Exploring invertebrate indicators of ecosystem health by focusing on the flow transitional zones in a large, shallow eutrophic lake.

The river-lake transitional zone provides a unique environment for the biological community and can reduce pollution inputs in lake ecosystems from their catchments. To explore environmental conditions with high purification potential in Lake Taihu and indicator species, we examined the river-to-lake changes in water and sediment quality and benthic invertebrate communities in the transitional zone of four regions. The spatial variations in the environment and invertebrate community observed in this study followed the previously reported patterns in Taihu; the northern and western regions were characterized by higher nutrient concentrations in water, higher heavy metal concentrations in sediment, and higher total invertebrate density and biomass dominated by pollution-tolerant oligochaetes and chironomids. Although nutrient concentrations were low and transparency was high in the eastern region, the taxon richness was the lowest there, which disagreed with the previous findings and might be due to a poor cover of macrophytes in this study. The river-to-lake change was large in the southern region for water quality and the invertebrate community. Water circulation induced by strong wind-wave actions in the lake sites of the southern region is assumed to have promoted photosynthetic and nutrient uptake activities and favored invertebrates that require well-aerated conditions such as polychaetes and burrowing crustaceans. Invertebrates usually adapted to brackish and saline environments are suggested to be indicators of a well-circulated environment with active biogeochemical processes and a less eutrophic state in Taihu, and wind-wave actions are key to maintaining such a community and natural purifying processes.

A new species of Enchytraeus (Enchytraeidae, Clitellata) from sewage sludge of a plum processing plant in Japan.

Enchytraeus ohtakai sp. nov. (Enchytraeidae, Clitellata, Oligochaeta) was discovered in the organic matter of a wastewater treatment facility of a plums processing plant in Honshu, Japan. The wastewater is characterized by high organic matter content and low salt concentration. Morphological analysis and DNA-sequencing of a fragment of the COI barcoding gene show that the new species belongs to the E. albidus species group. Within this group it differs in: vasa deferentia restricted to XII, preclitellar bundles with mostly three chaetae, postclitellar bundles with two or three, dorsal blood vessel from XII or XIII, spermathecal ectal duct completely glandular. spermatheca with a large diverticulum, accessory sexual glands present in XII, clitellum ventrally almost absent. The individual gene trees of COI analysis recovered this new species as a monophyletic group within the genus Enchytraeus, closely related to E. albidus species group.

Hyporheic zone, a blind spot: Discovery of the larva of Kisaura (Trichoptera: Philopotamidae) from Japan.

Four genera of Philopotamidae (Trichoptera) are known from Japan: Chimara, Dolophilodes, Kisaura, and Wormaldia. Among them, adults of the genus Kisaura are known in the Oriental and East Palearctic region; but until now, larvae of this genus have not been observed. In this study, molecular evidence is presented to support the relationship between adults and larvae of Kisaura minakawai Arefina 2005 from hyporheic zones of Japanese rivers. Morphological features of the larva of K. minakawai, which include very small eyes and somewhat dorsoventrally flattened (depressed) head capsules, compared with those of other philopotamid species, are also suggested to be adapted to the hyporheic zone. Detailed morphology of K. minakawai larval characters are provided.

Redescription of Rhyacophila yukii Tsuda 1942 and description of three new Rhyacophila species from Japan (Trichoptera: Rhyacophilidae).

Three new species of Rhyacophila (Trichoptera: Rhyacophilidae) from Japan are described. Among them, R. hattorii n. sp. and R. kobayashii n. sp. are assigned to the Rhyacophila sibirica Group. Another new species, R. kuranishii n. sp. is assigned to the Rhyacophila anatina Group. The figures of R. yukii by Schmid (1970) are actually of R. hattorii, not R. yukii Tsuda 1942. We describe these three new species, redescribe R. yukii, and discuss the diversity of this genus.

An interlaboratory comparison exercise for the determination of microplastics in standard sample bottles.

An interlaboratory comparison exercise was conducted to assess the consistency of microplastic quantification across several laboratories. The test samples were prepared by mixing one liter seawater free of plastics, microplastics made from polypropylene, high- and low-density polyethylene, and artificial particles in two plastic bottles, and analyzed concurrently in 12 experienced laboratories around the world. The minimum requirements to quantify microplastics were examined by comparing actual numbers of microplastics in these sample bottles with numbers measured in each laboratory. The uncertainty was due to pervasive errors derived from inaccuracies in measuring sizes and/or misidentification of microplastics, including both false recognition and overlooking. The size distribution of microplastics should be smoothed using a running mean with a length of >0.5 mm to reduce uncertainty to less than ±20%. The number of microplastics <1 mm was underestimated by 20% even when using the best practice for measuring microplastics in laboratories.

Differences in the ability of two marine annelid species, Thalassodrilides sp. and Perinereis nuntia, to detoxify 1-nitronaphthalene.

Bioremediation is a promising method for remediating environmentally polluted water. We investigated the abilities of two benthic annelid species to biotransform 1-nitronaphthalene, a nitrated polycyclic aromatic hydrocarbon. We used an oligochaete, Thalassodrilides sp. (Naididae), collected from the sediment beneath a fish farm and a polychaete, Perinereis nuntia, which was obtained from a commercial source. Populations of both organisms were exposed to 1400 µg L(-1) of 1-nitronaphthalene in seawater for 3 days in the dark at 20 °C. The concentration of the pollutant decreased to 12 µg L(-1) in the seawater containing the Thalassodrilides sp. and to 560 µg L(-1) in the seawater containing P. nuntia. The 1-nitronaphthalene concentration in the bodies of the animals increased from 12 to 94 µg kg(-1) in Thalassodrilides sp. and from 0.90 µg kg(-1) to 38,000 µg kg(-1) in P. nuntia. After 3 days, 99% and 40% of the 1-nitronaphthalene had been biotransformed in the Thalassodrilides sp. and P. nuntia experimental groups, respectively. We then tested the acute toxicity of residual 1-nitronaphthalene from the same water using mummichog (fish) larvae. After the larvae had been exposed for 96 h, the percentage of apparently unaffected larvae remaining was 83.3% in Thalassodrilides sp. group but only 16.7% in the P. nuntia group. Clearly, of the two species we studied, Thalassodrilides sp. had a superior ability to convert 1-nitronaphthalene into substances that were nontoxic to mummichog larvae. Therefore, we recommend the use of this species for bioremediation of chemically polluted sediments.

Descriptions of two new and one newly recorded enchytraeid species (Clitellata, Enchytraeidae) from the Ozegahara Mire, a heavy snowfall highmoor in Central Japan.

Three species of semi-aquatic freshwater Enchytraeidae of the genera Mesenchytraeus Eisen, 1878, Chamaedrilus Friend, 1913 and Globulidrilus Christensen & Dózsa-Farkas, 2012 are described from stream, wet soil or snow habitats in the Ozegahara Mire, an extensive high moor in heavy snowfall area in central Japan. Among Mesenchytraeus speies, Mesenchytraeus nivalis sp. nov. is distinguished by not having enlarged chaetae and spermathecal diverticula, vas deferens with atrial glands 3 or 4 in number and club-shaped, spermathecal ental duct short, with sperm bundles in the sperm sack. Chamaedrilus ozensis sp. nov. closely resembles C. floridae, but the length of the sperm funnel and character of the coelomocytes are different. Globulidrilus helgei Christensen & Dózsa-Farkas, 2012 is recorded for the first time from Japan.

Long-term effects of oral L-carnitine supplementation on anemia in chronic hemodialysis.

BACKGROUND: The therapeutic role of L-carnitine (LC) on the anemia of chronic hemodialized patients is still controversial. In order to clarify the long-term effects of LC administration on renal anemia, an open, observational 12-month study was performed. METHODS: Twenty stable outpatients undergoing hemodialysis were administered LC 900 mg p.o. daily for 12 months. The recombinant human erythropoietin (rHuEPO) dose was adjusted monthly when necessary to maintain the target hemoglobin (Hb) levels. RESULTS: The free LC level increased, while the acyl/free LC ratio decreased significantly 3 months after administration and was then maintained until the end of the study. There was no difference in Hb levels and the erythropoietin resistance index (ERI) during the study period. However, it was observed that ERI decreased significantly in 7 out of 18 patients (responders) 5 months after LC administration and was maintained thereafter (almost 40% reduction of the rHuEPO dose). The acyl/free carnitine ratio at baseline was the most contributing factor distinguishing responders from nonresponders. CONCLUSION: Although the beneficial effect of LC supplementation on renal anemia was not observed in all patients, at least 40% of the patients (responders) showed a significant improvement in ERI after long-term LC administration.

The effects of oral L-carnitine supplementation on physical capacity and lipid metabolism in chronic hemodialysis patients.

BACKGROUND: It is well known that the physical activity in chronic hemodialysis patients decreases compared to that in normal subjects. In order to investigate the effects of L-carnitine on physical capacity and lipid metabolism, a cardiopulmonary exercise test using a bicycle ergometer was performed before and after 3 months of oral L-carnitine supplementation under double-blind conditions. METHODS AND RESULTS: A total of 20 stable outpatients undergoing hemodialysis treatment were randomly divided into 2 groups: controls receiving placebo and patients receiving 900 mg L-carnitine p.o. daily. The levels of free and acyl carnitine increased significantly from 22.9 ± 7.3 to 149.9 ± 51.8 µmol/l and from 16.0 ± 2.8 to 100.3 ± 50.2 µmol/l, respectively, in the L-carnitine group; however, there was no significant change in other plasma lipid profiles. The exercise time was decreased and the heart rate at the anaerobic threshold was increased in the control group 3 months after the study period, but there were no such changes observed in the L-carnitine group. The minute ventilation/CO2 output slope increased significantly from 38.9 ± 7.8 to 43.8 ± 11.8 in the L-carnitine group. It has been speculated that a shift in the energy source occurs from carbohydrate to lipid, in terms of an increase of oxygen demand. CONCLUSION: L-Carnitine supplementation might have some beneficial effects on the physical capacity of chronic hemodialysis patients due to the improvement of the lipid metabolism in the muscle.

[Ampulla cardiomyopathy induced by meningitis: two case reports].

Two patients presented with ampulla cardiomyopathy induced by meningitis. A 71-year-old man with meningitis was admitted to our neurosurgery division. Emergent coronary angiography was performed, because of sudden blood pressure fall and ST elevation in the precordial leads. Left ventriculography and coronary angiography revealed apical ballooning without coronary stenosis. A 73-year-old woman with meningitis was admitted to another hospital. She felt chest pain. Electrocardiography showed ST elevation in the precordial leads. She was transferred to our division. Echocardiography revealed apical ballooning and hyperkinesis of the base. Creatine kinase level showed no elevation on admission or 8 hr later. Ampulla cardiomyopathy with cerebrovascular disease is common, but rare with meningitis, which needs intensive care because of the risk of respiratory arrest.