Mycosporine-Like Amino Acids Promote Wound Healing through Focal Adhesion Kinase (FAK) and Mitogen-Activated Protein Kinases (MAP Kinases) Signaling Pathway in Keratinocytes

Mycosporine-like amino acids (MAAs) are secondary metabolites found in diverse marine, freshwater, and terrestrial organisms. Evidence suggests that MAAs have several beneficial effects on skin homeostasis such as protection against UV radiation and reactive oxygen species (ROS). In addition, MAAs are also involved in the modulation of skin fibroblasts proliferation. However, the regulatory function of MAAs on wound repair in human skin is not yet clearly elucidated. To investigate the roles of MAAs on the wound healing process in human keratinocytes, three MAAs, Shinorine (SH), Mycosporine-glycine (M-Gly), and Porphyra (P334) were purified from Chlamydomonas hedlyei and Porphyra yezoensis. We found that SH, M-Gly, and P334 have significant effects on the wound healing process in human keratinocytes and these effects were mediated by activation of focal adhesion kinases (FAK), extracellular signal-regulated kinases (ERK), and c-Jun N-terminal kinases (JNK). These results suggest that MAAs accelerate wound repair by activating the FAK-MAPK signaling pathways. This study also indicates that MAAs can act as a new wound healing agent and further suggests that MAAs might be a novel biomaterial for wound healing therapies.     

Detection of classical and newly described staphylococcal superantigen genes in coagulase-negative staphylococci isolated from bovine intramammary infections

The coagulase-negative staphylococci (CNS) are the most prevalent mastitis pathogen group yet their virulence characteristics have not been well described. We investigated the presence of 19 classical and newly described staphylococcal superantigen (SAg) genes in CNS isolates from bovine intramammary infections (IMI). A total of 263 CNS representing 11 different Staphylococcus spp. were examined, and 31.2% (n = 82) of CNS isolates had one or more SAg genes; there were 21 different SAg gene combinations. The most prevalent combination of SAg genes (seb, seln and selq; n = 45) was found in S. chromogenes, S. xylosus, S. haemolyticus, S. sciuri subsp. carnaticus, S. simulans and S. succinus. The genes for SAgs appear to be widely distributed amongst CNS isolated from bovine IMI.     

Stabilizing isopeptide bonds revealed in gram-positive bacterial pilus structure

Many bacterial pathogens have long, slender pili through which they adhere to host cells. The crystal structure of the major pilin subunit from the Gram-positive human pathogen Streptococcus pyogenes at 2.2 angstroms resolution reveals an extended structure comprising two all-beta domains. The molecules associate in columns through the crystal, with each carboxyl terminus adjacent to a conserved lysine of the next molecule. This lysine forms the isopeptide bonds that link the subunits in native pili, validating the relevance of the crystal assembly. Each subunit contains two lysine-asparagine isopeptide bonds generated by an intramolecular reaction, and we find evidence for similar isopeptide bonds in other cell surface proteins of Gram-positive bacteria. The present structure explains the strength and stability of such Gram-positive pili and could facilitate vaccine development.     

Evaluation of commercial polyclonal- and monoclonal-antibody-based immunohistochemical tests for 2 genotypes of Porcine circovirus type 2 and comparison with in-situ hybridization assays

The objective of the present study was to evaluate polyclonal- and monoclonal-antibody-based immunohistochemical (IHC) tests for the detection of 2 genotypes of Porcine circovirus type 2 (PCV2), a and b, in formalin-fixed, paraffin-embedded lymph-node tissue from pigs with experimental or natural postweaning multisystemic wasting syndrome and to compare the IHC results with those of in-situ hybridization (ISH) assays. The ISH assays proved more sensitive than the IHC tests for the detection of PCV2a and PCV2b. According to these findings, polyclonal-antibody-based IHC testing is the most practical routine diagnostic method for the detection of PCV2 regardless of genotype because IHC testing is less technically complex than ISH testing. However, ISH assays are useful to differentiate between PCV2a and PCV2b in surveillance programs for the monitoring of PCV2 in swine herds.     

Importance of rice root oxidation potential as a regulator of CH4 production under waterlogged conditions

Biology and Fertility of Soils - One of the most important characteristics of a rice cultivar controlling methane (CH4) production can be the root oxidation potential because a cultivar with a high...     

Diet of introduced largemouth bass in Korean rivers and potential interactions with native fishes

Abstract –  A dietary analysis of largemouth bass ( Micropterus salmoides ), an exotic, piscivorous species, was conducted in large South Korean river systems (>third order streams, 31 sites). Micropterus salmoides larger than 100 mm exhibited intense piscivory on native Korean juvenile fishes, with levels of piscivory amongst the highest recorded globally, for native and introduced populations. Largemouth bass exhibited an ontogenetic shift in diet, showing a progressive increase in piscivory with size, typical of this species within its native range but unlike several studies on introduced largemouth bass in Europe and Africa. Sampling of fish communities at the same sites used for diet studies showed that native piscivores and the main food fish species of largemouth bass were significantly less abundant ( P  = 0.049 and 0.045, respectively) at sites where bass were present than at sites where no bass were recorded. Largemouth bass may pose a threat to the structure of fish assemblages in Korean river systems and further study of their population interactions and how to minimise their spread is needed.     

Comparison of field methods for measuring soil respiration: a static alkali absorption method and two dynamic closed chamber methods

The objectives of the present study were to compare the static alkali absorption (AA) and dynamic closed chamber (DC) methods for measuring soil respiration, and to evaluate the effects of methodological differences on estimating annual mean soil respiration rate in a natural forest. For the AA method, we used Kirita’s method [Jpn. J. Ecol. 21 (1971) 119] using an alkali-soaked sponge disc that covers nearly the same area as that covered by a chamber. For the DC method, we used both the LI-6200 system (DC-62 method) and the newer LI-6400 system (DC-64 method) (LI-COR, Lincoln, NE, USA). Comparative measurements were conducted on five occasions during the study period (November 1998–October 1999) at a Quercus serrata forest in Japan. Daily mean soil respiration rates obtained by the AA, DC-62 and DC-64 methods for a 24 h period were in the ranges 205–578, 147–629 and 165–734 mg CO₂ m⁻² h⁻¹, respectively. The daily mean soil respiration rates obtained by the AA method were 79–128% of those obtained by the DC-64 method. When the daily mean soil respiration rate obtained by the DC-64 method was below 300 mg CO₂ m⁻² h⁻¹, the daily mean soil respiration rate obtained by the AA method was an average of 26% higher than that obtained by the DC-64 method. When the daily mean soil respiration rate obtained by the DC-64 method was above 300 mg CO₂ m⁻² h⁻¹, the daily mean soil respiration rate obtained by the AA method was an average of 19% lower than that obtained by the DC-64 method. However, at the present site, there was a little difference between the two methods as for estimating annual mean soil respiration rate, and therefore the AA method improved by Kirita [Jpn. J. Ecol. 21 (1971) 119] is suggested to be a useful method for estimating annual mean soil respiration in the forest. The daily mean soil respiration rates obtained by the DC-62 method were systematically 10–24% lower (an average of 15% lower) than those obtained with the DC-64 method, and the annual mean rate was lower than that estimated by the AA method.     

Variation in isoflavone of soybean cultivars with location and storage duration

Fifteen soybean [Glycine max (L.) Merrill] cultivars were grown in Seoul, Suwon, and Kyongsan, Korea, in 1998, 1999, and 2000, and their isoflavone contents were assessed. After harvest, the beans were stored for 3 years at room temperature. Soybean isoflavones were analyzed using high-performance liquid chromatography (HPLC) within each crop year and after storage. Total isoflavone contents ranged from 188.4 to 685.6 mg 100 g(-1) in 1998, from 218.8 to 948.9 mg 100 g(-1) in 1999, and from 293.1 to 483.0 mg 100 g(-1) in 2000. The year x variety, and year x location x variety interactions were significantly different in 1998, the year x location, year x variety, and year x location x variety interactions were significantly different in 1999, and the year x variety interaction was significantly different in 2000 for total and individual isoflavone contents. Total isoflavone contents of soybeans stored for 1 year were only slightly higher than those of soybeans stored for 2 or 3 years. However, the concentrations of individual isoflavones, especially 6' '-O-malonyldaidzin and 6' '-O-malonylgenistin, decreased markedly in soybeans stored for 2 or 3 years. These data suggest that it may be feasible to improve soybean cultivars with higher antioxidative substances.