Analysis of Methylglyoxal Metabolism in CHO Cells Grown in Culture

Recent evidence suggests that several unknown or ill-characterized factors strongly influence cell growth and function in culture. Isolating these factors is necessary in order to maximize culture productivities. Methylglyoxal (MG), a potent protein and nucleic acid modifying agent, has been identified as a player in the signaling pathways associated with cell death and is known to be detrimental to cultured cells. This compound is produced in all mammalian systems by spontaneous phosphate elimination from glycolytic pathway intermediates. A kinetic model that qualitatively describes the cellular distribution of protein-associated MG in the absence of enzymatic adduct formation predicted far lower levels of reversibly bound MG than measured in cultured CHO cells. This suggests that the targeted modification of proteins through enzymatically mediated mechanisms is a significant sink for cellular methylglyoxal. The model was validated with measurements of carbon flux through the glyoxalase pathway to d-lactic acid, a unique end product of MG metabolism in mammalian systems. Fluxes to d-lactic acid of up to 16.8 mmol ml-packed cells⁻¹ day⁻¹ were measured with CHO cells grown in batch culture or 100-fold more than found in normal tissues.     

Novel elongase of Pythium sp. with high specificity on Δ-18C desaturated fatty acids

We identified a novel elongase gene from a selected strain of the Oomycete, Pythium sp. BCC53698. Using a PCR approach, the cloned gene (PyElo) possessed an open reading frame (ORF) of 834 bp encoding 277 amino acid residues. A similarity search showed that it had homology with the PUFA elongases of several organisms. In addition, the signature characteristics, including four conserved motifs, a histidine-rich catalytic motif and membrane-associated feature were present in the Pythium gene. Heterologous expression in Saccharomyces cerevisiae showed that it was specific for fatty acid substrates, having a double bond at Δ⁶-position, which included γ-linolenic acid (GLA) and stearidonic acid (STA), and preferentially elongated the n3-18C PUFA. This is an elongase in Oomycete fungi, which displays very high specificity on Δ⁶-18C desaturated fatty acids. This will be a powerful tool to engineer PUFA biosynthesis in organisms of interest through the n-6 series pathway for producing value-added fatty acids.     

Water footprint inventory database of Thai rice farming for water policy decisions and water scarcity footprint label

The International Journal of Life Cycle Assessment - Rice is a major economic crop which has created local livelihood, careers and incomes in the agricultural sector in Thailand, one of the leading...     

No Proof of HTLV-I/II in Intravenous Drug Abusers with a High Rate of HIV-1 Infection in Central Thailand

Serum specimens of 1,074 intravenous drug abusers (IVDA) were examined for infection with HIV-1, HTLV-I and HTLV-II in central Thailand. Three hundred and sixty-two of the specimens were seropositive for HIV-1 (33.7%). The HIV-1 seropositive IVDAs exhibited increased seropositivity with age through group 40–44 and significantly decreased seropositivity over the age of 45. In contrast, no seropositivity to either HTLV-I or -II was detected in the samples tested by a particle-agglutination assay for HTLV followed by type-specific Western blotting for HTLV. Reference to previous reports suggested that the rate of HIV infection in IVDAs has decreased with no HTLV-I or HTLV-II in Thailand when compared with that of the HIV infection in 1992.