Publications by authors named "R Ashwini"

9 Publications

Early-stage culprit in protein misfolding diseases investigated using electrochemical parameters: New insights over peptide-membrane interactions.

Biomed Pharmacother 2021 Jul 28;142:111964. Epub 2021 Jul 28.

Department of Applied Chemistry, School of Applied Natural Science, Adama Science and Technology University, P O Box 1888, Adama, Ethiopia. Electronic address:

The dysfunctioning of β-cells caused by the unspecific misfolding of the human islet amyloid polypeptide (hIAPP) at the membrane results in type 2 diabetes mellitus. Here, we report for the first time, the early-stage interaction of hIAPP oligomers on the DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) lipid membrane using electrochemical parameters. Electrochemical techniques are better than other techniques to detect hIAPP at significantly lower concentrations. The surface level interactions between the peptide (hIAPP) and lipid membrane (DMPC) were investigated using atomic force microscopy (AFM), confocal microscopy (CM) and electrochemical techniques such as Tafel polarization, cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Inserting IAPP into the fluid domains results in breaking the lipid-to-lipid interaction, leading to restriction of membrane mobility. The S values of the liposome and IAPP co-solubilized liposome indicates the cooperative insertion of IAPP. Further, a new method of immobilizing a membrane to the gold surface has been employed, resulting in an electrical contact with the buffer, preventing the direct utilization of a steady-state voltage across the bilayer. The electrochemical studies revealed that the charge transfer resistance decreased for 3-mercaptopropanoic acid modified gold (MPA-Au) electrode coated with the liposome and after the addition of IAPP, followed by an increase in the capacitance. The present study has opened up new dimensions to the understanding of peptide-membrane interactions and shows different experimental approaches for the future researchers in this domain.
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http://dx.doi.org/10.1016/j.biopha.2021.111964DOI Listing
July 2021

Effects of salivary thiocyanate levels on oral mucosa in young adult smokers: A biochemical and cytological study.

J Oral Maxillofac Pathol 2018 May-Aug;22(2):204-209

Department of Oral Pathology and Microbiology, College of Dental Sciences, Davangere, Karnataka, India.

Background And Objectives: Cigarette smoking is one of the major global health issues. Accurate measurement of smoking is essential for accepting patterns of adolescent smoking behavior and for the evaluation of health education programs aimed at reducing or preventing the habit. The aim of the present study was to estimate and compare the salivary thiocyanate levels in young adult smokers and nonsmokers and also to evaluate and correlate the cellular and nuclear changes in cytological smears with salivary thiocyanate levels.

Materials And Methods: The study included a total of 70 individuals in the age range of 18-25 years comprising of 35 smokers and 35 nonsmokers. A volume of 2 ml unstimulated whole saliva samples were collected by spitting method and were carried in a vaccine carrier with ice pack to the laboratory to avoid biochemical changes. Each sample was analyzed on the same day of collection by spectrophotometric method. In addition, cytosmears were prepared using Cytobrush plus and stained with rapid Papanicolaou stain for cytological evaluation.

Results: Salivary thiocyanate levels were significantly higher in smokers than nonsmokers. When these levels were compared with pack-years, there was a progressive significant increase in salivary thiocyanate levels as the pack-years increased. Duration of habit showed no statistically significant effect on salivary thiocyanate levels. Cytological evaluation revealed increase in nuclear-cytoplasmic area ratio and number of micronuclei in smokers than nonsmokers. The correlation between salivary thiocyanate levels and cytological changes showed insignificant result.

Conclusion: Salivary thiocyanate levels were significantly higher in smokers than controls and showed significant correlation with the number of pack years. Although the present study failed to reveal any significant correlation between salivary thiocyanate level and cytological alterations, few early alterations in the oral mucosa even in the absence of clinical manifestations were detected by exfoliative cytology. Salivary thiocyanate determination is a safe, inexpensive, noninvasive method to differentiate early smokers from nonsmokers.
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http://dx.doi.org/10.4103/jomfp.JOMFP_49_17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097367PMC
August 2018

Oral carriage of cariogenic bacteria and in asthmatic adults before and after anti-asthma medication: A longitudinal study.

J Oral Maxillofac Pathol 2018 Jan-Apr;22(1):144

Department of Oral Pathology and Microbiology, College of Dental Sciences, Davangere, Karnataka, India.

Background: Antiasthmatic medications such as β2 agonists and corticosteroids have shown potential side effects such as increased caries risk and oral candidiasis. Studies evaluating microbial changes in adult asthmatics are very scanty in the literature. The present study aimed to evaluate the effects of asthma and its medication on cariogenic bacteria and in adult asthmatics.

Aim And Objectives: Our aim was to evaluate and compare counts of (SM) and lactobacilli in plaque and in saliva samples of adult asthmatics with controls and during the course of medication longitudinally.

Methodology: Samples were collected from twenty recently diagnosed asthmatic adults and twenty controls for estimation of microbial counts at baseline and at 3 and 6 month after initiation of medication among cases.

Results: Asthmatics at baseline had higher microbial counts than controls, but the difference was not statistically significant. Comparison between asthmatics at baseline and 3 month after initiation of medication showed an increase in counts of SM, lactobacilli and decreased counts though the difference was not significant. Comparison between asthmatics at baseline and 6 month and also between 3 and 6 month showed significantly increased counts of SM. Although there was an increase in counts of lactobacilli and decreased counts, significant results were not noted. Asthmatics showed increased microbial counts than controls overall.

Conclusion: Asthmatics were found to have higher microbial counts than controls at baseline. Increase in SM and lactobacilli counts in asthmatics after medication emphasizes the need to monitor these patients regularly.
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http://dx.doi.org/10.4103/jomfp.JOMFP_235_15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5917526PMC
May 2018

Photonic Potential of Haloarchaeal Pigment Bacteriorhodopsin for Future Electronics: A Review.

Curr Microbiol 2017 Aug 2;74(8):996-1002. Epub 2017 Jun 2.

Department of Microbiology, DKM College for Women, Vellore, Tamilnadu, 632001, India.

Haloarchaea are known for its adaptation in extreme saline environment. Halophilic archaea produces carotenoid pigments and proton pumps to protect them from extremes of salinity. Bacteriorhodopsin (bR) is a light-driven proton pump that resides in the membrane of haloarchaea Halobacterium salinarum. The photocycle of Bacteriorhodopsin passes through several states from K to O, finally liberating ATP for host's survival. Extensive studies on Bacteriorhodopsin photocycle has provided in depth knowledge on their sequential mechanism of converting solar energy into chemical energy inside the cell. This ability of Bacteriorhodopsin to harvest sunlight has now been experimented to exploit the unexplored and extensively available solar energy in various biotechnological applications. Currently, bacteriorhodopsin finds its importance in dye-sensitized solar cell (DSSC), logic gates (integrated circuits, IC's), optical switching, optical memories, storage devices (random access memory, RAM), biosensors, electronic sensors and optical microcavities. This review deals with the optical and electrical applications of the purple pigment Bacteriorhodopsin.
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http://dx.doi.org/10.1007/s00284-017-1271-5DOI Listing
August 2017

Paediatric Geographic Tongue: A Case Report, Review and Recent Updates.

J Clin Diagn Res 2016 Feb 1;10(2):ZE05-9. Epub 2016 Feb 1.

Reader, Department of Oral Pathology, College of Dental Science , Davangere, Karnataka, India .

Geographic tongue is a benign recurrent condition of uncertain aetiology affecting the tongue characterized by loss of epithelium especially filiform papillae giving a characteristic appearance. The clinical presentation may vary from asymptomatic to painful and burning ulceration. The condition is commonly seen in adults but few cases are reported in children. A case of asymptomatic geographic tongue in three-year-old male child and literature review with new insight in aetiology is presented here. Management depends on the clinical condition and underlying aetiology.
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http://dx.doi.org/10.7860/JCDR/2016/16452.7191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4800664PMC
February 2016
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