Mycobacterium tuberculosis (Mtb) causes death of 2-3 million people annually and is considered one of the most successful intracellular pathogens to persist inside the host macrophage. Recent studies have implicated the role of RD-1 region of Mtb genome in the mycobacterial pathogenesis. The role of RD-1-encoded secretory proteins of Mtb in modulation of macrophage function has not been investigated in detail. Here we show that RD-1 encoded two major secretory proteins, namely, culture filtrate protein-10 kDa (CFP-10) and early secreted antigenic target-6 kDa (ESAT-6), and their 1:1 CFP-10:ESAT6 complex inhibit production of reactive oxidative species (ROS) in RAW264.7 cells. These proteins also downregulated the bacterial lipopolysaccharide (LPS)-induced ROS production, which, in turn, downregulated LPS-induced nuclear factor-jB (NF-jB) p65 DNA-binding activity, as well as inhibited the NF-jB-dependent reporter gene (chloramphenicol acetyl transferase) expression in the treated macrophages. Moreover, addition of N-acetyl cysteine, which is a scavenger of ROS, also inhibited LPS-induced reporter gene expression by scavenging the ROS, thereby preventing NF-jB transactivation. These studies indicate that the secretory proteins CFP-10, ESAT-6 and the CFP10:ESAT6 complex of Mtb can inhibit LPS-induced NF-jB-dependent gene expression via downregulation of ROS production.

No abstract

No abstract

Background: Mycobacterium tuberculosis (Mtb) causes death of 2-3 million people every year. The persistence of the pathogenic mycobacteria inside the macrophage occurs through modulation of host cell signaling which allows them, unlike the other non-pathogenic species, to survive inside the host. The secretory proteins of M. tuberculosis have gained attention in recent years both as vaccine candidates and diagnostic tools; they target the immune system and trigger a putatively protective response; however, they may also be involved in the clinical symptoms of the disease.

No abstract

No abstract

Hanoi, the capital of Vietnam, is facing rapid modernization, leading to the improper management of waste and wastewater. The purpose of this study was to evaluate the impacts of waste and wastewater management on water environment, in terms of nitrogen and phosphorus flows. Trai hamlet, located in the south part of Hanoi, was selected as a research community. A waste and wastewater stream survey was implemented by a door-to-door interview for 100 households. A material flow model of nitrogen and phosphorus was developed with focus on suburban waste and wastewater management. Then, the model was applied for the study area. The results showed that the component receiving the largest amount of nutrients was paddy field, 435.1 kg-N/ha/year and 89.8 kg-P/ha/year, in which 40% of N and 65% of P were derived from chemical fertilizer. Although waste and wastewater recycling is widely implemented, the management of pig liquid waste is a serious problem in this area since 100% of them were discharged directly to the water bodies. The total nutrient loads to the water bodies in 2010 was 187.3 kg-N/ha/year and 13.4 kg-P/ha/year, of which paddy field accounted for 70% of nitrogen and fish pond did for 60% of phosphorus.

Rapid socio-economic development in suburban areas of developing countries has induced changes in agricultural waste and nutrient management, resulting in water pollution. The study aimed at estimating agricultural nutrient cycles and their contribution to the water environment. A material flow model of nitrogen (N) and phosphorus (P) was developed focusing on agricultural activities from 1980 to 2010 in Trai hamlet, an agricultural watershed in Nhue-Day River basin, Vietnam. The model focused on the change in household management of human excreta and livestock excreta, and chemical fertilizer consumption. The results showed that the proportion of nutrients from compost/manure applied to paddy fields decreased from 85 to 41% for both N and P between 1980 and 2010. The nutrient inputs derived from chemical fertilizer decreased 6% between 1980 and 2000 for both N and P. Then, these nutrients increased 1.4 times for N and 1.2 times for P from 2000 to 2010. As of 2010, the total inputs to paddy fields have amounted to 435 kg-N/ha/year and 90 kg-P/ha/year. Of these nutrient inputs, 40% of N and 65% of P were derived from chemical fertilizer. Thirty per cent (30%) of total N input was discharged to the water bodies through agricultural runoff and 47% of total P input accumulated in soil.