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OBJECTIVE: I review the status of dichlorodiphenyltrichloroethane (DDT), used for disease vector control, along with current evidence on its benefits and risks in relation to the available alternatives. DATA SOURCES [...]

Studies in animal and human feeding or supplementation have demonstrated interactions between carotenoids during absorption and during post absorptive metabolism. Numerous studies have suggested carotenoid interactions are caused by competition for micellar incorporation in the gastrointestinal tract. Carotenoid interactions can be beneficial or adverse, but supplementation with high doses of beta-carotene might disturb the carotenoid balance.

Researchers examined the convergence of two diagnostic approaches used in child psychopathology. They found that scores obtained from applying the clinical-diagnostic approach of the Diagnostic Interview Schedule after application of the empirical quantitative approach of the Child Behaviour Checklist did not converge significantly enough to allow one approach to be used in place of the other. Both approaches may deliver specific information with, for example, the Attention Problems scale being the only predictor of Attention Deficit Hyperactivity Disorder.

Inadequate vitamin B-6 status is common among elderly people. It is still unclear to what extent factors other than reduced vitamin B-6 intake are responsible for this. We studied the vitamin B-6 intake and status [measured as plasma pyridoxal 5[prime]-phosphate (PLP)] in 546 elderly Europeans, aged 74-76 years, with no known vitamin B-6 supplement use. In addition, we examined interrelations and associations with other dietary and lifestyle factors, including indicators of physical health. Overall, 27% of the males and 42% of the females had dietary vitamin B-6 intakes below the mean minimum requirements (.015 mg/g protein and/or < 1.0 mg/day), and 22% of both males and females had low plasma PLP levels (< 20 nmol/L). Plasma PLP was positively associated with vitamin B-6 intake, alcohol intake, and serum albumin, and was weakly negatively associated with body mass index. Although the serum albumin levels fell within the normal range, these findings suggest that this transport protein is related with vitamin B-6 status of elderly people, either directly or as a result of underlying health problems. It is concluded that, based on the references for younger adults, the vitamin B-6 status of elderly people is marginal. Trials are needed to quantify functional and health consequences of improving the vitamin B-6 status of elderly people.

The purpose of this study was to examine whether intestinal [Beta]-carotene cleavage activity, measured with the dioxygenase assay, is affected by vitamin A intake and whether this in vitro activity is a determinant of [Beta]-carotene cleavage in vivo, measured in lymph-cannulated rats. Six groups of 10-20 rats were fed a diet with a low, normal or high retinyl palmitate concentration (120 RE, 1200 RE and 12,000 RE per kg, respectively) for 14 to 18 wk, either supplemented or not with 50 mg [Beta]-carotene/kg in the last 6 wk. intestinal dioxygenase activity was 90% higher (P < 0.05) in the animals fed the unsupplemented low vitamin A diet than in the animals fed the unsupplemented high vitamin A diet, whereas in [Beta]-carotene-supplemented rats intestinal dioxygenase activity was significantly lower than in unsupplemented rats. The molar ratio between retinyl esters and [Beta]-carotene in lymph collected over 8 h after a single intestinal dose of [Beta]-carotene (250 [[micro]grams]) to [Beta]-carotene-unsupplemented rats fed the three levels of vitamin A was correlated with intestinal dioxygenase activity (r = 0.66, P = 0.003). Dioxygenase activity in the liver was not affected by the vitamin A concentration of the diet but was 70% higher in the [Beta]-carotene-supplemented rats. Based on the difference in liver vitamin A contents between [Beta]-carotene-supplemented and unsupplemented rats we estimated [Beta]-carotene conversion factors of 9:1 for the rats fed the high vitamin A diet and 4:1 for the rats fed the normal and low vitamin A diets. Intestinal [Beta]-carotene cleavage activity is higher in vitamin A-deficient rats than in rats with a high intake of either vitamin A or [Beta]-carotene. The intestinal dioxygenase activity as measured in vitro is an adequate indicator of in vivo [Beta]-carotene cleavage activity. INDEXING KEY WORDS: rats, [Beta]-carotene metabolism, vitamin A, dioxygenase assay, lymph cannulation

Vitamin B-6 metabolism was studied as a function of dietary protein intake. Subjects were 29 young adults (29 [+ or -] 1 y old) and 26 elderly adults (70 [+ or -] 1 y old) who consumed standardized diets containing 12% (Diet A) and 21% (Diet B) of total energy as protein for 3 wk each, according to a randomized crossover design. Vitamin B-6 intake for young and elderly subjects was 1.52 [+ or -] 0.08 mg/d (21.74 [+ or -] 0.45 [micro]g/g protein) and 1.47 [+ or -] 0.05 mg/d (23.81 [+ or -] 0.08 [micro]g/g protein), respectively, during consumption of Diet A and 1.79 [+ or -] 0.07 mg/d (14.49 [+ or -] 0.11 [micro]g/g protein) and 1.73 [+ or -] 0.05 mg/d (16.24 [+ or -] 0.06 [micro]g/g protein) during consumption of Diet B. Plasma pyridoxal phosphate (PLP), pyridoxal and total vitamin B-6 concentrations were significantly lower in the elderly subjects compared with the young adult subjects during both diet periods. In the elderly subjects, PLP was significantly higher during Diet B consumption (Diet A: 27 [+ or -] 3 nmol/L; Diet B: 32 [+ or -] 3 nmol/L), whereas the level of protein intake had no significant effect on plasma PLP in the young adults (Diet A: 47 [+ or -] 6 nmol/L; Diet B: 45 [+ or -] 5 nmol/L). Plasma pyridoxal and plasma total vitamin B-6 concentrations were not influenced by the amount of protein intake in young and elderly subjects. Relative urinary pyridoxic acid excretion did not differ significantly between diet periods in the elderly subjects (Diet A: 37 [+ or -] 3%; Diet B: 43 [+ or -] 3%), whereas pyridoxic acid excretion was lower in young adults when Diet B was consumed (Diet A: 46 [+ or -] 3%; Diet B: 38 [+ or -] 2%; P < 0.001). The results of this study suggest an age-dependent difference in the protein intake-related vitamin B-6 needs, whereby elderly subjects apparently need less vitamin B-6 at a higher protein intake as compared with young adults. J. Nutr. 124: 1207--1214, 1994.

A preliminary study based on a conceptual process design methodology that includes a technical evaluation and an economic study has been carried out for the use of the metal-organic framework NH2-MIL-53(Al) as adsorbent for the separation of carbon dioxide from methane. Among the alternatives considered, a vacuum pressure swing adsorption was chosen in the detailed design phase. The combination of a design with columns in parallel and the possibility of recirculating some of the streams ensures a high degree of separation and a final product with high quality without compromising the operation costs. A comparison with the state-of-the-art technology, amine scrubbing, and with a process based on membranes demonstrates that the proposed process is competitive as a result of its low operation costs and the energy demand. [ABSTRACT FROM AUTHOR]

The article discusses the sustainable management of malaria vectors. It explores the malaria vector control, as well as the emerging insecticide resistance crisis. It describes several sustainable integrated vector management (IVM) strategies that use optimal suites of control tactics to prevent the insecticide resistance crisis. According to agricultural industry, such integrated approaches can provide more effective and durable pest management.

Background: Data on insecticide use for vector control are essential for guiding pesticide management systems on judicious and appropriate use, resistance management, and reduction of risks to human health and the environment. Objective: We studied the global use and trends of insecticide use for control of vector-borne diseases for the period 2000 through 2009. Methods: A survey was distributed to countries with vector control programs to request national data on vector control insecticide use, excluding the use of long-lasting insecticidal nets (LNs). Data were received from 125 countries, representing 97% of the human populations of 143 targeted countries. Results: The main disease targeted with insecticides was malaria, followed by dengue, leishmaniasis, and Chagas disease. The use of vector control insecticides was dominated by organochlorines [i.e., DDT (dichlorodiphenyltrichloroethane)] in terms of quantity applied (71% of total) and by pyrethroids in terms of the surface or area covered (81% of total). Global use of DDT for vector control, most of which was in India alone, was fairly constant during 2000 through 2009. In Africa, pyrethroid use increased in countries that also achieved high coverage for LNs, and DDT increased sharply until 2008 but dropped in 2009. Conclusions: The global use of DDT has not changed substantially since the Stockholm Convention went into effect. The dominance of pyrethroid use has major implications because of the spread of insecticide resistance with the potential to reduce the efficacy of LNs. Managing insecticide resistance should be coordinated between disease-specific programs and sectors of public health and agriculture within the context of an integrated vector management approach. [ABSTRACT FROM AUTHOR]

Background: Legislation and regulation of pesticides used in public health are essential for reducing risks to human health and the environment. Objective: We assessed the global situation on legislation and regulatory control of public health pesticides. Methods: A peer-reviewed and field-tested questionnaire was distributed to 142 member states of the World Health Organization (WHO); 113 states completed the questionnaire. Results: Legislation on public health pesticides was absent in 25% of the countries. Where present, legislation often lacked comprehensiveness, for example, on basic aspects such as labeling, storage, transport, and disposal of public health pesticides. Guidelines or essential requirements for the process of pesticide registration were lacking in many countries. The capacity to enforce regulations was considered to be weak across WHO regions. Half of all countries lacked pesticide quality control laboratories, and two-thirds reported high concern over quality of products on the market. National statistics on production and trade of pesticides and poisoning incidents were lacking in many countries. Despite the shortcomings, WHO recommendations were considered to constitute a supportive or sole basis in national registration. Also, some regions showed high participation of countries in regional schemes to harmonize pesticide registration requirements. Conclusions: Critical deficiencies are evident in the legislative and regulatory framework for public health pesticides across regions, posing risks to human health and the environment. Recent experience in some countries with situational analysis, needs assessment, action planning, and regional collaboration has signaled a promising way forward. [ABSTRACT FROM AUTHOR]

The article presents response of the authors on comments made by researcher Richard Tren and Donald Roberts on their study "DDT and Malaria Prevention: Addressing the Pradox." The authors tell that Robert Tren and colleagues failed to add the qualification included in the same paragraph in which the World Health Organization (WHO has assessed DDT.