Molecular and biochemical identification of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of bunching onion (A. fistulosum L.).

To develop the bunching onion (Allium fistulosum L.; genomes, FF) chromosome-specific genetic markers for identifying extra chromosomes, eight shallot (A. cepa L. Aggregatum group; genomes, AA)--A. fistulosum monosomic addition plants (AA+nF) and 62 shallot--A. fistulosum single-alien deletion plants (AAF-nF) were analyzed by 23 different chromosome-specific genetic markers of shallot. The eight monosomic addition plants consisted of one AA+2F, two AA+6F, and five AA+8F. Of the 62 single-alien deletion plants, 60 could be identified as six different single-alien deletion lines (AAF-1F, -3F, -4F, -6F, -7F, and -8F) out of the eight possible types. Several single-alien deletion lines were classified on the basis of leaf and bulb characteristics. AAF-8F had the largest number of expanded leaves of five deletion plants. AAF-7F grew most vigorously, as expressed by its long leaf blade and biggest bulb size. AAF-4F had very small bulbs. AAF-7F and AAF-8F had different bulbs from those of shallot as well as other types of single-alien deletion lines in skin and outer scale color. Regarding the sugar content of the bulb tissues, the single-alien deletion lines showed higher fructan content than shallot. Moreover, shallot could not produce fructan with degree of polymerization (DP) 12 or higher, although the single-alien deletion lines showed DP 20 or higher. The content of S-alk(en)yl-L-cysteine sulfoxide (ACSO) in the single-alien deletion lines was significantly lower than that in shallot. These results indicated that chromosomes from A. fistulosum might carry anonymous factors to increase the highly polymerized fructan production and inhibit the synthesis of ACSO in shallot bulbs. Accordingly, alien chromosomes from A. fistulosum in shallot would contribute to modify the quality of shallot bulbs.

Development and validation of food frequency questionnaire to assess calcium intake in postmenopausal Vietnamese women.

This study was done to develop a Food Frequency Questionnaire (FFQ) for assessing calcium intake in Vietnamese based on data from the National Nutrition Survey in 2000. From the data, a total of 36 calcium-rich food items were selected for the FFQ by ranking food items according to their contribution to the population intake of nutrients. The FFQ was validated in 140 postmenopausal women by comparing estimates of calcium intake from the FFQ with those from multi-pass 24 h recalls. The results showed that the Pearson correlation coefficient between the 2 methods was 0.84 (p<0.001), and that the weighted kappa value was 0.44. Cross-classification analysis indicated that 82.1% of subjects were classified into the same or adjacent quartile by both methods. No subject was grossly misclassified by the FFQ. There is no significant difference of calcium intake between the 2 methods (by paired t test, p>0.05). A reproducibility study also presented good correlation between 2 administrations of the FFQ, with Pearson correlation coefficient being 0.93 (p<0.001) and weighted kappa value being 0.67. In conclusion, this FFQ is useful and reliable for estimating calcium intake in population-based epidemiological studies in postmenopausal Vietnamese women.

Micronutrient deficiencies and anemia among preschool children in rural Vietnam.

The prevalence of trace elements deficiencies, vitamin A deficiency, anemia, and their relationships were investigated in a cross sectional study involving 243 children aged from 12 to 72 months in rural Vietnam. Serum levels of copper, zinc, selenium and magnesium were determined by inductively coupled plasma mass spectrometer and that of retinol by high performance liquid chromatography. Hemoglobin concentration in whole blood was measured by the cyanmethemoglobin method. The prevalence of deficiencies in zinc, selenium, magnesium, and copper was 86.9%, 62.3%, 51.9%, and 1.7%, respectively. On the other hand, 55.6% were anemic and 11.3% had vitamin A deficiency. Deficiency in two or more micronutrient was found in 79.4% of the children. Parameters associated significantly with anemia were selenium deficiency (OR 2.80 95% CI 1.63-4.80, p=0.0002) and serum retinol<1.05 micromol/L (OR 1.83, 95% CI 1.10-3.05, p=0.021). Magnesium deficiency (OR 3.09 95% CI 1.36-7.03) was found to be a risk factor for zinc deficiency and vice versa. The results indicate that micronutrient deficiencies are prevalent among preschool children in Vietnam. In addition, the results also demonstrate a strong relationship between selenium deficiency and anemia. Clearly, sustainable strategies are urgently required to overcome the problems in the country.

Noninvasive intravital imaging of thymocyte dynamics in medaka.

In vivo imaging of thymocytes has not been accomplished due to their localization deep within opaque body and high susceptibility to surgical stress. To overcome these problems, medaka is useful because of transparency and ex-uterine development. We report the noninvasive detection of thymocytes in transgenic medaka that express fluorescent protein under the control of immature-lymphocyte-specific rag1. We show that lymphoid progenitor cells colonize the thymus primordium in an anterior-to-posterior orientation-specific manner, revealing that extrathymic anterior components guide prevascular thymus colonization. We also show that developing thymocytes acquire "random walk motility" along with the expression of Ag receptors and coreceptors, suggesting that thymocyte walking is initiated at the developmental stage for repertoire selection. Thus, transgenic medaka enables real-time intravital imaging of thymocytes without surgical invasion.