Description of Discocotyle ciray n. sp. (Monogenea: Discocotylidae) from Parahucho perryi (Brevoort) from Hokkaido, Japan, with a redescription of D. sagittata (Leuckart, 1842).

Discocotyle sagittata (Leuckart, 1842) (Monogenea: Discocotylidae) is redescribed, based on specimens collected from the type host, Salmo trutta Linnaeus, from the type locality, Freiburg, Germany, supplemented with specimens from S. trutta and rainbow trout, Oncorhynchus mykiss (Walbaum) reared in an Austrian aquarium. The diagnosis of the genus Discocotyle Diesing, 1850 is emended. Discocotyle ciray n. sp. is described, based on immature, preadult and adult specimens from the salmonid, Parahucho perryi (Brevoort) at Eniwa, Hokkaido, Japan. Adult specimens of the new species were about twice as large as those of D. sagittata from S. trutta. When the type specimens of D. ciray n. sp. were examined together with museum specimens from P. perryi at Tsurui, Hokkaido, the body and clamp sizes were positively correlated to the host size. Their measurements from a smaller P. perryi at Tsurui overlapped with those of D. sagittata, showing that these size differences were not suitable differentiating keys. Discocotyle ciray n. sp. can be separated from D. sagittata by the morphologies of the female genital system (relatively anteriorly positioned ovary, short joint vaginal duct and much more strongly winding uterus). The genetic distances of COI mtDNA sequence between D. ciray n. sp. and D. sagittata were 18.0-18.6%. These remarkable genetic divergences also supported the distinct taxonomic status of D. ciray n. sp.

Identification of glycine betaine as a host-derived molecule required for the vegetative proliferation of the protozoan parasite Perkinsus olseni.

Perkinsus olseni is an industrially significant protozoan parasite of Manila clam, Ruditapes philippinarum. So far, various media, based on Dulbecco's Modified Eagle Medium and Ham's F-12 nutrient mixture with supplementation of fetal bovine serum (FBS), have been developed to proliferate the parasitizing trophozoite stage of P. olseni. The present study showed that P. olseni did not proliferate in FBS-deficient Perkinsus broth medium (PBMΔF), but proliferated well in PBMΔF supplemented with tissue extract of host Manila clams, indicating that FBS and Manila clam tissue contained molecule(s) required for P. olseni proliferation. Preliminary characterization suggested that the host-derived molecule(s) was a heat-stable molecule(s) with a molecular weight of less than 3 kDa, and finally a single molecule required for the proliferation was purified by high-performance liquid chromatography processes. High-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance analyses identified this molecule as glycine betaine (=trimethylglycine), and the requirement of this molecule for P. olsseni proliferation was confirmed by an assay using chemically synthesized, standard glycine betaine. Although glycine betaine was required for the proliferation of all examined Perkinsus species, supplementation of glycine betaine precursors, such as choline and betaine aldehyde, enhanced the proliferation of 4 Perkinsus species (P. marinus, P. chesapeaki, P. mediterraneus and P. honshuensis), but not of 2 others (P. olseni and P. beihaiensis). Thus, it was concluded that the ability to biosynthesise glycine betaine from its precursors varied among Perkinsus species, and that P. olseni and P. beihaiensis lack the ability required to biosynthesize glycine betaine for proliferation.

Supplementation with lipids enhances zoosporulation of Perkinsus species.

The protozoan parasite Perkinsus olseni is a major pathogen of marine mollusks. A large number of zoospores (the most infective stage) is required to experimentally examine the transmission and invasion processes of this parasite, but the conventional zoosporulation method in seawater is inefficient. A recent study found that P. olseni zoosporulation was highly enhanced in a nutrient-rich medium which was developed for trophozoite proliferation in Perkinsus. Here, we examined the effect of each medium component on P. olseni zoosporulation and found that lipids enhanced zoosporulation. Moreover, zoospores failed to develop into trophozoites in seawater supplemented with lipids, indicating that this zoosporulation method using seawater supplemented with lipids is ideal for preparing a large number of P. olseni zoospores for various biological assays. Lipid supplementation also significantly enhanced zoosporulation in P. honshuensis, P. chesapeaki, and P. marinus, although the enhancing effect of the lipid supplementation varied by species. Considering the limited availability of lipids in the sea water column, our findings suggest that Perkinsus zoosporulation likely occurs mainly in the vicinity of hosts (not in the sea water column), such as in the mantle cavity or on the body surface of mollusk hosts.

A rise-assisting robot extends life space and improves facial expressions of nursing home residents.

BACKGROUND: The introduction of nursing care-support devices using robotic technology is expected to reduce the task burden in long-term care facilities. OBJECTIVE: To investigate the use of the rise-assisting robot, Resyone, in extending and improving the life space of nursing home residents with severe care needs. METHODS: We performed a feasibility study in which Resyone was used to facilitate visits to additional sites in and around the nursing home as part of the care package of three residents. Two weeks before and four weeks after implementation of the new arrangements, the 30 caregivers involved were asked to record transfer times and destinations, while also checking the residents' facial expressions. RESULTS: Before implementation, participants had limited life spaces, but afterwards they regularly visited additional destinations including the garden, home entrance and corridors, which previously they had not visited frequently. The residents' facial expressions became more positive and less negative. This study demonstrates that Resyone can enrich care activities in severely disabled individuals. CONCLUSION: These findings suggest that the sustainable use of Resyone would improve the quality of care at care facilities. Moreover, the extension of otherwise limited life space has the potential to improve care receivers' quality of life. TRIAL REGISTRATION: UMIN Clinical Trials Registry No. UMIN000039204 (20/01/2020); retrospectively registered; interventional study; parallel, non-randomized, single blinded. URL of trial registry records: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000044709 .

Establishment and characteristics of Perkinsus beihaiensis in vitro isolates from Mediterranean mussels Mytilus galloprovincialis.

Two monoclonal in vitro isolates of Perkinsus beihaiensis were established from tissues of infected Mediterranean mussels Mytilus galloprovincialis, using a lipid concentrate and yeast extract medium (LpcYM) to induce enlarged prezoospoangia from histozoic trophozoites, and Perkinsus broth medium (PBM) to support subsequent zoosporulation and schizogonic proliferation from those cells. Zoospores of the isolates developed into uninucleate signet-ring trophozoites followed by schizonts typical of Perkinsus spp., but an additional type of unknown botryoidal cell clusters appeared and increased in density. These botryoidal cell clusters had second-generation daughter schizonts within which further internal cells were produced. Although botryoidal cell clusters in primary cultures rarely proliferated in PBM, cells contained by botryoidal clusters enlarged as prezoosporangia in LpcYM, and a large number of proliferative stages (i.e. trophozoites and schizonts typical for Perkinsus spp.) were obtained from these prezoosporangia in PBM. At lower cell density, trophozoites transformed into the botryoidal cell clusters in PBM, and the number of cells increased little, while trophozoites rapidly increased by typical schizogony at higher density in PBM. Based on these observations, we determined an optimal cell density for continuous culture of P. beihaiensis isolates, confirmed their ability to proliferate and survive after cryopreservation, and describe an experimental protocol to culture this most recently described species in the genus Perkinsus.

Molecular and microscopic identification of Eomarteilia granula infection in Manila clam Ruditapes philippinarum off the south coast of Korea.

A report on the new species Eomarteilia (=Marteilia) granula infecting Manila clam Ruditapes philippinarum from Japan in 2014 suggests the possibility of E. granula infecting other Manila clam populations in the Northwest Pacific region, including Korea. In this study, we report the first infections by E. granula in Manila clams off the south coast of Korea. Histology revealed Marteilia-like plasmodia in the digestive tubule epithelia. Tissue imprints demonstrated that each parasite sporangium enclosed 4 spores and transmission electron microscopy (TEM) revealed ultrastructure of primary cells enclosing secondary cells, which contained spores. Mature spores consisted of 3 sporoplasms: outermost, intermediate, and innermost. The outermost sporoplasm showed a peripheral electron-dense monolayer characteristic of E. granula. The 18S rDNA amplified from the Marteilia-like parasite yielded 1784-bp PCR amplicon sequences which were 99.8% similar to that of E. granula previously reported (as M. granula) from Japan. In the molecular phylogenetic analysis, the novel Marteilia-like organism formed a well-supported clade with E. granula. Accordingly, we concluded that the novel Marteilia-like parasite that we found infecting some Korean Manila clams is Eomarteilia granula. Field surveys revealed that the infection was limited to clams of the south coast of Korea, with the prevalence ranging from 3.3 to 5.0%.

Five new and two known species of Heterobothrium (Monogenea: Diclidophoridae) infecting puffers of the genus Takifugu from Japanese waters.

Seven species of puffers of the genus Takifugu caught in Japanese waters were examined for monogeneans on the gills. Five new species of Heterobothrium (H. gotoi n. sp. from T. porphyreus, H. tabetai n. sp. from T. vermicularis, H. aljufailiae n. sp. and H. iwatai n. sp. from T. snyderi, H. matsubarai n. sp. from T. stictonotus) and two known species (H. praeorchis Bychowsky, Mamaev & Nagibina, 1976 from T. pardalis, T. chrysops and T. flavipterus and H. bychowskyi Ogawa, 1991 from T. flavipterus) were found and described. Heterobothrium tetrodonis of Iwata (1991) was synonymized with H. bychowskyi. Currently, a total of 11 species of Heterobothrium, including the seven species in this study, were recorded from nine species of Japanese Takifugu spp. Ten species excluding H. praeorchis were found from a single host species, suggesting that they are highly host-specific and have co-evolved with the host Takifugu spp. Tagia Sproston, 1946 is synonymized with Heterobothrium. Earlier divergence of Heterobothrium of tetraodontid puffers in Diclidophoridae was suggested by the large subunit ribosomal DNA (rDNA) analyses, and interspecific relationships in this genus inferred from the internal transcribed spacer region of rDNA well corresponded to those inferred from their morphology and adhesive mode to the gills. Including the five new species and synonymization of Tagia with Heterobothrium, the genus Heterobothrium now comprises 19 species.

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) in urological malignancies: a multi-center retrospective study.

INTRODUCTION: We evaluated the incidence and risk factors for antiresorptive agent-related osteonecrosis of the jaw (ARONJ) in prostate and kidney cancer patients. MATERIALS AND METHODS: We retrospectively reviewed the clinical data of 547 patients from 13 hospitals. Prostate and kidney cancer patients with bone metastases who were treated with a bone-modifying agent (BMA) between January 2012 and February 2019 were enrolled. Exclusion criteria were BMA use for hypercalcemia, a lack of clinical data, a follow-up period of less than 28 days and a lack of evaluation by dentists before BMA administration. The diagnosis and staging of ARONJ were done by dentists. RESULTS: Two-hundred eighteen patients were finally enrolled in the study, including 168 prostate cancer patients and 50 kidney cancer patients. Of them, 49 (29%) prostate cancer patients and 18 (36%) kidney cancer patients needed tooth extraction prior to BMA initiation. The mean follow-up period after BMA initiation was 552.9 ± 424.7 days (mean ± SD). In the cohort, 23% of the patients were diagnosed with ARONJ in the follow-up period. The 1-year cumulative incidences of ARONJ were 9.4% and 15.4% in prostate and kidney cancer patients, respectively. Multivariate analysis indicated that kidney cancer, tooth extraction before BMA and a body mass index (BMI) ≥ 25 kg/m2 were significant predictors for ARONJ. CONCLUSION: ARONJ is not a rare adverse event in urological malignancies. Especially, kidney cancer, high BMI patients and who needed tooth extraction before BMA were high risk for developing ARONJ.

Identification of care tasks for the use of wearable transfer support robots - an observational study at nursing facilities using robots on a daily basis.

BACKGROUND: To reduce the physical burden of caregivers, wearable transfer support robots are highly desirable. Although these robots are reportedly effective for specific tasks in experimental environments, there is little information about their effectiveness at nursing care facilities. The aim of this study was to identify care tasks and operations suitable for the use of these robots among caregivers in nursing facilities where these robots have been in use on a daily basis. METHODS: A 1-min observational time-motion analysis was conducted to examine care tasks and operations in two nursing facilities where wearable transfer support robots, namely Muscle Suit or HAL® Lumbar Type for Care Support, have been used routinely on a daily basis for more than 24 months. RESULTS: Analysis of the care tasks and their time ratio while wearing the equipment revealed that both robots were used conspicuously for direct care in over 70% of transits, especially during transfer assistance and toileting care. Furthermore, these robots were used intensively in the morning along with wake-up calls to care recipients, where pre-assigned wearers used them as part of their "routine work." CONCLUSIONS: We found that these wearable transfer support robots enabled effective performance of care tasks and operations in nursing facilities where these robots have been used on a daily basis for an extended period of time. These results may lead to the effective implementation and sustained operation of other types of care robots in the future. TRIAL REGISTRATION: UMIN Clinical Trials Registry no. UMIN000039204 . Trial registration date: January 21, 2020. Interventional study. Parallel, non-randomized, single blinded.

Francisellosis of Yesso scallops Mizuhopecten yessoensis in Japan is caused by a novel type of Francisella halioticida.

Francisella halioticida, the causative agent of francisellosis of the giant abalone Haliotis gigantea, has also been isolated from Yesso scallops Mizuhopecten yessoensis, which presented with orange/pinkish lesions in the adductor muscle and experienced high mortality. However, it is not clear whether the F. halioticida isolated from the giant abalone and Yesso scallops are phenotypically and genetically identical to each other. The present study revealed that isolates from the giant abalone and Yesso scallops were phenotypically different, with slower growth in modified eugon broth and a lack of prolyl aminopeptidase and phenylalanine aminopeptidase in Yesso scallop isolates. Additionally, we found that 3 of 8 housekeeping genes were different between them. Based on these phenotypic and genetic differences, we propose that F. halioticida isolated from Yesso scallops in Japan be designated as the 'J-scallop type' to distinguish it from strains from abalone ('abalone type'). Whole-genome sequencing analysis of a strain belonging to the J-scallop type showed that the overall similarity between the J-scallop and abalone type strains was estimated to be 99.84%. In accordance with a lack of prolyl aminopeptidase activity, in general, all of the J-scallop type strains examined have a 1 bp deletion in the responsible gene encoding prolyl aminopeptidase. This deletion was confirmed in all F. halioticida in diseased Yesso scallops examined, suggesting that in Japan, francisellosis of Yesso scallops is caused by a novel type of F. halioticida and not by the abalone type.

A new myxosporean species, Henneguya lata n. sp. (Myxozoa: Myxobolidae), from the gills of yellowfin seabream Acanthopagrus latus (Perciformes: Sparidae) in the Gulf of Tonkin, Vietnam.

During a survey of myxosporean parasites of marine fish in the coastal region of Vietnam, a species of the genus Henneguya (Myxosporea: Bivalvulida) was found in the gill of yellowfin seabream Acanthopagrus latus (Perciformes: Sparidae). White and oval cysts, measuring 145-220 µm in diameter, were detected in the gill lamellae of 4 of 15 fish examined (26.7%). Mature myxospores were elongate, with smooth valves, two similar polar capsules, and having the following dimensions: spore body length 9.9 ± 0.5 (8.9-12.5) µm, body width 6.7 ± 0.3 (6.1-7.6) µm, thickness 5.1 ± 0.2 (4.8-5.4) µm, caudal appendage length 10.0 ± 1 (8.3-11.6) µm, and total myxospore length 19.3 ± 1.4 (16.5-21.5) µm. The polar capsules were ovoid, measuring 3.2 ± 0.2 (2.8-3.9) µm long and 1.9 ± 0.2 (1.5-2.3) µm wide. Each polar capsule has a polar filament with 4-5 coils. Histological analysis revealed plasmodia in the connective tissues of the gill lamellae, but inflammation and deformation of the gills were not observed. In the phylogenetic tree reconstructed from the small subunit ribosomal DNA (SSU rDNA), sequences of the Henneguya specimens found in this study form a distinct branch. Morphological characteristics and molecular data identified a new species, namely Henneguya lata n. sp.

Therapeutic options to reduce intravesical recurrence in newly diagnosed Ta high-grade bladder cancer according to risk stratification: A multicenter retrospective study.

OBJECTIVES: To evaluate the risk factors for intravesical recurrence in patients with newly diagnosed Ta high-grade non-muscle-invasive bladder cancer and the optimal management to reduce the risk of recurrence. METHODS: We retrospectively evaluated Ta high-grade bladder cancer in patients who were newly diagnosed by transurethral resection from January 2007 through October 2018. Using multivariate analyses, we evaluated the risk factors and therapeutic options affecting intravesical recurrence and stratified the patients according to the risk numbers. RESULTS: We included 390 patients and the median follow-up period was 31 months after the initial transurethral resection. According to multivariate analysis, having a previous history of upper urinary tract carcinoma, and multiple and sessile tumors were risk factors for intravesical recurrence (P = 0.001, P = 0.02 and P = 0.01, respectively). Risk groups were stratified according to these risk factors into favorable, intermediate and poor. In the entire cohort, induction and immediate intravesical instillation therapy were treatment options to reduce intravesical recurrence (P < 0.01 and P = 0.02, respectively). Analyses in each risk group showed that a second transurethral resection was the only therapeutic option to reduce intravesical recurrence in the favorable group (P = 0.048), whereas induction intravesical instillation therapy was effective in the intermediate and poor risk groups (P = 0.01 and P < 0.01, respectively), as was immediate intravesical instillation for the poor risk group (P < 0.001). CONCLUSIONS: Sessile, multiple tumors and a history of upper urinary tract carcinoma are risk factors for intravesical recurrence in Ta high-grade bladder cancer patients.

Emendation of the genus Neoheterobothrium and a proposal of a new genus Paraheterobothrium (Monogenea: Diclidophoridae) for five species of diclidophorids from Pleuronectiform fishes.

Neoheterobothrium chilense González, Oliva & Acuña, 2002 is redescribed based on newly collected specimens from the type host, Hippoglossina macrops and type locality (Coquimbo, Northern Chile). Type specimens of Neoheterobothrium hippoglossini Piasecki, Wierzbicka & Kempter, 2000 and Choricotyle exilis Crane, 1972 are also redescribed. These three diclidophorid monogeneans infecting pleuronectiform flatfishes have pre-ovarian seminal receptacle, ootype inside the semicircle of ovary and elongated pharynx, differentiated from the most similar Orbocotyle Euzet & Suriano, 1975 in that members of the latter genus possess post-ovarian seminal receptacle, post-ovarian ootype and cylindrical or pyriform pharynx. Paraheterobothrium n. g. is proposed for P. chilense n. comb. (type), P. hippoglossini n. comb., P. exilis n. comb., P. papillosum n. comb. and P. syacii n. comb. A redescription of Neoheterobothrium affine (Linton, 1898), the type species of the genus, based on voucher specimens confirmed differences from the new genus in the presence of lamellate plate in the anterior jaw of clamps, absence of seminal receptacle and ovoid pharynx. The genus Neoheterobothrium was emended and N. cynoscioni (MacCallum, 1917) and N. mcdonaldi Payne, 1987 were removed from the genus. Neoheterobothrium now comprises N. affine (type), N. insulare Oliva & Luque, 1995, N. hirame Ogawa, 1999, and N. paralichthyi Suriano & Labriola, 1999, all of them parasites of flatfishes of the genus Paralichthys. Molecular analyses with the internal transcribed spacer 1 distinguished the clade for Paraheterobothrium spp. (P. chilense n. comb. and P. papillosum n. comb.) and Neoheterobothrium spp. (N. hirame, N. affine and N. paralichthyi), supporting this taxonomic emendation.

[A Case of Prostate Cancer with Multiple Bone Metastasis with High FGF23 Value Indicated by Intractable Hypocalcemia and Hypophosphatemia].

A 53-year-old man was diagnosed with prostate cancer with multiple bone metastasis. Therefore androgen deprivation therapy was initiated. After treatment with denosumab injection for bone metastasis, hypocalcemia and hypophosphatemia occurred. Despite treatment for hypocalcemia with vitamin D and calcium lactate,his serum calcium and phosphate levels were refractory to treatment. The etiology of hypophosphatemia was investigated,and the level of serum fibroblast growth factor 23 (FGF23) was abnormally elevated. Three months after the first measurement of FGF23,the patient died of prostate cancer. Severe hypophosphatemia is a typical manifestation of tumor-induced hypophosphatemic osteomalacia (TIO),which is a paraneoplastic condition, mediated by FGF23 overexpression in most cases. His osteoblastic metastasis,however,did not meet the disease criteria of osteomalacia. Several reports have suggested that excessive FGF23 may mediate both severe hypophosphatemia and aggressive castrationresistant prostate cancer characteristics. Management of serum FGF23 may be a novel therapeutic strategy for castration-resistant prostate cancer with hypophosphatemia.

The effects of environmental and nutritional conditions on the development of Perkinsus olseni prezoosporangia.

Perkinsus olseni is a widely distributed protozoan pathogen that infects a wide range of marine mollusks. Prezoosporulation of P. olseni trophozoites is easily observed in Ray's fluid thioglycollate medium, but in nature, trophozoites within host tissue should be able to develop into prezoosporangia without any additional artificial medium after the host dies. How this process might work in field conditions remains poorly understood, however, partly because of the lack of appropriate in vitro assays. In this study, we observed that trophozoites of P. olseni successfully developed into prezoosporangia when mixed with minced tissue of the Manila clam Ruditapes philippinarum and placed in seawater. We were thus able to establish a new method to examine the development of P. olseni to prezoosporangia under artificially simulated natural environmental conditions. Using this method, we found that low temperatures (5 °C, 15 °C) significantly suppressed prezoosporangia development. In addition, we found that prezoosporangia were developed in a wide range of salinities (10-50 practical salinity unit) and that P. olseni requires some nutrition factors from host tissue for prezoosporulation to occur. Because the transmission of P. olseni among a host population highly depends on the developmental process of prezoosporangia, which leads to production of the infective zoospore stage, these results will help further our understanding of the parasite's infection dynamics in nature.

A novel dimorphic microsporidian Ameson iseebi sp. nov. infecting muscle of the Japanese spiny lobster, Panulirus japonicus, in western Japan.

Japanese spiny lobsters (Panulirus japonicus) exhibiting white opaque abdominal muscle were found in Mie and Wakayama prefectures, in mid-Western Japan. Microscopically, two types of microsporidian spores, ovoid and rod-shaped, were observed infecting the muscle. Histologically, both types of spore were detected inside myofibers of the abdomen, appendages, and cardiac muscles and were often both observed in a single myofiber simultaneously. Transmission electron microscopy revealed that ovoid spores have villous projections on the surface, and that ovoid and rod-shaped spores have a polar filament with 12 coils and 6 to 8 coils respectively. Merogonic and sporogonic stages were observed around ovoid spores, but rarely around rod-shaped spores. The small subunit ribosomal DNA sequences obtained from both spore types were identical to each other, indicating that this microsporidian exhibits a clear spore dimorphism. Phylogenetic analysis based on the rDNA sequences indicates that this microsporidian is part of a clade consisting of the genera Ameson and Nadelspora, with the most closely related species being A. herrnkindi found in the Caribbean spiny lobster P. argus. Based on ultrastructural features, molecular phylogenetic data, host type and geographical differences among known species in these genera, the species found in whitened abdominal muscles of the Japanese spiny lobster is described as Ameson iseebi sp. nov.

Incidence and risk factors of postoperative delirium in elderly patients undergoing urological surgery: A multi-institutional prospective study.

OBJECTIVES: To investigate the incidence and risk factors of postoperative delirium among patients aged ≥65 years undergoing elective urological surgery. METHODS: From April 2015 through December 2016, 1023 consecutive patients aged ≥65 years who received transurethral, laparoscopic (with or without robot assistance) or open surgery in eight institutions were enrolled in this prospective observational study. Their preoperative cognitive status was assessed with the Hasegawa Dementia Scale-Revised score. The treating physician or nurse assessed delirium using the Intensive Care Delirium Screening Checklist. Multivariate logistic regression analysis was used to determine predictive factors for postoperative delirium. RESULTS: We analyzed 946 patients whose median age was 74 years (range 65-95 years). Postoperative delirium was observed in 32 patients (3.4%). Multivariate analysis showed that a history of cerebrovascular disease (odds ratio 5.24, 95% confidence interval 2.05-13.40), low Hasegawa Dementia Scale-Revised score <20 points (odds ratio 3.50, 95% confidence interval 1.36-9.02), low serum albumin level <3.5 g/dL (odds ratio 3.12, 95% confidence interval 1.25-7.83) and long surgery duration >4 h (odds ratio 4.94, 95% confidence interval 2.20-11.10) were independent risk factors for the development of postoperative delirium. CONCLUSIONS: The preoperative medical history, cognitive status, low serum albumin level and operative duration were associated with the development of postoperative delirium, although the incidence was just 3.4% in elective urological surgery. The present results suggest that the Hasegawa Dementia Scale-Revised is a useful tool for assessment of the risk for delirium.

First discovery of Perkinsus beihaiensis in Mediterranean mussels (Mytilus galloprovincialis) in Tokyo Bay, Japan.

During analyses of the invasive Mediterranean mussel Mytilus galloprovincialis for pathologies in Tokyo Bay, infection by the protozoan parasite Perkinsus beihaiensis was found through histological examination, Ray's Fluid Thioglycollate Medium assays, and molecular analyses. Specific PCR assays for each Perkinsus species also revealed the presence of an indigenous congeneric species, Perkinsus olseni, but P. beihaiensis was dominant in M. galloprovincialis. Sequences of the ribosomal internal transcribed spacer region I of P. beihaiensis found in Japan were genetically more similar to those found in South American countries (Panama and Brazil) than in Asian countries (China and India). Though Mediterranean mussels have become widespread in Japanese waters since their invasion in the 1930s, epidemiological surveys show that mussels collected outside Tokyo Bay are free of any Perkinsus infections. Based on these results, it was strongly suggested that P. beihaiensis invaded Tokyo Bay by transportation of bivalves originating from South America but has not yet spread to other parts of Japan. The possibility is not ruled out, however, that the parasite is indigenous in Japan but the environment in Tokyo Bay favors its transmission to Mediterranean mussels.

A novel paramyxean parasite, Marteilia tapetis sp. nov. (Cercozoa) infecting the digestive gland of Manila clam Ruditapes philippinarum from the southeast coast of Korea.

Paramyxean parasites in the genus Marteilia deteriorate digestive tissues of the host organisms, resulting in mortality of oysters, cockles, and mussels. Most reports of infection by Marteilia spp. are from Europe, while a new species of Marteilia was identified recently in Japan. Here, we report a previously unidentified species in the genus Marteilia from digestive diverticula of Manila clam Ruditapes philippinarum from the south coast of Korea. Prevalence of the parasite was low, 0.5-3.3% in the study sites. We characterized this species using light and transmission electron microscopy (TEM), and analyzed the 18S rDNA sequence. Light microscopy revealed the sporulation process from uninucleated stage to spore in the epithelial tissues of the digestive gland. TEM revealed that the parasites produced four secondary cells containing four tri-cellular spores. An electron-dense haplosporosome-like structure and striated inclusions were evident in the spore and the primary cells, respectively, while refringent granules were rarely observed in the secondary cells. Phylogenetic analyses of the 18S rDNA sequence placed this isolate in the genus Marteilia, although it is not identical to other known species in the genus. Based on morphological and molecular characters, we describe this species as Marteilia tapetis sp. nov., the second Marteilia species reported parasitizing Manila clams in Asian waters.

Parallel studies confirm Francisella halioticida causes mortality in Yesso scallops Patinopecten yessoensis.

Francisella halioticida is a marine bacterium originally described as the causative agent of mass mortality among giant abalone Haliotis gigantea. Recent field studies in Canada and Japan have suggested that this bacterium is also the cause of adductor muscle lesions and high mortality of Yesso scallops Patinopecten yessoensis, although a causal relationship has not been established. In the present study, the pathogenicity of F. halioticida in Yesso scallops was assessed in both Canada and Japan using bacteria isolated from diseased Yesso scallops in each respective country. Independent laboratory experiments revealed that scallops challenged with F. halioticida via bath exposure resulted in high mortality and histological lesions characterized by massive haemocyte infiltration. The presence of F. halioticida was confirmed using PCR, and F. halioticida was re-isolated from a portion of dead and surviving specimens. These results fulfill Koch's classic criteria for establishing disease causation and provide conclusive evidence that F. halioticida causes adductor muscle lesions and high mortality in Yesso scallops.