ABSTRACT
Objective@#To explore the prospective effect of dietary intake of total fat and fatty acids on menarcheal timing among girls,and to provide a theoretical basis for preventing the early puberty development of Chinese children.@*Methods@#Using the data from 1997-2015 China Health and Nutrition Survey (CHNS), 1 240 girls aged 6-13 with menarche information, baseline dietary survey data and at least one follow up assessment were selected. Cox regression analysis was performed to examine the prospective effect of dietary intake of total fat and fatty acids before menarche on age at menarche.@*Results@#The mean baseline age of the participants was (8.3±1.8). After adjustment for year of birth, residence, household income, dietary energy intake and body mass index Z score at baseline, girls in the highest quartile of intake of total fat and polyunsaturated fatty acid (PUFA) had a 30% and 34% higher probability of experiencing menarche at an earlier age than those in the lowest quartile [ HR(HR 95%CI )=1.30 (1.01~1.68)，1.34(1.05~1.70)]. After adjusting for the confounders, there were no correlations between the intake of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) and the onset of menarche [ HR(HR 95%CI )=1.24(0.98~1.58),1.25(0.97~ 1.62 )]( P >0.05).@*Conclusion@#Higher dietary intake of total fat and PUFA before menarche may lead to earlier age at menarche and no correlation between intake of SFA and MUFA before menarche with age at menarche is found among Chinese girls.
ABSTRACT
Objective@#To examine the prospective association between peripubertal diet quality and pubertal timing.@*Methods@#Multivariate regression analyses were performed using data obtained from 1 588 SCCNG (Southwest China Childhood Nutrition and Growth) study participants, which included dietary data, anthropometric parameters, and information about potential confounders during peri puberty, two and four years before the onset of menarche or voice break. Dietary intake in peri puberty was assessed using a validated food frequency questionnaire. Diet quality was determined using the Chinese Children Dietary Index (CCDI), which measures adherence to current dietary recommendations. Age at menarche or voice break (M/VB) were used as pubertal markers.@*Results@#The CCDI score ranged from 58.0 to 132.5 for girls and from 48.3 to 129.9 for boys. The pubertal markers consistently indicated that girls and boys with a higher peripubertal diet quality entered puberty later than their counterparts with lower CCDI scores (higher vs. lower CCDI tertiles: age at M was 13.1 years (11.2-13.3) and 12.5 years (12.0-13.9)(P<0.01); VB was 13.8 years (12.1-14.8) and 13.4 years (12.5-15.1)（P=0.03), after adjusting for paternal education level, energy intake, and pre pubertal body fat.@*Conclusion@#Children with a higher diet quality during peri puberty entered puberty at a later age. Dietary guidance and intervention are needed for better dietary quality among children during pubertal transition.
ABSTRACT
Objective:Dendrobium officinale (Orchidaceae) (D. officinale) is one of the world’s most endangered plants with great medicinal value. It is mainly distributed in south China, and is often used as auxiliary treatment for a variety of tropical diseases. The strictly demanding for growing environment and climate conditions making its wild resources endangered. In nature, the relationship between seeds of D. officinale and fungi must be established by symbiotic system. Our purpose is to analyze the molecular events involved in the interaction between fungus and plant during this process, and provide scientific basis for the protection of its germplasm resources.Methods:Beta-1,3-glucan (Glu) is a key enzyme in the biosynthesis of polyamines, which is essential to the basic physiological and biochemical processes of plants. In this study, the full-length cDNA of Glu gene was obtained from symbiotic germinating seeds of medicinal plants by rapid amplified cDNA terminal (RACE) - PCR, and its expression characteristics were analyzed for the first time.Results:Glu has a full length cDNA of 1 317 bp, with one open reading frame (ORF). The deduced protein was 356 amino acids (aa) with molecular weight of 37.24 KDa and a theoretical isoelectric point of 5.17. The deduced β-1,3-Dextran protein, without signal peptide, had three transmembrane domain each contained 23,17 and 20 aa. Multiple sequence alignment and phylogenetic analysis showed that the sequence similarity between beta-1,3-glucan and rice beta-1,3-glucan was higher than that of dicotyledons. The expression pattern analyzed by qPCR showed that Glu transcripts were expressed in four tissues (non-infected fungi) without significant change. In symbiotic germinating seeds, the expression level is 23.67 times higher than that of ungerminated seeds.Conclusion:These results indicated that β-1,3-Dextran was possible involved in the symbiotic seed germination of D. officinale, and played an important role in the symbiosis system of mycorrhizal mutual.