To explore the immunological roles of dietary fiber, male 4-wk-old Sprague-Dawley rats were fed for 2 wk cellulose (water-insoluble), konjak mannan (water-soluble), pectin (water-soluble) or chitosan (acid-soluble) at 5 g/100 g diet. Serum IgE concentrations in rats fed konjak mannan, pectin and chitosan were significantly lower than in those fed cellulose (mean +/- SEM: 5.0 +/- 1.1, 3.6 +/- 1.3, 3.0 +/- 1.2 and 9.6 +/- 1.9 microg/L, respectively). Rats fed pectin had significantly higher serum IgA and IgG concentrations (358 +/- 38 and 424 +/- 36 mg/L for IgA and IgG, respectively) than those fed cellulose (240 +/- 31 and 337 +/- 25 mg/L) or chitosan (176 +/- 22 and 379 +/- 23 mg/L), while the IgM concentration did not differ among the groups. Concentrations of IgA, IgG and IgM in mesenteric lymph node (MLN) lymphocytes generally were greater, while IgE concentration was lower, in rats fed pectin and chitosan than in those fed cellulose. The proportion of CD4+ T-cells in MLN lymphocytes was also dietary fiber-dependent, and the CD4+/CD8+ ratio was significantly higher in the pectin fed group than in all other groups. Under certain experimental conditions, MLN lymphocytes from rats fed pectin had markedly greater interferon-gamma concentration than cells from other groups, while the effect on tumor necrosis factor-alpha concentration was less marked. Thus, dietary fiber may have an immunoregulatory effect on the intestinal immune system of rats.

Land fragmentation, where a single farm has a number of parcels of land, is a common feature of agriculture in many countries, especially in developing countries. In Vietnam, land fragmentation is common, especially in the north. For the whole country, there are about 75 million parcels of land, an average of seven to eight plots per farm household. Such fragmentation can be seen to have negative and positive benefits for farm households and the community generally. Comparative statics analysis and analysis of survey data have led to the conclusion that small‐sized farms are likely to be more fragmented, and that fragmentation had a negative impact on crop productivity and increased family labour use and other money expenses. Policies which allow the appropriate opportunity cost of labour to be reflected at the farm level may provide appropriate incentives to trigger farm size change and land consolidation. Policies which tip the benefits in favour of fewer and larger plots, such as strong and effective research and development, an active extension system and strong administrative management, may also lead to land consolidation.

Cross-border disease transmission is a key challenge for prevention and control of outbreaks. Variation in surveillance structure and national guidelines used in different countries can affect their data quality and the timeliness of outbreak reports. This study aimed to evaluate timeliness and data quality of national outbreak reporting for four countries in the Mekong Basin Disease Surveillance network (MBDS). Data on disease outbreaks occurring from 2010 to 2015 were obtained from the national disease surveillance reports of Cambodia, Lao PDR, Myanmar, and Vietnam. Data included total cases, geographical information, and dates at different timeline milestones in the outbreak detection process. Nine diseases or syndromes with public health importance were selected for the analysis including: dengue, food poisoning & diarrhea, severe diarrhea, diphtheria, measles, H5N1 influenza, H1N1 influenza, rabies, and pertussis. Overall, 2,087 outbreaks were reported from the four countries. The number of outbreaks and number of cases per outbreak varied across countries and diseases, depending in part on the outbreak definition used in each country. Dates on index onset, report, and response were >95% complete in all countries, while laboratory confirmation dates were 10%-100% incomplete in most countries. Inconsistent and out of range date data were observed in 1%-5% of records. The overall timeliness of outbreak report, response, and public communication was within 1–15 days, depending on countries and diseases. Diarrhea and severe diarrhea outbreaks showed the most rapid time to report and response, whereas diseases such as rabies, pertussis and diphtheria required a longer time to report and respond. The hierarchical structure of the reporting system, data collection method, and country’s resources could affect the data quality and timeliness of the national outbreak reporting system. Differences in data quality and timeliness of outbreak reporting system among member countries should be considered when planning data sharing strategies within a regional network.

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The effect of UFA on Ig production by rat MLN lymphocytes was examined to clarify their influence on allergic reactions. A 4-h treatment at 1 mM inhibited the production of IgA, IgG, and IgM by the lymphocytes, but stimulated IgE production. The IgE production-stimulating activity became stronger with increasing number of carbon atoms and/or double bonds. However, no saturated fatty acid with carbon numbers from 12 to 18 affected IgE production by the lymphocytes. Hydrogen peroxide exerted Ig production-regulating activity similar to that of UFA, suggesting that the effect of UFA is at least partly due to oxidation products. Thus, the effect of antioxidants on the Ig production-regulating activity of arachidonic acid was examined. alpha-Tocopherol and BHT annulled the stimulation of IgE production by arachidonic acid, but ascorbic acid was not effective. The IgE production-enhancing activity of UFA was closely related to their oxidation rate in culture medium. These results suggest that UFA enhance the allergic reaction through the stimulation of IgE production and the inhibition of IgA production, and that hydrophobic antioxidants are partially effective to annul the adverse effect of UFA.