In vitro Fertilization Outcomes of Frozen-thawed Embryo Transfer with Hatched Blastocysts versus with Hatching Blastocysts.

This study aimed to elucidate the effect of hatching status on in vitro fertilization (IVF) outcomes in frozen-thawed blastocyst transfer cycles. Frozen-thawed embryo transfer (FET) cycles performed at a single fertility center between 2016 and 2021 were retrospectively assessed. Analyses were restricted to 6,821 frozen-thawed blastocyst transfers in women aged 24-47 years. For optimal comparability, double embryo transfer (ET) cycles consisting of one hatching and one hatched blastocyst were excluded. The implantation and pregnancy rates were evaluated and compared between the hatching and hatched blastocyst transfer groups based on patients' age (<38 vs. ≥38 years), blastocyst grade (good vs. bad grade), and the number of transferred embryos (single ET vs. double ET). Hatched blastocyst transfer was associated with higher implantation and clinical pregnancy rates in the single ET group (15.7% and 15.6%, respectively; p<0.001). The transfer of two hatched blastocysts had higher implantation and clinical pregnancy rates compared to the transfer of two hatching blastocysts (19.5% and 20.4%, respectively; p<0.001) in the double ET group. In the hatched blastocyst transfer group, the clinical pregnancy and implantation rates were higher, regardless of each woman's age and embryo quality. The IVF treatment outcomes were improved when the blastocysts were hatched during FET cycles. Hence, hatched blastocyst transfer in FET cycles could be considered a superior method in IVF practice.

The LKB1-TSSK1B axis controls YAP phosphorylation to regulate the Hippo-YAP pathway.

The Hippo pathway's main effector, Yes-associated protein (YAP), plays a crucial role in tumorigenesis as a transcriptional coactivator. YAP's phosphorylation by core upstream components of the Hippo pathway, such as mammalian Ste20 kinase 1/2 (MST1/2), mitogen-activated protein kinase kinase kinase kinases (MAP4Ks), and their substrate, large tumor suppressor 1/2 (LATS1/2), influences YAP's subcellular localization, stability, and transcriptional activity. However, recent research suggests the existence of alternative pathways that phosphorylate YAP, independent of these core upstream Hippo pathway components, raising questions about additional means to inactivate YAP. In this study, we present evidence demonstrating that TSSK1B, a calcium/calmodulin-dependent protein kinase (CAMK) superfamily member, is a negative regulator of YAP, suppressing cellular proliferation and oncogenic transformation. Mechanistically, TSSK1B inhibits YAP through two distinct pathways. Firstly, the LKB1-TSSK1B axis directly phosphorylates YAP at Ser94, inhibiting the YAP-TEAD complex's formation and suppressing its target genes' expression. Secondly, the TSSK1B-LATS1/2 axis inhibits YAP via phosphorylation at Ser127. Our findings reveal the involvement of TSSK1B-mediated molecular mechanisms in the Hippo-YAP pathway, emphasizing the importance of multilevel regulation in critical cellular decision-making processes.

Ubiquitin E3 ligases in cancer: somatic mutation and amplification.

Defects in DNA double-strand break (DSB) repair signaling permit cancer cells to accumulate genomic alterations that confer their aggressive phenotype. Nevertheless, tumors depend on residual DNA repair abilities to survive the DNA damage induced by genotoxic stress. This is why only isolated DNA repair signaling is inactivated in cancer cells. DNA DSB repair signaling contributes to general mechanism for various types of lesions in diverse cell cycle phases. DNA DSB repair genes are frequently mutated and amplified in cancer; however, limited data exist regarding the overall genomic prospect and functional result of these modifications. We list the DNA repair genes and related E3 ligases. Mutation and expression frequencies of these genes were analyzed in COSMIC and TCGA. The 11 genes with a high frequency of mutation differed between cancers, and mutations in many DNA DSB repair E3 ligase genes were related to a higher total mutation burden. DNA DSB repair E3 ligase genes are involved in tumor suppressive or oncogenic functions, such as RNF168 and FBXW7, by assisting the functionality of these genomic alterations. DNA damage response-related E3 ligases, such as RNF168, FBXW7, and HERC2, were generated with more than 10% mutation in several cancer cells. This study provides a broad list of candidate genes as potential biomarkers for genomic instability and novel therapeutic targets in cancer. As a DSB related proteins considerably appear the possibilities for targeting DNA repair defective tumors or hyperactive DNA repair tumors. Based on recent research, we describe the relationship between unstable DSB repairs and DSB-related E3 ligases. [BMB Reports 2023; 56(5): 265-274].

Effect of different ceramic materials and substructure designs on fracture resistance in anterior restorations.

STATEMENT OF PROBLEM: Materials have been developed to reduce the chipping of ceramic veneer and improve the esthetics of anterior ceramic veneered restorations. However, studies of the effects of material and substructure design on fracture resistance are sparse. PURPOSE: The purpose of this in vitro study was to investigate the fracture resistance of metal-ceramic (MC), zirconia-feldspathic porcelain (ZC), and zirconia-lithium disilicate (ZL) anterior restorations and evaluate the effect of material and substructure design. MATERIAL AND METHODS: After preparing and scanning artificial maxillary central incisor teeth, titanium abutments and restoration specimens (n=90) were fabricated. MC, ZC, and ZL materials were prepared with substructure designs A (two-third coverage of the palatal surface) and B (one-third coverage of the palatal surface). After cementation, the specimens were thermocycled (10 000 cycles, 5 and 55 °C). Fracture load measurements, failure mode analysis, energy dispersive X-ray spectroscopy (EDS), line scan analysis, fractography, finite element analysis (FEA), and Weibull analysis were performed. Two-way ANOVA was used to identify the effects of material and substructure design on fracture load. One-way ANOVA was used to identify significant differences of fracture load (α=.05). RESULTS: MC and ZL showed significantly higher fracture load than ZC (P<.05). MC_A showed a significantly higher fracture load than MC_B (P<.05). ZC_A exhibited the lowest Weibull modulus. FEA revealed that the maximum principal stress occurred near the loading area of the veneer. ZL displayed the lowest maximum principal stress among all the materials. CONCLUSIONS: ZL and MC_A exhibited more favorable fracture resistance. The substructure design of MC, with increased metal coverage of the palatal surface, improved fracture resistance significantly.

A comparison of surgical outcomes between robot and laparoscopy-assisted adenomyomectomy.

We aimed to investigate the feasibility of robotic adenomyomectomy and compared surgical outcomes between laparoscopic and robotic approaches for adenomyomectomy.We retrospectively reviewed the data of women who were diagnosed with adenomyosis and underwent adenomyomectomy through a minimally invasive approach between January 2014 and March 2018 at the CHA Gangnam Medical Center, Seoul, Republic of Korea. Patient demographics and operation-related outcomes were compared between the robotic and laparoscopic surgery groups.We evaluated 43 women who underwent adenomyomectomy through a minimally invasive approach (21 underwent a laparoscopic and 22 underwent a robotic adenomyomectomy). All 22 women who had originally been scheduled to undergo robotic adenomyomectomy could successfully undergo the robotic surgery without requiring conversion to laparotomy and/or serious complications. No statistically significant differences in patient demographics were observed between the robotic and the laparoscopic surgery groups. No significant intergroup difference was observed in the operative time, estimated blood loss, weight of the resected nodule, and length of hospitalization (160.0 vs 212.5 min, P = .106; 500.0 vs 300.0 mL, P = .309; 60.0 vs 70.0 g, P = .932; and 5.0 vs 6.0 days, P = .277). No serious perioperative complications were observed in either group.Robotic adenomyomectomy is feasible for women with adenomyosis. Surgical outcomes of robotic adenomyomectomy were comparable to those of a laparoscopic approach. There was, however, no superiority of robotic adenomyomectomy in terms of surgical outcomes. Further multicenter prospective studies using standardized surgical procedures are needed to confirm the conclusion of this study.

Effect of liners and primers on tensile bond strength between zirconia and resin-based luting agent.

PURPOSE: The effect of silica-based glass-ceramic liners on the tensile bond strength between zirconia and resin-based luting agent was evaluated and compared with the effect of 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primers. MATERIALS AND METHODS: Titanium abutments and zirconia crowns (n = 60) were fabricated, and the adhesive surfaces of the specimens were treated by airborne-particle abrasion. The specimens were divided into 5 groups based on surface treatment: a control group, 2 primer groups (MP: Monobond Plus; ZP: Z Prime Plus), and 2 liner groups (PL: P-containing Liner; PFL: P-free Liner). All specimens were cemented with self-adhesive resin-based luting agent. After 24-hour water storage and thermocycling (5,000 cycles, 5℃/55℃), the tensile bond strength was measured using a universal testing machine. Failure mode analysis and elemental analysis on the bonding interface were performed. The data were analyzed using Kruskal-Wallis test, Dunn's post hoc test, and Fisher's exact test. RESULTS: The liner groups and primer groups showed significantly higher tensile bond strengths than that of the control group (P<.05). PFL showed a significantly higher tensile bond strength than the primer groups (P<.05). The percentage of mixed failure was higher in the primer groups than in the control group (P<.001), and all the specimens showed mixed failure in the liner groups (P<.001). A chemical reaction area was observed at the bonding interface between zirconia and liner. CONCLUSION: The application of liner significantly increased the tensile bond strength between zirconia and resin-based luting agent. PFL was more effective than MDP-containing primers in improving the tensile bond strength with the resin-based luting agent.

LRRK2 functions as a scaffolding kinase of ASK1-mediated neuronal cell death.

Leucine-rich repeat kinase 2 (LRRK2), a multi-domain protein, is a key causative factor in Parkinson's disease (PD). Identification of novel substrates and the molecular mechanisms underlying the effects of LRRK2 are essential for understanding the pathogenesis of PD. In this study, we showed that LRRK2 played an important role in neuronal cell death by directly phosphorylating and activating apoptosis signal-regulating kinase 1 (ASK1). LRRK2 phosphorylated ASK1 at Thr832 that is adjacent to Thr845, which serves as an autophosphorylation site. Moreover, results of binding and kinase assays showed that LRRK2 acted as a scaffolding protein by interacting with each components of the ASK1-MKK3/6-p38 MAPK pathway through its specific domains and increasing the proximity to downstream targets. Furthermore, LRRK2-induced apoptosis was suppressed by ASK1 inhibition in neuronal stem cells derived from patients with PD. These results clearly indicate that LRRK2 acts as an upstream kinase in the ASK1 pathway and plays an important role in the pathogenesis of PD.

Parkin mediates neuroprotection through activation of Notch1 signaling.

Parkin, an E3 ubiquitin ligase, is the most frequently mutated gene in hereditary Parkinson's disease. Inactivation of Parkin leads to impairment of the ubiquitin-proteasome system, resulting in the accumulation of misfolded or aggregated proteins and ensuing neurodegeneration. In this study, we show that Parkin positively regulates the Notch1 signaling pathway. Overexpression of Parkin stabilized Notch1-IC protein levels, whereas knockdown of Parkin decreased Notch1-IC protein stability. Notably, overexpression of Parkin disrupted oxidative stress-induced apoptosis in neuronal cells. However, knockdown of Notch1 inhibited Parkin-induced neuronal cell survival. Together, these results indicate that Parkin is a novel regulator of the Notch1 signaling pathway, which promotes neuronal cell survival.

Autophagy negatively regulates tumor cell proliferation through phosphorylation dependent degradation of the Notch1 intracellular domain.

Autophagy is a highly conserved mechanism that degrades long-lived proteins and dysfunctional organelles, and contributes to cell fate. In this study, autophagy attenuates Notch1 signaling by degrading the Notch1 intracellular domain (Notch1-IC). Nutrient-deprivation promotes Notch1-IC phosphorylation by MEKK1 and phosphorylated Notch1-IC is recognized by Fbw7 E3 ligase. The ubiquitination of Notch1-IC by Fbw7 is essential for the interaction between Notch1-IC and p62 and for the formation of aggregates. Inhibition of Notch1 signaling prevents the transformation of breast cancer cells, tumor progression, and metastasis. The expression of Notch1 and p62 is inversely correlated with Beclin1 expression in human breast cancer patients. These results show that autophagy inhibits Notch1 signaling by promoting Notch1-IC degradation and therefore plays a role in tumor suppression.

Tumor Suppressor HIPK2 Regulates Malignant Growth via Phosphorylation of Notch1.

The receptor Notch1 plays an important role in malignant progression of many cancers, but its regulation is not fully understood. In this study, we report that the kinase HIPK2 is responsible for facilitating the Fbw7-dependent proteasomal degradation of Notch1 by phosphorylating its intracellular domain (Notch1-IC) within the Cdc4 phosphodegron motif. Notch1-IC expression was higher in cancer cells than normal cells. Under genotoxic stress, Notch1-IC was phosphorylated constitutively by HIPK2 and was maintained at a low level through proteasomal degradation. HIPK2 phosphorylated the residue T2512 in Notch1-IC. Somatic mutations near this residue rendered Notch1-IC resistant to degradation, as induced either by HIPK2 overexpression or adriamycin treatment. In revealing an important mechanism of Notch1 stability, the results of this study could offer a therapeutic strategy to block Notch1-dependent progression in many types of cancer. Cancer Res; 76(16); 4728-40. ©2016 AACR.

NOTCH1 intracellular domain negatively regulates PAK1 signaling pathway through direct interaction.

p21-Activated kinase 1 (PAK1) is a serine/threonine protein kinase implicated in cytoskeletal remodeling and cell motility. Recent studies have shown that it also promotes cell proliferation, regulates apoptosis, and increases cell transformation and invasion. In this study, we showed that NOTCH1 intracellular domain (NOTCH1-IC) negatively regulated PAK1 signaling pathway. We found a novel interaction between NOTCH1-IC and PAK1. Overexpression of NOTCH1-IC decreased PAK1-induced integrin-linked kinase 1 (ILK1) phosphorylation, whereas inhibition of NOTCH1 signaling increased PAK1-induced ILK1 phosphorylation. Notably, ILK1 phosphorylation was higher in PS1,2(-/-) cells than in PS1,2(+/+) cells. As expected, overexpression of NOTCH1-IC decreased ILK1-induced phosphorylation of glycogen synthase kinase 3 beta (GSK-3beta). Furthermore, NOTCH1-IC disrupted the interaction of PAK1 with ILK1 and altered PAK1 localization by directly interacting with it. This inhibitory effect of NOTCH1-IC on the PAK1 signaling pathway was mediated by the binding of NOTCH1-IC to PAK1 and by the alteration of PAK1 localization. Together, these results suggest that NOTCH1-IC is a new regulator of the PAK1 signaling pathway that directly interacts with PAK1 and regulates its shuttling between the nucleus and the cytoplasm.

Fe65 negatively regulates Jagged1 signaling by decreasing Jagged1 protein stability through the E3 ligase Neuralized-like 1.

Fe65 is a highly conserved adaptor protein that interacts with several binding partners. Fe65 binds proteins to mediate various cellular processes. But the interacting partner and the regulatory mechanisms controlled by Fe65 are largely unknown. In this study, we found that Fe65 interacts with the C-terminus of Jagged1. Furthermore, Fe65 negatively regulates AP1-mediated Jagged1 intercellular domain transactivation in a Tip60-independent manner. We found that Fe65 triggers the degradation of Jagged1, but not the Jagged1 intracellular domain (JICD), through both proteasome and lysosome pathways. We also showed that Fe65 promotes recruitment of the E3 ligase Neuralized-like 1 (Neurl1) to membrane-tethered Jagged1 and monoubiquitination of Jagged1. These three proteins form a stable trimeric complex, thereby decreasing Jagged1 targeting by ubiquitin-mediated degradation. Consequently, Jagged1 is a novel binding partner of Fe65, and Fe65 may act as a novel effector of Jagged1 signaling.

Alpha-synuclein negatively regulates Notch1 intracellular domain protein stability through promoting interaction with Fbw7.

Notch signaling pathway is well known that it is involved in regulating cell fate, proliferation and homeostasis. In this study, we show a novel function of alpha-synuclein (SNCA) to promote degradation of Notch1 intracellular domain (Notch1-IC) through Fbw7, ubiquitin E3 ligase. We identified that SNCA inhibits Notch1 transcription activity and diminishes the interaction between Notch1-IC and RBP-Jk. We also found decrease of Notch1-IC protein stability by exogenous and endogenous SNCA through proteasomal pathway, not through lysosomal pathway. And, we found that SNCA promotes interaction between Notch1-IC and Fbw7. Furthermore, SNCA directly interacts with Fbw7. SNCA increases ubiquitination of Notch-IC by Fbw7 through interaction with Fbw7. Together, these results suggest that SNCA is a novel regulator of Notch1-IC transcriptional activity with acting as an enhancer of the interaction of Notch1-IC and Fbw7 with increasing degradation of Notch1-IC.

Akt1 phosphorylates Nicastrin to regulate its protein stability and activity.

The gamma-secretase is a multiprotein complex that cleaves many type-I membrane proteins, such as the Notch receptor and the amyloid precursor protein. Nicastrin (NCT) is an essential component of the multimeric gamma-secretase complex and functions as a receptor for gamma-secretase substrates. In this study, we found that Akt1 markedly regulated the protein stability of NCT. Importantly, the kinase activity of Akt1 was essential for the inhibition of gamma-secretase activity through degradation of NCT. Notably, the protein level of endogenous NCT was higher in shAkt1-expressing cells than in shCon-expressing cells. Akt1 physically interacted with NCT and mediated its degradation through proteasomal and lysosomal pathways. We also found that Akt1 phosphorylates NCT at Ser437, resulting in a significant reduction in NCT protein stability. Importantly, a phospho-deficient mutation in NCT at Ser437 stabilized its protein levels. Collectively, our results reveal that Akt1 functions as a negative regulator of the gamma-secretase activity through phosphorylation and degradation of NCT. Generation of the amyloid peptide (A-beta) and the amyloid precursor protein (APP) intracellular domain (AICD) can happen by sequential proteolysis of APP by beta and gamma-secretase. The gamma-secretase complex consists of four essential proteins: presenilin (PS1 or PS2), presenilin enhancer 2 (PEN-2), anterior pharynx-defective 1 (APH-1), and the Nicastrin (NCT). NCT can interact and be phosphorylated by Akt1, and phosphorylated NCT promotes its proteasomal and lysosomal degradation. As a result, Akt1 plays role in reducing gamma-secretase activity through phosphorylation-dependent regulation of NCT protein degradation.

Safety evaluation of filamentous fungi isolated from industrial doenjang koji.

A few starters have been developed and used for doenjang fermentation but often without safety evaluation. Filamentous fungi were isolated from industrial doenjang koji, and their potential for mycotoxin production was evaluated. Two fungi were isolated; one was more dominantly present (90%). Both greenish (SNU-G) and whitish (SNU-W) fungi showed 97% and 95% internal transcribed spacer sequence identities to Aspergillus oryzae/flavus, respectively. However, the SmaI digestion pattern of their genomic DNA suggested that both belong to A. oryzae. Moreover, both fungi had morphological characteristics similar to that of A. oryzae. SNU-G and SNU-W did not form sclerotia, which is a typical characteristic of A. oryzae. Therefore, both fungi were identified to be A. oryzae. In aflatoxin gene cluster analysis, both fungi had norB-cypA genes similar to that of A. oryzae. Consistent with this, aflatoxins were not detected in SNU-G and SNU-W using ammonia vapor, TLC, and HPLC analyses. Both fungi seemed to have a whole cyclopiazonic acid (CPA) gene cluster based on PCR of the maoA, dmaT, and pks-nrps genes, which are key genes for CPA biosynthesis. However, CPA was not detected in TLC and HPLC analyses. Therefore, both fungi seem to be safe to use as doenjang koji starters and may be suitable fungal candidates for further development of starters for traditional doenjang fermentation.

Diversity of rotavirus strain circulated in gwangju, republic of Korea.

OBJECTIVES: The introduction of new rotavirus vaccines into the public sphere makes it necessary to maintain constant surveillance and to heighten public awareness of the appearance of new rotavirus strains. We describe the molecular epidemiology of circulating rotavirus strains after vaccine introduction. METHODS: We collected a total of 1070 stool samples from children with gastroenteritis from January 2013 to June 2013. The antigenic prevalence of rotavirus group A was distinguished using enzyme immunoassay. The G and P genotypes of enzyme immunoassay-positive samples were determined with reverse transcription-polymerase chain reaction and nucleotide sequencing analysis. RESULTS: Of the 1070 samples collected, 277 (25.9%) tested positive for rotaviruses by enzyme-linked immunoabsorbent assay. The most prevalent circulating genotype G was G1 (51.3%), followed by G2 (34.7%) and G9 (10.8%). The predominant type of genotype P was P[8] (66.1%), followed by P[4] (31.4%). In this study, nine genotypes were found. G1P[8] was the most prevalent (51.8%), followed by G2P[4] (30.5%), G9P[8] (9.9%), and G2P[8] (4.0%). Several unusual combinations (G1P[4], G3P[9], G3P[8], G4P[6], and G9P[4]) were also identified. CONCLUSION: Molecular epidemiological knowledge of rotaviruses is critical for the development of effective preventive measures, including vaccines. These data will help us monitor the effectiveness of current rotavirus vaccines.

Stepwise embryonic toxicity of silver nanoparticles on Oryzias latipes.

The developmental toxicity of silver nanoparticles (AgNPs) was investigated following exposure of Oryzias latipes (medaka) embryos to 0.1-1 mg/L of homogeneously dispersed AgNPs for 14 days. During this period, developmental endpoints, including lethality, heart rate, and hatching rate, were evaluated by microscopy for different stages of medaka embryonic development. To compare toxic sensitivity, acute adult toxicity was assessed. There was no difference in acute lethal toxicity between embryo and adult medaka. Interestingly, we found that the increase in stepwise toxicity was dependent on the developmental stage of the embryo. Lethal embryonic toxicity increased from exposure days 1 to 3 and exposure days 5 to 8, whereas there was no change from exposure days 3 to 5. In addition, 7 d exposure to 0.8 mg/L AgNPs resulted in significant heart beat retardation in medaka embryos. AgNPs also caused a dose-dependent decrease in the hatching rate and body length of larvae. These results indicate that AgNP exposure causes severe developmental toxicity to medaka embryos and that toxicity levels are enhanced at certain developmental stages, which should be taken into consideration in assessments of metallic NPs toxicity to embryos.

Niabella terrae sp. nov. isolated from greenhouse soil.

An orange-colored bacterial strain, ICM 1-15(T), was isolated from greenhouse soil. The 16S rRNA gene sequence of this strain showed the highest sequence similarity with Niabella ginsengisoli GR10-1(T) (95.2%) and Niabella yanshanensis CCBAU 05354(T) (95.0%) among the type strains. The strain ICM 1-15(T) was a strictly aerobic, Gram-negative, non-spore-forming, non-motile, flexirubin pigment-producing, short rod-shaped bacterium. The strain grew at 15-35°C (optimum, 25°C), at a pH of 5.0-8.5 (optimum, pH 6.5), and in the presence of 0-3% NaCl (optimum, 1%). The DNA G+C content of strain ICM 1-15(T) was 43.6 mol%. It contained MK-7 as the major isoprenoid quinone and iso-C15:0 (38.9%), iso-C15:1 G (20.3%), and iso-C17:0 3-OH (12.9%) as the major fatty acids. On the basis of evidence from our polyphasic taxonomic study, we concluded that strain ICM 1-15(T) should be classified within a novel species of the genus Niabella, for which the name Niabella terrae sp. nov. is proposed. The type strain is ICM 1-15(T) (=KACC 17443(T) =JCM 19502(T)).

Effects of sulfathiazole, oxytetracycline and chlortetracycline on steroidogenesis in the human adrenocarcinoma (H295R) cell line and freshwater fish Oryzias latipes.

Pharmaceuticals in the environment are of growing concern for their potential consequences on human and ecosystem health. Alterations in the endocrine system in humans or wildlife are of special interest because these alterations could eventually lead to changes in reproductive fitness. Using the H295R cell line, the potential endocrine disrupting effects of six pharmaceuticals including diclofenac, erythromycin, sulfamethazine, sulfathiazole, oxytetracycline, and chlortetracycline were investigated. After exposure to each target pharmaceutical for 48 h, production of 17beta-estradiol (E2) and testosterone (T), aromatase (CYP19) enzyme activity, or expression of steroidogenic genes were measured. Concentrations of E2 in blood plasma were determined in male Japanese medaka fish after 14 d exposure to sulfathiazole, oxytetracycline, or chlortetracycline. Among the pharmaceuticals studied, sulfathiazole, oxytetracycline and chlortetracycline all significantly affected E2 production by H295R cells. This mechanism of the effect was enhanced aromatase activity and up-regulation of mRNAs for CYP17, CYP19, and 3betaHSD, all of which are important components of steroidogenic pathways. Sulfathiazole was the most potent compound affecting steroidogenesis in H295R cells, followed by chlortetracycline and oxytetracycline. Sulfathiazole significantly increased aromatase activity at 0.2 mg/l. In medaka fish, concentrations of E2 in plasma increased significantly during 14-d exposure to 50 or 500 mg/l sulfathiazole, or 40 mg/l chlortetracycline. Based on the results of this study, certain pharmaceuticals could affect steroidogenic pathway and alter sex hormone balance. Concentrations of the pharmaceuticals studied that have been reported to occur in rivers of Korea are much less than the thresholds for effects on the endpoints studied here. Thus, it is unlikely that these pharmaceuticals are causing adverse effects on fish in those rivers.

Description of Microvirga aerophila sp. nov. and Microvirga aerilata sp. nov., isolated from air, reclassification of Balneimonas flocculans Takeda et al. 2004 as Microvirga flocculans comb. nov. and emended description of the genus Microvirga.

Two bacterial strains, 5420S-12(T) and 5420S-16(T), isolated from air samples, were characterized using a polyphasic approach. 16S rRNA gene sequence analysis showed that strain 5420S-12(T) was related phylogenetically to Microvirga subterranea FaiI4(T) (97.4 % sequence similarity) and Microvirga guangxiensis 25B(T) (97.1 %) and that strain 5420S-16(T) was closely related to Balneimonas flocculans TFB(T) (98.0 %) and Microvirga guangxiensis 25B(T) (97.2 %). The G+C content of the genomic DNA was 62.2 mol% for strain 5420S-12(T) and 61.5 mol% for strain 5420S-16(T). The major fatty acid was C(18 : 1)ω7c. The results of DNA-DNA hybridization and the phenotypic data showed that strains 5420S-12(T) and 5420S-16(T) could be distinguished from phylogenetically related species and represent two novel species within the genus Microvirga, for which the names Microvirga aerophila sp. nov. (type strain 5420S-12(T) =KACC 12743(T) =NBRC 106136(T)) and Microvirga aerilata sp. nov. (type strain 5420S-16(T) =KACC 12744(T) =NBRC 106137(T)) are proposed. Furthermore, the reclassification of Balneimonas flocculans as Microvirga flocculans comb. nov. (type strain TFB(T) =JCM 11936(T) =KCTC 12101(T) =IAM 15034(T) =ATCC BAA-817(T)) is proposed and an emended description of the genus Microvirga is provided.