Identifying the true drivers of abrupt changes in ecosystem state with a focus on time lags: Extreme precipitation can determine water quality in shallow lakes

A better understanding of abrupt ecosystem changes is needed to improve prediction of future ecosystem states under climate change. Chronological analysis based on long-term monitoring data is an effective way to estimate the frequency and magnitude of abrupt ecosystem changes. In this study, we used abrupt-change detection to differentiate changes of algal community composition in two Japanese lakes and to identify the causes of long-term ecological transitions. Additionally, we focused on finding statistically significant relationships between abrupt changes to aid with factor analysis. To estimate the strengths of driver-response relationships underlying abrupt algal transitions, the timing of the algal transitions was compared to that of abrupt changes in climate and basin characteristics to identify any synchronicities between them. The timing of abrupt algal changes in the two study lakes corresponded most closely to that of heavy runoff events during the past 30-40 years. This strongly suggests that changes in the frequency of extreme events (e.g., heavy rain, prolonged drought) have a greater effect on lake chemistry and community composition than do shifts in the means of climate and basin factors. Our analysis of synchronicity (with a focus on time lags) could provide an easy method to identify better adaptative strategies for future climate change.

Terahertz-field-induced polar charge order in electronic-type dielectrics

Ultrafast electronic-phase change in solids by light, called photoinduced phase transition, is a central issue in the field of non-equilibrium quantum physics, which has been developed very recently. In most of those phenomena, charge or spin orders in an original phase are melted by photocarrier generations, while an ordered state is usually difficult to be created from a non-ordered state by a photoexcitation. Here, we demonstrate that a strong terahertz electric-field pulse changes a Mott insulator of an organic molecular compound in κ-(ET)₂Cu[N(CN)₂]Cl (ET = bis(ethylenedithio)tetrathiafulvalene), to a macroscopically polarized charge-order state; herein, electronic ferroelectricity is induced by the collective intermolecular charge transfers in each dimer. In contrast, in an isostructural compound, κ-(ET)₂Cu₂(CN)₃, which shows the spin-liquid state at low temperatures, a similar polar charge order is not stabilized by the same terahertz pulse. From the comparative studies of terahertz-field-induced second-harmonic-generation and reflectivity changes in the two compounds, we suggest the possibility that a coupling of charge and spin degrees of freedom would play important roles in the stabilization of polar charge order.

Increased winter drownings in ice-covered regions with warmer winters

Winter activities on ice are culturally important for many countries, yet they constitute a high safety risk depending upon the stability of the ice. Because consistently cold periods are required to form stable and thick ice, warmer winters could degrade ice conditions and increase the likelihood of falling through the ice. This study provides the first large-scale assessment of winter drowning from 10 Northern Hemisphere countries. We documented over 4000 winter drowning events. Winter drownings increased exponentially in regions with warmer winters when air temperatures neared 0°C. The largest number of drownings occurred when winter air temperatures were between -5°C and 0°C, when ice is less stable, and also in regions where indigenous traditions and livelihood require extended time on ice. Rates of drowning were greatest late in the winter season when ice stability declines. Children and adults up to the age of 39 were at the highest risk of winter drownings. Beyond temperature, differences in cultures, regulations, and human behaviours can be important additional risk factors. Our findings indicate the potential for increased human mortality with warmer winter air temperatures. Incorporating drowning prevention plans would improve adaptation strategies to a changing climate.

Combined impact of pesticides and other environmental stressors on animal diversity in irrigation ponds

Rice paddy irrigation ponds can sustain surprisingly high taxonomic richness and make significant contributions to regional biodiversity. We evaluated the impacts of pesticides and other environmental stressors (including eutrophication, decreased macrophyte coverage, physical habitat destruction, and invasive alien species) on the taxonomic richness of freshwater animals in 21 irrigation ponds in Japan. We sampled a wide range of freshwater animals (reptiles, amphibians, fishes, mollusks, crustaceans, insects, annelids, bryozoans, and sponges) and surveyed environmental variables related to pesticide contamination and other stressors listed above. Statistical analyses comprised contraction of highly correlated environmental variables, best-subset model selection, stepwise model selection, and permutation tests. Results showed that: (i) probenazole (fungicide) was a significant stressor on fish (i.e., contamination with this compound had a significantly negative correlation with fish taxonomic richness), (ii) the interaction of BPMC (insecticide; also known as fenobucarb) and bluegill (invasive alien fish) was a significant stressor on a "large insect" category (Coleoptera, Ephemeroptera, Hemiptera, Lepidoptera, Odonata, and Trichoptera), (iii) the interaction of BPMC and concrete bank protection was a significant stressor on an "invertebrate" category, (iv) the combined impacts of BPMC and the other stressors on the invertebrate and large insect categories resulted in an estimated mean loss of taxonomic richness by 15% and 77%, respectively, in comparison with a hypothetical pond with preferable conditions.

Clinically Infrequent Arcanobacterium haemolyticum Bacteremia Complicated by Foot Decubitus Ulcer: An Educational Reminder for Primary Care Physicians

An 81-year-old Japanese man with no history of diabetes mellitus was admitted to our hospital for a fever with a new ulcerative lesion on the left heel. Blood cultures on admission grew Arcanobacterium haemolyticum in aerobic bottles. He was therefore diagnosed with A. haemolyticum bacteremia and osteomyelitis complicated with foot decubitus ulcer. He was successfully treated with intravenous antibiotic therapy and debridement of the left heel. Our case and literature review show that it is important to recognize that A. haemolyticum is a systemic causative pathogen in immunocompetent patients in primary care practice.

Development of polymyalgia rheumatica during hospitalization and diagnosis based on history taking by physical and occupational therapists

Polymyalgia rheumatica (PMR) is frequently reported in the outpatient setting and presents with pain, morning stiffness, mild fever, and fatigue. However, the clinical course of PMR during hospitalization is unknown. We report a case of PMR that developed during hospitalization. PMR diagnosis should begin with an evaluation of core inclusion and exclusion criteria. However, when examining elderly patients, retrieving symptom information from the patient or their family is often difficult, especially during prolonged hospitalization. History taking by physical and occupational therapists or by other health care professionals is paramount in the symptomatic diagnoses of inpatients.

Landscape- and Local-Scale Actions Are Essential to Conserve Regional Macrophyte Biodiversity

Regional-scale pond diversity is supported by high variation in community composition. To effectively and efficiently conserve pond regional diversity, it is essential to recognize the community types in a focal region and the scales of the factors influencing the occurrence of respective community types. Based on a flora survey and GIS analysis of 367 ponds in western Japan, we developed a multinomial regression model that describes the relationship between aquatic macrophyte community type (based on cluster analysis) and five environmental factors that differ in the spatial scale at which they operate (i.e., landscape or local scale) and origin (i.e., natural or anthropogenic). A change in topographic configuration resulted in a transition of the community types with high species richness. Increasing urban and agricultural area around ponds resulted in a decrease in species-rich community occurrence; an increase in urban area increased the probability of a pond having no macrophytes, whereas that of paddy field increased the probability of a pond having only a few macrophytes. Pond surface area and proportion of artificial embankment significantly defined the pond community: greater embankment proportions increased the probability of ponds having few or no macrophytes. Our results suggest that conserving regional pond biodiversity will require actions not only at a local scale but also at a sufficiently large spatial scale to cover the full gradient of topographic configurations that influence the macrophyte species composition in ponds.

Frequent Community Use of Antibiotics among a Low-Economic Status Population in Manila, the Philippines: A Prospective Assessment Using a Urine Antibiotic Bioassay

The widespread unregulated use of antibiotics without medical consultation contributes to the burden of antibiotic resistance in Southeast Asian countries. This study investigated antibiotic use before hospital consultation. In a prospective observational study from February 2, 2015, to July 2, 2015, we enrolled febrile patients attending the emergency room in San Lazaro Hospital, Manila, the Philippines. A urine sample was collected and a bioassay was used to detect antibiotic activity in urine using Bacillus stearothermophilus (ATCC7953), Escherichia coli (ATCC25922), and Streptococcus pyogenes (ATCC19615). Patients or caregivers reported their medication history, clinical information, and socioeconomic status. During the study period, 410 patients were enrolled. The median (interquartile range) age was 14 (7-23) years and 158 (39%) reported prior antibiotic use, predominantly a beta-lactam antibiotic. A total of 164 (40%, 95% confidence interval [CI]: 35-45) patients were urine bioassay positive with any of three organisms. The Bacillus assay was the most sensitive, detecting 162 (99%, 95% CI: 96-100) cases. Among bioassay positive patients, dengue (N = 91, 55%, 95% CI: 48-63) was the most frequent diagnosis, followed by other viral infections, including measles, rubella, and mumps (N = 17, 10%, 95% CI: 6-16). Patients with a positive bioassay were significantly more likely to be from the lowest-income group (adjusted odds ratio [AOR]: 1.7; 95% CI: 1.1-2.6) and required hospital admission (AOR: 2.1; 95% CI: 1.3-3.5). Unnecessary antibiotic use for febrile illnesses before hospital consultation is common in a low-income, highly populated urban community in Manila. Education targeting this group should be implemented to reduce unnecessary antibiotic use.

Predators regulate prey species sorting and spatial distribution in microbial landscapes

The role of predation in determining the metacommunity assembly model of prey communities is understudied relative to that of interspecific competition among prey. Previous work on metacommunity dynamics of competing species has shown that sorting by habitat patch type and spatial patterning can be affected by disturbances. Microcosms offer a useful model system to test the effect of multi-trophic interactions and disturbance on metacommunity dynamics. Here, we investigated the potential role of predators in enhancing or disrupting sorting and spatial pattern among prey in experimental landscapes. We exposed multi-trophic protist microcosm landscapes with one predator, two competing prey, two patch resource types, and localized dispersal to three disturbance regimes (none, low, and high). Then, we used variation partitioning and spatial clustering analysis to analyse the results. In contrast with previous experiments that did not manipulate predators, we found that patch type did not structure prey communities very well. Instead, we found that it was the distribution of the predator that most strongly predicted the composition of the prey community. The predator impacted species sorting by (1) preferentially consuming one prey, thereby acting as a strong local environmental driver, and by (2) indirectly magnifying the impact of patch food resources on the less preferred prey. The predator also enhanced spatial signal in the prey community because of its limited dispersal. Our results indicate that predators can strongly influence prey species sorting and spatial patterning in metacommunities in ways that would otherwise be attributed to stochastic effects, such as dispersal limitation or demographic drift. Therefore, whenever possible, predators should be explicitly included as separate explanatory factors in variation partitioning analyses.

Radiocesium Transfer in Forest Insect Communities after the Fukushima Dai-ichi Nuclear Power Plant Accident

To understand radiocesium transfer in the forest insect food web, we investigated the activity concentrations of radiocesium in forest insects in the Fukushima and Ibaraki Prefectures approximately 1.5–2.5 years after the Fukushima Dai-ichi Nuclear Power Plant. We analyzed 34 species of insects sampled from 4 orders and 4 feeding functional groups (herbivore, carnivore, omnivore, and detritivore) from three sites in each prefecture. ¹³⁷Cs activity concentrations were lowest in herbivorous species and were especially high in detritivorous and omnivorous species that feed on forest litter and fungi. Radiocesium activity concentrations in any given species reflected the degree of contamination of that species’ primary food sources since radiocesium activity concentrations were found to be the lowest in leaves and grass and the highest in litter, bark, and fungi. This study confirmed that litter and other highly contaminated forest components such as fungi, decaying wood, bryophytes, and lichens serve as sources of ¹³⁷Cs transfer into the forest insect community.

Bacteremic renal stone-associated urinary tract infection caused by nontypable Haemophilus influenzae: A rare invasive disease in an immunocompetent patient

Haemophilus species are known to colonize the upper respiratory tract and can cause infections. However Haemophilus influenzae has been rarely described as a cause of genitourinary tract infection. We report a 44-year-old nonimmunocompromised Japanese man with bacteremic pyelonephritis caused by a nontypable H. influenzae associated with a left ureteral calculus. The organism was isolated from both blood and urine cultures. Treatment consisted of 14 days of intravenous ceftriaxone and oral amoxicillin one after than other and insertion of a left ureteral stent. After discharge, he underwent extracorporeal shock wave lithotrity for the left ureteral calculus. He had no recrudescence of the symptoms. H. influenzae should be considered as a genitourinary pathogen among patients with certain risk factors such as anatomical or functional abnormality of genitourinary tract. Collaboration between clinicians and microbiology laboratory personnel is essential for correct identification of the organism and appropriate therapy for genitourinary tract infections due to this organism.

Comparative Studies on Lipid Peroxidation in the Kidney of Rats, Mice, and Hamsters and on the Effect of Cysteine, Glutathione, and Diethyl Maleate Treatment on Mortality and Nephrotoxicity After Administration of Potassium Bromate

As an index of lipid peroxidation (LPO), levels of thiobarbituric acid (TBA)-reactive substances were examined in the kidneys of male F344 rats, BDF1, CDF1, and B6C3F1 mice, and Syrian golden hamsters after a single intravenous (IV) administration of potassium bromate (KBrO3) at various doses. In the rats, LPO levels were significantly increased in both a dose-dependent and time-dependent manner. However, when the rats were given intraperitoneal (IP) injection of cysteine, the levels of LPO were not significantly different between KBrO3-treated animals and controls. In CDF1 mice, the slight increases in LPO levels observed were much weaker and not statistically significant. On the other hand, treatment of BDF1 and B6C3F1 mice or hamsters with KBrO3 resulted in decreased values as compared to controls. The effect of treatment with cysteine, glutathione (GSH), or diethyl maleate (DEM) on mortality was tested in male F344 rats given IV injection of KBrO3 at various doses. Significant reduction and elevation in the mortality were observed in rats treated with cysteine or GSH and DEM, respectively. Significant dose-dependent and time-dependent increases were observed in the levels of serum non-protein nitrogen (NPN), blood urea nitrogen (BUN), and creatinine, and absolute and relative weight of the kidneys in male F344 rats administered KBrO3 IV. Microscopically, the appearance of numerous eosinophilic droplets in the cytoplasm of proximal tubular epithelium of KBrO3-treated rats was noteworthy. All these changes were reduced and exacerbated by treatment with cysteine or GSH and DEM, respectively. The possibility of LPO formation in the kidney by active oxygen radicals generated by KBrO3 is suggested. A possible relationship between LPO levels in the kidney and species differences in the renal toxicity and carcinogenicity of KBrO3 is implicated.

Promoting Effect of Metal Compounds on Rat Renal Tumorigenesis

Five metal compounds, zinc chloride (ZnCl2), mercury chloride (HgCl2), chromium chloride (CrCl3) hexahydrate, cadmium chloride (CdCl2) hemidihydrate, and nickel chloride (NiCl2) hexahydrate, were selected and tested for potential modifying influence on renal tumorigenesis. Six groups, each consisting of 15 male F344 rats, were given N-ethyl-N-hydroxyethylnitrosamine (EHEN) at a concentration of 500 ppm in their drinking water for the first 2 weeks as the initiation of carcinogenesis. Thereafter, the rats were treated orally for 25 weeks with ZnCl2, HgCl2, CrCl3, CdCl2, and NiCl2, respectively, at concentrations of 450, 40, 600, 100, and 600 ppm in the drinking water. The control group was given unsupplemented distilled water (DW) after EHEN initiation. Renal neoplastic lesions were classified histologically into dysplastic foci (DF) and renal cell tumors (RCT). As a result, statistically significant increases were found in the mean numbers of DF per cm2 in rats treated with the five metal compounds. On the other hand, the incidence of RCT was significantly higher only in rats treated with NiCl2. It is concluded that NiCl2 exerted a potential for promotion of renal tumorigenesis under the conditions of this study.

Lack of Promoting Effect of Sodium Chlorate and Potassium Chlorate in Two-Stage Rat Renal Carcinogenesis

Sodium chlorate (NaClO3) and potassium chlorate (KClO3), which are byproducts of water disinfection with chlorine dioxide (ClO2), were tested for potential promoting effect in two-stage rat renal carcinogenesis. Three groups of 15 male F344 rats each were given N-ethyl-N-hydroxyethylnitrosamine (EHEN) at the level of 0.05% for the first 2 weeks during the initiation phase. Thereafter, the rats were treated orally for 25 weeks with NaClO3 (1%), KClO3 (1%), or distilled water (DW). Three other groups (controls) were treated similarly, except that DW was given in the initiation phase. All animals survived for the duration of the experiment. Renal neoplastic lesions were classified histologically as dysplastic foci (DF) and renal cell tumors (RCT). The number of these lesions per unit area, in six sections from each kidney, was determined microscopically. There were no statistically significant differences in the incidences and in the mean number of DF and RCT of the kidney between compound-and DW-treated rats initiated with EHEN. It is concluded that NaClO3 and KClO3 show no promoting effect in rat renal carcinogenesis under the conditions of this study.

Radiation Exposure and Thyroid Cancer Risk After the Fukushima Nuclear Power Plant Accident in Comparison with the Chernobyl Accident

The actual implementation of the epidemiological study on human health risk from low dose and low-dose rate radiation exposure and the comprehensive long-term radiation health effects survey are important especially after radiological and nuclear accidents because of public fear and concern about the long-term health effects of low-dose radiation exposure have increased considerably. Since the Great East Japan earthquake and the Fukushima Daiichi Nuclear Power Plant accident in Japan, Fukushima Prefecture has started the Fukushima Health Management Survey Project for the purpose of long-term health care administration and medical early diagnosis/treatment for the prefectural residents. Especially on a basis of the lessons learned from the Chernobyl accident, both thyroid examination and mental health care are critically important irrespective of the level of radiation exposure. There are considerable differences between Chernobyl and Fukushima regarding radiation dose to the public, and it is very difficult to estimate retrospectively internal exposure dose from the short-lived radioactive iodines. Therefore, the necessity of thyroid ultrasound examination in Fukushima and the intermediate results of this survey targeting children will be reviewed and discussed in order to avoid any misunderstanding or misinterpretation of the high detection rate of childhood thyroid cancer.

Communicating Radiation Risk to the Population of Fukushima

Radiological specialists from Nagasaki University have served on the medical relief team organized at Fukushima Medical University Hospital (Fukushima City) ever since the accident at the Fukushima Dai-ichi nuclear power plant. Furthermore, we have conducted the radiation crisis communication efforts by spreading correct information on the health effects of radiation as 'advisors on radiation health risk control'. Nagasaki University has been assisting the reconstruction efforts of Kawauchi Village in Fukushima Prefecture, which was the first village to declare that residents could safely return to their homes because radiation doses were found to be at comparatively low levels. In April 2013, Nagasaki University and the Kawauchi government office concluded an agreement concerning comprehensive cooperation toward reconstruction of the village. As a result, we established a satellite facility of the university in the village. In conclusion, training of specialists who can take responsibility for long-term risk communication regarding the health effects of radiation as well as crisis communication in the initial phase of the accident is an essential component of all such recovery efforts. Establishment of a training system for such specialists will be very important both for Japan and other countries worldwide.

Phylogeographic insights into the invasion history and secondary spread of the signal crayfish in Japan

Successful invasion by nonindigenous species is often attributed to high propagule pressure, yet some foreign species become widespread despite showing reduced genetic variation due to founder effects. The signal crayfish (Pacifastacus leniusculus) is one such example, where rapid spread across Japan in recent decades is believed to be the result of only three founding populations. To infer the history and explore the success of this remarkable crayfish invasion, we combined detailed phylogeographical and morphological analyses conducted in both the introduced and native ranges. We sequenced 16S mitochondrial DNA of signal crayfish from across the introduced range in Japan (537 samples, 20 sites) and the native range in western North America (700 samples, 50 sites). Because chela size is often related to aggressive behavior in crayfish, and hence, their invasion success, we also measured chela size of a subset of specimens in both introduced and native ranges. Genetic diversity of introduced signal crayfish populations was as high as that of the dominant phylogeographic group in the native range, suggesting high propagule pressure during invasion. More recently established crayfish populations in Japan that originated through secondary spread from one of the founding populations exhibit reduced genetic diversity relative to older populations, probably as a result of founder effects. However, these newer populations also show larger chela size, consistent with expectations of rapid adaptations or phenotypic responses during the invasion process. Introduced signal crayfish populations in Japan originate from multiple source populations from a wide geographic range in the native range of western North America. A combination of high genetic diversity, especially for older populations in the invasive range, and rapid adaptation to colonization, manifested as larger chela in recent invasions, likely contribute to invasion success of signal crayfish in Japan.

A Case of Fascioliasis Treated Successfully Without Sequelae in a Japanese Expatriate Living in Jakarta

A 46-year-old Japanese female expatriate living in Jakarta presented with intermittent fever lasting for a month. Although she was considered at low risk of Fasciola spp. infection because she lived in an upper-class residential area of the city, the patient presented with eosinophilia after consuming organic raw vegetables; in addition, contrast-enhanced computed tomography detected microabscesses in a tractlike pattern in the liver. These findings led to an early diagnosis of fascioliasis, which was successfully treated without sequelae. In any patient with a history of consuming raw vegetables, fascioliasis should be suspected regardless of where the patient has lived.

Multiple drug combination of anti-diabetic agents as a predictor for poor clinical response to liraglutide

AIM

Aim of the study was to retrospectively analyze the clinical parameters that contribute to the therapeutic outcome of GLP-1 analogues.

METHODS

We enrolled 106 patients with type 2 diabetes mellitus (T2DM), treated with liraglutide (N.=69) or exenatide (N.=37) for longer than three months. The patients were divided into two groups: good responders and poor responders to GLP-1 analogues, based on pretreatment and post-treatment HbA1c levels. Good responders were those whose HbA1c level had decreased by 1% or more, or maintained at less than 7%. All other patients were categorized as poor responders. We used univariate and multivariate analyses to assess pretreatment parameters between the two groups.

RESULTS

Approximately 35% of the patients were poor responders. Our analysis of the pretreatment clinical parameters revealed that number of anti-diabetic agents and use of sulfonylurea were significantly associated with poor response to liraglutide (P=0.02 and P=0.03, respectively) in a multivariate analysis. We were not able to find any candidate related to clinical response to exenatide.

CONCLUSION

Our study showed that the therapeutic effects of GLP-1 analogues on T2DM patients were heterogeneous. T2DM patients who require multiple anti-diabetic agents, especially sulfonylurea, do not benefit from liraglutide treatment.

Visibility from roads predict the distribution of invasive fishes in agricultural ponds

Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that spread with frequent instances of human-mediated introduction.

Infective endocarditis caused by Streptococcus gallolyticus subspecies pasteurianus and colon cancer

A 56-year-old man presented to our department with a 2-month history of fever and chills. He had received a mitral valvuloplasty 3 years ago. He had been administered levofloxacin for 2 months. We discontinued levofloxacin and repeated the blood cultures. Bacterial blood cultures were positive and transoesophageal echocardiography revealed vegetation attached to the posterior mitral leaflet. We started the patient on intravenous antibiotic therapy for infectious endocarditis by Streptococcus gallolyticus subspecies pasteurianus. A colonoscopic screening revealed adenomatoid intracellular carcinoma. Previous studies have reported a weak association between colorectal cancer and Streptococcus bovis biotype II/2, which includes S gallolyticus subspecies pasteurianus; however, the rate is notably higher than the rate of colorectal cancer as indicated by positive faecal occult-blood test results. We conclude that colonoscopies should be routine while scanning for colorectal cancer in all patients with S bovis bacteraemia, regardless of the subspecies.

A case of subacute infective endocarditis and blood access infection caused by Enterococcus durans

Background

Infection by Enterococcus durans (E. durans) is very rare; reported cases are often preceded by therapy or an immunosuppressed state, including infective endocarditis, urinary tract infection, or wound infection. A few reported cases of infective endocarditis exist, with no reports describing involvement of blood access infection.

Case presentation

The patient is an 83-year-old man who had been undergoing hemodialysis for 8 years due to renal failure caused by diabetic nephropathy. He developed infective endocarditis and blood access infection/infective aneurysm due to Enterococcus durans; these conditions were treated with the antibiotic regimen of ampicillin + gentamicin. There have been only a few reported cases of infective endocarditis caused by E. durans, and to our knowledge, this is the first report of blood access infection.

Conclusions

We have experienced a case of concurrent infective endocarditis and blood access infection/infective aneurysm caused by E. durans. This is the world’s first reported case of blood access infection/infective aneurysm by E. durans.

Effects of pond draining on biodiversity and water quality of farm ponds

Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo.

Quantitative ultrasound and radiographic absorptiometry are associated with vertebral deformity in Japanese Women: the Hizen-Oshima study

We evaluated the ability of heel quantitative ultrasound (QUS) and metacarpal radiographic absorptiometry (RA) to identify subjects with vertebral deformities in Japanese women aged ≥40. Both QUS and RA were associated with vertebral deformities, and the estimated prevalence at each T-score widely varied with age.

INTRODUCTION

Heel QUS and metacarpal RA have been used for screening patients to evaluate risk of osteoporotic fractures. The aim of this study was to evaluate the ability of QUS and RA to identify women with vertebral deformities in 570 Japanese women aged ≥40, and to estimate the prevalence of vertebral deformity at each T-score.

METHODS

Calcaneal QUS and metacarpal RA were performed. Radiographic vertebral deformities were assessed by quantitative morphometry, defined as vertebral heights more than 3 SD below the normal mean.

RESULTS

The receiver operating characteristic analysis showed that both calcaneal stiffness index (SI) and metacarpal bone mineral density (BMD) were associated with vertebral deformities. Using the T-score of -2.5 as a cutoff value, the specificity and sensitivity for identifying individuals with vertebral deformities was 65% and 83% for calcaneal SI, and 40% and 88% for metacarpal BMD, respectively. The prevalence of vertebral deformity was estimated using age-adjusted logistic regression models. Women with calcaneal SI T-score of -2.5 had a 2% estimated probability of vertebral deformity at age 40, and 22% at age 80. For metacarpal BMD T-score of -2.5, estimated probability was less than 1% at age 40, and 27% at age 80.

CONCLUSION

Both calcaneal SI and metacarpal BMD were associated with prevalence of vertebral deformity. Furthermore, the prevalence widely varied with age at any given bone value.

Microcystin production by Microcystis aeruginosa exposed to phytoplanktivorous and omnivorous fish at different kairomone concentrations

We investigated microcystin (MC) production by three Microcystis aeruginosa strains in response to different kairomone concentrations (indirect exposure: 0%, 10%, 25%, and 50%) of Hypophthalmichthys molitrix and Carassius gibelio langsdorfi. The MC production was significantly different among control and three kairomone treatment levels. MC production was higher with increasing concentration of kairomones and the peak intracellular and extracellular MC contents showed clear dose-dependent response (p < 0.05). This study provides the first indirect evidence of increased MC production of M. aeruginosa in response to increasing kairomone concentrations released by phytoplanktivorous and omnivorous fish.

Behavioural and morphological differences between feral and domesticated strains of common carp Cyprinus carpio

Morphological and behavioural traits of a feral strain of the common carp Cyprinus carpio from Lake Biwa in Japan were compared with those of two domesticated strains reared in Japan (one commercial strain and one ornamental koi). To compare genetically inherited traits, all fish were reared from eggs under similar environmental conditions. Using these fish, the following five traits were compared among the three strains: body shape, consumption rate of two types of free-swimming shrimp, medaka Oryzias latipes and bottom-dwelling chironomid larvae prey items, preference for a bottom habitat, feeding skills in detecting prey and escape response to predator attack. The feral strain of fish had more streamlined bodies, higher consumption rates for free-swimming prey, a greater preference for a bottom habitat, possessed greater skill in detecting prey and were more cautious of predator attacks, compared with the fish of the two domesticated strains. These characteristics shown by the feral fish are probably adaptive to the natural environment. A genetic analysis based on five nuclear single nucleotide polymorphism markers, however, suggested that the feral strain was relatively recently derived from domesticated stocks. Considering this, the present results appear to indicate the possibility that domesticated C. carpio could re-adapt to the wild environment during a short evolutionary period, although further research using more feral strains is required.

Prevalence of chronic obstructive pulmonary diseases in general clinics in terms of FEV1/FVC

BACKGROUND

The prevalence of chronic obstructive pulmonary disease (COPD) continues to increase all over the world. Nonetheless, COPD is often misdiagnosed in general clinics because of insufficient use of spirometry.

OBJECTIVES

To estimate the prevalence of COPD in general clinics in Japan, we performed spirometry to screen patients who consulted general clinics.

METHODS

Patients 40 years of age and older who consulted clinics in Nagasaki Prefecture, Japan, for non-respiratory diseases and who met certain inclusion criteria had their airflow limitation measured by spirometry. We defined COPD as forced expiratory volume in the first second (FEV(1)) over forced vital capacity (FVC) (FEV(1)/FVC) of < 70% in patients without active pulmonary disease, including physician-diagnosed asthma.

RESULTS

Of the 1424 patients included in the study, 193 (13.6%) showed airflow limitation. Airflow limitation was significantly related to older age, male gender and cumulative pack-years. FEV(1)/FVC in patients with hypertension and chronic hepatitis were significantly lower than in patients without these diseases when adjusted for age, gender and pack-years.

CONCLUSIONS

We showed that there are potentially a number of cases with COPD that are undiagnosed by general physicians in Japan. Measuring airflow limitation by spirometry in smokers with coexisting diseases, such as hypertension and chronic hepatitis, may be very beneficial because COPD is thought to be a systemic disease. The distribution of spirometers to general clinics is definitely needed to detect undiagnosed COPD.

Microcystin production by Microcystis aeruginosa exposed to different stages of herbivorous zooplankton

Microcystin (MC) production by four monoclonal Microcystis aeruginosa strains was evaluated in response to infochemicals (indirect exposure) released from different stages of herbivorous zooplankton (neonate/juvenile and adult Daphnia magna and Moina macrocopa). The intracellular MC and extracellular MC concentrations were significantly different among the control and treatments with zooplankton culture media filtrates (p<0.05), and in most cases MC production was significantly higher (p<0.05) in strains exposed to infochemicals released from adult zooplankton rather than those of neonate/juvenile zooplankton in four strains of M. aeruginosa. Compared to intracellular MC (385.0-5598.6microg g(-1)DW), very low concentrations of extracellular MC (9.9-737.6microg ml(-1)) were released, but both showed similar temporal patterns over the course of the experiment. This result might be attributed to the fact that adult zooplankton produced more infochemical signals than equal numbers of smaller juveniles and neonates. It is the first study to provide evidence that MC production might be impacted by infochemicals released from different stages of zooplankton, mediated with physiological characteristics, body size, and feeding habits.

Reciprocal allelopathic responses between toxic cyanobacteria (Microcystis aeruginosa) and duckweed (Lemna japonica)

We examined cyanobacterial toxin production in response to direct exposure to an axenically cultured aquatic plant (Lemna japonica Landolt) using two toxic monoclonal strains of Microcystis aeruginosa Küzing (NIES strains 103 and 107). The patterns of nutrient concentrations were similar between the controls and treatments. The exposure to toxic M. aeruginosa inhibited growth in L. japonica, and exposure to the aquatic plant caused an increase in microcystin (MC) production and inhibited growth in M. aeruginosa. The respective biomasses of M. aeruginosa and L. japonica differed significantly between control and treatments (p<0.05). Both intracellular MC and extracellular MC productions were significantly higher in the treatment than in the control for both strains (p<0.01). Increased MC production in response to direct exposure to this aquatic plant could be an induced defense mediated by the release of allelochemicals from the plant. This study revealed reciprocal allelopathic responses between Microcystis and Lemna, which can be applied to the management of eutrophic waters as well as an important information concerning strategies for recovering eutrophic waters.