A Preliminary Study of How the Viscosity of Dietary Fluids and Videofluoroscopy Fluids can be Matched.

This study examined the method by which the viscosity of mealtime and videofluoroscopy fluid can be matched through adjustment of the amount of xanthan gum-based thickener added to them. Viscosity measurement was made with a cone-plate viscometer. Samples were tested at 5, 25, 45, and 65 ± 0.1 °C and shear rates of 5-200 s(-1). We found that the adjusted amount of thickener differs depending on the shear rate and temperature, and that the amount of thickener added to samples without barium sulfate should be increased by 26.8-37.5 % as compared to samples with barium sulfate at a shear rate of 50 s(-1) and temperature of 25 °C. Further research is needed in terms of the shear rate and temperature during swallowing.

Proteasome activity correlates with male BMI and contributes to the differentiation of adipocyte in hADSC.

We have previously reported that 26S proteasome subunit mRNA expressions correlate with male body mass index (BMI). In this study, to investigate whether proteasome activities are correlated with BMI, we recruited 61 healthy young Japanese male subjects, measured proteasome activities in their plasma, and correlated them with their BMI and various metabolic factors. We found that among three different proteasome activities, chymotrypsin-like activity in plasma was positively correlated with BMI in healthy Japanese male subjects. Furthermore, we analyzed proteasome activity in vitro during the differentiation of human adipose-derived stem cell (hADSC) into mature adipocytes. In the early stage of differentiation, proteasome activity was at its highest level, and proteasome inhibitor could inhibit hADSC adipocyte differentiation. Our findings suggest that proteasome is an important controlling factor for the development of obesity and adipogenesis.

Prediction of Japanese children at risk for complications of childhood obesity: gender differences for intervention approaches.

Childhood obesity is one of the most serious public health problems in Japan, especially in Tokushima compared with other prefectures. This study was designed to clarify the life habits which predispose to development of obesity and can be modified through an appropriate intervention program to combat childhood obesity and its lifestyle-related diseases. A total of 216 school children from Itano Town, a municipality of Tokushima Prefecture, Japan, who are attending the fourth grade (9-10 years) of elementary schools, participated in the study from 2004 to 2007. The study included child's life habits questionnaire, investigating physical activity by recording the daily steps using a pedometer, anthropometric measurements, hematological examination and hemodynamometry in a cross-sectional survey during a two-month period from June to July every year. We conclude that there are considerable gender-related differences for developing obesity and other lifestyle-related diseases; and all intervention strategies against obesity must consider such gender differences. For example, restriction of television watching hours must be intervened for controlling obesity in boys, however for girls, promotion of exercise practice or making more steps per day with adequate sleeping periods should be intervened as the proper approaches for preventing and controlling obesity and other lifestyle-related diseases.

The male-determining gene SRY is a hybrid of DGCR8 and SOX3, and is regulated by the transcription factor CP2.

In mammals, sex is determined by the presence or absence of the Y chromosome that bears a male-dominant sex-determining gene SRY, which switches the differentiation of gonads into male testes. The molecular signaling mechanism turning on the switch, however, has remained unclear for 18 years since the identification of the gene. Here, we describe how this gene emerged and started to work. From amino acid homology, we realized that SRY is a hybrid gene between a portion of the first exon of DiGeorge syndrome critical region gene 8 (DGCR8) and the high-mobility group (HMG) box of SRY box-3 (SOX3) gene. We identified the regulatory sequence in the SRY promotor region by searching for a common motif shared with DGCR8 mRNA. From the motif search between DGCR8 mRNA and the SRY upstream sequence, we found that the transcription factor CP2 (TFCP2) binding motif is present in both. TFCP2 overexpression did not show a significant increase of SRY mRNA expression, and TFCP2 suppression by RNA interference (RNAi) significantly reduced SRY mRNA expression. Furthermore, electrophoretic mobility shift assay (EMSA) demonstrated that TFCP2 acts as a regulator by directly binding to the SRY promoter. We conclude that SRY is a hybrid gene composed of two genes, DGCR8 and SOX3; and TFCP2 is an essential transcription factor for SRY expression regulation.

Proteomics and transcriptome approaches to investigate the mechanism of human sex determination.

The SRY gene (sex-determining region on the Y chromosome) was isolated in 1990 and is known as the testis-determining factor on the Y chromosome. The SRY has been considered as a transcription factor since it contains an HMG box, which functions as a DNA-binding domain. However, a direct target for SRY remains to be identified. We have investigated the function of SRY through proteomics and transcriptome approaches, and by using two stable SRY-overexpressing cell lines (SRY1 and SRY2) in NT2/D1 cells derived from human testicular embryonal cell carcinoma. The results of 2-dimensional gel electrophoresis show that SRY overexpression causes a considerable downregulation of many chaperone proteins. SRY also upregulates laminin, which is important for Sertoli cell differentiation. Additionally, transcriptome analysis shows that SRY overexpression upregulates many zinc finger proteins and downregulates cellular growth factors with S or G(2)/M arrest of the cell cycle and inhibition of cellular proliferation.

Proteasome subunits mRNA expressions correlate with male BMI: implications for a role in obesity.

Obesity as well as its associated chronic diseases and adverse health consequences such as type 2 diabetes mellitus, dyslipidemia, hypertension, and coronary artery disease are afflicting middle-aged adults and an ever greater number of children globally. We planned to investigate new obesity-related factors using proteomics approaches in a randomly selected three high and three low BMI samples of Epstein-Barr-transformed B (EBV-B) lymphoblastoid cell lines prepared from two groups of young Japanese men with different BMI. To search novel obesity-related factors, comparisons of protein expressions between high and low BMI groups were carried out by two-dimensional gel electrophoresis (2-DE). Gene transcripts of proteasome subunits found out from 2-DE were further determined by quantitative real-time PCR. Results from proteomics approach showed that the expression of proteasome alpha subunit type 5 (PSMA5) was significantly lower in the high BMI male group than in those with low BMI (P < 0.05). To validate these results, we expanded the study to include 20 more men and used real-time PCR to quantify the mRNA expression level in their EBV-B cells. Both PSMA5 and PSMA2 of EBV-B cells showed negative correlation with BMI. Furthermore, the mRNA levels measured in the peripheral blood B lymphocytes for many proteasome subunits in 75 healthy men and women showed significant negative correlation with BMI in healthy men. Our findings suggest that proteasome expression may play a key role in obesity.

Proteasome subunits are regulated and expressed in comparable concentrations as a functional cluster.

The proteasome is the main proteolytic enzyme that functions in the ubiquitin-proteasome system. The 26S proteasome has multi-subunit protease complexes consisting of 20S subunits composed of four seven-numbered rings with two outer rings containing alpha subunits and two central rings composed of beta subunits, and 19S caps of 6 ATPase and 11 non-ATPase subunits; however, it is unclear how these subunits are regulated and the 26S proteasomes assembled. To verify whether each subunit's mRNA expression is associated with the mRNA expression of other proteasome subunits, we carried out expression analysis of 34 proteasome subunits mRNA on peripheral blood from 75 subjects. The expression of proteasome subunits mRNA was comparable in each individual of the studied population and the mRNA expression has been investigated in each 20S or 19S proteasome. Our results suggest that each type of subunit is regulated by respectively common factors, and that the 20S and 19S proteasomes are regulated by different systems.

Overexpression of SOX15 inhibits proliferation of NT2/D1 cells derived from a testicular embryonal cell carcinoma.

SOX (Sry-related HMG box) family proteins, which have an evolutionarily conserved DNA binding domain, have crucial roles in cell differentiation. However, their target genes remain enigmatic. Some members of the SOX family may have roles in regulation of cell proliferation. We established stable NT2/D1 cell lines overexpressing SOX15 (SOX15-NT2/D1), and a modified 3-(4,5-dime-thylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the SOX15-NT2/D1 cells exhibited significantly slower growth than the controls. Flow cytometry analysis revealed that an increased fraction of the SOX15-NT2/D1 cells were in G1-G0. In addition, a microarray analysis identified 26 genes that were up-regulated in the SOX15-NT2/D1 cells, but none that were down-regulated genes. Among the up-regulated genes, IGFBP5, S100A4, ID2, FABP5, MTSS1, PDCD4 have been shown to be related to cell proliferation and/or the cell cycle.

A/G heterozygote of the A-3826G polymorphism in the UCP-1 gene has higher BMI than A/A and G/G homozygote in young Japanese males.

UCP-1 is suggested to have important roles for thermogenesis and energy expenditure. To elucidate whether the A-3826G polymorphism that is located in the 5' flanking region of the UCP-1 gene has roles in healthy young people, the polymorphism was genotyped among 251 young Japanese men whose mean age is 22.7 years old. We analyzed relationship between the A-3826G polymorphism and body mass index (BMI) or six biochemical parameters, serum concentration of total cholesterol (TC), high density lipoprotein (HDL) cholesterol, triglyceride (TG), asparatate aminotransferase (AST), alanine aminotransferase (ALT), fasting plasma glucose. The genotype frequencies were observed at the frequencies of 24.3% for AA, 48.2% for AG and 27.5% for GG, respectively. When BMI and the biochemical parameters were compared by ANOVA among individuals with each genotype, the statistical difference was observed only for BMI (P=0.016). Bonferroni's test demonstrated that the men with the AG genotype have higher BMI than those with the AA genotype (22.4+/-2.8 vs. 21.4+/-2.2) (P=0.04). The individuals with the AG genotype also showed trend to have higher BMI than those with the GG, although the difference was not statistically apparent (22.4+/-2.8 vs. 21.5+/-2.3) (P=0.07). Our results indicated that the young healthy Japanese men with the AG heterozygote showed higher BMI than those with other genotypes.