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From the moment of their birth, a person's life is determined by their sex. Goroshko wanted to find out why this difference is so striking, why society is so determined to sustain it, and how it can persist even when certain national or behavioural stereotypes are erased. She believes there are both social and biological differences between men and women, and set out to analyse these distinctions as they are manifested in language. Certain general characteristics can be identified. Males tend to write with less fluency, to refer to events in a verb phrase, to be time-oriented, to involve themselves more in their references to events, to locate events in their personal sphere of activity, and to refer less to others. Goroshko therefore concludes that the male is more active, more ego-involved in what he does and less concerned about others. Women were more fluent, referred to events in a noun-phrase, were less time-oriented, tended to be less involved in their event references, located events within their interactive community, and referred more to others. They spent much more time discussing personal and domestic subjects, relationship problems, family, health and reproductive matters, weight, food and clothing, men, and other women. Computer analysis showed that female speech was substantially more emotional, using hyperbole, metaphor, comparisons, epithets, ways of enumeration, interjections, rhetorical questions and exclamations. The level of literacy was higher in female speech, and women made fewer grammatical and spelling mistakes in written texts. Goroshko believes that her findings have relevance beyond the linguistic field. When working on anonymous texts she has been able to decide on the sex of the author and so believes that her research may even be of benefit to forensic science.

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BACKGROUND: Starches are the major source of dietary glucose in weaned children and adults. However, small intestine alpha-glucogenesis by starch digestion is poorly understood due to substrate structural and chemical complexity, as well as the multiplicity of participating enzymes. Our objective was dissection of luminal and mucosal alpha-glucosidase activities participating in digestion of the soluble starch product maltodextrin (MDx). PATIENTS AND METHODS: Immunoprecipitated assays were performed on biopsy specimens and isolated enterocytes with MDx substrate. RESULTS: Mucosal sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM) contributed 85% of total in vitro alpha-glucogenesis. Recombinant human pancreatic alpha-amylase alone contributed <15% of in vitro alpha-glucogenesis; however, alpha-amylase strongly amplified the mucosal alpha-glucogenic activities by preprocessing of starch to short glucose oligomer substrates. At low glucose oligomer concentrations, MGAM was 10 times more active than SI, but at higher concentrations it experienced substrate inhibition whereas SI was not affected. The in vitro results indicated that MGAM activity is inhibited by alpha-amylase digested starch product "brake" and contributes only 20% of mucosal alpha-glucogenic activity. SI contributes most of the alpha-glucogenic activity at higher oligomer substrate concentrations. CONCLUSIONS: MGAM primes and SI activity sustains and constrains prandial alpha-glucogenesis from starch oligomers at approximately 5% of the uninhibited rate. This coupled mucosal mechanism may contribute to highly efficient glucogenesis from low-starch diets and play a role in meeting the high requirement for glucose during children's brain maturation. The brake could play a constraining role on rates of glucose production from higher-starch diets consumed by an older population at risk for degenerative metabolic disorders.

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The detailed mechanistic aspects for the final starch digestion process leading to effective alpha-glucogenesis by the 2 mucosal alpha-glucosidases, human sucrase-isomaltase complex (SI) and human maltase-glucoamylase (MGAM), are poorly understood. This is due to the structural complexity and vast variety of starches and their intermediate digestion products, the poorly understood enzyme-substrate interactions occurring during the digestive process, and the limited knowledge of the structure-function properties of SI and MGAM. Here we analyzed the basic catalytic properties of the N-terminal subunit of MGAM (ntMGAM) on the hydrolysis of glucan substrates and compared it with those of human native MGAM isolated by immunochemical methods. In relation to native MGAM, ntMGAM displayed slower activity against maltose to maltopentose (G5) series glucose oligomers, as well as maltodextrins and alpha-limit dextrins, and failed to show the strong substrate inhibitory "brake" effect caused by maltotriose, maltotetrose, and G5 on the native enzyme. In addition, the inhibitory constant for acarbose was 2 orders of magnitude higher for ntMGAM than for native MGAM, suggesting lower affinity and/or fewer binding configurations of the active site in the recombinant enzyme. The results strongly suggested that the C-terminal subunit of MGAM has a greater catalytic efficiency due to a higher affinity for glucan substrates and larger number of binding configurations to its active site. Our results show for the first time, to our knowledge, that the C-terminal subunit of MGAM is responsible for the MGAM peptide's "glucoamylase" activity and is the location of the substrate inhibitory brake. In contrast, the membrane-bound ntMGAM subunit contains the poorly inhibitable "maltase" activity of the internally duplicated enzyme.