Nutrient adequacy of Japanese schoolchildren on days with and without a school lunch by household income.

BACKGROUND: Evidence for whether the nutrient intakes of Japanese schoolchildren differ according to household income is sparse. OBJECTIVE: We investigated the role of school lunches for nutrient adequacy among Japanese primary school children using dietary reference intakes in a cross-sectional survey. DESIGN: Participants were 10- to 11-year-old (5th grade) children from 19 public primary schools in four prefectures of East Japan, and 836 children were analyzed. The participants completed 24-h dietary records with photographs of their meals for 4 consecutive days, composed of 2 days with and 2 days without a school lunch. -Children's household income was obtained from questionnaires that were completed by the participants' guardians and divided into the following three categories: low (0.2236-2.2361 million yen; n = 319), middle (2.3333-2.8868 million yen; n = 194), and high (3.1305-6.3640 million yen; n = 323). Logistic regression analyses were used to estimate the odds ratios for whether participants had poor nutrient intakes, with adjustment for confounders. RESULTS: On days without a school lunch, the prevalence of nutrient shortages was significantly higher compared with those on days with a school lunch for most macro- and micronutrients among all three levels of household income. Children from low-income households had higher rates of nutrient shortages for vitamin B6, pantothenic acid, K, Mg, P, Fe, and Zn than those from middle-income households on days without a school lunch (P = 0.004, 0.001, 0.001, 0.006, 0.037, <0.001, and 0.015, respectively), but those differences were not significant on days with a school lunch. CONCLUSION: The findings suggest that school lunches are important for achieving adequate nutrient intakes in schoolchildren and reduce disparities of adequate nutrient intake by household income levels.

Association between parents' work hours and nutrient inadequacy in Japanese schoolchildren on weekdays and weekends.

OBJECTIVES: Evidence is sparse concerning whether the nutrient intake in schoolchildren differs according to parents' work hours. The aim of this study was to investigate the relationship between parents' work hours and nutrient inadequacy among Japanese primary schoolchildren using dietary reference intakes on days with and without a school lunch. METHODS: Participants included 10- to 11-y-old children in grade 5 from 19 public primary schools in four prefectures of east Japan. Data for 699 children were analyzed. Participants completed 24-h dietary records with photographs of their meals for 4 d consecutively, which included of 2 d of weekdays and 2 d of weekends. Their mothers' and fathers' work hours were obtained from questionnaires that were completed by the participants' guardians. Logistic regression analyses were used to estimate the odds ratios for whether participants had poor nutrient intake, with adjustment for confounders. RESULTS: Children whose mothers worked ≥40 h/wk had significantly higher rates of nutrient shortages for vitamins A, E, K, and B6, pantothenic acid, potassium, magnesium, and iron (P = 0.007, 0.003, 0.007, 0.023, 0.021, 0.045, 0.004, and 0.009, respectively) than those in the 0 h/wk group. These differences were not significant based on fathers' working hours, with the exception of vitamin A (≥40 versus 0-39 h/wk, P = 0.032). Additionally, nutrient shortages for children were more pronounced on weekdays than on weekends. CONCLUSIONS: This evidence revealed the necessity to improve nutrition intake in children whose mothers work more than statutory working hours, which would enable children to have adequate nutrient intake, especially on weekdays.

Household income is associated with food and nutrient intake in Japanese schoolchildren, especially on days without school lunch.

OBJECTIVE: The present study aimed to examine the association between household income and the intake of foods and nutrients by Japanese schoolchildren, and any differences between days with and without school lunch. DESIGN: This was a cross-sectional study. Children, with the support of their parents, kept dietary records with photographs for 4 d (2 d with school lunch and 2 d without). The socio-economic status of each family was obtained from a questionnaire completed by the parents. SETTING: Japan. SUBJECTS: All students in 5th grade (10-11 years old) at nineteen schools in four prefectures and their parents (1447 pairs of students and parents) were invited to take part in the study; 836 pairs of complete data sets were analysed. RESULTS: The average results of four days of dietary records showed that lower income level was associated with a lower intake of fish/shellfish, green vegetables and sugar at the food group level, a lower intake of protein and several micronutrients, and a higher energy intake from carbohydrates at the nutrient level among the children. These associations between income and food/nutrient intake were not significant on days with school lunches, but were significant on days without school lunch. CONCLUSIONS: Our study confirmed an association between household income and the amount of foods and nutrients consumed by Japanese schoolchildren, and suggested that school lunches play a role in reducing disparities in the diets of children from households with various incomes.

Preparation of a polyclonal antibody that recognizes a unique galactoseß1-4fucose disaccharide epitope.

Galactoseß1-4fucose (Galß1-4Fuc) is a unique disaccharide unit that has been found only in the N-glycans of protostomia. We demonstrated that this unit has a role as an endogenous ligand for Caenorhabditis elegans galectins. This unit is also recognized by fungal and mammalian galectins possibly as a non-self glycomarker. In order to clarify its biological function, we made a polyclonal antibody using (Galß1-4Fuc)n-BSA as the antigen, which was prepared by crosslinking Galß1-4Fuc-O-(CH2)2-SH and BSA. The binding specificity of the antibody was analyzed by frontal affinity chromatography, and it was confirmed that it recognizes naturally occurring N-glycans containing the Galß1-4Fuc unit linked to the reducing-end GlcNAc via α1-6 linkage. By western blotting analysis, the antibody was also found to bind to (Galß1-4Fuc)n-BSA but not to BSA or asialofetuin, which has N-glycan chains containing Galß1-4GlcNAc. Western blotting experiments also revealed presence of stained proteins in crude extracts of C. elegans, the parasitic nematode Ascaris suum, and the allergenic mite Dermatophagoides pteronyssinus, while those from Drosophila melanogaster, Mus musculus, and the allergenic mites Dermatophagoides farinae and Tyrophagus putrescentiae were negative. This antibody should be a very useful tool for research on the distribution of the Galß1-4Fuc disaccharide unit in glycans in a wide range of organisms.

Molecular cloning of cDNA for trehalase from the European honeybee, Apis mellifera L., and its heterologous expression in Pichia pastoris.

cDNA encoding the bound type trehalase of the European honeybee was cloned. The cDNA (3,001 bp) contained the long 5' untranslated region (UTR) of 869 bp, and the 3' UTR of 251 bp including a poly(A) tail, and the open reading frame of 1,881 bp consisting of 626 amino acid residues. The Mr of the mature enzyme comprised of 591 amino acids, excluded a signal sequence of 35 amino acid residues, was 69,177. Six peptide sequences analyzed were all found in the deduced amino acid sequence. The amino acid sequence exhibited high identity with trehalases belonging to glycoside hydrolase family 37. A putative transmembrane region similar to trehalase-2 of the silkworm was found in the C-terminal amino acid sequence. Recombinant enzyme of the trehalase was expressed in the methylotrophic yeast Pichia pastoris as host, and displayed properties identical to those of the native enzyme except for higher sugar chain contents. This is the first report of heterologous expression of insect trehalase.

Structural elements in dextran glucosidase responsible for high specificity to long chain substrate.

Dextran glucosidase from Streptococcus mutans (SMDG) and Bacillus oligo-1,6-glucosidases, members of glycoside hydrolase family 13 enzymes, have the high sequence similarity. Each of them is specific to alpha-1,6-glucosidic linkage at the non-reducing end of substrate to liberate glucose. The activities toward long isomaltooligosaccharides were different in both enzymes, in which SMDG and oligo-1,6-glucosidase showed high and low activities, respectively. We determined the structural elements essential for high activity toward long-chain substrate. From conformational comparison between SMDG and B. cereus oligo-1,6-glucosidase (three-dimensional structure has been solved), Trp238 and short beta-->alpha loop 4 of SMDG were considered to contribute to the high activity to long-chain substrate. W238A had similar kcat/Km value for isomaltotriose to that for isomaltose, suggesting that the affinity of subsite +2 was decreased by Trp238 replacement. Trp238 mutants as well as the chimeric enzyme having longer beta-->alpha loop 4 of B. subtilis oligo-1,6-glucosidase showed lower preference for long-chain substrates, indicating that both Trp238 and short beta-->alpha loop 4 were important for high activity to long-chain substrates.

Transduction of dominant negative ATF-1 suppresses the pX gene expression in joint fibroblastic cells derived from HTLV-I transgenic rats.

Tax (p40Tax) encoded by the env-pX gene of human T-cell leukemia virus type I (HTLV-I) interacts with cyclic adenosine-3',5'-monophosphate response element binding protein/activation transcription factor 1 (CREB/ATF-1) transcription factors of host cells and activates the viral long terminal repeat (LTR) promoter. This molecular interaction induces augmentation of viral gene expression and may result in development of HTLV-I-associated diseases, including adult T-cell leukemia, HTLV-I associated myelopathy/tropical spastic paraparesis, and HTLV-I uveitis. To inhibit this pathway, a dominant negative molecule of ATF-1, ATF-1DN, was used. We transduced ATF-1DN into joint fibroblastic cells derived from transgenic rats carrying the LTR-env-pX-LTR gene of HTLV-I, using the Sindbis virus-based vectors. Expression of the pX gene in cells transduced with ATF-1DN was lower than that in cells with control transfection. A possible application of ATF-1DN to suppress viral gene expression in HTLV-I infected cells can be considered.