socioecological systems to build new approaches found on the functionality of such ecosystems.

A previous genome-wide association study (GWAS) performed in 963 Japanese individuals (487 primary biliary cholangitis [PBC] cases and 476 healthy controls) identified TNFSF15 (rs4979462) and POU2AF1 (rs4938534) as strong susceptibility loci for PBC. In this study, we performed GWAS in additional 1,923 Japanese individuals (894 PBC cases and 1,029 healthy controls), and combined the results with the previous data. This GWAS, together with a subsequent replication study in an independent set of 7,024 Japanese individuals (512 PBC cases and 6,512 healthy controls), identified PRKCB (rs7404928) as a novel susceptibility locus for PBC (odds ratio [OR] = 1.26, P = 4.13 × 10-9). Furthermore, a primary functional variant of PRKCB (rs35015313) was identified by genotype imputation using a phased panel of 1,070 Japanese individuals from a prospective, general population cohort study and subsequent in vitro functional analyses. These results may lead to improved understanding of the disease pathways involved in PBC, forming a basis for prevention of PBC and development of novel therapeutics., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Elderly donor grafts for liver transplantation (LT) are recognized to be marginal grafts. The present study investigated the impact of using elderly donors for LT. Between June 1990 and August 2012, 1631 patients received LT at Kyoto University Hospital. Out of 1631 patients, 1597 patients received living donor liver transplantation (LDLT), whereas the other 34 patients underwent deceased donor liver transplantation (DDLT). Seventy-five grafts that were used came from individuals who were ≥60 years old. We retrospectively analyzed the recipients' survival rates according to donor age. The overall survival rates of the recipients of all LDLT (P < 0.001), adult-to-adult LDLT (P = 0.007), all DDLT (P = 0.026), and adult-to-adult DDLT (P = 0.011) were significantly lower for the elderly donor group versus the younger group and especially for those who were hepatitis C-positive. A multivariate analysis revealed that donor age, ABO incompatibility, and preoperative intensive care unit stay were independent risk factors for poor patient survival in adult-to-adult LDLT. However, no significant differences existed between the 2 groups among those who received adult-to-adult LDLT in and after April 2006. No significant association was found between donor age and incidence of acute cellular rejection. In conclusion, donor age was closely related to the survival rate for LDLT and DDLT, although the impact of donor age was not shown in the recent cases., (© 2015 American Association for the Study of Liver Diseases.)

Many animals sequester dietary defensive compounds and incorporate them into the offspring, which protects the young against predation. One possible but poorly investigated question is whether females of such species actively prey upon toxic diets. The snake Rhabdophis tigrinus sequesters defensive steroids from toads consumed as prey; it also feeds on other amphibians. Females produce chemically armed offspring in direct proportion to their own level of toad-derived toxins by provisioning the toxins to their eggs. Our field observations of movements and stomach contents of radio-tracked R. tigrinus showed that gravid snakes preyed upon toads by actively foraging in the habitat of toads, even though toads were a scarce resource and toad-searching may incur potential costs. Our Y-maze experiments demonstrated that gravid females were more likely to trail the chemical cues of toads than were males or non-gravid females. These results showed behavioural switching in females and active foraging for scarce, toxic prey during gestation. Because exploitation of toads by gravid females results in their offspring being more richly endowed with prey-derived toxins, active foraging for toxic prey is expected to be an adaptive antipredator trait, which may enhance chemical defence in offspring., (© 2014 The Author(s) Published by the Royal Society. All rights reserved.)

Intramuscular fat accumulation has come to be associated with loss of muscle strength and function, one of the components of sarcopenia. However, the impact of preoperative quality of skeletal muscle on outcomes after living donor liver transplantation (LDLT) is unclear. The present study evaluated the intramuscular adipose tissue content (IMAC) and psoas muscle mass index (PMI) in 200 adult patients undergoing LDLT at our institution between January 2008 and October 2013. Correlations of IMAC with other factors, overall survival rates in patients classified according to IMAC or PMI, and risk factors for poor survival after LDLT were analyzed. IMAC was significantly correlated with age (r = 0.229, P = 0.03) and PMI (r = -0.236, P = 0.02) in males and with age (r = 0.349, P < 0.001) and branched-chain amino acid (BCAA)-to-tyrosine ratio (r = -0.250, P = 0.01) in females. The overall survival rates in patients with high IMAC or low PMI were significantly lower than those for patients with normal IMAC or PMI (P < 0.001, P < 0.001, respectively). Multivariate analysis showed that high IMAC [odds ratio (OR) = 3.898, 95% confidence interval (CI) = 2.025-7.757, P < 0.001] and low PMI (OR = 3.635, 95% CI = 1.896-7.174, P < 0.001) were independent risk factors for death after LDLT. In conclusion, high IMAC and low PMI were closely involved with posttransplant mortality. Preoperative quality and quantity of skeletal muscle could be incorporated into new selection criteria for LDLT. Perioperative nutritional therapy and rehabilitation could be important for good outcomes after LDLT., (© 2014 American Association for the Study of Liver Diseases.)

Living donor liver transplantation (LDLT) for patients with high model for end-stage liver disease score and acute liver failure patients have little or not gained any substantial following among Western centers because of the "donor high risk-low recipient benefit scenario" that puts the donor at a significant risk against the survival odds for a recipient who is receiving a partial graft and considered marginal by Western standards. In most Asian countries, there is sometimes no other source of live graft but a willing live liver donor. There are individual Asian center reports that conclude that LDLT has comparable outcome to deceased donor liver transplant. However, the outcomes of a large number of patients after undergoing adult LDLT for high model for end-stage liver disease scores and acute liver failure at a single center have not been investigated. Here in, we present our experience with such subgroup of patients undergoing LDLT.

Background: Previously, we proposed expanded selection criteria for liver transplantation (LT) for hepatocellular carcinoma (HCC), the Kyoto criteria, involving a combination of tumor number ≤10, maximal diameter of each tumor ≤5 cm, and serum des-gamma-carboxy prothrombin levels ≤400 mAU/mL, and we have used these criteria since January 2007. In the present study, the usefulness of the criteria was validated prospectively as well as retrospectively., Methods: One hundred ninety-eight patients with HCC who underwent living donor LT (LDLT) from February 1999 through December 2011 were enrolled in this study. Overall survival and recurrence rates were investigated in patients classified according to the Kyoto criteria, the Milan criteria, or previous treatments for HCC. Tumor biological aggressiveness, including microvascular invasion and histologic differentiation, according to selection criteria was also examined., Results: The 5-year overall survival for patients within the Kyoto criteria (n = 147; 82%) was greater than that for the 49 patients exceeding them (n = 49; 42%; P < .001). The 5-year recurrence rate for patients within the Kyoto criteria (4.4%) was less than that for patients exceeding them (51%; P < .001). Intention-to-treat analysis of the 62 patients who underwent LDLT after implementation of the Kyoto criteria showed that the 5-year overall survival rate and the recurrence rate were 82% and 7%, respectively. Tumor biology was significantly less aggressive in patients within the Kyoto criteria., Conclusion: The Kyoto criteria are useful expanded criteria for LDLT for HCC and could help to achieve favorable outcomes., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Objective: Infectious complications, including sepsis, that often occur after liver transplantation (LT) comprise the most frequent causes of in-hospital death. This study investigated the predictors of post-transplantation infectious complications to establish a strategy with which to improve short-term outcomes after LT., Methods: We used univariate and multivariate analyses to assess pre- and perioperative risk factors for post-transplantation infectious complications in 100 consecutive patients who underwent living donor LT from February 2008 through February 2010 at our institute., Results: Multivariate analysis showed that low preoperative body cell mass and the absence of preoperative supplementation with branched-chain amino acids were of prognostic significance for post-transplantation sepsis. In addition, Child-Pugh classification C and massive operative blood loss were independent risk factors for post-transplantation bacteremia, and preoperative low body cell mass was an independent risk factor for in-hospital death from infection., Conclusion: Pretransplantation nutritional intervention and decreases in operative blood loss would help prevent post-transplantation infectious complications from developing during living donor LT. Branched-chain amino acid supplementation before LT affects the occurrence of infectious complications., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Little is known about outcomes and indications for living donor liver transplantation in patients with recurrent hepatocellular carcinoma after liver resection., Methods: We analyzed retrospectively 176 patients with hepatocellular carcinoma who underwent living donor liver transplantation at our institute between February 1999 and December 2009. Among 128 of 176 patients with a history of pretreatment for hepatocellular carcinoma, 19 patients underwent radical liver resection. We compared patient characteristics, intraoperative blood loss, operative duration, and long-term outcomes including overall survival and recurrence rates between patients who had received hepatectomy, other pretreatments, and no pretreatments., Results: The surgical duration was significantly longer in patients with pretransplant hepatectomy than in those who had undergone other types of pretreatment (n = 109) or none (n = 48), whereas intraoperative blood loss did not differ among the 3 groups. Overall survival and recurrence rates did not significantly differ among the 3 groups. In patients with pretransplant hepatectomy, survival rates were significantly higher among patients who met the Kyoto criteria (≤10 tumors, all ≤5 cm in diameter and serum des-gamma-carboxy prothrombin levels ≤400 mAU/mL; n = 15) than those with values that exceeded the Kyoto criteria (n = 4) (5-year survival rates, 93% vs 25%, P = .005). Similarly, recurrence rates were significantly lower among patients meeting than exceeding the Kyoto criteria (5-year recurrence rates, 10% vs 67%, P = .011)., Conclusion: Patients with hepatocellular carcinoma recurrence after liver resection can safely undergo living donor liver transplantation. Long-term outcomes can be particularly favorable in patients who meet the Kyoto criteria., (Copyright © 2012 Mosby, Inc. All rights reserved.)

To prevent small-for-size syndrome in adult-to-adult living donor liver transplantation (A-LDLT), larger grafts (ie, right lobe grafts) have been selected in many transplant centers. However, some centers are investigating the benefits of portal pressure modulation. Five hundred sixty-six A-LDLT procedures using right or left lobe grafts were performed between 1998 and 2008. In 2006, we introduced intentional portal pressure control, and we changed the graft selection criteria to include a graft/recipient weight ratio >0.7% instead of the original value of >0.8%. All recipients were divided into period I (1998-2006, the era of unintentional portal pressure control; n = 432) and period II (2006-2008, the era of intentional portal pressure control; n = 134). The selection of small-for-size grafts increased from 7.8% to 23.9%, and the selection of left lobe grafts increased from 4.9% to 32.1%. Despite the increase in the number of smaller grafts in period II, 1-year patient survival was significantly improved (87.9% versus 76.2%). In 129 recipients in period II, portal pressure was monitored. Patients with a portal pressure <15 mm Hg demonstrated better 2-year survival (n = 86, 93.0%) than patients with a portal pressure >or=15 mm Hg (n = 43, 66.3%). The recovery from hyperbilirubinemia and coagulopathy after transplantation was significantly better in patients with a portal pressure <15 mm Hg. In conclusion, our strategy for A-LDLT has changed from larger graft-based A-LDLT to controlled portal pressure-based A-LDLT with smaller grafts. A portal pressure <15 mm Hg seems to be a key for successful A-LDLT., ((c) 2010 AASLD.)

The aim of this study was to determine the prevalence of Cryptosporidium in snakes in Japan. Fecal samples or intestinal contents of 469 snakes, consisting of five species, were analyzed and Cryptosporidium oocysts were detected only from the Japanese grass snake Rhabdophis tigrinus. The mean prevalence of Cryptosporidium sp. in Japanese grass snakes was approximately 26% in the region studied. Histopathological observations revealed that the organism caused proliferative enteritis in the small intestine. Sequence analysis of a fragment of the small subunit rRNA gene has shown that the partial sequence of Cryptosporidium sp. isolated from the snakes was identical to that of the Cryptosporidium snake genotype W11 from New Guinea viper boa.

Light-related plasticity of crown morphology and within-crown characteristics were investigated in understory sun and shade saplings of three codominant subalpine conifers, Abies mariesii M.T. Mast., Abies veitchii Lindl. and Picea jezoensis var. hondoensis (Mayr) Rehd. Compared with those of sun saplings, current-year shoots of shade saplings allocated less biomass to needles, resulting in less dense needle packing and hence less mutual needle shading. The proportion of lateral branch biomass in foliage was either similar in sun and shade saplings or greater in shade saplings, depending on the species, suggesting that, over the lifetime of a branch, greater needle longevity in shade compensates for reduced biomass investment in needles of current-year shoots of shade saplings. Saplings with slower-growing branches tended to have greater needle life spans, suggesting that plasticity of branch growth rate and plasticity of needle life span are interdependent. Both Abies species showed greater light-related plasticity of needle life span and branch growth than P. jezoensis. The greater shade tolerance of the Abies species derives from their broad flattened crowns with slow-growing branches. This type of crown development incurs substantial support costs, but the long needle life span of shade saplings of the Abies species compensates, at least in part, for their low annual investment in foliage, especially in the case of A. mariesii, which has a longer needle life span and slower-growing and stouter branches than A. veitchii. Compared with the Abies species, P. jezoensis had a less plastic crown morphology, and less variability of needle life span and branch growth in response to light, resulting in lower shade tolerance. However, compared with the flattened crown of Abies shade saplings, the conical crown of P. jezoensis saplings imposes a smaller support cost, making this species better adapted to rapid height growth than to survival in shade.