Apolipoprotein A-IV regulates chylomicron metabolism-mechanism and function.

Dietary fat is an important mediator of atherosclerosis and obesity. Despite its importance in mediating metabolic disease, there is still much unknown about dietary fat absorption in the intestine and especially the detailed biological roles of intestinal apolipoproteins involved in that process. We were specifically interested in determining the physiological role of the intestinal apolipoprotein A-IV (A-IV) using A-IV knockout (KO) mice. A-IV is stimulated by fat absorption in the intestine and is secreted on nascent chylomicrons into intestinal lymph. We found that A-IV KO mice had reduced plasma triglyceride (TG) and cholesterol levels and that this hypolipidemia persisted on a high-fat diet. A-IV KO did not cause abnormal intestinal lipid absorption, food intake, or adiposity. Additionally, A-IV KO did not cause abnormal liver TG and cholesterol metabolism, as assessed by measuring hepatic lipid content, lipogenic and cholesterol synthetic gene expression, and in vivo VLDL secretion. Instead, A-IV KO resulted in the secretion of larger chylomicrons from the intestine into the lymph, and those chylomicrons were cleared from the plasma more slowly than wild-type chylomicrons. These data suggest that A-IV has a previously unknown role in mediating the metabolism of chylomicrons, and therefore may be important in regulating plasma lipid metabolism.

Estrogen response system in the reproductive tract of the male turtle: an immunocytochemical study.

Portions of the reproductive tract of the male (Trachemys scripta) turtle were examined by immunocytochemistry for evidence of the capacity to produce and respond to estrogen hormones (via the expression of P450 aromatase and estrogen receptors). Aromatase was detected in both the Sertoli and Leydig cells of the testis and was expressed at different levels during the spermatogenic cycle, being highest in the quiescent testis and lowest during germ cell meiosis. ERalpha was found in the Leydig cells surrounding the seminiferous tubules as well as in the epithelial cells of the excurrent canals (rete testis, efferent ductule, and epididymis). ERbeta immunoreactivity was found in both the spermatogonia and Sertoli cells in the testis, and in the epithelial cells of excurrent canals.

How well do children aged 5-7 years recall food eaten at school lunch?

OBJECTIVE: This study aimed to determine the accuracy with which children aged 5 to 7 years were able to report the food eaten at a school lunch. SUBJECTS/SETTING: Two hundred and three children (103 boys, 100 girls) aged 5-7 years were recruited from three primary schools in Oxford. DESIGN: Trained investigators made observational records of the school dinner and packed lunch intakes of four or five children per session. Children were interviewed within two hours of finishing the lunchtime meal and asked to provide a free recall of their meal. When the child had completed the recall, non-directive prompts were used to assess if the child was able to remember anything else. Foods recalled were classified as matches (recalled food agreed with observation), omissions (failed to report a food observed) or phantoms (recalled food was not observed). RESULTS: The percentage of accurate recall was significantly higher (P<0.01) in children eating packed lunch (mean 70 +/- 29%) than in children consuming school dinners (mean 58 +/- 27% ). This difference may have been due to increased familiarity of foods in packed lunches. Leftovers were not readily reported in this age group. Prompts and cues enhanced recall by all children. CONCLUSIONS: This study indicated that there was a wide range in the ability of children aged 5-7 years to recall intake from a packed lunch and/or school dinner. This dietary assessment method is unlikely to be suitable at an individual level. Investigators using dietary recall to estimate food intake in children aged 5-7 years need to be aware of the limitations of this method.