In vitro digestion of starches in a dynamic gastrointestinal model: an innovative study to optimize dietary management of patients with hepatic glycogen storage diseases

Uncooked cornstarch (UCCS) is a widely used treatment strategy for patients with hepatic glycogen storage disease (GSD). It has been observed that GSD-patients display different metabolic responses to different cornstarches. The objective was to characterize starch fractions and analyze the digestion of different starches in a dynamic gastrointestinal in vitro model. The following brands of UCCS were studied: Argo and Great Value from the United States of America; Brazilian Maizena Duryea and Yoki from Brazil; Dutch Maizena Duryea from the Netherlands. Glycosade, a modified starch, and sweet polvilho, a Brazilian starch extracted from cassava, were also studied. The starch fractions were analyzed by glycemic TNO index method and digestion analyses were determined by the TIM-1 system, a dynamic, computer-controlled, in vitro gastrointestinal model, which simulates the stomach and small intestine. The final digested amounts were between 84 and 86% for the UCCS and Glycosade, but was 75.5% for sweet povilho. At 180 min of the experiment, an important time-point for GSD patients, the digested amount of the starches corresponded to 67.9-71.5 for the UCCS and Glycosade, while it was 55.5% for sweet povilho. In an experiment with a mixture of sweet polvilho and Brazilian Maizena Duryea, a final digested amount of 78.4% was found, while the value at 180 min was 61.7%. Sweet polvilho seems to have a slower and extended release of glucose and looks like an interesting product to be further studied as it might lead to extended normoglycemia in GSD-patients

Adult anopheline ecology and malaria transmission in irrigated areas of South Punjab, Pakistan.

Surface irrigation in the Punjab province of Pakistan has been carried out on a large scale since the development of the Indus Basin Irrigation System in the late 19th century. The objective of our study was to understand how the population dynamics of adult anopheline mosquitoes (Diptera: Culicidae) could be related to malaria transmission in rural areas with intensive irrigation and a history of malaria epidemics. In this paper we present our observations from three villages located along an irrigation canal in South Punjab. The study was carried out from 1 April 1999 to 31 March 2000. Mosquitoes were collected from bedrooms using the pyrethroid spraycatch method and from vegetation and animal sheds using backpack aspirators. Overall, Anopheles subpictus Grassi sensu lato predominated (55.6%), followed by An. stephensi Liston s.l. (41.4%), An. culicifacies Giles s.l. (2.0%), An. pulcherrimus Theobald (1.0%) and An. peditaeniatus Leicester (0.1%). Most mosquitoes (98.8%) were collected from indoor resting-sites whereas collections from potential resting-sites outdoors accounted for only 1.2% of total anopheline densities, confirming the endophilic behaviour of anophelines in Pakistan. Anopheles stephensi, An. culicifacies and An. subpictus populations peaked in August, September and October, respectively. High temperatures and low rainfall negatively affected seasonal abundance in our area. There were interesting differences in anopheline fauna between villages, with An. culicifacies occurring almost exclusively in the village at the head of the irrigation canal, where waterlogged and irrigated fields prevailed. Monthly house-to-house fever surveys showed that malaria transmission remained low with an overall slide positivity rate of 2.4% and all cases were due to infection with Plasmodium vivax. The most plausible explanation for low transmission in our study area seems to be the low density of Pakistan's primary malaria vector, An. culicifacies. The role of other species such as An. stephensi is not clear. Our observations indicate that, in South Punjab, irrigation-related sites support the breeding of anopheline mosquitoes, including the vectors of malaria. As our study was carried out during a year with exceptionally hot and dry climatic conditions, densities and longevity of mosquitoes would probably be higher in other years and could result in more significant malaria transmission than we observed. To assess the overall importance of irrigation-related sites in the epidemiology of malaria in the Punjab, more studies are needed to compare irrigated and non-irrigated areas