Publications by authors named "Biswajoy Ghosh"

10 Publications

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Comprehensive Evaluation of PAXgene Fixation on Oral Cancer Tissues Using Routine Histology, Immunohistochemistry, and FTIR Microspectroscopy.

Biomolecules 2021 Jun 15;11(6). Epub 2021 Jun 15.

School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.

The choice of tissue fixation is critical for preserving the morphology and biochemical information of tissues. Fragile oral tissues with lower tensile strength are challenging to process for histological applications as they are prone to processing damage, such as tissue tear, wrinkling, and tissue fall-off from slides. This leads to loss of morphological information and unnecessary delay in experimentation. In this study, we have characterized the new PAXgene tissue fixation system on oral buccal mucosal tissue of cancerous and normal pathology for routine histological and immunohistochemical applications. We aimed to minimize the processing damage of tissues and improve the quality of histological experiments. We also examined the preservation of biomolecules by PAXgene fixation using FTIR microspectroscopy. Our results demonstrate that the PAXgene-fixed tissues showed significantly less tissue fall-off from slides. Hematoxylin and Eosin staining showed comparable morphology between formalin-fixed and PAXgene-fixed tissues. Good quality and slightly superior immunostaining for cancer-associated proteins p53 and CK5/6 were observed in PAXgene-fixed tissues without antigen retrieval than formalin-fixed tissues. Further, FTIR measurements revealed superior preservation of glycogen, fatty acids, and amide III protein secondary structures in PAXgene-fixed tissues. Overall, we present the first comprehensive evaluation of the PAXgene tissue fixation system in oral tissues. This study concludes that the PAXgene tissue fixation system can be applied to oral tissues to perform diagnostic molecular pathology experiments without compromising the quality of the morphology or biochemistry of biomolecules.
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http://dx.doi.org/10.3390/biom11060889DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8232633PMC
June 2021

Arecanut-induced fibrosis display dual phases of reorganising glycans and amides in skin extracellular matrix.

Int J Biol Macromol 2021 Jun 20;185:251-263. Epub 2021 Jun 20.

School of Medical Science and Technology, Indian Institute of Technology Kharagpur, West Bengal 721302, India.

The habit of chewing arecanut leads to fibrosis in the oral tissues, which can lead to cancer. Despite high mortality, fibrosis has limited clinical success owing to organ-specific variations, genetic predispositions, and slow progression. Fibrosis is a progressive condition that is unresponsive to medications in the severe phase. To understand underlying macromolecular changes we studied the extracellular matrix's (ECM) key molecular modifications in the early and late phase of arecanut-induced fibrosis in skin. To study the fibrosis, we topically applied arecanut extract on the mice skin. We observed that the matrix changes observe early and late phases based on ECM characteristics including the matrix proteins and the glycans. A spike in the levels of proteoglycans and β-sheet structures are noted in the early phase. A significant drop in the proteoglycans and strengthening of amide covalent interactions is observed in the late phase. Although, almost no physical changes are noticeable only in the early phase; the late phase observes thick collagen bundling and a 4-fold stiffening of the skin tissue. The study indicates that the temporal interplay of proteins and glycans determine the matrix's severity state while opening avenues to research directed towards the phase-specific clinical discovery.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.06.093DOI Listing
June 2021

Quantitative in situ imaging and grading of oral precancer with attenuation corrected-optical coherence tomography.

Oral Oncol 2021 Jun 16;117:105216. Epub 2021 Feb 16.

School of Medical Science and Technology, Indian Institute of Technology Kharagpur, India.

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http://dx.doi.org/10.1016/j.oraloncology.2021.105216DOI Listing
June 2021

Pathophysiological relationship between hypoxia associated oxidative stress, Epithelial-mesenchymal transition, stemness acquisition and alteration of Shh/ Gli-1 axis during oral sub-mucous fibrosis and oral squamous cell carcinoma.

Eur J Cell Biol 2021 Jan 23;100(1):151146. Epub 2020 Dec 23.

School of Medical Science and Technology, Indian Institute of Technology, Kharagpur, West Bengal 721302, India.

Oral sub-mucous fibrosis (OSF) is a pathophysiological state of oral cavity or oropharynx having a high chance of conversion to oral squamous cell carcinoma (OSCC). It involves fibrotic transformation of sub-epithelial matrix along with epithelial abnormalities. The present work aims to unveil the mechanistic domain regarding OSF to OSCC conversion exploring the scenario of hypoxia associated oxidative stress, epithelial-mesenchymal transition (EMT), metastasis and stemness acquisition. The study involves histopathological analysis of the diseased condition along with the exploration of oxidative stress status, assessment of mitochondrial condition, immunohistochemical analysis of HIF-1α, E-cadherin, vimentin, ERK, ALDH-1, CD133, Shh, Gli-1 and survivin expressions in the oral epithelial region together with the quantitative approach towards collagen deposition in the sub-epithelial matrix. Oxidative stress was found to be associated with type-II EMT in case of OSF attributing the development of sub-epithelial fibrosis and type-III EMT in case of OSCC favoring malignancy associated metastasis. Moreover, the acquisition of stemness during OSCC can also be correlated with EMT. Alteration of Shh and Gli-1 expression pattern revealed the mechanistic association of hypoxia with the phenotypic plasticity and disease manifestation in case of OSF as well as OSCC. Shh/ Gli-1 signaling can also be correlated with survivin mediated cytoprotective phenomenon under oxidative stress. Overall, the study established the correlative network of hypoxia associated oxidative stress, EMT and manifestation of oral pre-cancerous and cancerous condition in a holistic approach that may throw rays of hope in the therapeutic domain of the concerned diseases.
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http://dx.doi.org/10.1016/j.ejcb.2020.151146DOI Listing
January 2021

Attenuation corrected-optical coherence tomography for quantitative assessment of skin wound healing and scar morphology.

J Biophotonics 2021 04 29;14(4):e202000357. Epub 2020 Dec 29.

School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, India.

Imaging the structural modifications of underlying tissues is vital to monitor wound healing. Optical coherence tomography (OCT) images high-resolution sub-surface information, but suffers a loss of intensity with depth, limiting quantification. Hence correcting the attenuation loss is important. We performed swept source-OCT of full-thickness excision wounds for 300 days in mice skin. We used single-scatter attenuation models to determine and correct the attenuation loss in the images. The phantom studies established the correspondence of corrected-OCT intensity (reflectivity) with matrix density and hydration. We histologically validated the corrected-OCT and measured the wound healing rate. We noted two distinct phases of healing-rapid and steady-state. We also detected two compartments in normal scars using corrected OCT that otherwise were not visible in the OCT scans. The OCT reflectivity in the scar compartments corresponded to distinct cell populations, mechanical properties and composition. OCT reflectivity has potential applications in evaluating the therapeutic efficacy of healing and characterizing scars.
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http://dx.doi.org/10.1002/jbio.202000357DOI Listing
April 2021

Structural mechanics modeling reveals stress-adaptive features of cutaneous scars.

Biomech Model Mechanobiol 2021 Feb 12;20(1):371-377. Epub 2020 Sep 12.

School of Medical Science and Technology, IIT Kharagpur, Kharagpur, India.

The scar is a predominant outcome of adult mammalian wound healing despite being associated with partial function loss. Here in this paper, we have described the structure of a full-thickness normal scar as a "di-fork" with dual biomechanical compartments using in vivo and ex vivo experiments. We used structural mechanics simulations to model the deformation fields computationally and stress distribution in the scar in response to external forces. Despite its loss of tissue components, we have found that the scar has stress-adaptive features that cushion the underlying tissues from external mechanical impacts. Thus, this new finding can motivate research to understand the biomechanical advantages of a scar in maintaining the primary function of the skin, i.e., mechanical barrier despite permanent loss of some tissues and specialized functions.
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http://dx.doi.org/10.1007/s10237-020-01384-7DOI Listing
February 2021

Impact of intercellular connectivity on epithelial mesenchymal transition plasticity.

Biochim Biophys Acta Mol Cell Res 2020 10 23;1867(10):118784. Epub 2020 Jun 23.

School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.

Epithelial mesenchymal transition (EMT) in development, tissue repair and carcinogenesis involves cellular plasticity with varying degrees of epithelial and mesenchymal properties. Several recent studies have focused on EMT phenotypic dynamism; however, information on cellular interaction in the context of EMT is inadequate. In our previous study, we investigated EMT phenotypic plasticity and anticipated it as a population driven interactive process. Present study has characterized cellular connectivity as a representative of interactivity during EMT in epithelial normal and cancer cell. It has also explored dynamism of connectivity and phenotype employing Markov model. Further, plasticity was substantiated with cell surface microvilli and molecular marker. The study unveiled interplay between phenotype and connectivity too. Findings have revealed that intercellular connectivity fueled EMT plasticity and its dynamism was more prominent in cancer population. However, normal cells are more vibrant in transition and phenotypic plasticity. We have proposed connectivity plasticity as a hallmark of EMT and needs to be studied in depth. Present study also paves the way in translating in vitro EMT findings in histopathological practices.
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http://dx.doi.org/10.1016/j.bbamcr.2020.118784DOI Listing
October 2020

Antagonist Effects of l-Phenylalanine and the Enantiomeric Mixture Containing d-Phenylalanine on Phospholipid Vesicle Membrane.

Langmuir 2020 03 2;36(9):2459-2473. Epub 2020 Mar 2.

One of the congenital flaws of metabolism, phenylketonuria (PKU), is known to be related to the self-assembly of toxic fibrillar aggregates of phenylalanine (Phe) in blood at elevated concentrations. Our experimental findings using l-phenylalanine (l-Phe) at millimolar concentration suggest the formation of fibrillar morphologies in the dry phase, which in the solution phase interact strongly with the model membrane composed of 1,2-diacyl--glycero-phosphocholine (LAPC) lipid, thereby decreasing the rigidity (or increasing the fluidity) of the membrane. The hydrophobic interaction, in addition to the electrostatic attraction of Phe with the model membrane, is found to be responsible for such phenomena. On the contrary, various microscopic observations reveal that such fibrillar morphologies of l-Phe are severely ruptured in the presence of its enantiomer d-phenylalanine (d-Phe), thereby converting the fibrillar morphologies into crushed flakes. Various biophysical studies, including the solvation dynamics experiment, suggest that this l-Phe in the presence of d-Phe, when interacting with the same model membrane, now reverts the rigidity of the membrane, i.e., increases the rigidity of the membrane, which was lost due to interaction with l-Phe exclusively. Fluorescence anisotropy measurements also support this reverse rigid character of the membrane in the presence of an enantiomeric mixture of amino acids. A comprehensive understanding of the interaction of Phe with the model membrane is further pursued at the single-molecular fluorescence detection level using fluorescence correlation spectroscopy (FCS) experiments. Therefore, our experimental conclusion interprets a linear correlation between increased permeability and enhanced fluidity of the membrane in the presence of l-Phe and certifies d-Phe as a therapeutic modulator of l-Phe fibrillar morphologies. Further, the study proposes that the rigidity of the membrane lost due to interaction with l-Phe was reinstated-in fact, increased-in the presence of the enantiomeric mixture containing both d- and l-Phe.
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http://dx.doi.org/10.1021/acs.langmuir.9b03543DOI Listing
March 2020

Modeling continuum of epithelial mesenchymal transition plasticity.

Integr Biol (Camb) 2016 Feb 14;8(2):167-76. Epub 2016 Jan 14.

School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, India.

Living systems respond to ambient pathophysiological changes by altering their phenotype, a phenomenon called 'phenotypic plasticity'. This program contains information about adaptive biological dynamism. Epithelial-mesenchymal transition (EMT) is one such process found to be crucial in development, wound healing, and cancer wherein the epithelial cells with restricted migratory potential develop motile functions by acquiring mesenchymal characteristics. In the present study, phase contrast microscopy images of EMT induced HaCaT cells were acquired at 24 h intervals for 96 h. The expression study of relevant pivotal molecules viz. F-actin, vimentin, fibronectin and N-cadherin was carried out to confirm the EMT process. Cells were intuitively categorized into five distinct morphological phenotypes. A population of 500 cells for each temporal point was selected to quantify their frequency of occurrence. The plastic interplay of cell phenotypes from the observations was described as a Markovian process. A model was formulated empirically using simple linear algebra, to depict the possible mechanisms of cellular transformation among the five phenotypes. This work employed qualitative, semi-quantitative and quantitative tools towards illustration and establishment of the EMT continuum. Thus, it provides a newer perspective to understand the embedded plasticity across the EMT spectrum.
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http://dx.doi.org/10.1039/c5ib00219bDOI Listing
February 2016

Computational pharmacokinetics and in vitro-in vivo correlation of anti-diabetic synergistic phyto-composite blend.

World J Diabetes 2015 Sep;6(11):1179-85

Baishakhi De, Koushik Bhandari, Nishant Chakravorty, Ranjan Mukherjee, Biswajoy Ghosh, Analava Mitra, School of Medical Science and Technology, IIT Kharagpur 721302, India.

Despite tremendous strides in modern medicine stringent control over insulin resistance or restoration of normoglycemia has not yet been achieved. With the growth of molecular biology, omics technologies, docking studies, and in silico pharmacology, modulators of enzymes and receptors affecting the molecular pathogenesis of the disease are being considered as the latest targets for anti-diabetic therapy. Therapeutic molecular targets are now being developed basing on the up or down regulation of different signaling pathways affecting the disease. Phytosynergistic anti-diabetic therapy is in vogue both with classical and non-classical medicinal systems. However its chemo-profiling, structural and pharmacokinetic validation awaits providing recognition to such formulations for international acceptance. Translational health research with its focus on benchside product development and its sequential transition to patient bedside puts the pharma RDs to a challenge to develop bio-waiver protocols. Pharmacokinetic simulation models and establishment of in vitro-in vivo correlation can help to replace in vivo bioavailability studies and provide means of quality control for scale up and post approval modification. This review attempts to bring different shades highlighting phyto-synergy, molecular targeting of antidiabetic agents via different signaling pathways and bio-waiver studies under a single umbrella.
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http://dx.doi.org/10.4239/wjd.v6.i11.1179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4564813PMC
September 2015
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