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The geographical range of invasive cyanobacteria with high toxigenic potential is widening because of eutrophication and global warming, thus, monitoring their appearance is necessary for safe water quality control. Most invasive cyanobacteria are nostocalean species, and their accurate identification by classical morphological methods may be problematic. In this study, we developed polymerase chain reaction (PCR) primers to selectively identify five invasive cyanobacterial genera, namely, Chrysosporum, Cuspidothrix, Cylindrospermopsis, Raphidiopsis, and Sphaerospermopsis, using genetic markers such as rbcLX, rpoB, rpoC1, and cpcBA, and determined the amplification conditions for each pair of primers. The primer performances were verified on single or mixed nostocalean cyanobacterial isolates. The five primers allowed selective identification of all the target genera. In field samples collected during summer, when cyanobacteria flourished in the Nakdong River, the respective PCR product was observed in all samples where the target genus was detected by microscopic analysis. Besides, weak bands corresponding to Sphaerospermopsis and Raphidiopsis were observed in some samples in which these genera were not detected by microscopy, suggesting that the cell densities were below the detection limit of the microscopic method used. Thus, the genus-specific primers developed in this study enable molecular monitoring to supplement the current microscopy-based monitoring.

The extent and frequency of harmful cyanobacterial blooms are increasing, owing to the climate change caused by global warming, and some harmful filamentous cyanobacteria that were first reported in the tropics are spreading to temperate regions, such as North America, Europe, and Northeast Asia. Although these exotic invasive cyanobacteria have a high toxigenic potential, they are not targeted in management plans in many countries. This study analyzed the occurrence of and potential toxin and off-flavor secondary metabolite production by invasive nostocalean cyanobacteria in the Nakdong River in Korea, which is a temperate region. The occurrence of four species belonging to three genera of cyanobacteria was confirmed in the Nakdong River. The quantities of cyanobacteria in the Nakdong River were mostly low, fewer than 1,000 cells mL-1. Twenty-four strains belonging to four species in three genera of cyanobacteria were isolated from the Nakdong River. Analysis revealed no off-flavor secondary metabolite production by any of the isolates, and those belonging to Cylindrospermopsis raciborskii, Sphaerospermopsis aphanizomenoides, and S. reniformis were identified as nontoxic strains. However, anatoxin-a production was observed in two of the eleven isolates of Cuspidothrix issatschenkoi. Given the sites and the timing of its occurrence, C. issatschenkoi had the highest potential for toxin production among the invasive nostocalean cyanobacteria appearing in the Nakdong River.

Following the construction of eight large weirs in a 200-km section of the Nakdong River, which is a major water source for the region, harmful cyanobacterial blooms have been occurring annually, causing severe problems with water quality. The present study investigated the community structure of harmful cyanobacteria and identified temporal and spatial patterns in harmful cyanobacterial blooms and their dynamic relationships with physicochemical, hydrological, and meteorological variables in the eight weir sections for 6 years from 2013 to 2018. The dominant harmful cyanobacteria in the eight weir sections were Aphanizomenon and Microcystis spp. There was a successional phenomenon wherein Aphanizomenon spp. first bloomed in spring, and then Microcystis spp. bloomed as water temperatures increased. Additionally, the initiation and duration of the blooms of both genera were affected by the timing and volume of heavy rainfall that caused flushing of cyanobacterial biomass, resulting in direct reduction of cyanobacterial growth in all sections. The harmful cyanobacteria of upstream weirs did not affect the biomass of downstream weirs in terms of either growth initiation or time taken to reach peak biomass, despite being physically connected. Owing to the long retention time during the dry season, similar to what occurs in separate reservoirs, the water quality of each weir section, particularly regarding nutrient characteristics and retention time, were the major factors determining the harmful cyanobacterial abundance, resulting in heterogeneous spatial distribution of harmful cyanobacterial blooms in the Nakdong River.

Demands for water quality improvement and reduction of harmful algal blooms in Korean lakes and rivers due to eutrophication and climate change have been increasing. As an environmentally friendly measure to mitigate the eutrophication and phytoplankton growth, a full-scale artificial floating vegetation island (AFVI) was installed in Lake Paldang, a large on-river reservoir. This study investigated the detailed mechanisms for improving water quality and reducing the phytoplankton growth of the AFVI by comparing the biotic and abiotic environmental factors between the AFVI and the adjacent pelagic part of the lake. Much lower chlorophyll a concentration, much higher zooplankton biomass, especially large crustacean zooplankton, and a higher proportion of active bacteria in total bacteria in the AFVI indicate an effective reduction of phytoplankton growth and vigorous decomposition of organic matter. The major mechanisms for improving water quality of the AFVI are shown to be inhibition of phytoplankton growth by attenuating light and top-down control by zooplankton grazing. Active microbial decomposition of organic matters and nitrate reduction in the hypoxic rhizospheric zone also would be a major mechanism for improving water quality, even though it is difficult to quantify in the open water system.

To investigate the effect of summer monsoon-derived inputs of particulate organic matter (POM) on patterns of stable isotopes in the food web in a reservoir, we traced dietary sources of carbon and nitrogen in pelagic zooplankton and herbivorous littoral zoobenthos following a monsoonal disturbance in Lake Paldang, a large regulated reservoir in Korea. Carbon and nitrogen stable isotopes were analyzed in POM, zooplankton, sedimentary organic matter, zoobenthos, and piscivorous fishes in pre- and post-summer monsoon periods. Sharp depletion of 13C and enrichment of 15N of POM along with elevated POC/Chl a ratios occurred following the summer monsoon period, reflecting the rapid reduction of phytoplankton biomass and a pulsed supply of terrestrial organic detritus. Herbivorous zooplankton δ13C values, which were initially similar to POM δ13C values in the pre-summer monsoon period, decreased to nearly that of terrestrial organic matter, providing isotopic evidence of allochthonous contribution to zooplankto...

Flow regulation is one of the most common anthropogenic factors affecting rivers worldwide. In Korea, 16 weirs were constructed along four major rivers from 2009 to 2012. This study aimed to elucidate initial changes in physical, chemical, and biological variables after the construction of consecutive weirs on the Nakdong River, a major large river system. Water quality variables and phytoplankton cell densities were investigated at eight representative sites and compared with the data recorded before the weir construction. There were spatial and temporal changes in the hydraulic retention time (HRT), total phosphorus (TP), and chlorophyll a concentrations among the eight weir sections. HRT increased after the weir construction, while TP and chlorophyll a tended to decrease from the middle to lower section of the Nakdong River. Furthermore, differences were observed in the phytoplankton community composition between 2006&ndash, 2007 and 2013. There was a marginal decrease in the duration of centric diatom (Stephanodiscus hantzschii) blooms after weir construction. However, Microcystis aeruginosa proliferated more extensively during summer and autumn than it did before the weir construction. Our results suggest that changes in hydrological factors, in response to consecutive weir construction, may contribute to greater physical, chemical, and ecological variability.

Temporal and spatial characteristics of cyanobacterial communities at the monitoring stations for Harmful Algal Bloom Alert System (HABAS) in Nakdong River and Lake Dukdong were investigated for two years (2013 to 2014). A total of 30 cyanobacterial species from 14 genera were found at the survey stations. Microcystis sp. showed maximum cell density in the total cyanobacterial community in August, 2014 at ND-2 and in September, 2013 at ND-3 station. Lynbya limnetica and Geitlerinema sp., non-target species for alert criteria showed maximum cell density at ND-1 (August, 2013) and Dam station of Lake Dukdong (September, 2014), respectively. Total cyanobacterial cell density and the relative abundance of four target genera (Microcystis, Anabaena, Aphanizomenon and Oscillatoria spp.) for alert criteria was relatively lower in the mesotrophic Lake Dukdong than at the eutrophic riverine stations of Nakdong River, indicating cyanobacterial density and the RA of target genera is affected by the trophic state of the monitoring stations. Simulating the alert system using phycocyanin concentration as an alert criterion resulted in the longer period of alert issued compared to the period of alert issued using the current criterion of harmful cyanobacterial cell density due to the influence of phycocyanin concentration from non-target cyanobacterial species.

Functional brain imaging studies have suggested that the superior temporal gyrus (STG) and the middle temporal gyrus (MTG) are involved in phonological and lexical-semantic processing, respectively. However, the precise role of the posterior temporal lobe is not fully understood. To clarify the functional relevance of the left posterior STG and MTG during language processing, we used neuronavigation-guided repetitive transcranial magnetic stimulation (rTMS). The reaction times and error rates for 12 healthy volunteers performing auditory repetition and lexical-semantic decision tasks were compared before and during rTMS stimulation. We applied 1 Hz rTMS over the left posterior STG or MTG or sham stimulation for 10 min in a random order. Stimulation of the left posterior MTG significantly slowed the response time for the lexical-semantic decision task from 478.9±56.5 to 583.1±80.0 ms. However, stimulation over the left posterior STG or MTG did not affect the response time or the error rate for the auditory repetition task. Our results suggest that the left posterior MTG might be involved in lexical decision making. Neuronavigation-guided rTMS virtual lesion studies could help determine the functional roles of specific brain areas in language processing, and our findings provide new evidence supporting the use of neuromodulation through rTMS for patients with aphasia.

Elemental cellular stoichiometry of natural phytoplankton communities was examined in six large dam reservoirs in the Han River system. Carbon (C) and nitrogen (N) contents of the phytoplankton-dominated seston from Lake Soyang was higher than that from other lakes. Phosphorus (P) content showed slight variations among six lakes in the range of 0.04~0.18 μmol P mg DW -1 . The phosphorus concentrations of lake water showed obvious positive relationship with P and C contents of the phytoplankton-dominated seston. In all six lakes, N:P ratios and C:P ratios in the phytoplankton-dominated seston were more than 23 and 133 respectively, indicating the phytoplankton communities in six lakes have been exposed in phosphorus limited condition. The relative abundance of diatoms showed significant negative correlation with C, N, P contents of the phytoplankton-dominated seston and that of cyanobacteria showed significant positive correlation. Elemental stoichiometry of diatoms-dominated seston showed distinctive less content than that of cyanobacteria-dominated seston. The cellular N:P ratios of diatoms- and cyanobacteria-dominated seston indicate that both main classes of phytoplankton in six lakes are in phosphorus deficiency. Elemental stoichiometry of the phytoplankton-dominated seston in this study could be used for the further ecological stoichiometric studies in six lakes.

The impact of climate change on a large river reservoir ecosystem was investigated. Long-term meteorological data showed that recent climate change, including warmer winters, increased precipitation intensity and extended dry periods, may have influenced the basin of Lake Paldang, the most downstream reservoir of a series of on-river reservoirs. Extreme hydrologic events and climate warming, acting independently and in combination, appear to be related to changes in the Lake Paldang ecosystem. A significant increase in chlorophyll a concentrations in early spring corresponded to the timing of ice break-up. An increase in winter temperatures, which resulted in a shorter time period of ice-cover and earlier ice break-up, appears to have stimulated phytoplankton growth in winter and early spring. Repeated intensive and extended influxes of turbid water, associated with more frequent extreme rainfall events, have increased concentration of suspended solids and may have influenced the biotic community structure of Lake Paldang. In the mid-2000s, the area vegetated by submerged hydrophytes, the abundance and biomass of the phylum Mollusca, as well as the abundance of fish from the subfamily Acheilognathinae, which spawn in the body of bivalve molluscs, was all smaller than in the late 1980s and early 1990s. Together, these results suggest that climate change may have contributed directly and indirectly to changes in each trophic level of the Lake Paldang ecosystem.

The cumulative effect of land-use changes is one of the most important factors contributing to the continuous deterioration of river ecosystems. We used ecological exergy to evaluate the impacts of land-use changes on functional guilds of benthic macroinvertebrates. We classified 353 sampling sites into 3 groups based on land-use types: forested, agricultural, and urban rivers. For each sampling site, we calculated ecological exergy based on 5 trophic groups of macroinvertebrates. Differences in exergy, specific exergy, and structural metrics (i.e. species richness and Shannon index) suggested that land-use type was an important determinant of the composition of macroinvertebrate communities. Exergy values of the functional feeding groups and trophic groups were used as input data to train self-organizing maps – unsupervised artificial neural networks. The results showed that functional guilds responded differently to different land-use types: scrapers and carnivores dominated the forested rivers, whilst predators and omnivores, and gatherer-collectors and detritivores dominated agricultural and urban rivers, respectively. These results suggest that ecological exergy can be used as a functional bioassessment indicator to evaluate river condition. A generalized additive model and random forest also highlighted that a combination of both conventional structural indicators (e.g. species richness and Shannon index) and novel functional indicators (e.g. exergy and specific exergy) can be used to assess biotic integrity.

Benthic macroinvertebrates are considered as a representative taxon that indicates the ecological status of freshwater ecosystems. Numerous indices derived from community data have been proposed to estimate either biological water quality or ecosystem health. In this study, metrics based on benthic macro- invertebrates at the family level were screened using ecological informatics to provide a multi-metric measurement that would be suitable for presenting ecological integrity across different levels of environmental impact. Benthic macroinvertebrates were collected at a total of 720 sample sites from river basins and streams in Korea in 2009. Based on four categories of community status (i.e., diversity, richness, tolerance, and composition), 37 metrics were selected as initial candidates according to the literature. The candidate metrics were evaluated according to parameters including discriminatory power, redundancy, and responsiveness to stressors. Self-organizing map was utilized to assist the screening procedure by providing ordination, clustering, and visualization of metric and environmental data. Six metrics were finally selected as a multi- metric and were compared with conventional indicators for presenting the ecological integrity of streams.

The purpose of this research was to characterize physicochemical properties and sensory evaluation of schizandra wines fermented by the yeasts, Sacchromyces cerevisiae SH8094 (S. cerevisiae SH8094) and Sacchromyces cerevisiae SH2855 (S. cerevisiae SH2855) isolated from schizandra fruits and stems and compare these results with the results from commercial activated yeast (Lalvin 1118) and a commercial schizandra wine. Three different schizandra wines fermented by S. cerevisiae SH8094, S. cerevisiae SH2855, and Lalvin 1118 showed similar results in pH and titratable acidity. On the other hand, the schizandra wines fermented by S. cerevisiae SH8094 and S. cerevisiae SH2855 showed high brix (brix), low alcohol content (9%), and low yeasts count (4.1 log CFU/mL), compared with the schizandra wine fermented by Lalvin 1118. Both schizandra wines made with S. cerevisiae SH8094 and S. cerevisiae SH2855 showed higher scores in swallowing and overall acceptability than the schizandra wine made with Lalvin 1118. When compared with a commercial schizandra wine, the schizandra wine fermented with S. cerevisiae SH8094 showed better qualities in aroma (), color (), and overall acceptability (). In conclusion, S. cerevisiae SH8094 which was isolated from schizandra fruits and stems has a high potential in schizandra wine fermentation.

Aphanizomenon spp. have formed harmful cyanobacterial blooms in the Nakdong River during spring, autumn, and now in winter, and the expansion of blooming period and area, associated with the global warming is predicted. The genus Aphanizomenon has been described to produce harmful secondary metabolites such as off-flavors and cyanotoxins. Therefore, the production of harmful secondary metabolites from the Aphanizomenon blooms in the Nakdong River needs to be monitored to minimize the risk to both water quality and public health. Here, we sampled the cyanobacterial blooms in the Nakdong River and isolated ten Aphanizomenon strains, morphologically classified as Aphanizomenon flos-aquae Ralfs ex Bornet et Flahault 1888. Phylogenetic analysis using 16S rRNA and internal transcribed spacer (ITS) region nucleotide sequences confirmed this classification. We further verified the harmful secondary metabolites-producing potential of A. flos-aquae isolates and water samples containing cyanobacterial blooms using PCR with specific primer sets for genes involved in biosynthesis of off-flavor metabolites (geosmin) and toxins (microcystins, saxitoxins and cylindrospermopsins). It was confirmed that these metabolite biosynthesis genes were not identified in all isolates and water samples containing only Aphanizomenon spp. Thus, it is likely that there is a low potential for the production of off-flavor metabolites and cyanotoxins in Aphanizomenon blooms in the Nakdong River.

Escherichia coli is the most frequently identified microbiological agent in childhood urinary tract infections (UTIs). However, the pathogenic role of this organism in young children remains to be clearly elucidated. So far, no studies have been conducted in which multiplex polymerase chain reaction (PCR) has been applied to determine the association between childhood UTIs and E. coli and urovirulent genes.Altogether, 330 suprapubic urine specimens from febrile young children were cultured. In 33 of the cases, E. coli was identified; among these cases, 18 had a UTI (10(4)-10(5) cfu/ml), four had a suspected UTI (10(2)-10(3) cfu/ml) and 11 did not have UTIs (10(2) cfu/ml). Using multiplex PCR, three uropathogenic E. coli (UPEC) genes and two enteroaggregative E. coli (EAEC) genes were detected.In the UTI-UPEC cases, the kps gene was detected in 18 of 22 cases (82%) and the usp gene in 16 of 22 cases (73%). Among the 18 cases of children with UTIs characterized by 10(4)-10(5) E. coli cfu/ml, urinary tract abnormalities were identified via dimercaptosuccinic acid scans in seven of 18 cases (39%) and via voiding cystourethrograms in four of the 18 cases (22%).The UPEC kps and usp genes were clearly associated with childhood UTIs, and may also be associated with kidney or urinary tract dysfunctions in young children. Escherichia coli colony count numbers in excess of 10(4)-10(5) cfu/ml in the suprapubic urine were considered to be strong evidence of UTI in infants.

Context.—Kikuchi disease is a self-limiting febrile lymphadenopathy characterized by a patchy area of apoptosis. Kikuchi disease is thought to be caused by a virus, but this has not been clearly demonstrated. Human herpesviruses 6 and 7 (HHV-6 and HHV-7) are lymphotropic viruses that can induce apoptosis in infected lymphocytes. Recently, HHV-8 was reported to be a possible etiologic agent of Kikuchi disease. Objective.—To investigate the incidence of HHV-6, HHV-7, and HHV-8 infection in patients with Kikuchi disease. Design.—Seventy archival tissue specimens (from 50 Kikuchi disease cases and 20 control cases) were tested for the presence of HHV-6 and HHV-7 using a nested polymerase chain reaction, and for the presence of HHV-8 using single-step polymerase chain reaction. Immunohistochemistry for HHV-8 expression was carried out in those cases in which HHV-8 was detected using polymerase chain reaction. Results.—Of the 50 cases with Kikuchi disease, 21 (42%) were HHV-6 positive and 32 (64%) were HHV-7 positive. Eight (40%) of the 20 control cases were HHV-6 positive and 9 (45%) were HHV-7 positive. Both HHV-6 and HHV-7 were detected in 15 (30%) of the cases with Kikuchi disease and in 3 (15%) of the control cases. Three (6%) of the 50 cases of Kikuchi disease were HHV-8 positive but revealed no positive cells on immunohistochemical analysis for HHV-8. Human herpesvirus 8 was not expressed in any of the control cases. Conclusions.—There was no association between the presence of HHV-6 or HHV-7 and Kikuchi disease. Because the HHV-8 genome but not protein was detected in a small proportion of the cases of Kikuchi disease, its potential causative role in this disease should be determined by further studies.

Intensive speech therapy improves language function in patients with chronic aphasia, although treatment in the acute phase is more effective than in the chronic phase. Unfortunately, most patients with stroke go untreated due to socioeconomic problems. This study was performed to develop and test a speech therapy-based telerehabilitation program (iAphasia), suitable for use on a mobile device platform, which would expand access to therapy to patients who frequently go untreated.We enrolled 8 patients with chronic poststroke aphasia to receive therapy via our iPad(®) (Apple, Cupertino, CA)-based telespeech therapy program, iAphasia. Participants received 4 weeks of telespeech therapy using iAphasia, which generates six domains with six levels of difficulty. We compared pre- and posttreatment scores on the Korean version of the Western Aphasia Battery (K-WAB) to evaluate effectiveness. Additionally, a 1-month follow-up assessment was performed.We investigated user satisfaction using a questionnaire to assess the feasibility of iAphasia. After the 4-week treatment, language function as measured by the K-WAB improved significantly. The improvement was persistent at the 1-month follow-up visit. The degree of improvement was strongly associated with usage time, regardless of participants' age and severity of aphasia. Overall, satisfaction with iAphasia was rated high.The results from this study suggest it to be an effective and feasible treatment method for chronic aphasia, although follow-up studies with more subjects and a control group are needed for a more thorough assessment.

Early identification of patients with stroke-induced aphasia is essential because it is a significant disability affecting daily life and is linked to poor functional outcome after stroke. However, most patients with stroke are unable to undergo aphasia evaluation and detection and therefore remain undiagnosed. The purpose of this study is to develop a valid, reliable mobile aphasia screening test (MAST) for patients in remote locations.To accomplish this, we enrolled patients with (n=30) and without (n=30) stroke-induced aphasia. A MAST, which adopted the Korean version of the shortened version of the Frenchay Aphasia Screening Test (K-FAST), was designed as an iPad(®) (Apple, Cupertino, CA) application. To validate the MAST, we compared its performance with that of the Korean version of the Western Aphasia Battery (K-WAB) and conventional shortened FAST paper version (K-FAST). We analyzed interrater and internal reliability, using Cronbach's alpha coefficient, and assessed the diagnostic sensitivity, specificity, and power.There was significant correlation between K-FAST and MAST (intraclass correlation coefficient [ICC]=0.995, p0.001). MAST also had a high correlation with K-WAB (ICC=0.752, p0.001). Interrater reliability was very high (ICC=0.999, p0.001). The test had high sensitivity (90.0%) and specificity (73.3%) with an accuracy of 0.930 (95% confidence interval=0.853-1.000). The MAST is a valid and reliable tool for detecting aphasia in patients with stroke.This telescreening test may overcome the limitations of test administration and may be a convenient and cost-effective alternative to the existing aphasia screening tests for patients with stroke.

To understand the factors controlling algal production in two lakes located on the Han River in South Korea, Lake Cheongpyeong and Lake Paldang, a principal component regression model study was conducted using environmental monitoring and primary productivity data. Although the two lakes were geographically close and located along the same river system, the main factors controlling primary productivity in each lake were different: hydraulic retention time and light conditions predominantly influenced algal productivity in Lake Cheongpyeong, while hydraulic retention time, chlorophyll a-specific productivity, and zooplankton grazing rate were most important in Lake Paldang. This investigation confirmed the utility of principal component regression analysis using environmental monitoring data for predicting complex biological processes such as primary productivity; in addition, the study also increased the understanding of explicit interactions between environmental variables. The findings obtained in this research will be useful for the adaptive management of water reservoirs. The results will also aid in the development of management strategies for water resources, thereby improving total environmental conservation.

The aim of this study was to compare the serum cytokine profiles of Plasmodium vivax malaria patients who presented with and without hepatic dysfunction. This is a retrospective analysis of 74 consecutive cases of P. vivax malaria seen at 3 military hospitals near the Demilitarized Zone in South Korea from 1999 to 2000. All patients studied were adult active duty servicemen. On admission, the mean (+/- SEM) age of the patients who presented with (n = 36) and without hepatic dysfunction (n = 38) was 21.6 +/- 0.24 and 22.5 +/- 0.44 years, respectively (P = 0.72). On admission, there was no significant difference between the 2 patient populations in terms of mean temperature, haemoglobin level, haematocrit, total white blood cell count, platelet count, parasite index, and serum concentration of transforming growth factor-beta. Plasmodium vivax malaria patients who presented with hepatic dysfunction had significantly higher mean serum concentrations of soluble Fas ligand, interleukin (IL)-l, IL-4, IL-6, IL-10, tumor necrosis factor-alpha, and interferon-gamma than those without hepatic dysfunction, suggesting the involvement of these cytokines in the development of hepatic dysfunction. The mean serum concentration of IL-12 was significantly lower in patients with hepatic dysfunction. The mean body temperature was not significantly different between the 2 patient populations.

Serum cytokine profiles in patients with Plasmodium vivax malaria who presented with and without hyperpyrexia were compared by a retrospective review of the medical records of the consecutive patients seen at the military hospitals near the demilitarized zone in the Republic of Korea from April 2000 through October 2001. Of 162 male patients studied, 120 (86.4%) presented with hyperpyrexia (i.e., an axillary temperatureor = 40 degrees C). The mean +/- SEM ages of the patients with and without hyperpyrexia were 21.5 +/- 0.14 and 21.9 +/- 0.39 years, respectively (P = 0.33). The mean +/- SEM concentrations of serum interleukin (IL)-6 (379.7 +/- 44.1 pg/mL versus 105.4 +/- 26.8 pg/mL; P = 0.002), IL-10 (583.4 +/- 58.2 pg/mL versus 142.4 +/- 39.7 pg/mL; P = 0.0001), and interferon-gamma (312.6 +/- 33.9 pg/mL versus 112.9 +/- 27.1 pg/mL; P = 0.0001) were significantly higher in patients with hyperpyrexia compared with those without hyperpyrexia. The mean +/- SEM concentrations of serum tumor necrosis factor-alpha were 155.5 +/- 54.5 pg/mL and 109.9 +/- 29.3 pg/mL (P = 0.27) in patients who presented with and without hyperpyrexia, respectively. Further studies are needed to examine whether serum concentrations of these cytokines also parallel their concentrations at the tissue sites of their production and action.

Thrombopoietin (TPO) is one of the most promising stimulants for ex vivo expansion of haematopoietic stem cells. Previously, we have found that TPO induces a characteristic pattern of apoptosis during ex vivo expansion of human cord blood (CB) CD34+ cells and that the TPO-induced apoptotic cells belong to megakaryocyte (MK) lineage. In this study, we have examined the maturation of MK and platelet production in association with the TPO-induced apoptosis. CD34+ cells, purified from human CB, were expanded in serum-free conditions stimulated with TPO. Apoptosis was confirmed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) assay and electron microscopy (EM). Simultaneous measurement of DNA content and immunophenotyping revealed that the cells with higher DNA content (>8 N) constituted less than 5% of the CD41+ fractions until day 14, implying premature apoptosis of MKs before full polyploidization. Nevertheless, EM observation showed not only platelet territories but also newly produced platelets in which granules and microfilaments could be identified. Furthermore, flow cytometry demonstrated that the platelet fraction expressed P-selectin and an activation motif on GPIIb/IIIa recognized by monoclonal antibody PAC-1 upon stimulation with adenosine diphosphate (ADP). In addition, periodic acid-Schiff (PAS)-positive materials and nonspecific esterase activities could be demonstrated. Therefore, it is suggested that platelet production and the accompanying processes, rather than apoptosis only, be hastened during the ex vivo expansion of CB CD34+ cells when using TPO.

Part of the neurodegenerative cascade in AIDS dementia may involve overexpression of matrix metalloproteinases (MMPs). Here, we examined the possible effect of HIV-1 gp41, which has been shown as a key determinant associated with pathogenesis of AIDS dementia, on the activity of MMPs using human neuronal and glial cell lines. Zymographic analysis revealed that treatment with the gp41 peptide (aa 583-599) for 24 h markedly elevated the activity of MMP with Mr 66 kDa in the cultured media of glioblastoma cell line T98G in a concentration-dependent manner as well as of neuroblastoma cell line SK-N-SH despite of lower magnitude of the activity. In contrast, the immediately adjacent gp41 peptide (aa 598-613) as well as the reverse peptide (aa 598-583) had a little effect. Recombinant gp41 protein containing extracellular domain also elicited a similar effect, although with a lesser extent. This 66 kDa MMP was confirmed as gelatinase A (MMP-2) based on the results of its activity dependent on Ca2+ and inhibited in the presence of 1,10-phenanthroline or EDTA, as well as its specific immunoreactivity on the Western blot. N-acetyl cysteine (NAC) downregulated this gp41 peptide-induced MMP-2 activity in T98G. The soluble form of amyloid precursor protein (sAPP), which is synthesized in the Escherichia coli system, also inhibited the MMP-2 activity in vitro. Taken together, these results implicate that high production of HIV-1 gp41 or its metabolites containing aa 583-599 within central nervous system (CNS) could result in the increased activity of MMP-2 and that the extracellular deficiency of reducing agent or decreased level of sAPP within CNS could exacerbate this gp41-induced MMP-2 activity.

The production and release of microcystins during the batch culture of Microcystis aeruginosa LERL 031 which was isolated from Korean freshwater were investigated. Total amounts of two major toxins (microcystin-RR and -LR) did not decrease at the death phase of the culture while chlorophyll-a concentration decreased. The ratio of two major intracellular microcystin amounts of the cyanobacteria was changed depending on the growth phase.The grazing effects on Microcystis biomass and microcystins by micrometazoa and protozoan which were isolated from biofilm oxidation reactor were examined. Among three microanimals Monas guttula was turned out to be the most effective grazer of M. aeruginosa LERL-031. In the condition of coexistence of Aeolosoma hemprichi, Philodina erythrophthalma, Monas guttula in the cyano-bacterial as grazer, chlorophyll-a concentration decreased by 73% of initial concentration after 31 days. In the condition of no addition of microanimals, intracellular microcystins were released to surrounding water during the lysis of cells but not degraded.

Background Several experimental studies in stroke patients suggest that mirror therapy and various virtual reality programs facilitate motor rehabilitation. However, the underlying mechanisms for these therapeutic effects have not been previously described. Objectives We attempted to delineate the changes in corticospinal excitability when individuals were asked to exercise their upper extremity using a real mirror and virtual mirror. Moreover, we attempted to delineate the role of visual modulation within the virtual environment that affected corticospinal excitability in healthy subjects and stroke patients. Methods A total of 18 healthy subjects and 18 hemiplegic patients were enrolled into the study. Motor evoked potential (MEP)s from transcranial magnetic stimulation were recorded in the flexor carpi radialis of the non-dominant or affected upper extremity using three different conditions: (A) relaxation; (B) real mirror; and (C) virtual mirror. Moreover, we compared the MEPs from the virtual mirror paradigm using continuous visual feedback or intermittent visual feedback. Results The rates of amplitude increment and latency decrement of MEPs in both groups were higher during the virtual mirror task than during the real mirror. In healthy subjects and stroke patients, the virtual mirror task with intermittent visual feedback significantly facilitated corticospinal excitability of MEPs compared with continuous visual feedback. Conclusion Corticospinal excitability was facilitated to a greater extent in the virtual mirror paradigm than in the real mirror and in intermittent visual feedback than in the continuous visual feedback, in both groups. This provides neurophysiological evidence supporting the application of the virtual mirror paradigm using various visual modulation technologies to upper extremity rehabilitation in stroke patients.

Objective To delineate the changes in corticospinal excitability when individuals are asked to exercise their hand using observation, motor imagery, voluntary exercise, and exercise with a mirror. Method The participants consisted of 30 healthy subjects and 30 stroke patients. In healthy subjects, the amplitudes and latencies of motor evoked potential (MEP) were obtained using seven conditions: (A) rest; (B) imagery; (C) observation and imagery of the hand activity of other individuals; (D) observation and imagery of own ipsilateral hand activity; (E) observation and imagery of the hand activity of another individual with a mirror; (F) observation and imagery of own symmetric ipsilateral hand activity (thumb abduction) with a mirror; and (G) observation and imagery of own asymmetric ipsilateral hand activity (little fi nger abduction) with a mirror. In stroke patients, MEPs were obtained in the A, C, D, E, F conditions. Results In both groups, increment of the percentage MEP amplitude (at rest) and latency decrement of MEPs were significantly higher during the observation of the activity of the hand of another individual with a mirror and during symmetric ipsilateral hand activity on their own hand with a mirror than they were without a mirror. In healthy subjects, the increment of percentage MEP amplitude and latency decrement were signifi cantly higher during the observation of the symmetric ipsilateral hand activity with a mirror compared to the observation of the activity of the asymmetric ipsilateral hand with a mirror of their own hand. Conclusion In both groups, corticospinal excitability was facilitated by viewing the mirror image of the activity of the ipsilateral hand. Th ese fi ndings provide neurophysiological evidence supporting the application of various mirror imagery programs during stroke rehabilitation.

Human immunodeficiency virus-1 (HIV-1) associated dementia (HAD) has been attributed to an encephalitis resulting from intense infiltration of monocytes. Evidence suggests that the viral protein Tat, which is released actively from HIV-1 infected cells, can contribute significantly to this process. Therefore, the principal objective of this study was to evaluate the potential molecular basis for the role of extracellular HIV-1 Tat in the induction of monocyte chemotactic protein-1 (MCP-1/CCL2) in the hippocampus, which is primarily linked to cognitive function and most commonly damaged in HAD. We also attempted to identify the mechanism by which resveratrol (trans-3,5,4'-trihydroxystilbene) modulates MCP-1 release in hippocampal tissues exposed to Tat. An ex vivo study using rat hippocampal slices demonstrated a time- and dose-dependent increase in MCP-1 production from Tat-treated hippocampal tissues. This increase was accompanied by the activation of the MEK/ERK pathway and TNF-α production. Tat-induced MCP-1 release was abrogated by inhibitors of tyrosine kinases (TK), herbimycin A or genistein, a finding that supports the MAPK signaling mechanism. The inhibition of the ERK1/2 pathway with SL327 induced a near-complete abolition of the observed Tat-induced effects. Furthermore, anti-TNF-α antibodies suppressed Tat-induced MCP-1 release. Resveratrol, to a level similar to that of SL327, downregulated Tat-induced proinflammatory responses via the inactivation of ERK1/2. These results indicate that the activation of the ERK1/2 pathway and TK are critical factors in the production of TNF-α and MCP-1 in the Tat-exposed hippocampus. Additionally, the inhibition of Tat-induced production of MCP-1 and TNF-α via the inactivation of the ERK1/2 pathway may represent the anti-inflammatory mechanism of resveratrol in the hippocampus.

[1] We investigated the sources, fluxes, and spatial and temporal distribution of organic carbon in two large reservoirs in Korea having different trophic and hydrologic features. In Lake Paldang (river-type reservoir) most of the organic carbon comes from allochthonous sources (88%), while in Lake Chungju (lake-type reservoir) the allochthonous load contributed 52% (48% autochthonous). Strong correlations were found between the amount and contribution of allochthonous and autochthonous organic carbon and hydrologic parameters in Lake Paldang but not in Lake Chungju. The spatiotemporal fluctuation patterns of C/N ratios of particulate organic matter, chlorophyll a/particulate organic carbon values, and specific ultraviolet absorption of dissolved organic carbon were different, indicating differences in state and source of organic carbon in the two reservoirs. Our results indicate that meteorologic and hydrologic controls directly determine the state of lacustrine organic carbon in Lake Paldang, whereas autochthonous production and in situ transformation may play important roles in determining the state of lacustrine organic carbon in Lake Chungju.

Background: Eosinophils are multifunctional leukocytes. Under physiological conditions, they circulate in the blood and through the tissues to serve their functions. In certain inflammatory states, they enter the T-cell areas of lymph nodes (LNs) that drain the inflamed tissue and communicate with T cells in LNs, but the underlying mechanism that regulates their trafficking to LNs is not yet fully explored. Here, we report that a human eosinophilic leukemia cell line, EoL-1, and human peripheral blood (PB) eosinophils become reactive to the lymphoid chemokines CCL21 and CCL25 upon stimulation. Methods: EoL-1 cells were differentiated with dibutyryl cyclic AMP (dEoL-1) and subsequently pulsed with IFN-γ, IL-3 and GM-CSF. The eosinophil fraction was purified from normal human adult PB and incubated for 1 day with the same cytokine combination. Results: Upon cytokine stimulation, dEoL-1 cells expressed chemokine receptors CCR7, CCR9 and CCR3 and developed chemotactic responsiveness to CCL21, CCL25 and CCL11, which bind to the respective receptors. Human PB eosinophils also showed chemotactic responsiveness to CCL21 and CCL25 upon stimulation with IFN-γ, IL-3 and GM-CSF. In addition, the cytokine-stimulated dEoL-1 cells expressed costimulatory molecules, including CD40, CD80, CD86 and HLA-DR, and also expressed a tolerogenic and Th2-polarizing enzyme, indoleamine 2,3-dioxygenase. Conclusions: These in vitro observations raise the possibility that eosinophils may utilize lymphoid chemokines to enter LNs and serve antigen-presenting functions in the LN under certain inflammatory conditions.

We report on the fabrication and characterization of Al0.1Ga0.9N/GaN heterojunction field effect transistors, both an enhancement mode and a depletion mode with a low pinchoff voltage, suitable for digital integrated circuit applications. For an enhancement mode device with a 1 μm gate length and 5 μm drain‐to‐source separation, the dc transconductance is around 23 mS/mm. Connecting the enhancement mode device as a switching transistor and a depletion mode device as a load, we demonstrate an AlGaN/GaN inverter.

Thrombopoietin (TPO) is widely used for ex vivo expansion of hematopoietic stem cells. Previously, we have reported that TPO induces a characteristic pattern of apoptosis, and the TPO-induced apoptosis is closely associated with megakaryocyte (MK) differentiation. In the present study, several cytokines, flt3-ligand, stem cell factor (SCF), interleukin-3 (IL-3), IL-6, IL-11, leukemia inhibitory factor, G-CSF, and erythropoietin, which are known to affect megakaryocytopoiesis, have been evaluated to elucidate their effects on the TPO-induced apoptosis. Measurement of apoptosis by flow cytometry revealed that only SCF absolutely reduced the TPO-induced apoptosis in MK fractions, particularly in the late phase of ex vivo expansion. Platelet production was demonstrated by electron microscopy in a later phase when SCF was added. Simultaneous measurement of DNA contents with immunophenotyping demonstrated a significant increase in polyploidization in the CD41+ cell fraction when cultured with SCF. These results suggested that SCF not only inhibited premature senescence but also enhanced maturation of the differentiating cells of MK lineage during ex vivo expansion using TPO.

To elucidate the pathogenic mechanisms involved in neurodegeneration in AIDS patients with cognitive deficits, we have examined the toxic effect of the lentivirus lytic peptide 1 (LLP-1) corresponding to the carboxyl terminus of HIV-1 transmembrane glycoprotein gp41 on human neuronal and glial cell lines. LLP-1 induced a significant lactate dehydrogenase (LDH, a marker of cell death) release from these cells in a concentration- and time-dependent manner, while the noncytolytic LLP-1 analog 2 had little effect. Application of LLP-1 to SH-SY5Y, a well-characterized human neuronal cell line, caused the decline of intracellular glutathione (GSH) content that appeared to occur before a significant LDH release. Furthermore, LLP-1 elicited a significant loss of mitochondrial function as measured by mitochondrial transmembrane potential (MTP). Among the reducing agents and antioxidants tested, GSH and a GSH prodrug N-acetylcysteine (NAC) provided protection against LLP-1-induced neuronal cell death, evidently by restoring the intracellular GSH levels and blocking the disruption of mitochondrial integrity. Thus, gp41-derived LLP-1 may be a potential neurotoxic agent capable of causing the intracellular GSH depletion and disturbing the mitochondrial function, possibly contributing to the neurodegenerative cascade as seen in HIV-1-associated dementia. Our data indicate that restoring both GSH concentration and mitochondrial function may hold promise as possible therapeutic strategies for slowing disease progression of dementia in AIDS patients.

In infants, urinary tract infections (UTIs) are quite common and primarily caused by bacterial pathogens. However, little research has been conducted regarding the relationship between uropathogenic bacteria, virulent genes, and uropathogenic viruses that might induce UTIs in infants. In this study, we evaluated infants with UTIs to determine the influence of bacterial virulent genes and type of viral infections on clinical aspects. First, we detected 44 cases of bacterial UTI from 600 suspected cases in infants and children. We detected E. coli urovirulence genes (kps, usp, pap, ireA, and cnf), two enteropathogenic E. coli genes (bfpA, and eae) and four S. aureus and S. epidermidis genes (mecA, pvl, bbp, and icaA) in urine samples from infant UTI cases. We also simultaneously detected hematuria-related adenovirus type 11, 21, and BK virus (BKV) in urine samples by PCR. As a result, E. coli was the most prevalent bacteria and in Dimercaptosuccinic acid (DMSA)-positive UTI cases, the uropathogenic E. coli virulence factor pap was significantly high. We found that BKV detection was significantly higher in DMSA-positive UTI infants (89%) compared with 50% of non-UTI (no bacteria detected) cases. These results are indicative of combined multiple bacterial and viral infections and show severe infant pyelonephritis.

While methicillin-resistant Staphylococcus aureus (MRSA) isolated from urinary tract infection (UTI) has recently increased in elderly adult urology patients, it has been only rarely reported in infants. Therefore, in this study to understand whether MRSA may be involved in UTI of infants who run fever without other apparent causes, we identified and counted S. aureus and S. epidermidis in suprapubic urine from 750 febrile infants via microbiological methods, and confirmed the counts via multiplex PCR. And we also detected four virulence genes, mecA, PVL, bbp and icaA genes for S. aureus and S. epidermidis via multiplex PCR in the same specimens. S. aureus (28 cases) counts were as follows: ＞10⁴ CFU/㎖ (3/28), 10²~10³ CFU/㎖ (1/28) and ＜10²~10³ CFU/㎖ (24/28). S. epidermidis (26 cases) counts were as follows: ＞10⁴ CFU/㎖ (2/26), 10²~10³ CFU/㎖ (4/26) and 10²~10³ CFU/㎖ (20/26). S. aureus virulence genes were detected in 26 cases as mecA (16/26, 59.3%), PVL (17/26, 63.0%), bbp (7/26, 26.9%) and icaA (20/26, 76.9%). S. epidermidis virulence genes were detected in 22 cases as mecA (17/22, 81.0%), PVL (15/22, 71.4%), bbp (3/22, 13.6%) and icaA (13/22, 50.1%). Therefore, mecA, PVL and icaA genes of MRSA and MRSE were detected with high positivity in urines from infants with fever. The results demonstrate that community-acquired MRSA or MRSE may be responsible for UTI incidence in febrile infants.

In order to obtain greater insight into the relevant genomic expression patterns of Trichinella spiralis, 992 expressed sequence tags (ESTs) were collected from a cDNA library of T. spiralis muscle stage larvae and assembled into 60 clusters and 385 singletons. Of them, 445 (44.7%) ESTs were annotated to their homologous genes, and small fractions were matched to known genes of nematodes. The annotated ESTs were classified into 25 eukaryotic orthologous groups (KOG). Cytochrome C oxidase (34 clones) was found to be most frequent species.

Objective: To investigate the influence of associated medical diseases and complications on functional improvement after in-patient through stroke rehabilitation. Method: We performed a retrospective analysis on medical records of 183 stroke patients who had admitted to the department of rehabilitation medicine. Functional Independence Measure (FIM), Modified Barthel Index (MBI) at admission and discharge were used to assess the functional status. We investigated medical diseases, such as hypertension, diabetes, myocardial infarct, atrial fibrillation osteoarthritis, rheumatoid arthritis, previous history of stroke and complications such as dementia, post-stroke depression, central post-stroke pain, complex regional pain syndrome, neglect and aphasia. Results: Post-stroke patients with myocardial infarct, atrial fibrillation, osteoarthritis, dementia, aphasia and neglect significantly showed lower gain of FIM and MBI, lower FIM and MBI efficacy during inpatient rehabilitation compared to without those (p 0.05). Total numbers of associated medical diseases and complications negatively affect on FIM and MBI efficacy (p

Background: CD27 is recently known as a memory B cell marker and is mainly expressed in activated T cells, some B cell population and NK cells. CD27 is a member of tumor necrosis factor receptor family. Like CD40 molecule, CD27 has (P/S/T/A) X(Q/E)E motif for interacting with TNF receptor-associated factors (TRAFs), and TRAF2 and TRAF5 bindings to CD27 in 293T cells were reported. Methods: To investigate the CD27 signaling effect in B cells, human CD40 extracellular domain containing mouse CD27 cytoplamic domain construct (hCD40-mCD27) was transfected into mouse B cell line CH12.LX and M12.4.1. Results: Through the stimulation of hCD40-mCD27 molecule via anti-human CD40 antibody or CD154 ligation, expression of CD11a, CD23, CD54, CD70 and CD80 were increased and secretion of IgM was induced, which were comparable to the effect of CD40 stimulation. TRAF2 and TRAF3 were recruited into lipid-enriched membrane raft and were bound to CD27 in M12.4.1 cells. CD27 stimulation, however, did not increase TRAF2 or TRAF3 degradation. Conclusion: In contrast to CD40 signaling pathway, TRAF2 and TRAF3 degradation was not observed after CD27 stimulation and it might contribute to prolonged B cell activation through CD27 signaling.

Salmonella penetrates the basement membrane of intestinal epithelial cells into deeper tissues, in which process extracellular matrix proteases should be required. Hypothesizing that the proteases might be provided by host cells, we investigated the changes of expression of urokinase type plasminogen activator(u-PA), plasminogen activator inhibitor-1(PAI-1), and collagenases in epithelial cells(Caco-2) infected with Salmonella typhimurium. The change of mRNA levels, amount of the enzyme secretion and functional activity were analyzed by Northern blot, ELISA, and Zymography. The mRNA level of u-PA was elevated by Salmonella infection itself without any exogenous transcription regulators. u-PA was actively secreted into the medium and was enzymatically active. The synthesis and secretion of PAI-1 was increased over time from 2 hrs post infection(pi) to 8 hrs pi. Zymographic assay revealed that the secretion of collagenases (type IV, type V and interstitial collagenase) were also increased. Taken together, S. typhimurium infection might induce accumulation of pericellular proteolytic activity and consequently degrade the extracellular matrix surrounding the infected cells. These in turn might enable Salmonella to invade into deeper tissues.