Protective effect of HV-P411, an herbal mixture,on carbon tetrachloride-induced liver fibrosis

This study was performed to examine the anti-fibrotic activity of HV-P411, an herbal mixture of seeds of Vitis vinifera, Schisandra chinensis and Taraxacum officinale extract, against carbon tetrachloride (CCl₄)-induced liver fibrosis. Hepatic fibrosis was induced by intraperitoneal injection of CCl₄ (0.5 ml/kg, twice weekly) for 8 weeks. Rats were treated orally with HV-P411 at 50, 100, 200, and 400 mg/kg once a day. After chronic exposure to CCl₄, the levels of hydroxyproline were markedly increased; these were significantly reduced by HV-P411 at all dose levels. The level of serum aminotransferases and lipid peroxidation were increased after the CCl₄ treatment, while reduced glutathione was decreased. These changes were attenuated by HV-P411. In addition, HV-P411 attenuated CCl₄-induced raised serum concentration of transforming growth factor-β1, and the levels of matrix metalloprotease-2 and tissue inhibitor of metalloprotease-1 mRNAs. Our results suggest that HV-P411 may prevent liver fibrosis by modulating fibrogenesis and fibrolysis.     

In vivo evidence for non-universal usage of the codon CUG in Candida maltosa

An alkane-assimilating yeast Candida maltosa had been studied in order to establish systems suitable for biotransformation of hydrophobic compounds. However, functional expression of heterologous genes tested for this purpose had not been successful in several cases. On the other hand, it had been reported that the codon CUG, a universal leucine codon, is read as serine in C. cylindracea. The same altered codon usage had also been suggested by in vitro experiments in some Candida yeasts which are phylogenetically closely related to C. maltosa. In this study we have shown that the failure in functional expression of a heterologous gene is due to the fact that the codon CUG is read as serine in C. maltosa. This conclusion was drawn from the following experimental results: (1) when a cytochrome P450 gene of C. maltosa containing a CTG codon was expressed in C. maltosa, the corresponding amino acid was found to be serine, and not leucine; (2) a tRNA gene with an almost identical structure to that of the tRNA ^SerCAG gene of C. albicans could be isolated from the genome of C. maltosa; (3) the Saccharomyces cerevisiae URA3 gene, which has one CTG codon, could not complement the ura3 mutation of C. maltosa as itself, but when the CTG codon was changed to another leucine codon, CTC, the mutated gene could complement the ura3 mutation. The last result is the first example of succeeding in functional expression of a heterologous gene in Candida species having an altered codon usage by changing the CTG codon in the gene to another codon. The nucleotide sequence datum reported in this paper will appear in the GSDB, DDBJ, EMBL and NCBI nucleotide sequence databases with the Accession Number D26074.     

Pathogenic microorganisms,heavy metals,and antibiotic residues in seven Korean freshwater aquaculture species

Food Science and Biotechnology - This survey was performed to estimate the levels of pathogenic microorganisms, antibiotic residues, and heavy metals in seven Korean freshwater aquaculture species...     

Synergy effects by combination with lactic acid bacteria and frutooligosaccharides on the cell growth and antimicrobial activity

The aim of this study was to identify probiotic possibility of lactic acid bacteria (LAB) from mustard leaf kimchi and investigate synergy effects of combination with LAB and fructooligosaccharide (FOS) on antimicrobial activity. Lactobacillus acidophilus GK20, L. paracasei GK74, and L. plantarum GK81 have high survival ratio under gastric and intestinal fluids and were resistant to ampicillin, streptomycin, or tetracycline. The pH of LAB gradually decreased but the titratable acidity increased owing to organic acids production. Especially, L. acidophilus GK20 and L. paracasei GK74 produced hydrogen peroxide and bacteriocin. When LAB was co-cultured with Listeria monocytogenes or Staphylococcus aureus in broth without FOS, the inhibition ratio of L. monocytogenes and S. aureus by L. acidophilus GK20 was 36 and 57%, but L. paracasei GK74 showed higher inhibitory effect against L. monocytogenes than S. aureus. Meanwhile, the cell growth, culture pH, titratable acidity, and bacteriocin activity of L. acidophilus GK20 and L. paracasei GK74 were significantly (p<0.05) increased in MRS with FOS than without prebiotic. In conclusion, L. acidophilus GK20 and L. paracasei GK74 could be potentially used as novel probiotic strains, moreover, the combination between L. acidophilus GK20 or L. paracasei GK74 and FOS has great potential as a synbiotic.     

Effect of metal powder packing on the conductivity of nanometal ink

The power of nanotechnology is realized in its application in numerous areas. One such area is undoubtedly the use of metallic nanoparticles as a direct write application. An effort in this area has resulted in a conductive ink whose conductivity approaches 60-70% that of the bulk copper. Such an ink has been developed by reducing silver, gold, and copper nano-sized powders by a wet method and followed by a heat treatment at less than 400 degrees C. The conductivity of the resulting ink product was found to be very much affected by how various sizes of metal powders are packed when particles were dried and packed on various substrates. The effect of packing and various kinds of metal powders on the eventual conductivity of the final product of the ink has been described and discussed in this paper.