Publications by authors named "Deepika Gupta"

41 Publications

Impact of SARS-CoV-2 Infection in Spinocerebellar Ataxia 12 patients.

Mov Disord 2021 Sep 16. Epub 2021 Sep 16.

Department of Neurology, All India Institute of Medical Sciences, New Delhi, 110,029, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mds.28811DOI Listing
September 2021

Phase transformation and enhanced blue photoluminescence of zirconium oxide poly-crystalline thin film induced by Ni ion beam irradiation.

Sci Rep 2021 Sep 3;11(1):17672. Epub 2021 Sep 3.

University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, New Delhi, 110078, India.

Swift heavy ions (SHI) irradiation of Nickel (Ni) beam with different ions fluence bring the modifications in the functional properties of radio frequency (RF) grown zirconium oxide (ZrO) nanocrystalline thin films. X-ray diffraction analysis affirms the monoclinic to tetragonal phase transformation and diminishing of peak at higher fluence 1 × 10 and 2 × 10 ions/cm induced by electronic excitation caused by SHI. Zirconium oxide thin films exhibit the same thickness (195 nm) of virgin and irradiated samples and whereas the nanocrystalline thin films have the elemental composition in proper stoichiometry (1:2) as analyzed by rutherford backscattering spectroscopy (RBS). Photoluminescence measurements confirm the blue emission of virgin and irradiated sample recorded at excitation wavelength 270 to 310 nm. The intensity of obtained emission bands varies with fluence which is interpreted in terms of generation and annihilation of defect centers. The characteristic A and B Raman modes of monoclinic and tetragonal ZrO are obtained at different positions. Moreover, the nanocrystalline ZrO thin films exhibits the most prominent absorption phenomenon in the visible range and the irradiation cause significant decrease in band gap to 3.69 eV compare to the virgin ZrO sample (3.86 eV). XPS analysis indicates the shifting of the core levels Zr 3d and O 1s towards higher binding energy and spin-orbit splitting of different states. The findings in this research justify that the irradiated thin films can be a potential candidate for designing of new materials, intense radiation environments, nuclear reactors, nuclear waste systems, clean energy sources.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-96961-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8417228PMC
September 2021

Photothermally switchable peptide nanostructures towards modulating catalytic hydrolase activity.

Nanoscale 2021 Aug 29;13(31):13401-13409. Epub 2021 Jul 29.

Chemical Biology Unit, Institute of Nano Science and Technology, Knowledge City, Sector 81, Mohali, Punjab 140306, India.

Enzymes are the most efficient catalysts in nature that possess an impressive range of catalytic activities, albeit limited by stability in adverse conditions. Functional peptides have emerged as alternative robust biocatalysts to mimic complex enzymes. Here, a rational design of minimalistic amyloid-inspired peptides 1-2 is demonstrated, which leads to pathway-driven self-assembly triggered by heat, light and chemical cues to render 1D and 2D nanostructures by the interplay of hydrogen bonding, host-guest interaction and reversible photodimerization. Such in situ transformable peptide nanostructures by means of external cues are envisaged as a catalytic amyloid for the first time to mimic the hydrolase enzyme activity. Michaelis Menten's enzyme kinetic parameters for the hydrolysis rate correlate the external cue-mediated structure-function augmentation with the twisted bundles, 1 being the most efficient biocatalyst among all the dimensionally diverse nanostructures. Unlike the natural enzyme, the peptide nanostructures exhibited the robust nature of the hydrolase activity over a broad range of temperature and pH. Finally, the peptide nanostructures are explored as efficient heterogeneous flow catalysts to improve the turnover number for the hydrolase activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d1nr03655fDOI Listing
August 2021

Graphene nanofiber composites for enhanced neuronal differentiation of human mesenchymal stem cells.

Nanomedicine (Lond) 2021 Sep 25;16(22):1963-1982. Epub 2021 Aug 25.

Stem Cell Facility, DBT-Centre of Excellence for Stem Cell Research, All India Institute of Medical Sciences, New Delhi, 110029, India.

To differentiate mesenchymal stem cells into functional dopaminergic neurons using an electrospun polycaprolactone (PCL) and graphene (G) nanocomposite. A one-step approach was used to electrospin the PCL nanocomposite, with varying G concentrations, followed by evaluating their biocompatibility and neuronal differentiation. PCL with exiguous graphene demonstrated an ideal nanotopography with an unprecedented combination of guidance stimuli and substrate cues, aiding the enhanced differentiation of mesenchymal stem cells into dopaminergic neurons. These newly differentiated neurons were seen to exhibit unique neuronal arborization, enhanced intracellular Ca influx and dopamine secretion. Having cost-effective fabrication and room-temperature storage, the PCL-G nanocomposites could pave the way for enhanced neuronal differentiation, thereby opening a new horizon for an array of applications in neural regenerative medicine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2217/nnm-2021-0121DOI Listing
September 2021

Post fine-needle aspiration near total infarction of Warthin tumor with squamous metaplasia: A diagnostic pitfall.

Diagn Cytopathol 2021 Oct 24;49(10):1144-1147. Epub 2021 Aug 24.

Department of Surgical Oncology, All India Institute of Medical Sciences, Jodhpur, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/dc.24860DOI Listing
October 2021

Experimental evaluation of safety and efficacy of plasma-treated poly-ε-caprolactone membrane as a substitute for human amniotic membrane in treating corneal epithelial defects in rabbit eyes.

Indian J Ophthalmol 2021 Sep;69(9):2412-2416

Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.

Purpose: To evaluate biocompatibility and safety of plasma-treated poly-ε-caprolactone (pPCL) membrane compared to the human amniotic membrane in the healing of corneal epithelial defects in an experimental model.

Methods: This is a prospective, randomized animal study including 12 rabbits. Circular epithelial injury measuring 6 mm in diameter was induced over the central cornea of one eye in twelve rabbits. The rabbits were randomized into two groups; in group A, the defect was covered with human amniotic membrane, while in group B, an artificial membrane made of bio-polymer plasma-treated poly-ε-caprolactone was grafted. Six rabbits were euthanized after 1 month and the other six after 3 months and the corneal epithelium was evaluated histopathologically and with immunohistochemistry.

Results: Light microscopy of the corneal tissue performed after 1 month and 3 months demonstrated similar findings with no significant complications in either group. Immunohistochemistry with anti-CK-3 antibody showed characteristic corneal phenotype in the healed epithelium. In eyes grafted with pPCL membrane, epithelial healing as estimated by a decrease in size of the defect was significantly better than the group treated with the human amniotic membrane at all time periods monitored (P < 0.05), except day 1 (P = 0.83). The percentage reduction in the size of the epithelial defect was also significantly more in the pPCL membrane group as compared to the human amniotic membrane at all time periods (P < 0.05 at all observations) post-implantation except day 1 (P = 0.73).

Conclusion: Plasma-treated poly-ε-caprolactone membrane is safe, biocompatible, and effective in the healing of corneal epithelial defects in rabbits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/ijo.IJO_2986_20DOI Listing
September 2021

Cytomorphological spectrum of cysticercosis: A study of 26 cases.

Cytopathology 2021 Jul 31. Epub 2021 Jul 31.

Department of Pathology, Atal Bihari Vajpayi Institute of Medical Sciences & Dr. Ram Manohar Lohia Hospital, New Delhi, India.

Background: Cysticercosis is a systemic parasitic disease caused by the larval stage of Taenia solium. It is the most common parasitic disease worldwide. Fine needle aspiration cytology can play an important role in prompt recognition of this disease.

Objective: To study the role of FNAC in the diagnosis of cysticercosis.

Materials And Methods: This study included 26 patients with parasitic infestation who presented with palpable subcutaneous and intramuscular nodules at different sites. Their clinical presentations and fine needle aspiration cytomorphological features are reported.

Results: The age range of these patients was 7-60 years. The majority were males. The most commonly affected site was head and neck followed by upper extremity. Most of the cases were clinically misdiagnosed as lipomas, neurofibromas, lymphadenitis, epidermal inclusion cyst, sialadenitis, and soft tissue tumours. The aspirate was clear fluid in the majority of cases. All of the cases revealed fragments of bladder wall with associated granulomas in seven cases and giant cells in four cases. However, none of the case revealed hooklets.

Conclusion: Fine needle aspiration cytology can provide a simple, minimally invasive, low-cost, outpatient diagnostic technique for the diagnosis of cysticercosis, as cytological diagnosis is quite clear when the actual parasitic structures are identified in the smear.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/cyt.13043DOI Listing
July 2021

Cytological diagnosis of microfilariae in clinically unsuspected cases: A retrospective review of 12 cases.

Cytopathology 2021 Jul 17. Epub 2021 Jul 17.

Department of Pathology, Atal Bihari Vajpayee Institute Of Medical Sciences & Dr. Ram Manohar Lohia Hospital, New Delhi, India.

Background: Filariasis is a major health problem in India. Despite the high prevalence, microfilariae are rarely found in cytology smears. Most of the cases are incidentally found, solely or in association with other pathologies.

Aims And Objectives: This study was undertaken to analyse the prevalence and cytological findings of cases of incidentally found microfilariae in cytology smears (fine needle aspiration cytology [FNAC]/exfoliative cytology) from different parts of the body.

Materials And Methods: This was a retrospective study over 3 years, in which cases of microfilariae in aspirates from swelling of different locations, body fluids, and pap smears were reviewed, and the clinicopathological data analysed.

Results And Analysis: Out of 11 530 cases of FNAC, 8700 cases of fluid cytology, and 9000 of conventional cervicovaginal smears, 12 cases (0.04%) of incidental findings of microfilariae were documented in cytology smears. The cases were diagnosed from lymph node (one case), hand (one case), scrotal area (one case), axilla (one case), breast (one case), subcutaneous tissue (three cases), urine (three cases), and Pap smear (one case). We found eosinophilia in one case (8.3%) of filarial lesions. We found two cases of incidental findings of microfilariae in association with malignant lesions.

Conclusion: Cytology smear examination can play an important role in diagnosing occult filariasis in clinically unsuspected cases in association with other pathologies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/cyt.13035DOI Listing
July 2021

Heterotopic pancreatic tissue in the gallbladder: A rare incidental finding.

Indian J Pathol Microbiol 2021 Jun;64(Supplement):S178-S179

Department of Pathology, PGIMER and Dr. RML Hospital, New Delhi, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/IJPM.IJPM_829_19DOI Listing
June 2021

Pediatric Care Struggles of US Trained International Medical Graduate Pediatricians in COVID-19 Pandemic.

J Clin Med Res 2021 Jan 12;13(1):20-25. Epub 2021 Jan 12.

Providence Hospital Group, Spokane, WA, USA.

Background: Pediatrician shortage and healthcare access has been a serious issue especially in medically underserved and rural areas aplenty in the USA and has further worsened during the coronavirus disease 2019 (COVID-19) pandemic. Many US trained international medical graduates (IMGs) on a visa status serve these areas to fill in the physician gap. These physicians are usually on a visa and the majority of them have approved immigration petitions. During this pandemic, the sudden changes in immigration policies in addition to the longstanding administrative backlog and processing times had posed new challenges to the pediatricians and the communities served by them. The objective of this study was to determine the demographics, level of training and practice, immigration status, the clinical role they played in the communities they served and the various professional and personal setbacks they faced during the pandemic.

Methods: A survey was created and data were collected using data collection platform "Survey Monkey". Screening questions were designed to include only IMG pediatricians on a visa status.

Results: A total of 267 IMG pediatricians qualified for the survey on a nationwide basis. Of the physicians that participated in the survey, 58.4% were working in either medically underserved or physician shortage areas, 36% of the total physicians were working in a rural setting, 10.6% of the pediatricians had to be quarantined due to exposure to COVID-19, 0.8% were infected with COVID-19 themselves, and 81.3% of the pediatricians had faced hindrance in being able to work at a COVID-19 hotspot due to work site restrictions because of their visa status.

Conclusion: IMG pediatricians play a valuable role in taking care of the children in medically underserved areas. The challenges surrounding the immigration backlog are contributing to significant hardships for these pediatricians and their families and are causing a hindrance to healthcare access to the children in medically underserved communities during the pandemic especially limiting the pediatricians' scope and geographic radius of the practice, thus not allowing them to practice to the full extent of their license.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14740/jocmr4403DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7869564PMC
January 2021

Evaluation of Patient Perceptions With Orthopedic Oncology Telehealth: A Pilot Project.

J Patient Exp 2020 Dec 14;7(6):1169-1173. Epub 2020 Aug 14.

University of Missouri, Missouri Telehealth Network, Columbia, MO, USA.

Telehealth has been used for decades to improve access to care for rural and underserved patients. The adoption of telehealth in orthopedic oncology is novel and expected to positively impact patient access and compliance. However, no previous evaluation has been published of this expected impact. The objective of this pilot project was to evaluate patients' perceptions regarding orthopedic oncology telehealth services. A 13-question satisfaction survey was distributed to patients who used tele-orthopedic oncology. Fifteen respondents (a response rate of 42%) reported satisfaction with services at 9.7 of 10. Median travel distance to the nearest in-person orthopedic oncologist was greater than 150 miles (241 km). These results are consistent with the previous findings of high satisfaction with telehealth in other specialties. Health care organizations are likely to benefit from offering telehealth to orthopedic oncology patients with limited access.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/2374373520948660DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7786647PMC
December 2020

Epithelioid angiomyolipoma with tumor thrombus in IVC and right atrium.

Autops Case Rep 2020 Sep 2;10(4):e2020190. Epub 2020 Sep 2.

All India Institute of Medical Sciences, Department of Pathology. Jodhpur, India.

Epithelioid angiomyolipoma is an uncommon subtype of renal angiomyolipoma associated with potentially malignant behavior and is considered a distinct entity by the World Health Organization classification of renal tumors. We present a case of an epithelioid variant of angiomyolipoma with extension into the renal vein, inferior vena cava reaching up to the right atrium. Pre-operatively, a diagnosis of renal cell carcinoma was considered based on imaging findings. Intra-operatively due to extensive adhesions, surgical resection was not performed and only tissue sampling was performed for histopathology. Microscopic examination revealed short fascicles of spindle cells and perivascular epithelioid cells. A differential diagnosis of renal cell carcinoma with sarcomatoid differentiation was considered. The immunohistochemical profile showed tumor cells that express Melan-A and smooth muscle actin, while they were negative for pan-cytokeratin, PAX8, CK7, CD117 and CD34. Therefore a diagnosis of epithelioid angiomyolipoma was rendered. The presence of intravascular thrombi on radiological investigation and carcinoma-like growth pattern on light microscopy may compound an erroneous diagnosis of renal cell carcinoma. Hence, it is prudent for the urologist to consider differential diagnosis other than renal cell carcinoma when confronted with a renal neoplasm presenting with intravascular thrombi. In these cases, a core biopsy should be planned pre-operatively and diagnosis should be made with aid of appropriate immunohistochemical markers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4322/acr.2020.190DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7703439PMC
September 2020

Cytopathologic findings in histiocytic sarcoma of thyroid mimicking as anaplastic carcinoma: A report of a rare case with review of literature.

Diagn Cytopathol 2021 Jun 5;49(6):E218-E221. Epub 2020 Dec 5.

Department of Pathology and Lab Medicine, All India Institute of Medical Sciences, Jodhpur, India.

Background: Histiocytic sarcoma is an extremely rare malignant hematological histiocytic neoplasm which is a diagnosis of exclusion based on its morphological and predominantly immunohistochemical criteria.

Case Description And Diagnosis: A 63-year female presented with complaints of a midline neck swelling along with right sided neck swelling. On fine-needle aspiration (FNA) from the thyroid lesion and the right cervical lymph node, the smears showed similar findings and a provisional morphological diagnosis of malignant spindle cell neoplasm was kept. On immunohistochemistry, the tumor cells showed immunoreactivity for vimentin, CD45, CD 68 and fascin and were immunonegative for thyroglobulin, S100, CD21, CD3, CD4 and other markers. Based on the immunohistochemical profile, a diagnosis of histiocytic sarcoma was established.

Conclusion: Histiocytic sarcoma is a rare malignant neoplasm that can be easily missed in thyroid resembling an anaplastic carcinoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/dc.24679DOI Listing
June 2021

Enzyme-responsive chiral self-sorting in amyloid-inspired minimalistic peptide amphiphiles.

Nanoscale 2020 Sep 4;12(36):18692-18700. Epub 2020 Sep 4.

Chemical Biology Unit, Institute of Nano Science and Technology, Sector 64, Mohali, Punjab 160062, India.

Self-sorting is a spontaneous phenomenon that ensures the formation of complex yet ordered multicomponent systems and conceptualizes the design of artificial and orthogonally functional compartments. In the present study, we envisage chirality-mediated self-sorting in β-amyloid-inspired minimalistic peptide amphiphile (C-l/d-VFFAKK)-based nanofibers. The fidelity and stereoselectivity of chiral self-sorting was ascertained by Förster resonance energy transfer (FRET) by the judicious choice of a pyrene (Py)-hydroxy coumarin (HOCou) donor-acceptor pair tethered to the peptide sequences. Seed-promoted elongation of the homochiral peptide amphiphiles investigated by AFM image analyses and Thioflavin-T (ThT) binding study further validated the chiral recognition of the l/d peptide nanofibers. Moreover, direct visualization of the chirality-driven self-sorted nanofibers is reported using super-resolution microscopy that exhibits enantioselective enzymatic degradation for l-peptide fibers. Such enantioselective weakening of the hydrogels may be used for designing stimuli-responsive orthogonal compartments for delivery applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0nr04581kDOI Listing
September 2020

Frontal swelling in adult male: Cytological consideration of an uncommon diagnosis.

Cytojournal 2020 31;17. Epub 2020 Mar 31.

Department of Pathology, Post Graduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.25259/Cytojournal_79_2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7210467PMC
March 2020

Photoresponsive chain collapse in a flexo-rigid functional copolymer to modulate the self-healing behaviour.

Soft Matter 2020 Mar;16(10):2506-2515

Institute of Nano Science and Technology, Phase 10, Sector 64, Mohali, Punjab-160062, India.

Synthetic systems mimicking the natural self-folding process are attractive to impart multiple structural control over polymer crosslinking and the subsequent alteration of their macroscopic self-healing properties. In that regard, polymers P1-P5 containing pendant photo-crosslinkable moieties were designed and underwent intra- or interchain collapse to form diverse nanostructures. The shape and dimension of the nanostructures could be efficiently controlled by the concentration, solvent compatibility and characteristics of the polymers. Photodimerization of the coumarin moieties transformed the extended coiled chain of the polymer to uniform sized nanoparticles in a dilute condition, while in the crowded macromolecular concentration regime, the polymer folded into nanostructures with polydisperse topologies that were far from a condensed globule or partially swollen globule conformation. Scaling law exponents for polymer chain compaction suggested an interchain collapse with rigid compact segments connected by flexible polymer chains that draws an analogy with elastomers. Such a hardening of the rigid segment as a consequence of photodimerization rendered a significant increase in the glass transition temperature (Tg), which could be reversibly controlled upon decrosslinking. Lastly, the structural variation of this class of polymers over self-healing was explored and the crosslinked polymers showed phototriggered non-autonomic and intrinsic self-healing behaviour under ambient conditions. This is an interesting approach to access a photomodulated self-healing system with low Tg polymers that shows the coexistence of autonomic and nonautonomic self-healing pathways and that may find application in designing smart coatings for photovoltaic devices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0sm00033gDOI Listing
March 2020

Fine-needle aspiration of axillary swelling: Cytodiagnosis of an unusual presentation of filariasis.

Cytojournal 2019 5;16:25. Epub 2019 Dec 5.

Address: Department of Pathology, Postgraduate Institute of Medical Education and Research, Dr. Ram Manohar Lohia Hospital, New Delhi, India.

Lymphatic filariasis is a major public health problem in tropical and subtropical countries. Fine-needle aspiration cytology (FNAC) is not routinely used for its identification. However, it has been detected incidentally, while doing FNAC for the evaluation of other lesions. We describe a presentation of occult filariasis with microfilariae (mf) in an isolated axillary swelling wherein FNAC was helpful in establishing the diagnosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/cytojournal.cytojournal_17_19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6909590PMC
December 2019

Capillary haemangioma of the spinal cord: Report of two cases and a review of literature.

Neurol India 2019 May-Jun;67(3):906-907

Department of Neurosurgery, Government Medical College and Hospital, Sector 32, Chandigarh, India.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/0028-3886.263193DOI Listing
March 2020

Tandem Interplay of the Host-Guest Interaction and Photoresponsive Supramolecular Polymerization to 1D and 2D Functional Peptide Materials.

ACS Appl Mater Interfaces 2019 Aug 26;11(31):28213-28220. Epub 2019 Jul 26.

Institute of Nano Science and Technology , Phase 10, Sector 64 , Mohali , Punjab 160062 , India.

Peptide with an Aβ42 amyloid nucleating core and a photodimerizable 4-methylcoumarin moiety at its N terminus demonstrates the step-wise self-assembly in water to form nanoparticles, with eventual transformation into 1D nanofibers. Addition of γ-cyclodextrin to with subsequent irradiation with UV light at 320 nm resulted in morphological conversion to free-standing 2D nanosheets mediated by the host-guest interaction. Mechanical agitation of the 1D and 2D nanostructures led to seeds with narrow polydispersity indices, which by mediation of seeded supramolecular polymerization found seamless control over the dimensions of the nanostructures. Such structural and temporal control to differentiate the pathway was exploited to tune the mechanical strength of hierarchical hydrogel materials. Finally, the dimensional characteristics of the positively charged peptide fibers and sheets were envisaged as excellent exfoliating agents for inorganic hybrid materials, for example, MoS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.9b09690DOI Listing
August 2019

Solution properties and electrospinning of poly(galacturonic acid) nanofibers.

Carbohydr Polym 2019 May 11;212:102-111. Epub 2019 Feb 11.

SMITA Research Lab, Department of Textile Technology, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India. Electronic address:

Poly(galacturonic acid) (PGuA) is an important natural biopolymer, however its potential has not been realized due to its anionic nature and rigid structure, which limits its processability into fine films and fibres. This study aims at modifying the solution properties of PGuA in alkaline medium (aq. sodium hydroxide) to enable their conversion into electrospun nanofibers. Addition of anionic surfactants was found to play an important role in individualizing the PGuA chains that lead to formation of small spindle shaped fibers of length ranging from 2 to 10 μm and diameter from 287 to 997 nm. However, continuous fibers were not formed even at concentrations higher than the critical concentration. Addition of small amount (10-30%) of high molecular weight PVA resulted in formation of continuous fibers. Correlation of fiber diameters of PGuA/PVA with the rheological properties suggested a strong dependence of diameter with the elasticity of the blend solutions. Such PGuA based fibers may be utilized in various biomedical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.carbpol.2019.02.023DOI Listing
May 2019

Pathway driven self-assembly and living supramolecular polymerization in an amyloid-inspired peptide amphiphile.

Chem Commun (Camb) 2018 Sep;54(76):10730-10733

Institute of Nano Science and Technology, Phase 10, Sector 64, Mohali, Punjab, India.

Peptide 1 with an Aβ42 amyloid nucleating core demonstrates step-wise self-assembly in water. Variation of temperature or solvent composition arrests the self-assembly to give metastable nanoparticles, which undergo self-assembly on gradual increase in temperature and eventually produce kinetically controlled nanofibers and thermodynamically stable twisted helical bundles. Mechanical agitation of the fibers provided access to short seeds with narrow polydispersity index, which by mediation of seeded supramolecular polymerization establishes perfect control over the length of the nanofibers. Such pathway dependence and the length control of the supramolecular peptide nanofibers is exploited to tune the mechanical strength of the resulting hydrogel materials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c8cc06266hDOI Listing
September 2018

Evaluation of the Effects of Fluoride Prophylactic Agents on Mechanical Properties of Nickel Titanium Wires using Scanning Electron Microscope.

J Contemp Dent Pract 2018 Mar 1;19(3):283-286. Epub 2018 Mar 1.

Align Dentals, Noida, Uttar Pradesh, India.

Introduction: Orthodontic treatment these days is increasing in demand, and therefore, it is relatively imperative for the orthodontist to prescribe the use of fluoride-containing products, such as mouthwashes and gels, to help prevent dental caries and maintain healthy oral health. The aim of the study was to assess and evaluate the effects of fluoride prophylactic agents on mechanical properties of nickel titanium (NiTi) wires during orthodontic treatment using scanning electron microscope (SEM).

Materials And Methods: We used the commercially available round preformed NiTi orthodontic archwire (3M company) and three different mouthwash solutions, i.e., Phos-Flur gel (1.1% sodium acidulated phosphate fluoride, APF, 0.5% w/v fluoride, pH = 5.1; Colgate Oral Pharmaceuticals) and Prevident 5000 (1.1% sodium fluoride neutral agent, 0.5% w/v fluoride, pH = 7; Colgate Oral Pharmaceuticals). All the specimens were subjected to a three-point bending test on a universal testing machine. To observe the surface morphological changes, one wire from each group was randomly selected and observed under a SEM.

Results: It was observed that there was not much difference in the values of both modulus of elasticity and yield strength obtained after loading of stress on the wires in all the three experimental conditions. A significant difference in both modulus of elasticity and yield strength was observed during unloading of stress. Further, when the surface characteristics were observed for all the specimens using SEM images, it was observed that NiTi wires treated with Phos-Flur showed large surface defects which appeared as round, pitted areas depicting corrosion, numerous white inclusions, and overall damaged surface structure of the wire as compared with the control.

Conclusion: Thus, fluoridated mouthwashes are essential to maintain good oral hygiene and decrease instance of caries in patients undergoing orthodontic treatment. The prophylactic usage of topical fluoride agents on NiTi wire seems to diminish the mechanical properties of the orthodontic wire that could significantly affect future treatment outcomes.

Clinical Significance: It has been proved that fluoride mouthwashes/gels do affect the structural surface qualities and strength of wires used during the orthodontic treatment irrespective of the composition of the wires. Therefore, it is the responsibility of the clinician to prescribe these prophylactic agents carefully while keeping in mind their pH so that the overall result of the treatment may not be hampered and delayed due to change in properties of the wires used.
View Article and Find Full Text PDF

Download full-text PDF

Source
March 2018

Physical shearing imparts biological activity to DNA and ability to transmit itself horizontally across species and kingdom boundaries.

BMC Mol Biol 2017 08 9;18(1):21. Epub 2017 Aug 9.

Translational Research Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi-Mumbai, 410210, India.

Background: We have recently reported that cell-free DNA (cfDNA) fragments derived from dying cells that circulate in blood are biologically active molecules and can readily enter into healthy cells to activate DNA damage and apoptotic responses in the recipients. However, DNA is not conventionally known to spontaneously enter into cells or to have any intrinsic biological activity. We hypothesized that cellular entry and acquisition of biological properties are functions of the size of DNA.

Results: To test this hypothesis, we generated small DNA fragments by sonicating high molecular weight DNA (HMW DNA) to mimic circulating cfDNA. Sonication of HMW DNA isolated from cancerous and non-cancerous human cells, bacteria and plant generated fragments 300-3000 bp in size which are similar to that reported for circulating cfDNA. We show here that while HMW DNAs were incapable of entering into cells, sonicated DNA (sDNA) from different sources could do so indiscriminately without heed to species or kingdom boundaries. Thus, sDNA from human cells and those from bacteria and plant could enter into nuclei of mouse cells and sDNA from human, bacterial and plant sources could spontaneously enter into bacteria. The intracellular sDNA associated themselves with host cell chromosomes and integrated into their genomes. Furthermore, sDNA, but not HMW DNA, from all four sources could phosphorylate H2AX and activate the pro-inflammatory transcription factor NFκB in mouse cells, indicating that sDNAs had acquired biological activities.

Conclusions: Our results show that small fragments of DNA from different sources can indiscriminately enter into other cells across species and kingdom boundaries to integrate into their genomes and activate biological processes. This raises the possibility that fragmented DNA that are generated following organismal cell-death may have evolutionary implications by acting as mobile genetic elements that are involved in horizontal gene transfer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12867-017-0098-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5550992PMC
August 2017

Cell-free chromatin from dying cancer cells integrate into genomes of bystander healthy cells to induce DNA damage and inflammation.

Cell Death Discov 2017 29;3:17015. Epub 2017 May 29.

Integrated Cancer Genomics Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Mumbai 410210, India.

Bystander cells of the tumor microenvironment show evidence of DNA damage and inflammation that can lead to their oncogenic transformation. Mediator(s) of cell-cell communication that brings about these pro-oncogenic pathologies has not been identified. We show here that cell-free chromatin (cfCh) released from dying cancer cells are the key mediators that trigger both DNA damage and inflammation in the surrounding healthy cells. When dying human cancer cells were cultured along with NIH3T3 mouse fibroblast cells, numerous cfCh emerged from them and rapidly entered into nuclei of bystander NIH3T3 cells to integrate into their genomes. This led to activation of H2AX and inflammatory cytokines NFB, IL-6, TNF and IFN. Genomic integration of cfCh triggered global deregulation of transcription and upregulation of pathways related to phagocytosis, DNA damage and inflammation. None of these activities were observed when living cancer cells were co-cultivated with NIH3T3 cells. However, upon intravenous injection into mice, both dead and live cells were found to be active. Living cancer cells are known to undergo extensive cell death when injected intravenously, and we observed that cfCh emerging from both types of cells integrated into genomes of cells of distant organs and induced DNA damage and inflammation. H2AX and NFB were frequently co-expressed in the same cells suggesting that DNA damage and inflammation are closely linked pathologies. As concurrent DNA damage and inflammation is a potent stimulus for oncogenic transformation, our results suggest that cfCh from dying cancer cells can transform cells of the microenvironment both locally and in distant organs providing a novel mechanism of tumor invasion and metastasis. The afore-described pro-oncogenic pathologies could be abrogated by concurrent treatment with chromatin neutralizing/degrading agents suggesting therapeutic possibilities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/cddiscovery.2017.15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5447133PMC
May 2017

Virulence determinants in enteroaggregative Escherichia coli from North India and their interaction in in vitro organ culture system.

FEMS Microbiol Lett 2016 09 3;363(17). Epub 2016 Aug 3.

Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India

Enteroaggregative Escherichia coli (EAEC) is an important diarrhoeal pathogen causing diseases in multiple epidemiological and clinical settings. In developing countries like India, diarrhoeal diseases are one of the major killers among paediatric population and oddly, few studies are available from Indian paediatric population on the variability of EAEC virulence genes. In this study, we examined the distribution of plasmid and chromosomal-encoded virulence determinants in EAEC isolates, and analysed cytokines response generated against EAEC with specific aggregative adherence fimbriae (AAF) type in duodenal biopsies using in vitro organ culture (IVOC) mimicking in vivo conditions. Different virulence marker combinations among strains were reflected as a function of specific adhesins signifying EAEC heterogeneity. fis gene emerged as an important genetic marker apart from aggA and aap Further, EAEC infection in IVOC showed upregulation of IL-8, IL-1β, IL-6, TNF-α and TLR-5 expression. EAEC with AAFII induced significant TLR-5 and IL-8 response, conceivably owing to more pathogenicity markers. This study sheds light on the pattern of EAEC pathotypes prevalent in North Indian paediatric population and highlights the presence of unique virulence combinations in pathogenic strains. Thus, evident diversity in EAEC virulence and multifaceted bacteria-host crosstalk can provide useful insights for the strategic management of diarrhoeal diseases in India, where diarrhoeal outbreaks are more frequent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/femsle/fnw189DOI Listing
September 2016

Inhibition of enteroaggregative Escherichia coli cell adhesion in-vitro by designed peptides.

Microb Pathog 2016 Sep 23;98:23-31. Epub 2016 Jun 23.

Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India. Electronic address:

Enteroaggregative Escherichia coli (EAEC) bears remarkable capacity to adhere the host intestinal mucosal surface and results in acute or persistent childhood diarrhea worldwide. In this study, an attempt has been made to inhibit EAEC cell adherence in-vitro using synthetic peptides. E. coli isolates (n = 54) were isolated from the stool samples of clinically diagnosed pediatric diarrheal patients. 92.8% isolates showed different types of aggregative adherence patterns with HEp-2 cells. AAF-II (Aggregative Adherence Fimbriae-II) EAEC exhibited the maximum ability to form biofilm and intracellular survival. Peptides were designed against the high antigenic epitopic regions of AAF-II adhesin of EAEC O42 using prediction algorithms like BcePred and ProPred software to block the EAEC cell adhesion in-vitro. Peptides P2 (DITITPATNRDVNV) and P3 (MRIKAWGEANHGQL) demonstrated higher inhibition of EAEC cell adhesion than P1 (GMQGSITPAIPLRPG). Interestingly, increasing the pre-incubation time of the peptides with HEp-2 cells from 1 h to 2 h showed the maximum inhibition. The data suggested the potential role of P2 and P3 peptides in successfully blocking the binding of AAF-II EAEC with HEp-2 cell receptors. Hence, the peptides may be efficacious in designing new chemotherapeutic for the management of EAEC mediated diarrhea.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.micpath.2016.06.014DOI Listing
September 2016

The laparoscopic management of Swyer syndrome: Case series.

J Turk Ger Gynecol Assoc 2015 2;16(4):252-6. Epub 2015 Nov 2.

Department of Obstetrics and Gynecology, All India Institute of Medical Sciences, New Delhi, India.

Swyer syndrome, also known as 46 XY pure gonadal dysgenesis, is a rare endocrine disorder. Affected individuals are phenotypically female with female genitalia, normal Mullerian structures, absent testicular tissue, and a 46 XY chromosomal constitution. We report a series of eight cases of Swyer syndrome, of which six were managed by laparoscopic gonadectomy. The two other cases had to undergo an exploratory laparotomy in view of their presentation with adnexal masses. Two of the girls were siblings. The chief presenting complaint was primary amenorrhea. Four girls also presented with a history of poor development of secondary sexual characters. The average age at presentation was 16.19±2.85 years. The average height was 158.33 ±4.63 cm, and the average weight was 49.33±8.44 kg. Breast development was either Tanner 2 or 3 in four girls, whereas three girls had a Tanner 1 underdeveloped breasts. Axillary and pelvic hair was sparse in all the girls. The vagina was well canalized in all the girls. Hormonal evaluation revealed hypergonadotropic hypogonadism with a mean follicle-stimulating hormone (FSH) level of 95.81 mIU/L and a mean luteinizing (LH) level of 24.15 mIU/L. Imaging analysis revealed the presence of a small uterus in all the cases, except one. Bilateral ovaries were either not visualized or streak gonads were present. Adnexal mass was detected in two of the six cases with raised carcinoembryonic antigen (CA) 125 levels in one case. Genetic analysis revealed a karyotype of 46 XY in six girls, 46 XY/45 X in one, and the culture repeatedly failed in one girl. Because of the risk of malignancy, bilateral gonadectomy was performed in all cases. Histopathological analysis revealed that three of the six cases had dysgerminoma. The patients have been started on hormone replacement therapy. Laparoscopy is a minimally invasive modality for the definitive diagnosis and treatment of cases with Swyer syndrome. An early diagnosis of Swyer syndrome is possible during workup for primary amenorrhea before they present with adnexal masses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5152/jtgga.2015.15061DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4664218PMC
December 2015

Long-term preservation of donor corneas in glycerol for keratoplasty: exploring new protocols.

Br J Ophthalmol 2016 Feb 27;100(2):284-90. Epub 2015 Oct 27.

Department of Ophthalmology, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.

Aim: To evaluate the role of temperature and adjunctive dehydration in better long-term preservation of human corneas when preserved and stored in glycerol.

Methods: Different preservation temperatures and effects of adding silica gel in glycerol-preserved corneal tissues were evaluated. Human corneal tissues not suitable for optical keratoplasty initially preserved in McCarey-Kaufman medium were transferred to glycerol and stored at four different temperatures for 3 months as follows: tissues in anhydrous glycerol with and without silica gel at -80°C, -20°C, 4°C and at room temperature (RT). Parameters evaluated included microbial sterility, thickness (Digimatic micrometer), transparency (slit lamp examination, UV-Vis spectrophotometer), mechanical strength (Instron 5848 Microtester), tissue integrity (H&E staining), antigenicity (immunohistochemistry) and ultrastructure of collagen (transmission electron microscopy, TEM).

Results: Microbial test after 3 months of glycerol preservation confirmed sterility of the tissues. The thickness increased in corneas preserved at RT with and without silica gel (p<0.001). RT corneas had the lowest transparency and tensile strength. Tissues in anhydrous glycerol stored with and without silica gel at -80°C were the most transparent (p<0.001) and had the highest tensile strength (p<0.001). Tissue integrity was maintained and expression of Human Leukocyte Antigen D related (HLA-DR) was less in glycerol-preserved corneas at -80°C. TEM studies indicated that parallel alignment of stromal collagen was disrupted at RT-preserved corneas.

Conclusions: Corneal tissue preserved at -80°C was the best method for preservation as it maintained the sterility, thickness, optical transparency, mechanical strength and ultrastructural features.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bjophthalmol-2015-306944DOI Listing
February 2016

Circulating nucleic acids damage DNA of healthy cells by integrating into their genomes.

J Biosci 2015 Mar;40(1):91-111

Translational Research Laboratory, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Kharghar, Navi Mumbai 410210, India,

Whether nucleic acids that circulate in blood have any patho-physiological functions in the host have not been explored.We report here that far from being inert molecules, circulating nucleic acids have significant biological activities of their own that are deleterious to healthy cells of the body. Fragmented DNA and chromatin (DNAfs and Cfs) isolated from blood of cancer patients and healthy volunteers are readily taken up by a variety of cells in culture to be localized in their nuclei within a few minutes. The intra-nuclear DNAfs and Cfs associate themselves with host cell chromosomes to evoke a cellular DNA-damage-repair-response (DDR) followed by their incorporation into the host cell genomes. Whole genome sequencing detected the presence of tens of thousands of human sequence reads in the recipient mouse cells. Genomic incorporation of DNAfs and Cfs leads to dsDNA breaks and activation of apoptotic pathways in the treated cells. When injected intravenously into Balb/C mice, DNAfs and Cfs undergo genomic integration into cells of their vital organs resulting in activation of DDR and apoptotic proteins in the recipient cells. Cfs have significantly greater activity than DNAfs with respect to all parameters examined, while both DNAfs and Cfs isolated from cancer patients are more active than those from normal volunteers. All the above pathological actions of DNAfs and Cfs described above can be abrogated by concurrent treatment with DNase I and/or anti-histone antibody complexed nanoparticles both in vitro and in vivo. Taken together, our results suggest that circulating DNAfs and Cfs are physiological, continuously arising, endogenous DNA damaging agents with implications to ageing and a multitude of human pathologies including initiation of cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779614PMC
http://dx.doi.org/10.1007/s12038-015-9508-6DOI Listing
March 2015
-->