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71.
D. Jagadeesh M.K. Prasanna Kumar R. Chandrakanth N.S. Devaki 《Journal of Genetic Engineering and Biotechnology》2018,16(2):631-638
Blast disease of rice plant is caused by Magnaporthe oryzae (anamorph Pyricularia oryzae). This disease is recognized to be one of the most serious diseases of rice crop around the world. A total of 72 monoconidial isolates of M. oryzae obtained from blast disease samples collected around Southern Karnataka were characterized using internal transcribed spacers of the ribosomal DNA sequences. These were analyzed by comparing with already deposited sequences in GenBank database. It helped in diagnosing the invasive pathogen in all locations. Variability of rDNA sequences was found to be highly polymorphic with 0.068962 nucleotide diversity showing 6 distinct clades. 33 haplotype groups were identified with haplotype diversity of 0.8881 and Tajima's neutrality test with a D value of ?1.96827 with P?<?0.05 showing the presence of variations among the sequences of pathogen isolates. The Tajima’s D value of less than one indicates the presence of a high number of rare alleles. Our study indicates that the pathogen might have undergone recent selection pressure because of the exposure to a large number of cultivars resulting in the evolution of rare alleles. This shows the importance of characterizing internal transcribed spacer (ITS) to know pathogen diversity and its fitness which has potential to contribute to the field of breeding for blast disease resistance. 相似文献
72.
Martha S. Lundberg Devaki N. Sadhu Vicky E. Grumman William M. Chilian Kenneth S. Ramos 《In vitro cellular & developmental biology. Animal》1995,31(8):595-600
Summary The occurrence of vascular domains with specific biological and pharmacological characteristics suggests that smooth muscle
cells in different arteries may respond differentially to a wide range of environmental stimuli. To determine if some of these
vessel-specific differences may be attributable to mechano-sensitive gene regulation, the influence of cyclical stretch on
the expression of actin isoform and α1B-adrenoceptor genes was examined in aortic and coronary smooth muscle cells. Cells were seeded on an elastin substrate and
subjected to maximal stretching (24% elongation) and relaxation cycles at a frequency of 120 cycles/min in a Flexercell strain
unit for 72 h. Total RNA was extracted and hybridized to radiolabeled cDNA probes to assess gene expression. Stretch caused
a greater reduction of actin isoform mRNA levels in aortic smooth muscle cells as compared to cells from the coronary artery.
Steady-state mRNA levels of α1B -adrenoceptor were also decreased by cyclical stretch in both cell types but the magnitude of the response was greater in
coronary smooth muscle cells. No changes in α1B-adrenoceptor or β/γ-actin steady-state mRNA levels were observed in H4IIE cells, a nonvascular, immortalized cell line. The
relative gene expression of heat shock protein 70 was not influenced by the cyclic stretch regimen in any of these cell types.
These results suggest that stretch may participate in the regulation of gene expression in vascular smooth muscle cells and
that this response exhibits some degree of cell-specificity. 相似文献
73.
SANDOZ 9785, also known as BASF 13.338, is a pyridazinone derivative that inhibits Photosystem II (PS II) activity leading to an imbalance in the rate of electron transport through the photosystems. Synechococcus sp. strain PCC 7942 cells grown in the presence of sublethal concentration of SANDOZ 9785 (SAN 9785) for 48 hours exhibited a 20% decrease in Chl a per cell. However, no changes were observed in the content of phycocyanin per cell, the size of the phycobilisomes or in the PS II:PS I ratio. From an estimate of PS II electron transport rate under varying light intensities and spectral qualities and analysis of room temperature Chl a fluorescence induction, it was deduced that growth of Synechococcus PCC 7942 in the presence of SAN 9785 leads to a redistribution of excitation energy in favour of PS II. Though the redistribution appears to be primarily caused by changes affecting the Chl a antenna of PS II, the extent of energetic coupling between phycobilisomes and PS II is also enhanced in SAN 9785 grown Synechococcus PCC 7942 cells. There was a reduction in the effective size of PS I antenna based on measurement of P700 photooxidation kinetics. These results indicate that when PS II is partially inhibited, the structure of photosynthetic apparatus alters to redistribute the excitation energy in favour of PS II so that the efficiency of utilization of light energy by the two photosystems is optimized. Our results suggest that under the conditions used, drastic structural changes are not essential for redistribution of excitation energy between the photosystems.Abbreviations APC
Allophycocyanin
- Chl a
chlorophyll a
- DBMIB
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone
- DCMU
3-(3,4-dichlorophyenyl)-1,1-dimethyl urea
- DCIP
2,6-dichlorophenolindophenol
- Fo
fluorescence when all the reaction centres are open
- fm
fluorescence yield when all the reaction centres are closed
- Fv
variable chlorophyll fluorescence
- HEPES
N-2-Hydroxyethylpiperazine-N-2-ethanesulphonic Acid
- I50
concentration that causes 50% inhibition in activity
- MV
methyl viologen
- pBQ
para benzoquinone
- PBS
phycobilisome
- PC
phycocyanin
- PS I, PS II
Photosystem I, Photosystem II
- P700
reaction centre Chl a of PS I
- SAN 9785
SANDOZ 9785 i.e. 4-chloro-5-dimethylamino-2-phenyl-3 (2H) pyridazinone, also known as BASF 13.338 相似文献
74.
75.
The use of enzymes in non-aqueous solvents expands the use of biocatalysts to hydrophobic substrates, with the ability to tune selectivity of reactions through solvent selection. Non-aqueous enzymology also allows for fundamental studies on the role of water and other solvents in enzyme structure, dynamics, and function. Molecular dynamics simulations serve as a powerful tool in this area, providing detailed atomic information about the effect of solvents on enzyme properties. However, a common protocol for non-aqueous enzyme simulations does not exist. If you want to simulate enzymes in non-aqueous solutions, how many and which crystallographic waters do you keep? In the present work, this question is addressed by determining which crystallographic water molecules lead most quickly to an equilibrated protein structure. Five different methods of selecting and keeping crystallographic waters are used in order to discover which crystallographic waters lead the protein structure to reach an equilibrated structure more rapidly in organic solutions. It is found that buried waters contribute most to rapid equilibration in organic solvent, with slow-diffusing waters giving similar results. 相似文献
76.
N. S. Devaki S. Shankara Bhat S. G. Bhat K. R. Manjunatha 《Journal of Phytopathology》1992,136(1):82-87
Trichoderma harzianum rendered Pythium aphanidermatum and P. myriotylum non-viable in Petri dish dual culture. The Pythium mycelia from such cultures showed natural autofluorescence in the regions of interactions, indicating their death. Non-volatile and volatile fungicidal activities were detected in T. harzianum culture. Lytic activity of β-(l,3)-glucanase was detected on the cell walls of the Pythium spp. There was a significant decrease in the disease incidence when T. harzianum was incorporated into sterile soil, whereas the effect was insignificant in natural soil. 相似文献
77.
Beena Elizabeth Thomas Banurekha Velayutham Kannan Thiruvengadam Dina Nair Sukendu Bikas Barman Lavanya Jayabal Senthanro Ovung Soumya Swaminathan 《PloS one》2016,11(1)
Background
The Government of India declared TB as a notifiable disease in 2012. There is a paucity of information on the government''s mandatory TB notification order from the perspective of private medical practitioners (PPs).Objective
To understand the awareness, perception and barriers on TB notification among PPs in Chennai, India.Methods
Total of 190 PPs were approached in their clinics by trained field staff who collected data using a semi-structured and pre-coded questionnaire after getting informed consent. The data collected included PPs'' specialization, TB management practices, awareness about the TB notification order, barriers in its implementation and their suggestions to improve notification.Results
Of 190 PPs from varied specializations, 138 (73%) had diagnosed TB cases in the prior three months, of whom 78% referred these patients to government facilities. Of 138 PPs, 73% were aware of the order on mandatory TB notification, of whom 46 (33%) had ever notified a TB case. Of 120 PPs, 63% reported reasons for not notifying TB cases. The main reasons reported for not notifying were lack of time (50%), concerns regarding patients'' confidentiality (24%) and fear of offending patients (11%). Of 145 PPs, 76% provided feedback about information they felt uncomfortable reporting during notification. PPs felt most uncomfortable reporting patient''s government-issued Aadhar number (77%), followed by patient''s phone number (37%) and residential address (26%). The preferred means of notification was through mobile phone communication (24%), SMS (18%) and e-mail (17%).Conclusion
This study highlights that one-fourth of PPs were not aware of the TB notification order and not all those who were aware were notifying. While it is important to sensitize PPs on the importance of TB notification it is also important to understand the barriers faced by PPs and to make the process user-friendly in order to increase TB notification. 相似文献78.
Baskar Venkidasamy Muthu Thiruvengadam Prabhu Thirupathi Umadevi Subramanian 《Journal of biochemical and molecular toxicology》2020,34(8)
Mastitis is a major inflammatory response of the mammary gland due to various pathogenic invasions and is a serious disease that affects the production yield and health status of cows. Astaxanthin (AST), a xanthophyll carotenoid, is a secondary metabolite synthesized by microalgae and yeasts that has been reported to suppress various inflammatory responses. However, the protective effect of AST on lipopolysaccharide (LPS)‐induced mammary epithelial cells has not yet been reported. The present study results indicated that AST treatment markedly attenuated the oxidative stress markers and nitric oxide (NO) while improving the anti‐oxidant enzymes in LPS exposed cells. On the other hand, LPS‐exposed cells showed nuclear translocation of nuclear factor‐κB (NF‐κB) with the activation of inflammatory cytokines such as monocyte chemoattractant protein‐1, tumor necrosis factor‐α, interferon‐γ, and interleukin‐6 (IL‐6). In addition, mRNA expression analysis revealed that the histone deacetylase (HDAC) ‐1, ‐2, ‐3, ‐6, ‐7 and pentraxin 3 (PTX3) expressions were increased in the LPS group. Furthermore, the activity of HDAC was increased to 2‐fold with a significant reduction in the histone acetyltransferase activity in cells exposed to LPS. However, AST was able to inhibit the nuclear translocation of NF‐κB with attenuated HDAC activity. Intriguingly, HDAC inhibition studies demonstrated that the cytokines such as IL‐4, IL‐8, granulocyte‐mcrophage colony stimulating factor, C‐reactive protein, IL‐17A, and IL‐22 were significantly suppressed which were upregulated in LPS treatment; while AST was found acting by improving the anti‐inflammatory cytokine IL‐10, and thioredoxin reductase levels. Collectively, these findings provide novel insights into the role of HDACs in regulating cellular processes involved in the pathogenesis of LPS‐induced mastitis as well as the potential use of AST as a therapeutic in treatment for controlling disease progression. 相似文献
79.
I-Chieh Chen Venkatesan Thiruvengadam Wei-De Lin Ho-Hsiung Chang Wen-Hwei Hsu 《Plant molecular biology》2010,72(1-2):153-169
A non-antibiotic based selection system using l-lysine as selection agent and the lysine racemase (lyr) as selectable marker gene for plant transformation was established in this study. l-lysine was toxic to plants, and converted by Lyr into d-lysine which would subsequently be used by the transgenic plants as nitrogen source. Transgenic tobacco and Arabidopsis plants were successfully recovered on l-lysine medium at efficiencies of 23 and 2.4%, respectively. Phenotypic characterization of transgenic plants clearly revealed the expression of normal growth and developmental characteristics as that of wild-type plants, suggesting no pleiotropic effects associated with the lyr gene. The specific activity of Lyr in transgenic tobacco plants selected on l-lysine ranged from 0.77 to 1.06 mU/mg protein, whereas no activity was virtually detectable in the wild-type plants. In addition, the composition of the free amino acids, except aspartic acid, was not affected by the expression of the lyr gene in the transgenic tobacco plants suggesting very limited interference with endogenous amino acid metabolism. Interestingly, our findings also suggested that the plant aspartate kinases may possess an ability to distinguish the enantiomers of lysine for feedback regulation. To our knowledge, this is the first report to demonstrate that the lysine racemase selectable marker system is novel, less controversial and inexpensive than the traditional selection systems. 相似文献
80.
Devaki A. Kelkar Arunima Chaudhuri Sourav Haldar Amitabha Chattopadhyay 《European biophysics journal : EBJ》2010,39(10):1453-1463
The relevance of partially ordered states of proteins (such as the molten globule state) in cellular processes is beginning
to be understood. Bovine α-lactalbumin (BLA) assumes the molten globule state at acidic pH. We monitored the organization
and dynamics of the functionally important tryptophan residues of BLA in native and molten globule states utilizing the wavelength-selective
fluorescence approach and fluorescence quenching. Quenching of BLA tryptophan fluorescence using quenchers of varying polarity
(acrylamide and trichloroethanol) reveals varying degrees of accessibility of tryptophan residues, characteristic of native
and molten globule states. We observed red edge excitation shift (REES) of 6 nm for the tryptophans in native BLA. Interestingly,
we show here that BLA tryptophans exhibit REES (3 nm) in the molten globule state. These results constitute one of the early
reports of REES in the molten globule state of proteins. Taken together, our results indicate that tryptophan residues in
BLA in native as well as molten globule states experience motionally restricted environment and that the regions surrounding
at least some of the BLA tryptophans offer considerable restriction to the reorientational motion of the water dipoles around
the excited-state tryptophans. These results are supported by wavelength-dependent changes in fluorescence anisotropy and
lifetime for BLA tryptophans. These results could provide vital insight into the role of tryptophans in the function of BLA
in its molten globule state in particular, and other partially ordered proteins in general. 相似文献