Promoting physical activity through exergaming in young adults with intellectual disabilities: a pilot study.

Various health problems of people with intellectual disabilities (ID) are associated with their physical inactivity. The present study aimed at the understanding of physiological and psychological responses toward exergaming in seven young adults with mild to moderate ID after a single-session and a multiple-session condition, respectively. Their heart rate (HR), the rating of perceived exertion (RPE), and physical activity enjoyment scale (PACES) were measured on control and exergaming sessions. The significant increased HR, which may represent the increased physical activity levels that led to energy expenditure, was observed after a single-session and a multiple-session condition. In addition, the significant increase in RPE and PACES were evident after a single-session condition but a multiple-session condition. The feeling of physical fatigue seems to be distracted by external motivators (e.g. music). However, the positive affectivity to exercise was not noted when exercise was scheduled as their daily routines. This phenomenon might explain the high prevalence of physical inactivity among this population.

Expression of interleukin-6, leukemia inhibitory factor and their receptors by colonic epithelium and pericryptal fibroblasts.

BACKGROUND AND AIM: The cellular configuration of the human colon suggests a predetermined organization that creates specific microenvironments. The role of pericryptal fibroblasts in this microenvironment has been the subject of considerable speculation. This study examined the expression of growth factors and their receptors by colonic crypt epithelium and pericryptal fibroblasts. METHODS AND RESULTS: Pericryptal fibroblast cells were isolated and cultured from decrypted human colonic mucosa. The pericryptal fibroblast cells expressed messenger RNA (mRNA) for interleukin-6 (IL-6), leukemia inhibitory factor (LIF), LIF receptor alpha, and the common coreceptor glycoprotein 130 (GP130), but not the IL-6 receptor alpha. Interleukin-6 protein expression was confirmed by the analysis of conditioned medium and immunohistochemistry. In comparison, normal colonic epithelial cells express mRNA for LIF but not IL-6 as well as the receptors for GP-130, IL-6 receptor alpha but not LIF receptor alpha. As cultures of normal human colonic epithelial cells were not available, the conditioned medium was assayed from established colon carcinoma cell lines and demonstrated a secretion of LIF but not IL-6 protein. CONCLUSION: The expression of reciprocal cytokine and receptor expression suggest that there is a paracrine relationship between pericryptal fibroblasts and colonic epithelium.

A study of AroP-PheP chimeric proteins and identification of a residue involved in tryptophan transport.

In vivo recombination has been used to make a series of AroP-PheP chimeric proteins. Analysis of their respective substrate profiles and activities has identified a small region within span III of AroP which can confer on a predominantly PheP protein the ability to transport tryptophan. Site-directed mutagenesis of the AroP-PheP chimera, PheP, and AroP has established that a key residue involved in tryptophan transport is tyrosine at position 103 in AroP. Phenylalanine is the residue at the corresponding position in PheP. The use of PheP-specific antisera has shown that the inability of certain chimeras to transport any of the aromatic amino acids is not a result of instability or a failure to be inserted into the membrane. Site-directed mutagenesis has identified two significant AroP-specific residues, alanine 107 and valine 114, which are the direct cause of loss of transport activity in chimeras such as A152P. These residues replace a glycine and an alanine in PheP and flank a highly conserved glutamate at position 110. Some suggestions are made as to the possible functions of these residues in the tertiary structure of the proteins.

A topological model for the general aromatic amino acid permease, AroP, of Escherichia coli.

The general aromatic amino acid permease, AroP, of Escherichia coli is responsible for the active transport of phenylalanine, tyrosine, and tryptophan. A proposed topological model for the AroP permease, consisting of 12 hydrophobic transmembrane spans connected by hydrophilic loops, is very similar to that of the closely related phenylalanine-specific permease. The validity of this model and its similarity to that of the PheP permease were investigated by studying fusion proteins of AroP permease and alkaline phosphatase. Based on the results obtained from the AroP-alkaline phosphatase sandwich fusions, we have significantly revised the proposed topological model for AroP in two regions. In this modified AroP topological model, the three charged residues E151, E153, and K160 are repositioned within the membrane in span 5. These three residues are conserved in a large family of amino acid transport proteins, and site-directed mutagenesis identifies them as being essential for transport activity. It is postulated that these residues together with E110 in transmembrane span 3 may be involved in a proton relay system.