Bidisha Banerjee

Publications (8)23.58 Total impact

• Article: Effect of creatine monohydrate in improving cellular energetics and muscle strength in ambulatory Duchenne muscular dystrophy patients: a randomized, placebo-controlled 31P MRS study.

  Bidisha Banerjee, Uma Sharma, Krithika Balasubramanian, M Kalaivani, Veena Kalra, Naranamangalam R Jagannathan
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  ABSTRACT: Randomized, placebo-controlled single blinded study was carried out to evaluate the effect of oral creatine supplementation on cellular energetics, manual muscle test (MMT) score and functional status in steroid-naive, ambulatory boys suffering with Duchenne muscular dystrophy (DMD; n=33). Eighteen patients received creatine monohydrate (Cr; 5 g/day for 8 weeks), while 15 received placebo (500 mg of vitamin C). Phosphorus metabolite ratios were determined from the right calf muscle of patients using phosphorus magnetic resonance spectroscopy ((31)P MRS) both prior to (baseline) and after supplementation of Cr or placebo. In addition, metabolite ratios were determined in normal calf muscle of age and sex matched controls (n=8). Significant differences in several metabolite ratios were observed between controls and DMD patients indicating a lower energy state in these patients. Analysis using analysis of covariance adjusted for age and stature showed that the mean phosphocreatine (PCr)/inorganic phosphate (Pi) ratio in patients treated with Cr (4.7; 95% CI; 3.9-5.6) was significantly higher (P=.03) compared to the placebo group (3.3; 95% CI; 2.5-4.2). The mean percentage increase in PCr/Pi ratio was also more in patients <7 years of age compared to older patients after Cr supplementation indicating variation in therapeutic effect with the age. In the placebo group, significant reduction in PCr/Pi (P=.0009), PCr/t-ATP (P=.05) and an increase in phosphodiester (PDE)/PCr ratios was observed after supplementation. Further, in the placebo group, patients <7 years showed reduction of PCr/t-ATP and Pi/t-ATP compared to older patients (>7 years), after supplementation. These results imply that the significant difference observed in PCr/Pi ratio between the Cr and the placebo groups after supplementation may be attributed to a decrease of PCr in the placebo group and an increase in PCr in the Cr group. Changes in MMT score between the two groups was significant (P=.04); however, no change in functional scale (P=.19) was observed. Parents reported subjective improvement on Cr supplementation versus worsening in placebo (P=.02). Our results indicated that Cr was well tolerated and oral Cr significantly improved the muscle PCr/Pi ratio and preserved the muscle strength in short term. However, this study provides no evidence that creatine will prove beneficial after long-term treatment, or have any positive effect on patient lifespan.
  Magnetic Resonance Imaging 06/2010; 28(5):698-707. · 1.99 Impact Factor
• Article: Midbrain and spinal cord magnetic resonance imaging (MRI) changes in poliomyelitis.

  Anita Choudhary, Suvasini Sharma, Naveen Sankhyan, Sheffali Gulati, Veena Kalra, Bidisha Banerjee, Atin Kumar
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  ABSTRACT: Poliomyelitis, though eradicated from most parts of the world, continues to occur in India. There is paucity of data on the magnetic resonance imaging (MRI) changes in poliomyelitis. We report a 3(1/2)-year-old boy who presented with subacute onset flaccid paralysis and altered sensorium. Stool culture was positive for wild polio virus type 3. Magnetic resonance imaging revealed signal changes in bilateral substantia nigra and anterior horns of the spinal cord. These MRI changes may be of potential diagnostic significance in a child with poliomyelitis.
  Journal of child neurology 02/2010; 25(4):497-9. · 1.59 Impact Factor
• Source

  Available from: ias.ac.in

  Article: Probing the dynamic organization of transcription compartments and gene loci within the nucleus of living cells.

  Deepak Kumar Sinha, Bidisha Banerjee, Shovamayee Maharana, G V Shivashankar
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  ABSTRACT: The three-dimensional organization of nuclear compartments within living cells determines genome function and yet their underlying self-organizing principles are unclear. We visualize in real-time transcriptionally active compartments (TCs) by the transient enrichment of fluorescently-labeled uridine 5'-triphosphate molecules within living cells. These TCs partially colocalize with active RNA-Pol II in the cell nucleus. Fluorescence anisotropy maps of chromatin compaction evidences a more open chromatin structure at the TCs. Using live-cell timelapse imaging, heterogeneity in the dynamic behavior of TCs has been revealed which falls into three distinct classes: subdiffusive, super-diffusive, and normal diffusive behavior. In contrast, the mobility of a candidate gene locus, either in the repressed or activated state, undergoes a differential restricted motion that is coupled to TC movement. Further TC dynamics is directly affected by small molecule chromatin structure modulators and adenosine triphosphate depletion. This heterogeneous behavior in TC dynamics within living cells could provide an interesting paradigm to explore the spatiotemporal dimension to gene transcription control.
  Biophysical Journal 10/2008; 95(11):5432-8. · 3.65 Impact Factor
• Article: Trichostatin-A induces differential changes in histone protein dynamics and expression in HeLa cells.

  Jyothsna Rao, Dipanjan Bhattacharya, Bidisha Banerjee, Apurva Sarin, G V Shivashankar
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  ABSTRACT: Trichostatin-A (TSA), a histone deacetylase (HDAC) inhibitor, results in enhanced acetylation of core histones thereby disrupting chromatin organization within living cells. We report on changes in chromatin organization and the resultant alteration in nuclear architecture following treatment with TSA using fluorescence imaging. TSA triggers an expected increase in the euchromatin fraction which is accompanied by a significant increase in nuclear volume and alterations in chromatin compaction mapped using fluorescence anisotropy imaging. We observe differential changes in the mobility of core and linker histones as measured by fluorescence recovery after photo-bleaching (FRAP) and fluorescence correlation spectroscopy (FCS) methods. Further TSA induces a differential increase in linker histone transcription and increased phosphorylation of linker histone proteins accompanying an expected increase in core histone acetylation patterns. Thus subtle feedback responses triggered by changes in chromatin configurations impinge selectively on linker histone mobility and its expression. These observations have implications for understanding the role of HDAC in the dynamic maintenance of chromatin organization.
  Biochemical and Biophysical Research Communications 12/2007; 363(2):263-8. · 2.48 Impact Factor
• Source

  Available from: Dipanjan Bhattacharya

  Article: Chromatin structure exhibits spatio-temporal heterogeneity within the cell nucleus.

  Bidisha Banerjee, Dipanjan Bhattacharya, G V Shivashankar
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  ABSTRACT: Local chromatin compaction undergoes dynamic perturbations to regulate genetic processes. To address this, the direct measurement of the fluidity of chromatin structure is carried out in single live cells using steady-state anisotropy imaging and polarization modulation microscopy. Fluorescently tagged core and linker histones are used to probe different structural aspects of chromatin compaction. A graded spatial heterogeneity in compaction is observed for the chromatin besides the distinct positional ordering of core and linker histones. These spatio-temporal features are maintained by active processes and perturbed during death. With cell cycle, the distribution in compaction heterogeneity continually changes maximizing during M-G1 transition where it displays bimodal behavior. Such measurements of spatio-temporal chromatin fluidity could have broader implications in understanding chromatin remodeling within living cells.
  Biophysical Journal 10/2006; 91(6):2297-303. · 3.65 Impact Factor
• Article: Superspecialty selection in postgraduate education.

  Bidisha Banerjee
  The Indian Journal of Pediatrics 11/2005; 72(10):900. · 0.52 Impact Factor
• Article: Stochastic simulations of the origins and implications of long-tailed distributions in gene expression.

  Sandeep Krishna, Bidisha Banerjee, T V Ramakrishnan, G V Shivashankar
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  ABSTRACT: Gene expression noise results in protein number distributions ranging from long-tailed to Gaussian. We show how long-tailed distributions arise from a stochastic model of the constituent chemical reactions and suggest that, in conjunction with cooperative switches, they lead to more sensitive selection of a subpopulation of cells with high protein number than is possible with Gaussian distributions. Single-cell-tracking experiments are presented to validate some of the assumptions of the stochastic simulations. We also examine the effect of DNA looping on the shape of protein distributions. We further show that when switches are incorporated in the regulation of a gene via a feedback loop, the distributions can become bimodal. This might explain the bimodal distribution of certain morphogens during early embryogenesis.
  Proceedings of the National Academy of Sciences 04/2005; 102(13):4771-6. · 9.68 Impact Factor
• Article: Trichostatin-A induces differential changes in histone protein dynamics and expression in HeLa cells

  Jyothsna Rao, Dipanjan Bhattacharya, Bidisha Banerjee, Apurva Sarin, G.V. Shivashankar
  [show abstract] [hide abstract]
  ABSTRACT: Trichostatin-A (TSA), a histone deacetylase (HDAC) inhibitor, results in enhanced acetylation of core histones thereby disrupting chromatin organization within living cells. We report on changes in chromatin organization and the resultant alteration in nuclear architecture following treatment with TSA using fluorescence imaging. TSA triggers an expected increase in the euchromatin fraction which is accompanied by a significant increase in nuclear volume and alterations in chromatin compaction mapped using fluorescence anisotropy imaging. We observe differential changes in the mobility of core and linker histones as measured by fluorescence recovery after photo-bleaching (FRAP) and fluorescence correlation spectroscopy (FCS) methods. Further TSA induces a differential increase in linker histone transcription and increased phosphorylation of linker histone proteins accompanying an expected increase in core histone acetylation patterns. Thus subtle feedback responses triggered by changes in chromatin configurations impinge selectively on linker histone mobility and its expression. These observations have implications for understanding the role of HDAC in the dynamic maintenance of chromatin organization.
  Biochemical and Biophysical Research Communications.