The detection and phylogenetic characterization of Cryptosporidium, Cystoisospora, and Giardia duodenalis of cats in South Korea.

Introduction: Cryptosporidium, Cystoisospora, and Giardia duodenalis are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization of gastrointestinal protozoa parasites in cats is limited throughout South Korea. Therefore, this study aimed to determine the detection and identify subspecies of gastrointestinal protozoa parasites in cats from South Korea. Methods: A total of 290 fecal samples were collected from stray, companion, and shelter cats in six provinces. Cryptosporidium, Cystoisospora, and G. duodenalis were identified by PCR. All positive samples were subtyped by PCR and sequencing of gp60, ITS-1, tpi, bg, and gdh. Results: The overall detection of gastrointestinal protozoan parasitic infection was 17.93%. G. duodenalis was the most prevalent, with 7.93%, followed by Cystoisospora spp. (7.24%) and Cryptosporidium spp. (4.48%). In addition, C. felis (n=10), C. parvum (n=2), C. ryanae (n=1), Cystoisospora felis (n=14), Cystoisospora suis (n=5), Cystoisospora ohioensis (n=1), Cystoisospora spp. were identified in subspecies analysis of positive samples. C. felis showed a significant association with diarrhea (7.81%) and living condition (6.04%), and Cystoisospora felis in diarreha (9.38%) according to detection. Through phylogenetic analysis of the tpi, bg, and gdh genes from 23 G. duodenalispositive samples, it was confirmed that the samples of present study belonged to assemblage A, B, C, and D. Discussion: South Korean cats have a high rate of gastrointestinal protozoan parasites infection with cat-specific Cryptosporidium and Cystoisospora, which are associated with living conditions and diarrhea symptoms. Moreover, zoonotic and other animal-specific subtype of protozoan parasites have been detected in cat feces.

Abiotic and biotic factors controlling sexual reproduction in populations of Pseudo-nitzschia pungens (Bacillariophyceae).

Pseudo-nitzschia pungens is a widely distributed marine pennate diatom. Hybrid zones, regions in which two different genotypes may interbreed, are important areas for speciation and ecology, and have been reported across the globe for this species. However, sexual reproduction between differing clades in the natural environment is yet to be observed and is difficult to predict. Here we carried out experiments using two mono-clonal cultures of P. pungens from different genotypes to measure the frequency and timing of sexual reproduction across varying biotic (growth phases and cell activity potential) and abiotic conditions (nutrients, light, turbulence). We found the mating rates and number of zygotes gradually decreased from exponential to late stationary growth phases. The maximum zygote abundance observed was 1,390 cells mL-1 and the maximum mating rate was 7.1%, both which occurred during the exponential growth phase. Conversely, only 9 cells mL-1 and a maximum mating rate of 0.1% was observed during the late stationary phase. We also found the higher the relative potential cell activity (rPCA) in parent cells, as determined by the concentration of chlorophyll a per cell and the ratio of colony formation during parent cultivations, revealed higher mating rates. Furthermore, sexual events were reduced under nutrient enrichment conditions, and mating pairs and zygotes were not formed under aphotic (dark) or shaking culture conditions (150 rpm). In order to understand the sexual reproduction of Pseudo-nitzschia in the natural environment, our results highlight that it is most likely the combination of both biotic (growth phase, Chl. a content) and abiotic factors (nutrients, light, turbulence) that will determine the successful union of intraspecific populations of P. pungens in any given region.

Sagittal spinal alignment in asymptomatic patients over 30 years old in the Korean population.

BACKGROUND: We aim to provide sagittal and pelvic parameters according to different age groups in an asymptomatic population all over 30 years old and to investigate the possible causes of changes in these parameters. METHODS: Whole-spine, standing lateral radiographs were taken in 128 asymptomatic Korean people over 30 years old. The spinal parameters (the total thoracic kyphosis (TTK), maximal lumbar lordosis (MLL), total lumbar lordosis (TLL), lower lumbar lordosis (LLL), thoracolumbar junctional angle (TLJA), and lumbar inclination (LI)), pelvic parameters (pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT)), and spinal balance parameters (spinal balance, sacropelvic balance, and spinopelvic balance) were measured. The body mass index, body protein mass, waist line, skeletal muscle mass, and body fat mass were also measured for potential causes. RESULTS: TTK and TLJA were significantly increased in the group over 70 years of age compared to the other age groups (p = 0.0002, <0.001). TLL was significantly decreased in the group over 70 years of age (p = 0.002), whereas the PI values were similar to PI even in over 70-year age group. LLL did not differ in the group over 70 years of age (p = 0.29), gradually increasing with an increase in age. SS was significantly decreased and PT was significantly increased in the group over 70 years of age as compared to the other age groups (p = 0.049, 0.049, respectively). PI was similar in all age groups (p = 0.75). Spinal balance was significantly decreased in the group over 70 years of age (p = <0.0001). PT was significantly associated with body protein mass and skeletal muscle mass (p = 0.01, 0.001, respectively). Body protein mass and skeletal muscle mass were significantly lower in the group over 70 years of age (p = 0.02, 0.02) and were possible causes. CONCLUSIONS: Several sagittal and pelvic parameters are different in asymptomatic adults over 70 years of age. Decreased body protein mass and skeletal muscle mass are possible causes of these changes.

Do the radiographic findings of symptomatic discoid lateral meniscus in children differ from normal control subjects?

PURPOSE: The aim of this study was to quantitatively compare radiographic findings of symptomatic discoid lateral meniscus in children with those of matched controls. METHODS: Seventy-eight consecutive children (91 knees) who underwent arthroscopic surgery for a symptomatic discoid lateral meniscus (discoid group) were included. Another 91 age- and sex-matched controls with normal medial and lateral menisci on the basis of magnetic resonance imaging findings were included in this study (control group). Each plain radiograph was evaluated from the anteroposterior view for the following variables: height of the lateral tibial spine, lateral joint space distance, height of the fibular head, squaring of the lateral femoral condyle, obliquity of the lateral tibial plateau and cupping of the lateral tibial plateau. Lateral femoral condylar notch was evaluated in lateral view. Statistical analyses were used to determine the differences between the two groups. RESULTS: A significant difference in the mean height of the lateral tibial spine, lateral joint space distance, height of the fibular head, and obliquity of the lateral tibial plateau distinguished the two groups (p < 0.0001). However, there was no statistical difference in the condylar off sign, squaring of the lateral femoral condyle, cupping of the lateral tibial plateau and lateral femoral condylar notch between groups (n.s.). The cut-off values for the height of the lateral tibial spine (6 mm), lateral joint space distance (8 mm), height of the fibular head (14.9 mm) and obliquity of the lateral tibial plateau (17.6°) were determined. With these cut-off values in diagnosing discoid lateral meniscus, the sensitivity and accuracy of height of the fibular head were 78 and 70 %, respectively. CONCLUSIONS: Several plain radiographic findings in symptomatic discoid lateral meniscus in children were significantly different from those in normal control. These findings would be helpful in screening tool of discoid lateral meniscus for children. LEVEL OF EVIDENCE: II.

Fractional pretreatment of hybrid poplar for accelerated enzymatic hydrolysis: characterization of cellulose-enriched fraction.

The efficient production of fermentable sugars is a prerequisite for economic ethanol production from lignocellulosic biomass. A cellulose-enriched fraction was obtained by complete dissolution of ball-milled hybrid poplar wood in dimethyl sulfoxide and lithium chloride (DMSO/LiCl). The cellulose-enriched fraction was mainly composed of glucose and xylose. Spectral fitting analysis of CP/MAS (13)C NMR revealed that the cellulose-enriched fraction had para-crystalline structures with somewhat larger contents of crystalline cellulose І(ß) than І(α). The cellulose-enriched fraction was much easier to be converted into mono sugars by cellulases than the untreated sample. Scanning electron microscopy (SEM) indicated that the cellulose-enriched fraction was porous, which could likely explain the high enzymatic hydrolysis efficiency. This study provides a novel pretreatment method based on fractional separation of the three biopolymers via complete dissolution system for enhancement of conversion from ignocellulose to biofuels.

Regulation of hepatitis C virus replication by the core protein through its interaction with viral RNA polymerase.

The hepatitis C virus (HCV) core protein is a structural component of the nucleocapsid and has been shown to modulate cellular signaling pathways by interaction with various cellular proteins. In the present study, we investigated the role of HCV core protein in viral RNA replication. Immunoprecipitation experiments demonstrated that the core protein binds to the amino-terminal region of RNA-dependent RNA polymerase (RdRp), which encompasses the finger and palm domains. Direct interaction between HCV RdRp and core protein led to inhibition of RdRp RNA synthesis activity of in vitro. Furthermore, over-expression of core protein, but not its derivatives lacking the RdRp-interacting domain, suppressed HCV replication in a hepatoma cell line harboring an HCV subgenomic replicon RNA. Collectively, our results suggest that the core protein, through binding to RdRp and inhibiting its RNA synthesis activity, is a viral regulator of HCV RNA replication.

Interaction of hepatitis C virus core protein with Hsp60 triggers the production of reactive oxygen species and enhances TNF-alpha-mediated apoptosis.

The hepatitis C virus (HCV) core protein is the primary protein component of the nucleocapsid that encapsidates the viral RNA genome. Besides its role as a viral structural protein, the core protein is implicated in HCV chronic infection-associated liver diseases by induction of reactive oxygen species (ROS) production and modulation of apoptosis. Here, we show that interaction of the core protein, through its N-terminal domain (amino acids 1-75), with heat shock protein (Hsp60) is critical for the induction of ROS production, leading to sensitization of core protein-expressing cells to apoptosis induced by tumor necrosis factor-alpha (TNF-alpha). Moreover, overexpression of Hsp60 rescued the core protein-expressing cells from cell death by reducing ROS production. Collectively, our results suggest that impairment of Hsp60 function through binding of HCV core protein contributes to HCV viral pathogenesis by ROS generation and amplification of the apoptotic effect of TNF-alpha.

Proteomic profiling of cellular proteins interacting with the hepatitis C virus core protein.

Hepatitis C virus (HCV) is a causative agent of chronic hepatitis and hepatocellular carcinoma. The core protein of HCV packages the viral RNA genome to form a nucleocapsid. In addition to its function as a structural protein, core protein is involved in regulation of cellular transcription, virus-induced transformation, and pathogenesis. To gain insights into cellular functions of the core protein by identification of cellular proteins interacting with the core protein, we employed a proteomic approach. Hepatocytes soluble cytoplasmic proteins were applied to the core proteins immobilized on Ni-nitrilotriacetic resin and total bound cellular proteins were resolved by 2-DE. Analyses of interacting proteins by matrix-assisted laser desorption/ionization-time of flight mass spectrometry allowed identification of 14 cellular proteins binding to the core protein. These proteins include DEAD-box polypeptide 5, similar in function to a known protein identified previously by yeast two-hybrid screening and 13 newly identified cellular proteins. Interestingly, nine protein spots were identified as intermediate microfilament proteins, including cytokeratins (five spots for cytokeratin 8, two for cytokeratin 19, and one for cytokeratin 18) and vimentin. Cytokeratin 8 and vimentin, which were previously shown to be involved in the infection processes of other viruses, were further analyzed to confirm their in vivo interactions with the core protein by immunoblotting and immunofluorescence microscopy. We discuss the functional implications of the interactions of the core protein with newly identified cellular proteins in HCV infection and pathogenesis.

Bacterial cell surface display for epitope mapping of hepatitis C virus core antigen.

Cell surface expression of protein has been widely used to display enzymes and antigens. Here we show that Pseudomonas syringae ice nucleation protein with a deletion of internal repeating domain (INC) can be used in Escherichia coli to display peptide in a conformationally active form on the outside of the folded protein by fusing to the C-terminus of INC. Diagnostic potential of this technology was demonstrated by effective mapping of antigenic epitopes derived from hepatitis C virus (HCV) core protein. Amino acids 1-38 and 26-53 of HCV core protein were found to react more sensitively in a native conformation with the HCV patient sera than commercial diagnostic antigen, c22p (amino acids 10-53) by display-ELISA. These results demonstrate that the bacterial cell surface display using INC is useful for peptide presentation and thus epitope mapping of antigen.