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751.
Shirin Hooshmand Anju Balakrishnan Richard M. Clark Kevin Q. Owen Sung I. Koo Bahram H. Arjmandi 《Phytomedicine》2008,15(8):595-601
Postmenopausal bone loss is a major public health concern. Although drug therapies are available, women are interested in alternative/adjunct therapies to slow down the bone loss associated with ovarian hormone deficiency. The purpose of this study was to determine whether dietary supplementation of l-carnitine can influence bone density and slow the rate of bone turnover in an aging ovariectomized rat model. Eighteen-month-old Fisher-344 female rats were ovariectomized and assigned to two groups: (1) a control group in which rats were fed ad libitum a carnitine-free (−CN) diet (AIN-93M) and (2) another fed the same diet but supplemented with l-carnitine (+CN). At the end of 8 weeks of feeding, animals were sacrificed and bone specimens were collected for measuring bone mineral content (BMC) and density (BMD) using dual energy X-ray absorptiometry. Femoral microarchitectural properties were assessed by microcomputed tomography. Femoral mRNA levels of selected bone matrix proteins were determined by northern blot analysis. Data showed that tibial BMD was significantly higher in the rat fed the +CN diet than those fed the −CN (control) diet. Dietary carnitine significantly decreased the mRNA level of tartrate-resistant acid phosphatase (TRAP), an indicator of bone resorption by 72.8%, and decreased the mRNA abundance of alkaline phosphatase (ALP) and collagen type-1 (COL), measures of bone formation by 63.6% and 61.2%, respectively. The findings suggest that carnitine supplementation slows bone loss and improves bone microstructural properties by decreasing bone turnover. 相似文献
752.
The factors influencing somatic embryo maturation, high frequency somatic embryo germination, and plantlet formation were
studied in Terminalia chebula Retz. Maturation of somatic embryo were influenced by a number of factors such as in vitro culture passage, concentrations
of sucrose, levels of abscisic acid (ABA), basal media and media additive combinations. Maximum frequency of somatic embryo
maturation (57.22 ± 2.02), was obtained on MS medium supplemented with 50 g/l sucrose. Different factors such as strengths
of MS nutrients, plant growth regulators, media additives and their combinations controlling somatic embryo germination and
plantlet formation were studied. High frequency of germination and plantlet formation (58.80 ± 1.47) were achieved by subsequent
subculture of mature somatic embryos on MS medium containing 30 g/l sucrose and 0.5 mg/l benzyladenine (BA). However, although
duration of in vitro passage of the callus tissue was critical, contribution of the combinations of plant growth regulators
and media additives showed nugatory effect on somatic embryo maturation and germination as evident from variable responses. 相似文献
753.
Pingali H Jain M Shah S Basu S Makadia P Goswami A Zaware P Patil P Godha A Giri S Goel A Patel M Patel H Patel P 《Bioorganic & medicinal chemistry letters》2008,18(20):5586-5590
A series of novel 1,3-dioxane-2-carboxylic acid derivatives containing alkyl chain tether and substituted phenyl group as a lipophilic tail have been prepared as agonists of PPARalpha and gamma. c-5-[6-(4-Methanesulfonyloxyphenyl)hexyl]-2-methyl-1,3-dioxane-r-2-carboxylic acid 13c exhibited potent hypoglycemic and lipid lowering activity with high oral bioavailability in animal models. 相似文献
754.
Population structure in an endangered songbird: maintenance of genetic differentiation despite high vagility and significant population recovery 总被引:1,自引:1,他引:0
Barr KR Lindsay DL Athrey G Lance RF Hayden TJ Tweddale SA Leberg PL 《Molecular ecology》2008,17(16):3628-3639
Black-capped vireos ( Vireo atricapilla ), an endangered, migratory species dependent upon early successional habitat, have experienced significant recovery since its protection. In light of its vagility and known increase in population size and range, limited genetic differentiation would be expected in the species. Using 15 microsatellite loci and an extensive sampling regime, we detected significant overall genetic differentiation ( F ST = 0.021) and high interpopulation differentiation compared to other migratory birds. Although proximate sites (separated by < 20 km) tended to be genetically similar, there was no apparent association of either geographical distance or landscape attributes with differentiation between sites. Evidence of a population bottleneck was also detected in a site located near other large concentrations of birds. Although black-capped vireos are capable of large-scale movements and the population has experienced a recent expansion, dispersal appears too insufficient to eliminate the genetic differentiation resulting from restricted colonization of ephemeral habitats. 相似文献
755.
A. G. Patankar A. M. Harsulkar A. P. Giri V. S. Gupta M. N. Sainani P. K. Ranjekar V. V. Deshpande 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):719-726
Developing seeds of eight chickpea (Cicer arietinum L.) cultivars (12–60 days after flowering) showed a significant variation in the trypsin inhibitor (TI) and the Helicoverpa armigera gut proteinase inhibitor (HGPI) content. For example, the highest TI (198 units/g) and HGPI (23 units/g) activities were
exhibited by mature seeds of cv ICCV-2, whereas the lowest inhibitor activities were observed in cv PG8505–7 (96.1 TI units/g)
and cv Vijay (5 HGPI units/g). Electrophoretic patterns showed a variation in TI bands during the early stages of seed development,
indicating cultivar-specific TI accumulation. Among the seed organs, TI and HGPI activities were highly localized in the embryo-axis
as compared to the cotyledons in immature and mature seeds. Moisture stress, as effected under rainfed conditions, resulted
in reduced PI levels. Wild relatives of chickpea revealed variability in terms of the number and intensity of TI bands. However,
when assessed for inhibition of HGP, none of the wild Cicer species showed more than 35% inhibition, suggesting that a large proportion of HGP was insensitive to PIs from Cicer. Our results provide a biochemical basis for the adaptation of H. armigera to the PIs of Cicer species and advocate the need for the transformation of chickpea with a suitable gene(s) for H. armigera resistance.
Received: 26 December 1998 / Accepted: 19 January 1999 相似文献
756.
Activation of mucosal immunity in the respiratory tract is crucial for protection against respiratory infections. Whether the intranasal route of vaccination imparts better protection against pulmonary tuberculosis than that of subcutaneous vaccination remains a debatable issue. In this study, we have investigated the effect of the routes of immunization on the induction of immunoprotection against experimental tuberculosis employing mycobacterial culture filtrate proteins complexed with dimethyldioctadecylammonium bromide. Vaccination via intranasal and subcutaneous routes triggered immune activation in the spleen and cervical lymph node, while the former route of vaccination lead to higher antigen-specific lymphocyte proliferation, interferon-gamma, interleukin-12 and interleukin-4 responses in cervical lymph node and induction of antigen-specific IgA responses at mucosal level of the respiratory tract. Mice vaccinated via the intranasal route were found to be better protected against experimental tuberculosis particularly in lung compared to subcutaneous-immunized mice. These results emphasize the importance of the intranasal route vaccination in tuberculosis. 相似文献
757.
Abhyankar G Reddy VD Giri CC Rao KV Lakshmi VV Prabhakar S Vairamani M Thippeswamy BS Bhattacharya PS 《Phytochemistry》2005,66(20):2441-2457
A reproducible protocol for establishment of hairy root cultures of Psoralea corylifolia L. was developed using Agrobacterium rhizogenes strain ATCC 15834. The hairy root clones exhibited typical sigmoid growth curves. Genomic and metabolomic profiles of hairy root clones along with that of untransformed control were analysed. Hairy root clones, Ps I and Ps II, showed significant differences in their amplified fragment length polymorphism (AFLP) profiles as compared to that of control, besides exhibiting Ri T-DNA-specific bands. These results amply indicate the stable integration of Ri T-DNA into the genomes of these clones. Further, the variations observed between clones in the AFLP profiles suggest the variable lengths and independent nature of Ri T-DNA integrations into their genomes. An isoflavonoid, formononetin, and its glycoside were present only in the hairy root clones while they were absent in the untransformed control. Variations observed in the metabolite profiles of these clones may be attributed to the random T-DNA integrations and associated changes caused by them in the recipient genomes. GC/MS analyses revealed the production of three and six clone-specific compounds in Ps I and Ps II, respectively, suggesting that the clones are dissimilar in their secondary metabolism. HPLC/UV-MS analyses disclosed substantial increases in the total isoflavonoids produced in Ps I (184%) and Ps II (94%) compared to untransformed control. 相似文献
758.
Vanadium compounds are potent in controlling elevated blood glucose levels in experimentally induced diabetes. However the
toxicity associated with vanadium limits its role as therapeutic agent for diabetic treatment. A vanadium compound sodium
orthovanadate (SOV) was given to alloxan-induced diabetic Wistar rats in lower doses in combination withTrigonella foenum graecum, a well-known hypoglycemic agent used in traditional Indian medicines. The effect of this combination was studied on lens
morphology and glucose metabolism in diabetic rats. Lens, an insulin-independent tissue, was found severely affected in diabetes
showing visual signs of cataract. Alterations in the activities of glucose metabolizing enzymes (hexokinase, aldose reductase,
sorbitol dehydrogenase, glucose-6-phosphate dehydrogenase) and antioxidant enzymes (glutathione peroxidase, glutathione reductase)
besides the levels of related metabolites, [sorbitol, fructose, glucose, thiobarbituric acid reactive species (TBARS) and
reduced glutathione (GSH)]were observed in the lenses from diabetic rats and diabetic rats treated with insulin (2 IU/day),
SOV (0.6 mg/ml),T. f. graecum seed powder (TSP, 5%) and TSP (5%) in combination with lowered dose of vanadium SOV (0.2 mg/ml), for a period of 3 weeks.
The activity of the enzymes, hexokinase, aldose reductase and sorbitol dehydrogenase was significantly increased whereas the
activity of glucose-6-phosphate dehydrogenase, glutathione peroxidase and glutathione reductase decreased significantly in
lenses from 3 week diabetic rats. Significant increase in accumulation of metabolites, sorbitol, fructose, glucose was found
in diabetic lenses. TBARS measure of peroxidation increased whereas the levels of antioxidant GSH decreased significantly
in diabetic condition. Insulin restored the levels of altered enzyme activities and metabolites almost to control levels.
Sodium orthovanadate (0.6 mg/ml) andTrigonella administered separately to diabetic animals could partially reverse the diabetic changes, metabolic and morphological, while
vanadate in lowered dose in combination withTrigonella was found to be the most effective in restoring the altered lens metabolism and morphological appearance in diabetes. It
may be concluded that vanadate at lowered doses administered in combination withTrigonella was the most effective in controlling the altered glucose metabolism and antioxidant status in diabetic lenses, these being
significant factors involved in the development of diabetic complications, that reflects in the reduced lens opacity 相似文献
759.
Anju?AroraEmail author Lata?Nain J.?K.?Gupta 《World journal of microbiology & biotechnology》2005,21(3):303-308
The actinomycete strain Streptomyces griseus B1 isolated from soil, when grown on cellulose powder as submerged culture produced high levels of all the three components i.e. filter paper lyase (FPase), CMCellulase and β-glucosidase of the cellulolytic enzyme system. FP activity and CMCellulase were present only extracellularly, while β-glucosidase was both intra- and extra-cellular. It produced highest FPase activity when grown on hardwood powder under submerged culture. It was unable to use lignin monomers (ferulic acid, vanillic acid and syringic acid) as carbon source. While growing on hardwood and softwood powders under solid-state conditions, it depleted them of cellulose (36.3 in the case of softwood and 14.4 in the case of hardwood). It also caused partial loss of lignin content in both the substrates by solubilizing them. These solubilized lignins could be recovered as acid precipitable polymeric lignins (APPL) from extracts of wood powders upon acidification. Extracts of inoculated wood powders yielded higher amounts of APPL than uninoculated controls. Also, the APPLs from Streptomyces-treated wood powders differed from control APPLs in their molecular weight distribution, as observed from their elution pattern using Sephadex G-100. 相似文献
760.
5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside inhibits cancer cell proliferation in vitro and in vivo via AMP-activated protein kinase 总被引:5,自引:0,他引:5
5-Aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR) is widely used as an AMP-kinase activator, which regulates energy homeostasis and response to metabolic stress. Here, we investigated the effect of AICAR, an AMPK activator, on proliferation of various cancer cells and observed that proliferation of all the examined cell lines was significantly inhibited by AICAR treatment due to arrest in S-phase accompanied with increased expression of p21, p27, and p53 proteins and inhibition of PI3K-Akt pathway. Inhibition in in vitro growth of cancer cells was mirrored in vivo with increased expression of p21, p27, and p53 and attenuation of Akt phosphorylation. Anti-proliferative effect of AICAR is mediated through activated AMP-activated protein kinase (AMPK) as iodotubericidin and dominant-negative AMPK expression vector reversed the AICAR-mediated growth arrest. Moreover, constitutive active AMPK arrested the cells in S-phase by inducing the expression of p21, p27, and p53 proteins and inhibiting Akt phosphorylation, suggesting the involvement of AMPK. AICAR inhibited proliferation in both LKB and LKB knock-out mouse embryo fibroblasts to similar extent and arrested cells at S-phase when transfected with dominant negative expression vector of LKB. Altogether, these results indicate that AICAR can be utilized as a therapeutic drug to inhibit cancer, and AMPK can be a potential target for treatment of various cancers independent of the functional tumor suppressor gene, LKB. 相似文献