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91.
Jain SK Wise R Yanamandra K Dhanireddy R Bocchini JA 《Molecular and cellular biochemistry》2008,309(1-2):217-221
Background Newborn birth weight has been shown to significantly correlate with the blood levels of vitamin C. Objective This study was planned to answer the question of why vitamin C levels correlate with birth weight; does such correlation
reflect a protective effect of vitamin C on fetal growth, by its antioxidant characteristics or does it correspond to the
nutritional status of both the mother and the fetus. We examined the hypothesis that maternal blood levels of vitamin C, but
not vitamin E influence newborn birth weight. We determined maternal and newborn blood levels of vitamin C, vitamin E, and
lipid peroxides (an index of oxidative insult) and the birth weights of full-term newborns delivered at our hospital. Results Compared with maternal blood levels, newborns have higher levels of vitamin C and lipid peroxides, but lower levels of vitamin
E. There was a significant correlation in levels between mothers and their newborns for blood levels of vitamin C (r = 0.82, P < 0.01) and vitamin E (r = 0.61, P < 0.02) but not for lipid peroxides (r = 0.001). This suggests that maternal vitamin C and vitamin E intake can influence fetal vitamin C and vitamin E levels.
Linear regression analysis shows a significant positive relationship between newborn birth weight and maternal plasma vitamin
C (r = 0.51, P < 0.02). Similarly, there was a modest but significant positive relationship between newborn birth weights and newborn vitamin
C levels (r = 0.61, P < 0.05). However, there was no relationship between maternal or fetal vitamin E or lipid peroxides levels and the newborn
birth weight. Conclusions This study with a small number of subjects suggests a significant association between newborn birth weight and maternal and
newborn plasma vitamin C levels. Lack of relationship between birth weight and vitamin E and lipid peroxides suggest that
antioxidant function of vitamin C does not appear to have a major role in the effect of vitamin C on birth weight. 相似文献
92.
Sushil Dhital Amy Hui-Mei Lin Bruce R. Hamaker Michael J. Gidley Anbuhkani Muniandy 《PloS one》2013,8(4)
Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing predominantly α-amylase, and intestinal extract containing a combination of α-amylase and mucosal α-glucosidase activities, were applied to three granular maize starches with different amylose contents in an in vitro system. Relative glucogenesis, released maltooligosaccharide amounts, and structural changes of degraded residues were examined. Pancreatic extract-treated starches showed a hydrolysis limit over the 12 h incubation period with residues having a higher gelatinization temperature than the native starch. α-Amylase combined with the mucosal α-glucosidases in the intestinal extract showed higher glucogenesis as expected, but also higher maltooligosaccharide amounts indicating an overall greater degree of granular starch breakdown. Starch residues after intestinal extract digestion showed more starch fragmentation, higher gelatinization temperature, higher crystallinity (without any change in polymorph), and an increase of intermediate-sized or small-sized fractions of starch molecules, but did not show preferential hydrolysis of either amylose or amylopectin. Direct digestion of granular starch by mammalian recombinant mucosal α-glucosidases was observed which shows that these enzymes may work either independently or together with α-amylase to digest starch. Thus, mucosal α-glucosidases can have a synergistic effect with α-amylase on granular starch digestion, consistent with a role in overall starch digestion beyond their primary glucogenesis function. 相似文献
93.
Properties of a mutant at theLLD (LEAF-LET DEVELOPMENT) locus in peaPisum sativum L. are reported in this paper. Plants homozygous for the Mendelian recessive mutationlld bear leaves in which a few to many leaflets are incompletely developed. Opposite pinnae of rachis nodes often formed fused
incompletely developed leaflets. Thelld mutation was observed to abort pinna development at almost all morphogenetic stages. Thelld mutation demonstrated high penetrance and low expressivity. The phenotypes oflld plants intl, tac, tl tac, tl af andtl af tac backgrounds suggested that LLD function is involved in the separation of lateral adjacent blastozones differentiated on primary,
secondary and tertiary rachides and lamina development in leaflets. The aborted development of tendrils and leaflets inlld mutants was related to deficiency in vascular tissue growth. The morphological and anatomical features of the leaflets formed
on atl lld double mutant permitted a model of basipetal leaflet development. The key steps of leaflet morphogenesis include origin of
the lamina by splitting of a radially symmetrical growing pinna having abaxial outer surface, opposite to the vascular cylinder,
through an invaginational groove, differentiation of adaxial surface along the outer boundary of split tissue in the groove
and expansion of the lamina ridges so formed into lamina spans. 相似文献
94.
Summary Twenty stable auxotrophs for the vitamin thiamine (Thi) were isolated in two cultivars of garden pea (Pisum sativum) and characterized. All thi mutations were recessive lethals. The mutant plants were indistinguishable from normal and heterozygous plants when provided exogenously with about 5 mg of Thi. Eighteen of the mutants were found to define three genes: ThiA, thiB and thiC. The thiA gene mapped very close to the marker k on chromosome 2. The thiB gene was found to be 11.3 crossover units away from pl on chromosome 6 and the thiC gene was located 20 crossover units from st on chromosome 3. The suppressive effects of supplementation with thiamine compounds on the phenotype of the mutants suggested that the thiA and thiC gene products participate in certain steps up to the biosynthesis of the thiazole and hydroxymethylpyrimidine moieties of thiamine, respectively, and that the thiB gene product participates in steps from thiazole and hydroxymethylpyrimidine to thiamine. 相似文献
95.
Edible oil seed crops, such as rapeseed, sunflower, soyabean and safflower and non-edible seed oil plantation crops Jatropha and Pongamia have proved to be internationally viable commercial sources of vegetable oils for biodiesel production. Considering the paucity of edible oils and unsustainability of arable land under perennial plantation of Jatropha and Pongamia in countries such as India, the prospects of seed oil producing Cleome viscosa, an annual wild short duration plant species of the Indogangetic plains, were evaluated for it to serve as a resource for biodiesel. The seeds of C. viscosa resourced from its natural populations growing in Rajasthan, Haryana and Delhi areas of Aravali range were solvent extracted to obtain the seed oil. The oil was observed to be similar in fatty acid composition to the non-edible oils of rubber, Jatropha and Pongamia plantation crops and soybean, sunflower, safflower, linseed and rapeseed edible oil plants in richness of unsaturated fatty acids. The Cleome oil shared the properties of viscosity, density, saponification and calorific values with the Jatropha and Pongamia oils, except that it was comparatively acidic. The C. viscosa biodiesel had the properties of standard biodiesel specified by ASTM and Indian Standard Bureau, except that it had low oxidation stability. It proved to be similar to Jatropha biodiesel except in cloud point, pour point, cold filter plugging point and oxidation stability. In view of the annual habit of species and biodiesel quality, it can be concluded that C. viscosa has prospects to be developed into a short-duration biodiesel crop. 相似文献
96.
Pathak SK Sköld AE Mohanram V Persson C Johansson U Spetz AL 《The Journal of biological chemistry》2012,287(17):13731-13742
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100.
Transforming growth factor-beta pathway: role in pancreas development and pancreatic disease 总被引:1,自引:0,他引:1
The pancreas is a complex exocrine and endocrine gland that controls many homeostatic functions. The exocrine pancreas produces and secretes digestive enzymes, whereas, the endocrine pancreas produces four distinct hormones, chief among them being the glucose regulating hormone-insulin. Diabetes, pancreatitis and pancreatic cancer are some of the main afflictions that result from pancreas dysfunction. Transforming growth factor-beta (TGF-beta) proteins are central regulators of pancreas cell function, and have key roles in pancreas development and pancreatic disease. Since expression levels and kinase activities of components of TGF-beta signaling are aberrantly altered in diseases of the pancreas, modulating the activity of TGF-beta provides a unique and rational opportunity for therapeutic intervention. Although TGF-beta still remains elusive in terms of our understanding of its multifunctional modes of action, research is moving closer to the design of approaches directed toward modulating its activities for therapeutic benefit. 相似文献