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911.
B. Bhaskar Gollapudi Diane J. Sutcliffe Anil K. Sinha 《In vitro cellular & developmental biology. Plant》1986,22(11):681-684
Summary Rat lymphocyte cultures were initiated in minimal essential medium containing 0, 0.01, 1.0, or 10 mg/l of folic acid to investigate
the influence of folic acid on cell kinetics, chromosome aberration, and sister chromatid exchange (SCE) frequencies. No significant
difference was observed between cultures with and without folic acid in mitotic index or cell cycle kinetics as judged by
the numbers of average lymphocyte divisions. However, a sequential reduction in the number of chromatid gaps occurred as the
concentration of folic acid increased. On the other hand, addition of folic acid did not significantly affect the SCE frequency.
Although folic acid does not seem to alter SCE formation, its significant influence in the reduction of chromatid gaps suggests
that caution should be exercised in selecting a medium regarding folic acid content especially because gaps alone are produced
by certain dose levels of some chemical clastogens. 相似文献
912.
Bhaskar N. Joshi Mary K. Vaughan Frank Nü rnberger Russel J. Reiter 《Chronobiology international》1985,2(1):47-54
Two different experimental models were used to test if a temporal relationship exists between the rhythm of adrenal steroid secretion and the vulnerability of the hamster reproductive system to short photoperiod exposure or to the daily afternoon injection of melatonin. In the first experiment adrenalectomized hamsters were implanted with a Cortisol pellet to provide a sustained, rather than rhythmic, level of the hormone. The animals were either placed in short photoperiod or given a daily afternoon melatonin injection. In both cases the gonads underwent atrophy. In the second experiment adrenalectomized hamsters were given a Cortisol injection either in the morning (approx. 8 hr before the subsequent afternoon injection of melatonin) or in the afternoon (approx. 1 hr before the subsequent melatonin injection). Measurements of testicular and accessory organ weights 7 weeks later indicated regression of the reproductive system in both the groups when compared with their appropriate controls. Depressed levels of plasma LH. PRL, testosterone and thyroxine (T4) in these animals confirmed the melatonin induced gonadal collapse. The results suggest that apparently there is no temporal correlation between the rhythm of secretion of the adrenal steroids and the responsiveness of the reproductive system to late afternoon injection of melatonin. Interestingly, all the adrenalectomized Cortisol injected control animals (not receiving melatonin) had depressed plasma LH and PRL while the testicular weights and plasma testosterone titers remain unaffected. 相似文献
913.
914.
Mobile genetic elements (MGEs) occupy major proportion of eukaryotic genomes and are present in significant numbers in
prokaryote genomes also. Here we report a new method which extracts a motif at the site of insertion of MGE using tools such as
DNA SCANNER. The flanking region of the insertion site is extracted and is analyzed in DNA Scanner for physiochemical
properties like protein-interaction measures, energy profiles as well as structural parameters. In case significant signals are
observed, the most frequently occurring n-mer (5E. histolytica, signals for EhSine1 are found at
around 5 bps upstream of insertion and most frequently occurring motif is found to be AAGGT and TCGAA. Signals for Ty3
element in S. cerevisiae are found at 0-3 bps upstream of tRNA, and most frequent motif is GTTCGA (6 bps), GGTTCGA (7 bps) and
GGTTCGAT (8 bps). P-element of Drosophila showed remarkable dyad peaks suggesting palindromic site of insertion. 相似文献
915.
Bhaskar Choudhury Souvik Mitra Asok K. Biswas 《Physiology and Molecular Biology of Plants》2010,16(1):59-68
The effect of arsenate with or without phosphate on the growth and sugar metabolism in rice seedlings cv. MTU 1010 was studied. Arsenate was found to be more toxic for root growth than shoot growth and water content of the seedlings gradually decreased with increasing concentrations. Arsenate exposure at 20 μM and 100 μM resulted in an increase in reducing sugar content and decrease in non-reducing sugar content. There was a small increase in starch content, the activity of starch phosphorylase was increased but α-amylase activity was found to be decreased. Arsenate toxicity also affected the activities of different carbohydrate metabolizing enzymes. The activities of sucrose degrading enzymes viz., acid invertase and sucrose synthase were increased whereas, the activity of sucrose synthesizing enzyme, viz. sucrose phosphate synthase declined. The combined application of arsenate with phosphate exhibited significant alterations of all the parameters tested under the purview of arsenate treatment alone which was congenial to better growth and efficient sugar metabolism in rice seedlings. Thus, the use of phosphorus enriched fertilizers may serve to ensure the production of healthy rice plants in arsenic contaminated soils. 相似文献
916.
Bhaskar Gaonkar Krishnananda Prabhu Pragna Rao Asha Kamat Krishna Rao Addoor Muralidhar Varma 《Biomarkers》2020,25(5):397-401
AbstractBackground: Neovascularization in the retina and hyperglycaemia-induced oxidative stress are implicated in the pathogenesis of diabetic retinopathy (DR). In this study, we hypothesized that the plasma angiogenic and oxidative stress markers associated with these derangements could aid in the screening of diabetic patients who are at an increased risk of developing retinopathy.Methods: This study included normal (n?=?148), type2 diabetes without retinopathy (DNR; n?=?148), proliferative DR (PDR; n?=?74) and non-PDR (NPDR; n?=?148) subjects. Plasma concentrations of vascular endothelial growth factor-A (VEGF-A), hypoxia-inducible factor-1α (HIF-1α), matrix metalloproteinase-9 (MMP-9), pigment epithelium-derived factor (PEDF), nitric oxide (NO), soluble receptors for advanced glycation end products (sRAGE), malondialdehyde (MDA) and protein thiols were estimated.Results: A statistically significant increase was observed in the plasma concentrations of pro-angiogenic factors and markers of oxidative stress in both retinopathy groups. By contrast, the concentrations of anti-angiogenic factors and antioxidants were decreased significantly in these groups. Receiver operating characteristic analysis indicated that the plasma thresholds of HIF-1α and PEDF can be suitable markers in case of NPDR. However, in PDR, HIF-1α, NO, MMP-9 and PEDF showed high sensitivity and specificity.Conclusions: The factors associated with hypoxia, matrix degradation and angiogenic inhibition play a crucial role in predicting DR. 相似文献
917.
918.
M. Kidwai B. Dave K. R. Bhushan P. Misra R. K. Saxena R. Gupta R. Gulati M. Singh 《Biocatalysis and Biotransformation》2002,20(5):377-379
Deacylation of cephalosporins has been investigated using enzymatic and microwave activated solid phase techniques. The lipase calatysed deacylation was achieved under cooling with good yields but the microwave method was much faster with better yields. All the synthesised compounds were screened for their antibacterial activity and showed good results. 相似文献
919.
Antibodies to sulfolipids were demonstrated in patients suffering from lepromatous leprosy. The antibody titre was found to decrease gradually on treatment with DDS. This effect was maximum for patients undergoing treatment for more than 1 year. 相似文献
920.
Amino-terminal sequence analysis of arachin, a peanut protein, using a modified Edman method has yielded the sequence of the first 60 residues. The PTH-amino acids have been identified on the basis of melting point, thin layer chromatography and UV spectroscopic data. For this purpose standard PTH-amino acids were prepared. In addition, two new solvent systems for thin layer chromatography of PTH-amino acids are reported. 相似文献