Prevalence of Vitamin D Deficiency in a Pediatric Hospital of Eastern India

Vitamin D deficiency is highly prevalent in Indian children of northern, western and southern states. Serum 25 hydroxy cholecalferol (ng/ml) was analyzed in 310 children and adolescents of pediatric hospital of Kolkata, India. Serum calcium (mg/dl), phosphorous (mg/dl) and alkaline phosphatase (IU/L) data was obtained. Median 25(OH)D was 19 ng/ml. 19.2 % of population had serum 25(OH)D < 10 ng/ml (severe deficiency), 52.9 % had <20 ng/ml (deficiency), 24.5 % had 20–29 ng/ml (insufficiency) and 22.6 % had >30 ng/ml (optimum). Deficiency was highest in adolescents (86.1 %), followed by school children (61.0 %), lowest in pre-school children (41.6 %). 25(OH)D concentrations was lowest in winters (P = 0.002) and spring (P = 0.03) compared to summer. There was no correlation with calcium (P = 0.99), phosphorous (P = 0.23) and ALP (P = 0.63). There is high prevalence of vitamin D deficiency in children and adolescents of eastern India. Prevalence was lower in younger subjects. 25(OH)D did not correlate with bone mineral markers.     

HPLC法测定维生素C口服液中维生素C的含量

目的:建立HPLC法测定维生素C口服液中维生素C含量的方法。方法:采用C18柱(250×4.6mm,5μm)为色谱柱;0.02mol·L-1醋酸钠缓冲溶液(p H3.5)-乙腈(85:15)为流动相;柱温30℃;检测波长270nm。结果:该方法在0.6095mg·m L-1~1.3207mg·m L-1浓度范围内具有良好的线性关系,R=0.9994;平均回收率为99.51%,RSD(%)=0.73%。结论:该测定方法准确、可行,适用于维生素C的测定,确保了维生素C口服液的质量安全。     

维生素E对力竭小鼠肺组织自由基代谢及其结构的影响

观察一次性力竭游泳后小鼠肺组织超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、SOD/MDA，和肺组织结构的变化情况；及维生素E对其的影响。结果发现，力竭游泳后即刻，SOD活性、MDA含量、SOD/MDA有明显变化，小鼠肺组织结构在光镜下可见明显充血、水肿；维生素E可抑制上述变化。     

Role of vitamin B12 on methylmalonyl-CoA mutase activity

Vitamin B₁₂ is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes, which have been grouped into three subfamilies depending on their cofactors. Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate. The crystal structure of MCM determined in Propionibacterium freudenreichii var. shermanii has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme, coenzyme, and substrate. The existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in metabolism. The recent crystallization of the human MCM has shown that despite being similar to the bacterial protein, there are significant differences in the structural organization of the two proteins. Recent studies have identified the involvement of an accessory protein called MMAA, which interacts with MCM to prevent MCM’s inactivation or acts as a chaperone to promote regeneration of inactivated enzyme. The interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase, the impact of mutations at a functional level and their repercussion in the development and progression of MMA in humans. It is still necessary to study the mechanisms involved in more detail using new methods.     

A preliminary study on the teratogenesis of dexamethasone and the preventive effect of vitamin B<Subscript>12</Subscript> on murine embryonic palatal shelf fusion in vitro

Excessive dexamethasone (Dex) administrated into pregnant mice during critical periods of palatal development can produce a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to antagonize the tera-togenic effects of Dex, which, however, remains controversial. In this study, we investigated the effects of Dex and vitamin B,2 on murine embryonic palatal shelf fusion using organ culture of murine embryonic shelves. The explanted palatal shelves on embryonic day 14 (E14) were cultured for 24,48,72 or 96 h in different concentrations of Dex and/or vitamin B12. The palatal shelves were examined histologically for the morphological alterations on the medial edge epithelium (MEE) and fusion rates among different groups. It was found that the palatal shelves were not fused at 72 h or less of culture in Dex group, while they were completely fused in the control and vitamin B12-treated groups at 72 and 96 h, respectively. The MEE still existed and proliferated. In Dex vitamin B12 group the palatal shelves were fused at each time point in a similar rate to controls. These results may suggest that Dex causes teratogenesis of murine embryonic palatal shelves and vitamin B12 prevents the teratogenic effect of Dex on palatogenesis on murine embryos in vitro.     

乌塌菜Vc含量动态变化的初步研究

研究了乌塌菜不同品种、不同生育期、不同叶片、叶柄与叶片的Vc含量.结果表明:乌塌菜不同品种间叶片的Vc含量存在显著差异,但叶柄间的Vc含量差异不大;莲座期叶片的Vc含量均显著高于幼苗期叶片的Vc含量,莲座叶的Vc含量均明显高于心叶的Vc含量,叶片的Vc含量均显著高于叶柄的Vc含量.     

分光光度法测定水果中Vc含量的研究

提出一个利用Vc分子中的烯二醇基的还原作用将Fe(Ⅲ)定量还原为Fe(Ⅱ)与邻二氮菲显色.在波长510nm处,其颜色的深浅在一定范围内与Vc含量成正比.     

草莓不同采收时期维生素C含量的测定

维生素C是人体所必须的营养物质之一,其含量是评价果实营养价值的重要参数。对草莓的维生素C的测定可让我们了解其最佳采收时期、了解影响维生素C在不同时期的变化因素,实验结果表明草莓中维生C的含量是随其成熟度的增加呈增长趋势,含量为33.79—46.91mg/100g。该方法的回收率为95.67—100.08%,相对标准偏差为0.59%。草莓中含有丰富的维生素C,其最佳采收期为全红期,是一种具有良好营养价值的水果。     

几种水溶性维生素对平菇生长发育的影响

研究了合成培养基中有无维生素及不同维生素对平菇（pleurotus ostreats Jacg Fr）生长发育的影响．实验结果表明，维生素对平菇生长发育有明显的影响，而且维生素种类齐全平菇生长势最佳．     

BP人工神经网络-光度法同时测定VB1、VB2、VB6和VPP

用BP人工神经网络解析了VB1、VB2、VB6和VPP的紫外吸收光谱,提出同时测定这四种维生素的计算分析方法,并对复合维生素片中的VB1、VB2、VB6和VPP进行了同时测定,VB1、VB2、VB6和VPP平均相对误差分别为1.45%,1.57%,4.08%和1.87%.使用了改进的BP算法,避免了神经网络学习过程中可能产生的麻痹现象;提出了目标向量的简单变换方法.