The radial variation of fiber length increment (due to intrusive growth) and its relation with internal and external (climatic) factors were investigated for Acacia mangium trees collected in Indonesia and Malaysia. Wood fiber length and fiber length increment were approximated with respect to the distance from the pith (x) by a logarithmic function and vessel element length by a linear function. The results were y = 0.14 . ln(x) + 0.48, y = 0.0005 . x + 0.20, and y = 0.13 . ln(x) + 0.31, respectively. The radial variation of fiber length was related to the growth rate rather than the age of the cambium. The results of the cross-correlation function between wood fiber length increment and climatic factors showed that fiber lengths responded to changes in precipitation with a time lag of between zero to four months.

Curcumin (CUR), a yellow pigment in turmeric, has marked potential for preventing colon cancer. We recently reported that ar-turmerone (ATM) suppressed nitric oxide (NO) generation in macrophages. In the present study, we explored the molecular mechanisms by which ATM attenuates NO generation and examined the anti-carcinogenesis activity of turmerones (TUR, a mixture of 5 sesquiterpenes including ATM). Both CUR and ATM inhibited lipopolysaccharide (LPS)-induced expression of inducible forms of both nitric oxide synthase and cyclooxygenase (iNOS and COX-2, respectively). A chase experiment using actinomycin D revealed that ATM accelerated the decay of iNOS and COX-2 mRNA, suggesting a post-transcriptional mechanism. ATM prevented LPS-induced translocation of HuR, an AU-rich element-binding protein that determines mRNA stability of certain inflammatory genes. In a colitis model, oral administration of TUR significantly suppressed 2% dextran sulfate sodium (DSS)-induced shortening of the large bowel by 52-58%. We also evaluated the chemopreventive effects of oral feeding of TUR, CUR, and their combinations using a model of dimethylhydradine-initiated and DSS-promoted mouse colon carcinogenesis. At the low dose, TUR markedly suppressed adenoma multiplicity by 73%, while CUR at both doses suppressed adenocarcinoma multiplicity by 63-69%. Interestingly, the combination of CUR and TUR at both low and high doses abolished tumor formation. Collectively, our results led to our hypothesis that TUR is a novel candidate for colon cancer prevention. Furthermore, we consider that its use in combination with CUR may become a powerful method for prevention of inflammation-associated colon carcinogenesis.

In Quercus serrata, radial variations of wood fibre length, earlywood vessel element length, and earlywood vessel lumen diameter were investigated and maturation ages of them were estimated using nonlinear segmented regression analysis as proposed by Peszlen (1994). In addition, the age at the maximum point of current annual increment and mean annual increment were estimated by using the Gompertz growth function fitted to the variation of cumulative ring width with ring number from the pith. In the same radial strip, the maturation ages both of wood fibre length and the earlywood vessel element length were similar, and those were close to the ages at the maximum point of current annual increment, whereas the maturation age of earlywood vessel lumen diameter was generally greater, close to the age at the maximum point of mean annual increment. These results indicate that earlywood vessel lumen diameter is the best indicator of the three anatomical properties tested and that a relationship exists between the maturation ages of the size of axial elements and radial stem increment.

Aims:  Aspartyl aminopeptidase (DAP) has a high degree of substrate specificity, degrading only amino‐terminal acidic amino acids from peptides. Therefore, attention is focused here on the efficient production of this enzyme by a recombinant Aspergillus oryzae and characterization of its biochemical properties. Methods and Results:  The gene encoding DAP was overexpressed under a taka‐amylase gene promoter, with His‐tag linker in A. oryzae, during cultivation in a Co2+‐containing medium. The enzyme was extracted from the mycelia and purified with immobilized nickel ion absorption chromatography using a buffer containing cobalt ion and imidazole. The active fraction was further purified with gel filtration chromatography. The resultant, electrophoretically pure enzyme displayed a molecular mass of 520 kDa. This enzyme displayed high reactivity towards peptide substrate rather than synthetic substrates. Conclusions:  Recombinant A. oryzae DAP was purified to homogeneity with an increased specific activity, when cultivated in a Co2+‐rich medium. Moreover, the use of suitable metal ions in microbial cultivation and purification processes may help in increasing the specific activity of other metalloproteases and their functional analysis. Significance and Impact of the Study:  Recombinant DAP produced using a cobalt ion in culture media of A. oryzae and purification process allow high yield of the enzyme activity.

Leucine aminopeptidase (LAP), an enzyme used in the food industry, is an exopeptidase that removes an amino acid residue, primarily leucine (Leu), from the N-terminus of peptides and protein substrates. In this study, we focused on the leucine aminopeptidase A (lapA) gene from Aspergillus oryzae RIB40. To purify and characterize the LapA, lapA was overexpressed in A. oryzae RIB40 using the amyB promoter. LAP activity in the culture supernatant of one transformant harboring the lapA expression plasmid was 33 times that of the host strain. LapA was purified from the culture supernatant of this lapA-overexpressing strain by column chromatography. The purified recombinant LapA had a molecular mass of 33 kDa, and its N-terminal amino acid was the tyrosine at position 80 of the deduced amino acid sequence. Optimal enzyme activity was observed at 60°C and pH 8.5, and the enzyme was stable at temperatures up to 60°C and in the pH range 7.5-11. In transcriptional analysis, lapA was induced under alkaline conditions and expressed at a relatively low level under normal conditions. LapA showed maximum hydrolyzing activity for the substrate leucine para-nitroanilide (Leu-pNA), followed by substrates Phe-pNA (39% activity compared with Leu-pNA), Met-pNA, Lys-pNA, and Arg-pNA. In addition, LapA preferentially hydrolyzed peptides longer than tripeptides.