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741.
Mukherjee K Chowdhury S Mondal S Mandal C Chandra S Bhadra RK Mandal C 《Biochemical and biophysical research communications》2007,362(3):651-657
An acetylated modification of a tumor-associated ganglioside GD3 (9-O-AcGD3) is expressed in certain tumors and present during early stages of development in different tissues. However, the status and the role of 9-O-AcGD3 in the erythroid progenitor cells remain unexplored. Here, we report the level of 9-O-AcGD3 during erythropoiesis in bone marrow is down regulated during maturation. Signaling via 9-O-AcGD3 induces alteration of morphology and membrane characteristics of mature erythrocytes. This process also induces, a cell death program in these erythrocytes even in the absence of nucleus, mitochondria and other cell organelles sharing features of apoptosis in nucleated cells like membrane alterations, vesicularization, phosphatidyl serine exposure, activation of cysteine proteases like caspase-3. This is the first report of a programmed cell death pathway in mature erythrocytes, triggered by 9-O-AcGD3 contrary to their anti-apoptotic role in lymphoblasts, which suggests a cell specific role of this O-acetyl ester of GD3. 相似文献
742.
Ghosh S Bandyopadhyay S Mukherjee K Mallick A Pal S Mandal C Bhattacharya DK Mandal C 《Glycoconjugate journal》2007,24(1):17-24
Exploiting the selective affinity of Achatinin-H towards 9-O-acetylneuraminic acid(α2-6)GalNAc, we have demonstrated the presence of 9-O-acetylated sialoglycoproteins (Neu5,9Ac2-GPs) on hematopoietic cells of children suffering from acute lymphoblastic leukemia (ALL), indicative of defective sialylation
associated with this disease. The carbohydrate epitope of Neu5,9Ac2-GPsALL was confirmed by using several synthetic sialic acid analogues. They are functionally active signaling molecules as demonstrated
by their role in mediating lymphoproliferative responses and consequential increased production of IFN-γ due to specific stimulation
of Neu5,9Ac2-GPs on PBMCALL with Achatinin-H. Cells devoid of 9-O-acetylations (9-O-AcSA−) revealed decreased nitric oxide production as compared to 9-O-AcSA+ cells on exposure to IFN-γ. Under this condition, a decrease in viability of 9-O-AcSA− cells as compared to 9-O-AcSA+ cells was also observed which was reflected from increased caspase 3 activity and apoptosis suggesting the protective role
of this glycotope. These Neu5,9Ac2-GPs are also capable of inducing disease-specific anti-Neu5,9Ac2-GPs antibodies in ALL children. Additionally, we have observed that disease-specific anti-Neu5,9Ac2-GPs have altered glycosylation profile, and they are incapable of exerting a few Fc-glycosylation-sensitive effector functions.
These observations hint toward a disbalanced homeostasis, thereby enabling the cancer cells to escape host defense. Taken
together, it may be hypothesized that Neu5,9Ac2-GPs and their antibodies play a prominent role in promoting the survival of lymphoblasts in ALL. 相似文献
743.
Interplay of polyethyleneimine molecular weight and oligonucleotide backbone chemistry in the dynamics of antisense activity 总被引:1,自引:0,他引:1
The widespread utilization of gene silencing techniques, such as antisense, is impeded by the poor cellular delivery of oligonucleotides (ONs). Rational design of carriers for enhanced ON delivery demands a better understanding of the role of the vector on the extent and time course of antisense effects. The aim of this study is to understand the effects of polymer molecular weight (MW) and ON backbone chemistry on antisense activity. Complexes were prepared between branched polyethyleneimine (PEI) of various MWs and ONs of phosphodiester and phosphorothioate chemistries. We measured their physico-chemical properties and evaluated their ability to deliver ONs to cells, leading to an antisense response. Our key finding is that the antisense activity is not determined solely by PEI MW or by ON chemistry, but rather by the interplay of both factors. While the extent of target mRNA down-regulation was determined primarily by the polymer MW, dynamics were determined principally by the ON chemistry. Of particular importance is the strength of interactions between the carrier and the ON, which determines the rate at which the ONs are delivered intracellularly. We also present a mathematical model of the antisense process to highlight the importance of ON delivery to antisense down-regulation. 相似文献
744.
The present study enlightens the role of Bacillus cereus ACE4 on biodegradation of commercial corrosion inhibitors (CCI) and the corrosion process on API 5LX steel. Bacillus cereus ACE4, a dominant facultative aerobic species was identified by 16S rDNA sequence analysis, which was isolated from the corrosion products of refined diesel-transporting pipeline in North West India. The effect of CCI on the growth of bacterium and its corrosion inhibition efficiency were investigated. Corrosion inhibition efficiency was studied by rotating cage test and the nature of biodegradation of corrosion inhibitors was also analyzed. This isolate has the capacity to degrade the aromatic and aliphatic hydrocarbon present in the corrosion inhibitors. The degraded products of corrosion inhibitors and bacterial activity determine the electrochemical behavior of API 5LX steel. 相似文献
745.
746.
747.
Md Akhlaqur Rahman Sukrat Sinha Shephali Sachan Gaurav Kumar Shailendra Kumar Singh Shanthy Sundaram 《Bioinformation》2014,10(7):449-453
Mycosporine- like amino acids (MAAs) are small (<400Da), colourless, water soluble compounds composed of cyclohexenone or
cyclohexinimine chromophere conjugated with the nitrogen substituent of amino acid or its amino alcohol. These compounds are
known for their UV- absorbing role in various organisms and seem to have evolutionary significance. The biosynthesis of MAAs is
presumed to occur via the first part of shikimate pathway. In the present work two cyanobacteria Synechocystis PCC 6803 and
Anabaena cylindrica were tested for their ability to synthesize MAAs and protein involved in the production of MAAs. It was found
that protein sequence 3-phosphoshikimate 1-carboxyvinyltransferase is involved in producing mycosporine glycine in Synechocystis
PCC 6803 and 3-dehydroquinate synthase is involved for producing shinorine in Anabaena cylindrica. Phylogenetic and
bioinformatic analysis of Mycosporine like amino acid producing protein sequence of both cyanobacterial species Synechocystis
PCC 6803 and Anabaena cylindrica provide a useful framework to understand the relationship of the different forms and how they
have evolved from a common ancestor. These products seem to be conserved but the residues are prone to variation which might
be due the fact that different cyanobacteria show different physiological process in response of Ultraviolet stress. 相似文献
748.
David L. McClure Burney A. Kieke Maria E. Sundaram Melissa D. Simpson Jennifer K. Meece Frangiscos Sifakis Robert A. Gasser Jr Edward A. Belongia 《PloS one》2014,9(7)
Background
Diagnostic testing for respiratory syncytial virus (RSV) is not routinely performed in adults. We estimated medically attended RSV seasonal incidence in a community cohort of adults ≥50 years old during four influenza seasons (2006–07 through 2009–10).Methods
Patients seeking care for acute respiratory illness (ARI) were prospectively enrolled and tested for RSV by multiplex RT-PCR. Results from enrolled patients were used to estimate projected cases among non-enrolled patients with ARI. The seasonal incidence of medically attended RSV was the sum of actual and projected cases divided by the community cohort denominator. Since each enrollment period did not include the entire RSV season, incidence estimates were adjusted to account for the statewide proportion of RSV occurring outside the study enrollment period.Results
There were 16,088 to 17,694 adults in the cohort each season and 164 RSV cases in all 4 seasons. The overall seasonal incidence of medically attended RSV was 154 episodes (95% CI, 132–180) per 10,000 persons; the incidence was highest in 2007–08 (179) and lowest in 2006–07 (110). Among persons 50–59, 60–69, and ≥70 years old, RSV incidence was 124 (95% CI, 99–156), 147 (95% CI, 110–196), and 199 (95% CI, 153–258), respectively.Conclusions
The incidence of medically attended RSV increased with age and was similar during four seasons. 相似文献749.
Lee Siew-Keah Arunkumar Sundaram K. N. S. Sirajudeen Rahimah Zakaria H. J. Singh 《Journal of physiology and biochemistry》2014,70(1):73-79
Antenatal and postnatal environments are hypothesised to influence the development of hypertension. This study investigates the synergistic effect of cross-fostering and melatonin supplementation on the development of hypertension and renal glutathione system in spontaneously hypertensive rats (SHR). In one experiment, 1-day-old male SHR pups were fostered to either SHR (shr-SHR) or Wistar-Kyoto rats, (shr-WKY). In a concurrent experiment, SHR dams were given melatonin in drinking water (10 mg/kg body weight) from day 1 of pregnancy. Immediately following delivery, 1-day-old male pups were fostered either to SHR (Mel-shr-SHR) or WKY (Mel-shr-WKY) dams receiving melatonin supplementation until weaning on day 21. Upon weaning, melatonin supplementation was continued to these pups until the age of 16 weeks. Systolic blood pressures (SBP) were recorded at the age of 4, 6, 8, 12 and 16 weeks. Renal antioxidant activities were measured. Mean SBP of shr-WKY, Mel-shr-SHR and Mel-shr-WKY was significantly lower than that in shr-SHR until the age of 8 weeks. At 12 and 16 weeks of age, mean SBP of Mel-shr-WKY was lower than those in non-treated shr-SHR and shr-WKY pups but was not significantly different from that in Mel-shr-SHR. Renal glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities were significantly higher in Mel-shr-SHR and Mel-shr-WKY at 16 weeks of age. It appears that combination of cross-fostering and melatonin supplementation exerts no synergistic effect on delaying the rise in blood pressure in SHR. The elevated GPx and GST activities are likely to be due to the effect of melatonin supplementation. 相似文献
750.