Publications by authors named "Paul Debashish"

Cancer cells produce extracellular vesicles (EVs) coated with an anionic sugar polymer, hyaluronan (HA), in the extracellular matrix. Hyaluronan is an established cancer biomarker in several cancer types. In this work, we thoroughly investigated the electrical properties of HA-coated EVs using advanced scanning probe microscopy (SPM) based nanoelectrical modes, which include EFM (electrostatic force microscopy), KPFM (Kelvin probe force microscopy), PFM (piezoresponse force microscopy) and C-AFM (conductive atomic force microscopy).

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Herb-based extracellular vesicles (EV), inherently replete with bioactive proteins, RNA, lipids, and other medicinal compounds, are noncytotoxic and uniquely capable of cellular delivery to meet the ever-stringent challenges of ongoing clinical applications. EVs are abundant in nature, affordable, and scalable, but they are also incredibly fragile and stuffed with many biomolecules. To address the low drug binding abilities and poor stability of EVs, we demonstrated herb-based EVs (isolated from neem, mint, and curry leaves) conjugated with chitosan (CS) and PEGylated graphene oxide (GP) that led to their transformation into robust and efficient vectors.

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Aberrantly glycosylated mucin 1 is a critical prognostic biomarker in breast epithelial cancers. Hypoglycosylated mucin 1 coats the surface of the cancer cells, where -glycans are predominantly linked via an -acetylgalactosamine moiety (GalNAc). Cancer cell-derived extracellular vesicles (EVs) carry biomarkers from parent cancer cells to the recipient cells and, therefore, could potentially be leveraged for diagnostics and noninvasive disease monitoring.

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Background: Infection Prevention and Control (IPC) is critical in controlling the COVID-19 pandemic and is one of the pillars of the WHO COVID-19 Strategic Preparedness and Response Plan 2020. We conducted an Intra-Action Review (IAR) of IPC response efforts to the COVID-19 pandemic in Cox's Bazar, Bangladesh, to identify best practices, challenges, and recommendations for improvement of the current and future responses.

Methods: We conducted two meetings with 54 participants purposively selected from different organizations and agencies involved in the frontline implementation of IPC in Cox's Bazar district, Bangladesh.

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Epigenetic dysregulation including DNA methylation and histone modifications is being increasingly recognized as a promising biomarker for the diagnosis and prognosis of cancer. Herein, we devised a label-free analytical toolbox comprising IR, UV-vis, CD spectroscopy, and cyclic voltammetry, which is capable to differentiate significantly hyper-methylated breast cancer chromosomes from the normal breast epithelial counterparts.

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Objectives: The study aimed to determine the seroprevalence, the fraction of asymptomatic infections, and risk factors of SARS-CoV-2 infections among the Forcibly Displaced Myanmar Nationals (FDMNs).

Design: It was a population-based two-stage cross-sectional study at the level of households.

Setting: The study was conducted in December 2020 among household members of the FDMN population living in the 34 camps of Ukhia and Teknaf Upazila of Cox's Bazar district in Bangladesh.

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Cancer cells secrete extracellular vesicles (EVs) covered with a carbohydrate polymer, hyaluronan (HA), linked to tumor malignancy. Herein, we have unravelled the contour lengths of HA on a single cancer cell-derived EV surface using single-molecule force spectroscopy (SMFS), which divulges the presence of low molecular weight HA (LMW-HA < 200 kDa). We also discovered that these LMW-HA-EVs are significantly more elastic than the normal cell-derived EVs.

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Subdural hematoma (SDH) is a common intracranial lesion seen in severe traumatic brain injury (TBI). The development of contralateral delayed extradural hematoma (EDH) after surgery is well described. But limited literature available about immediate contralateral EDH after subdural hematoma (SDH) evacuation.

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Background: The global COVID-19 pandemic has led to major changes in the surgical caseloads in the operation theatres across the world. Elective surgeries have been curtailed to a great extent and the number of emergency surgeries has risen. We conducted a study to assess the changes in the surgical caseloads in two tertiary care hospitals in India during the pandemic and to assess the changes in anaesthesia techniques used.

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Background Computed tomography (CT) scans and CT severity scores (CTSS) are widely used to assess the severity and prognosis in coronavirus disease 2019 (COVID-19). CTSS has performed well as a predictor in differentiating severe from non-severe cases. However, it is not known if CTSS performs similarly in hospitalized severe cases with hypoxia at admission.

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Background: The COVID-19 pandemic has put the entire medical fraternity into a very challenging and demanding situation. Along with always being at the risk of COVID infection, healthcare workers (HCWs) are also facing neurological problems due to long working hours in personal protective equipment (PPE). These symptoms and their characteristics need to be observed and studied in-depth to understand the problems experienced by HCWs and to design new solutions to overcome such problems.

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Colorectal cancer typically begins from a nonmalignant polyp formation in the large intestine that, over time, develops into colorectal cancer. The growth of benign polyps can be checked if detected in the early stages of the disease. Doctors usually recommend colonoscopy to average and high-risk individuals for colorectal cancer screening.

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The significant role of a vesicle is well recognized; however, only lately has the advancement in biomedical applications started to uncover their usefulness. Although the concept of vesicles originates from cell biology, it later transferred to chemistry and material science to develop nanoscale artificial vesicles for biomedical applications. Herein, we examine different synthetic and biological vesicles and their applications in the biomedical field in general.

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To realize a customizable biogenic delivery platform, herein we propose combining cell-derived extracellular vesicles (EVs) derived from breast cancer cell line MCF-7 with synthetic cationic liposomes using a fusogenic agent, polyethylene glycol (PEG). We performed a fluorescence resonance energy transfer (FRET)-based lipid-mixing assay with varying PEG 1000 concentrations (0%, 15%, and 30%) correlated with flow cytometry-based analysis and supported by dimensional analysis by dynamic light scattering (DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM) to validate our fusion strategy. Our data revealed that these hybrid vesicles at a particular concentration of PEG (∼15%) improved the cellular delivery efficiency of a model siRNA molecule to the EV parental breast cancer cells, MCF-7, by factors of 2 and 4 compared to the loaded liposome and EV precursors, respectively.

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The role of microscopic elasticity of nano-carriers in cellular uptake is an important aspect in biomedical research. Herein we have used AFM nano-indentation force spectroscopy and Förster resonance energy transfer (FRET) measurements to probe microelastic properties of three novel cationic liposomes based on di-alkyl dihydroxy ethyl ammonium chloride based lipids having asymmetry in their hydrophobic chains (Lip1818, Lip1814 and Lip1810). AFM data reveals that symmetry in hydrophobic chains of a cationic lipid (Lip1818) imparts higher rigidity to the resulting liposomes than those based on asymmetric lipids (Lip1814 and Lip1810).

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Extracellular vesicles (EVs), naturally occurring nanosized vesicles secreted from cells, are essential for intercellular communication. They carry unique biomolecules on the surface or interior that are of great interest as biomarkers for various pathological conditions such as cancer. In this work, we use high-resolution atomic force microscopy (AFM) and spectroscopy (AFS) techniques to demonstrate differences between EVs derived from colon cancer cells and colon epithelial cells at the single-vesicle level.

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Objective: Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance that is diagnosed for the first time during pregnancy. This prospective study was undertaken to validate the single-step non-fasting 75 gm Diabetes in Pregnancy Study Group of India (DIPSI) criteria of GDM in Indian patients in comparison with the two-step fasting 100 gm glucose challenge through the Carpenter Coustan criteria (CCC).

Materials And Methods: Two hundred patients underwent comparative testing using the DIPSI criteria and CCC.

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Objective: Static monitors for assessing the fluid status during major surgeries and in critically ill patients have been gradually replaced by more accurate dynamic monitors in modern-day anaesthesia practice. Pulse pressure variation (PPV) and systolic pressure variation (SPV) are the two commonly used dynamic indices for assessing fluid responsiveness.

Methods: In this prospective observational study, 50 patients undergoing major surgeries were monitored for PPV and SPV: after the induction of anaesthesia and after the administration of 500 mL of isotonic crystalloid bolus.

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Objective: The study was undertaken to compare the efficiency and outcome of Laparoscopic Assisted Vaginal Hysterectomy (LAVH) and Vaginal Hysterectomy (VH) in terms of operative time, cost, estimated blood loss, hospital stay, quantity of analgesia use, intra- and postoperative complication rates and patients recovery.

Materials And Methods: A total of 500 diabetic patients were prospectively collected in the study period from January 2005 through January 2009. The performance of LAVH was compared with that of VH, in a tertiary care hospital.

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