Ampicillin-improved glucose tolerance in diet-induced obese C57BL/6NTac mice is age dependent.

Ampicillin has been shown to improve glucose tolerance in mice. We hypothesized that this effect is present only if treatment is initiated prior to weaning and that it disappears when treatment is terminated. High-fat fed C57BL/6NTac mice were divided into groups that received Ampicillin at different ages or not at all. We found that both diet and Ampicillin significantly changed the gut microbiota composition in the animals. Furthermore, there was a significant improvement in glucose tolerance in Ampicillin-treated, five-week-old mice compared to nontreated mice in the control group. At study termination, expressions of mRNA coding for tumor necrosis factor, serum amyloid A, and lactase were upregulated, while the expression of tumor necrosis factor (ligand) superfamily member 15 was downregulated in the ileum of Ampicillin-treated mice. Higher dendritic cell percentages were found systemically in high-fat diet mice, and a lower tolerogenic dendritic cell percentage was found both in relation to high-fat diet and late Ampicillin treatment. The results support our hypothesis that a "window" exists early in life in which an alteration of the gut microbiota affects glucose tolerance as well as development of gut immunity and that this window may disappear after weaning.

Hans Christian Andersen's spelling and syntax: allegations of specific dyslexia are unfounded.

Sources contemporary with Danish author Hans Christian Andersen claimed that he did not master the Danish language, which modern studies interpret as specific dyslexia. A systematic study of his diaries from age 20 to age 70 found a mean spelling error percentage of approximately 1.7 (SD = 1%, range = 0%-4%). A methodologically independent reliability study confirmed these figures. Andersen's error percentages in poems and letters from ages 11 to 19 show a typical initial part of a learning curve that, together with the results from the diaries, gives a life span curve of his spelling development. The diaries, letters, and poems contain only insignificant syntactic errors. Andersen's spelling in the above studies is compared with that of his contemporaries and with data from modern studies. His mean error percentages at different ages are equal to the figures from nondisabled participants, but between 2 and 15 times lower than the mean percentages in studies of individuals with dyslexia. A structural analysis of Andersen's spelling errors shows that they are mainly phonologically plausible from ages 11 to 70, and that the proportions of plausible/implausible errors match those of normal achievers, but not those of individuals with dyslexia.