Mining proteomics data to extract post-translational modifications associated with gastric cancer.

Gastric cancers are highly heterogeneous, deep-seated tumours associated with late diagnosis and poor prognosis. Post-translational modifications (PTMs) of proteins are known to be well-associated with oncogenesis and metastasis in most cancers. Several enzymes which drive PTMs have also been used as theranostics in cancers of the breast, ovary, prostate and bladder. However, there is limited data on PTMs in gastric cancers. Considering that experimental protocols for simultaneous analysis of multiple PTMs are being explored, a data-driven approach involving reanalysis of mass spectrometry-derived data is useful in cataloguing altered PTMs. We subjected publicly available mass spectrometry data on gastric cancer to an iterative searching strategy for fetching PTMs including phosphorylation, acetylation, citrullination, methylation and crotonylation. These PTMs were catalogued and further analyzed for their functional enrichment through motif analysis. This value-added approach delivered identification of 21,710 unique modification sites on 16,364 modified peptides. Interestingly, we observed 278 peptides corresponding to 184 proteins to be differentially abundant. Using bioinformatics approaches, we observed that majority of these altered PTMs/proteins belonged to cytoskeletal and extracellular matrix proteins, which are known to be perturbed in gastric cancer. The dataset derived by this mutiPTM investigation can provide leads to further investigate the potential role of altered PTMs in gastric cancer management.

Helicobacter pylori regulated microRNA map of human gastric cells.

BACKGROUND: Helicobacter pylori is an infection of concern for its chronic colonization leading to peptic ulcers and gastric cancer. In recent times, microRNAs have been extensively studied to understand their role in the pathogenesis of this bacteria in diverse contexts of gastric diseases. The current analysis reports the microRNA-mRNA interactions that are associated with effective survival and virulence of this pathogen. MATERIALS AND METHODS: We convened differentially regulated human microRNAs responsive to H. pylori infection (HP-hDEmiRs) at different multiplicity of infection and time points in human gastric cell lines through retrospective data mining of experimental studies. In view of the molecular disparity of clinical samples and animal models, data from tissue, serum/plasma, urine, and ascites were excluded. Further, we utilized diverse bioinformatics approaches to retrieve experimentally validated, high-confidence targets of the HP-hDEmiRs to analyze the microRNA-mRNA interactions that are relevant to H. pylori pathogenesis. RESULTS: A total of 39 HP-hDEmiRs that showed unidirectional expression of either overexpression or downregulation were identified to modulate 23 targets explicitly studied under this infection. We also identified 476 experimentally validated targets regulated by at least 4 of the HP-hDEmiRs. In addition to the pathways prior-associated with H. pylori infection, the microRNA-mRNA interactome analysis identified several cellular processes and pathways highly associated with cell cycle, cell division, migration, and carcinogenesis. CONCLUSION: This study generated a platform to study the mechanisms utilized by this pathogen using microRNAs as surrogate.

6-Methylcoumarin rescues bacterial quorum sensing induced ribosome-inactivating stress in Caenorhabditis elegans.

INTRODUCTION: Bacterial pathogenicity has for long posed severe effects on patient care. Pseudomonas aeruginosa is a common cause of hospital-acquired infections and nosocomial illnesses. It is known to infect the host by colonizing through quorum sensing and the production of exotoxins. METHODS: The current effort is an analysis of proteomic alterations caused by P. aeruginosa PAO1 to study the effects of quorum sensing inhibitor 6-Methylcoumarin on PAO1 infectivity in the Caenorhabditis elegans model. RESULTS: Through tandem mass tag-based quantitative proteomics approaches, 229 proteins were found to be differentially regulated in infection and upon inhibition. Among these, 34 proteins were found to be dysregulated in both infection and quorum-sensing inhibition conditions. Along with the dysregulation of proteins involved in host-pathogen interaction, PAO1 was found to induce ribosome-inactivating stress accompanied by the downregulating mitochondrial proteins. This in turn caused dysregulation of apoptosis. The expression of multiple proteins involved in ribosome biogenesis and structure, oxidative phosphorylation, and mitochondrial enzymes were altered due to infection. This mechanism, adapted by PAO1 to survive in the host, was inhibited by 6-Methylcoumarin by rescuing the downregulation of ribosomal and mitochondrial proteins. CONCLUSIONS: Taken together, the data reflect the molecular alterations due to quorum sensing and the usefulness of inhibitors in controlling pathogenesis.

Molecular Profiling Associated with Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 (CAMKK2)-Mediated Carcinogenesis in Gastric Cancer.

Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related death worldwide. We showed previously that calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2), a serine-threonine kinase, is highly expressed in gastric cancer and leads to progression. In the present study, we identified the molecular networks involved in CAMKK2-mediated progression of gastric adenocarcinoma. Treatment of gastric cancer cell lines with a CAMKK2 inhibitor, STO-609, resulted in decreased cell migration, invasion, and colony-forming ability and a G1/S-phase arrest. In addition, tandem mass tag (TMT)-based quantitative proteomic analysis resulted in the identification of 7609 proteins, of which 219 proteins were found to be overexpressed and 718 downregulated (1.5-fold). Our data identified several key downregulated proteins involved in cell division and cell proliferation, which included DNA replication licensing factors, replication factor C, origin recognition complex, replication protein A and GINS, and mesenchymal markers, upon CAMKK2 inhibition. Immunoblotting and immunofluorescence results showed concordance with our mass spectroscopy data. Taken together, our study supports CAMKK2 as a novel therapeutic target in gastric cancer.

Efficacy of Ribbond and a fibre post on the fracture resistance of reattached maxillary central incisors with two fracture patterns: a comparative in vitro study.

AIM: To compare the fracture resistance of maxillary central incisor fragments having two different fracture patterns and re-attached using two different posts - fibre post and Ribbond. MATERIALS AND METHODS: Sixty extracted human maxillary central incisors were randomly divided into two groups of thirty samples each. Group A consisted of samples with 'labio-palatal' fracture pattern and Group B with a 'palato-labial' fracture pattern. The crowns of all the samples were sectioned using safe-sided diamond discs. Following cleaning and shaping and sectional obturation, the samples were randomly subdivided into two subgroups of 15 samples each. Prefabricated fibre post (Reforpost, Angelus, Londrina, PR, Brazil) was placed in all samples of Subgroup I, and Ribbond (Ribbond Inc., Seattle, WA, USA) was placed in all samples of Subgroup II. The fragments were re-attached, fracture resistance was tested using Instron Universal Testing Machine, and the failure modes were assessed using a stereomicroscope. RESULTS: Group A with a labio-palatal fracture pattern exhibited higher fracture resistance as compared to Group B (palato-labial) in both subgroups. The fibre post (Subgroup I) exhibited higher fracture resistance as compared to Ribbond (Subgroup II). The Ribbond group exhibited significantly more number of repairable failures as compared to fibre post group. CONCLUSION: The labio-palatal pattern of fracture is a favourable type of fracture on palatal load application. The fragments re-attached using the fibre post (Reforpost) had a higher resistance to fracture. However, teeth restored with Ribbond posts exhibited 100% repairable failures upon load application. The fracture pattern had no influence on the failure modes.

Guardians Turned Culprits: NETosis and Its Influence on Pulmonary Fibrosis Development.

Idiopathic pulmonary fibrosis (IPF) is a debilitating, life-threatening irreversible lung disease characterized by the excessive accumulation of fibrotic tissue in the lungs, impairing their function. The exact mechanisms underlying Pulmonary fibrosis (PF) are multifaceted and not yet fully understood. Reports show that during COVID-19 pandemic, PF was dramatically increased due to the hyperactivation of the immune system. Neutrophils and macrophages are the patrolling immune cells that keep the microenvironment balanced. Neutrophil extracellular traps (NETs) are a normal protective mechanism of neutrophils. The chief components of the NETs include DNA, citrullinated histones, and anti-microbial peptides which are released by the activated neutrophils. However, it is becoming increasingly evident that hyperactivation of immune cells can also turn into criminals when it comes to pathological state. Dysregulated NETosis may contribute to sustained inflammation, overactivation of fibroblasts, and ultimately promoting collagen deposition which is the characteristic feature of PF. The role of NETs along with inflammation is attaining greater attention. However, seldom researches are related to the relationship between NETs causing PF. This review highlights the cellular mechanism of NETs-induced pulmonary fibrosis, which could give a better understanding of molecular targets which may be helpful for treating NETs-induced PF.

Unveiling Actin Cytoskeleton Role in Mediating Chikungunya-Associated Arthritis: An Integrative Proteome-Metabolome Study.

Background: Chikungunya is a zoonotic disease caused by the Chikungunya virus (CHIKV), primarily transmitted to humans through infected Aedes mosquitoes. The infection is characterized by symptoms such as high fever, musculoskeletal pain, polyarthritis, and a rash, which can lead to severe complications such as encephalitis, meningitis, and even fatalities. While many disease manifestations resemble those of other viral infections, chronic arthritis caused by CHIKV is unique, and its molecular mechanisms remain ill-defined. Materials and Methods: Proteomics data from both cellular and patient levels of CHIKV infection were curated from PubMed and screened using inclusion and exclusion criteria. Patient serum proteomics data obtained from PRIDE underwent reanalysis using Proteome Discoverer 2.2. Enrichment and protein-protein interaction network analysis were conducted on differentially expressed proteins from both serum and cellular datasets. Metabolite data from CHIKV-infected patients were further retrieved, and their protein binding partners were identified using BindingDB. The protein-metabolite interaction pathway was further developed using MetaboAnalyst. Results: The proteomics data analysis revealed differential expression of proteins involved in critical host mechanisms, such as cholesterol metabolism and mRNA splicing, during CHIKV infection. Consistent upregulation of two actin cytoskeleton proteins, TAGLN2 and PFN1, was noted in both serum and cellular datasets, and their upregulations are associated with arthritis. Furthermore, alterations in purine metabolism were observed in the integrative proteome-metabolome analysis, correlating with cytoskeletal remodelling. Conclusion: Collectively, this integrative view sheds light on the involvement of actin cytoskeleton remodeling proteins and purine metabolic pathways in the development of arthritis during CHIKV infection.

Comprehensive insights into the impact of bacterial indole-3-acetic acid on sensory preferences in Drosophila melanogaster.

Several bacteria of environmental and clinical origins, including some human-associated strains secrete a cross-kingdom signaling molecule indole-3-acetic acid (IAA). IAA is a tryptophan (trp) derivative mainly known for regulating plant growth and development as a hormone. However, the nutritional sources that boost IAA secretion in bacteria and the impact of secreted IAA on non-plant eukaryotic hosts remained less explored. Here, we demonstrate significant trp-dependent IAA production in Pseudomonas juntendi NEEL19 when provided with ethanol as a carbon source in liquid cultures. IAA was further characterized to modulate the odor discrimination, motility and survivability in Drosophila melanogaster. A detailed analysis of IAA-fed fly brain proteome using high-resolution mass spectrometry showed significant (fold change, ± 2; p ≤ 0.05) alteration in the proteins governing neuromuscular features, audio-visual perception and energy metabolism as compared to IAA-unfed controls. Sex-wise variations in differentially regulated proteins were witnessed despite having similar visible changes in chemo perception and psychomotor responses in IAA-fed flies. This study not only revealed ethanol-specific enhancement in trp-dependent IAA production in P. juntendi, but also showed marked behavioral alterations in flies for which variations in an array of proteins governing odor discrimination, psychomotor responses, and energy metabolism are held responsible. Our study provided novel insights into disruptive attributes of bacterial IAA that can potentially influence the eukaryotic gut-brain axis having broad environmental and clinical implications.

Temporal phosphoproteomic analysis of VEGF-A signaling in HUVECs: an insight into early signaling events associated with angiogenesis.

Vascular endothelial growth factor-A (VEGF-A) is one of the primary factors promoting angiogenesis in endothelial cells. Although defects in VEGF-A signaling are linked to diverse pathophysiological conditions, the early phosphorylation-dependent signaling events pertinent to VEGF-A signaling remain poorly defined. Hence, a temporal quantitative phosphoproteomic analysis was performed in human umbilical vein endothelial cells (HUVECs) treated with VEGF-A-165 for 1, 5 and 10 min. This led to the identification and quantification of 1971 unique phosphopeptides corresponding to 961 phosphoproteins and 2771 phosphorylation sites in total. Specifically, 69, 153, and 133 phosphopeptides corresponding to 62, 125, and 110 phosphoproteins respectively, were temporally phosphorylated at 1, 5, and 10 min upon addition of VEGF-A. These phosphopeptides included 14 kinases, among others. This study also captured the phosphosignaling events directed through RAC, FAK, PI3K-AKT-MTOR, ERK, and P38 MAPK modules with reference to our previously assembled VEGF-A/VEGFR2 signaling pathway map in HUVECs. Apart from a significant enrichment of biological processes such as cytoskeleton organization and actin filament binding, our results also suggest a role of AAK1-AP2M1 in the regulation of VEGFR endocytosis. Taken together, the temporal quantitative phosphoproteomics analysis of VEGF signaling in HUVECs revealed early signaling events and we believe that this analysis will serve as a starting point for the analysis of differential signaling across VEGF members toward the full elucidation of their role in the angiogenesis processes. Workflow for the identification of early phosphorylation events induced by VEGF-A-165 in HUVEC cells.

Discovery of Molecular Networks of Neuroprotection Conferred by Brahmi Extract in Aß42-Induced Toxicity Model of Drosophila melanogaster Using a Quantitative Proteomic Approach.

Accumulation of Aß42 peptides forming plaque in various regions of the brain is a hallmark of Alzheimer's disease (AD) progression. However, to date, there is no effective management strategy reported for attenuation of Aß42-induced toxicity in the early stages of the disease. Alternate medicinal systems such as Ayurveda in the past few decades show promising results in the management of neuronal complications. Medhya Rasayana such as Brahmi is known for its neuroprotective properties via resolving memory-related issues, while the underlying molecular mechanism of the same remains unclear. In the present study, we aimed to understand the neuroprotective effects of the aqueous extract of Bacopa monnieri and Centella asiatica (both commonly known as Brahmi) against the Aß42 expressing model of the Drosophila melanogaster. By applying a quantitative proteomics approach, the study identified > 90% of differentially expressed proteins from Aß42 expressing D. melanogaster were either restored to their original expression pattern or showed no change in expression pattern upon receiving either Brahmi extract treatment. The Brahmi restored proteins were part of neuronal pathways associated with cell cycle re-entry, apoptosis, and mitochondrial dynamics. The neuroprotective effect of Brahmi was also validated by negative geotaxis behavioral analysis suggesting its protective role against behavioral deficits exerted by Aß42 toxicity. We believe that these discoveries will provide a platform for developing novel therapeutics for AD management by deciphering molecular targets of neuroprotection conferred by an aqueous extract of Bacopa monnieri or Centella asiatica.

Quantitative proteomics profiling of spermatozoa and seminal plasma reveals proteins associated with semen quality in Bos indicus bulls.

Cattle breeding approaches are an evolving field of research in veterinary science. Certain factors such as Ejaculate Rejection Rate (ERR) pose a limitation to such approaches. In this regard, we sought to investigate the spermatozoa and seminal plasma proteome of Hallikar bulls with low (n = 3) and high (n = 3) ERR. Through the Tandem mass spectrometry approach, we identified a total of 2409 proteins, in which 828 proteins were common in both the semen components, whereas 375 and 378 proteins were unique to spermatozoa and seminal plasma respectively. Tandem mass tags (TMT) based protein quantification resulted in 75 spermatozoal, and 42 seminal plasma proteins being differentially regulated between high and low ERR bulls. Proteins such as SPADH2, TIMP-2, and PLA2G7 which are negative regulators of motility were upregulated in the seminal plasma of high ERR bulls. Proteins such as OAZ3, GPx4, and GSTM3 whose upregulation leads to reduced motility were upregulated in the spermatozoa of high ERR bulls. Caltrin and ADM proteins that enhance sperm motility were downregulated in the seminal plasma of high ERR bulls. The regulation of ACE, a negative regulator of sperm motility was upregulated in both the spermatozoa and seminal plasma of high ERR bulls. SIGNIFICANCE: The saying "Bull is more than half of the herd" signifies the importance of bull in the genetic improvement of the herd. Traditionally used semen quality tests will provide limited information about the potential fertility of bulls. The proteomics approach is a promising omics technology to understand the factors involved in male fertility. The present study identified the spermatozoal and seminal plasma proteins that are differentially regulated between high and low ERR bulls. Sperm motility-associated proteins are differentially regulated. This study if improved further, can be used to develop markers associated with semen quality which is useful for the selection of bulls.

Exploring molecular dynamic indicators associated with reproductive performance of Bos indicus cattle in blood plasma samples through data-independent acquisition mass spectrometry.

Improving reproductive performance of cattle is of paramount importance for sustainable dairy farming. Poor reproduction performance (RP) hinders the genetic improvement of important Bos indicus cattle breeds. It is well known that incorporation of molecular information along with conventional breeding method is far better than use of conventional method alone for the genetic improvement of reproductive performance traits in cattle. Therefore, the present study sought to investigate the plasma proteome of the Deoni cows in cyclical (n = 6) and pregnant (n = 6) reproductive phases with varying reproductive performance (high and low). High-throughput data independent acquisition (DIA) based proteomics was performed to understand corresponding proteome. We identified a total of 430 plasma proteins. Among cyclic cows, twenty proteins were differentially regulated in low RP as compared to high RP. BARD1 and AFP proteins were observed upregulated in cyclical cows whose upregulation reported to affect reproductive performance in cattle. Among the pregnant cows, thirty-five proteins were differentially regulated, including the downregulation of FGL2 and ZNFX1 that modulates the maternal immune response mechanism which is required for successful implantation of the embryo. Also, proteins such as AHSG, CLU and SERPINA6 were upregulated in the pregnant cows whose upregulation reported to reduced reproductive performance. The results of this study will be helpful in establishing a framework for future research on the aspect of improving reproductive performance in Bos indicus cattle breeds. SIGNIFICANCE: The Indian subcontinent is the center of domestication for Bos indicus cattle breeds and they are known for their disease resistance, heat tolerance, ability to survive in low input regime and harsh climatic conditions. In recent times, population of many important Bos indicus breeds including Deoni cattle is declining due to various factors, especially due to reproductive performance. Traditional breeding methods are not sufficient enough to understand and improve the reproductive performance traits in important Bos indicus cattle breeds. Proteomics approach is a promising technology to understand the complex biological factors which leads to poor reproductive performance in cattle. The present study utilized DIA based LC- MS/MS analysis to identify the plasma proteins associated with reproductive performance in cyclical and pregnant cows. This study if improved further, can be used to develop potential protein markers associated with reproductive performance which is useful for the selection and genetic improvement of important Bos indicus breeds.

Evaluation of the effect of remineralization with strontium-doped nanohydroxyapatite with noncollagenous protein analog: Chitosan on the shear bond strength of resin composite to dentin - An in vitro study.

Context: The resin-dentin interface is less durable, which reduces the longevity of tooth-colored restorations. To encounter this shortcoming, the use of nanotechnology to mimic biomineralization proves beneficial. Aims: This study was conducted to evaluate the effect of remineralization with strontium-doped nanohydroxyapatite (Sr-nHAp) with chitosan on shear bond strength of resin composite to dentin. Materials and Methods: Sixty five extracted human premolars were divided into five groups (n = 13) based on remineralization protocol as: Group A - 20% (Sr-nHAp) with chitosan, Group B - 10% (Sr-nHAp) with chitosan, Group C - 20% (Sr-nHAp) with simulated body fluid, Group D - 10% (Sr-nHAp) with simulated body fluid, and Group E - control. Following bonding, resin composite of specified dimension was built and was subjected to shear bond strength test after 24 h and 1 week using Universal Testing Machine, and mode of failure was assessed. ANOVA and paired sample t-test were used for analyzing the data, and the level of significance was set at 5%. Results: The highest value of shear bond strength was obtained from Group A after aging for a week, and there is a significant increase in the value of all the groups as compared to the control group after 1 week of storage than 24 h. Conclusions: Remineralization with Sr-nHAp and chitosan has positively improved the bond strength of resin to dentin at the end of 1 week.

Comparative evaluation of decalcifying agents for dissolution of pulp stones: An in vitro study.

Background: Despite constant advances in science, obscurity remains in the efficient removal of pulp stones to aid in successful root canal treatment. In this context, chemical means of dissolving pulp stones were explored. Aim: The aim of this study is to evaluate and to compare the efficacy of decalcifying agents on the dissolution of pulp stones. Materials and Methods: The study was divided into two groups for pulp stone analysis (21 samples) and dentin analysis (54 samples). Twenty-one pulp stones from patients aged 18-70 who underwent root canal treatment were collected and divided into three subgroups (n = 7) randomly. They were subjected to chemical treatment in a labeled glass container with 5 ml of the respective chemical agents, such as 17% ethylenediaminetetraacetic acid solution (positive control), no treatment (negative control), and newly developed Physiological Simulated Decalcifying Agent (PSDA). At the end of the study period (24 h), the samples were removed, rinsed with deionized water, and subjected to physical analysis, scanning electron microscopy (SEM), and Energy -dispersive X-ray spectroscopy (EDS) analysis. Under dentin analysis, 54 maxillary premolars scheduled for orthodontic extraction without caries or extensive restorations were selected, following which 2-mm thick transverse dentinal sections at the cementoenamel junction level were obtained and randomly divided into two groups for SEM (n = 21) and microhardness analysis (n = 33). The samples were subjected to respective chemical treatment groups similar to pulp stones for 24 h and analyzed using SEM, EDS, and microhardness analysis. Results: Postchemical treatment with the newly developed decalcifying solution, the pulp stones showed the absence of nodular crystallites and surface softening under SEM and a decrease in the calcium level under EDS analysis. Concerning the microhardness of dentin, no significant changes could be observed. Conclusion: The newly explored PSDA was found to be efficacious in the decalcification of pulp stones at a clinically relevant time of 24 h, without significantly affecting the structural integrity and the hardness values of dentin.

Effect of nano-hydroxyapatite with biomimetic analogues on the characteristics of partially demineralised dentin: An in-vitro study.

BACKGROUND: Research on dentin remineralisation protocols in particular 'biomimetic remineralisation' has gained huge momentum. Aim of this study was to evaluate if biomimetic analogs, incorporated in n-HAp, as an experimental formulation could aid in remineralization of artificial caries-like dentin and have anti-microbial effect on cariogenic bacteria, S mutans. MATERIALS AND METHODOLOGY: An experimental paste was formulated using nano-hydroxyapatite (nHAp) with Non-Collagenous Protein analogs- polyacrylic acid (PAA), sodium tri-poly phosphate (STPP) with Simulated Body Fluid. Partially demineralised dentin specimens were divided into three groups (n=10) based on the remineralisation treatment as, Group A- n-HAp paste, Group B- n-HAp and NCP analogues and Group C (Control) - no treatment. At the end of the experimental period, the specimens were assessed using SEM-EDS analysis and Vickers microhardness testing. Further, the antimicrobial efficacy of the paste was assessed. STATISTICAL ANALYSIS: The results were statistically analyzed using ANOVA with post-hoc Bonferroni test. RESULTS: Dentin specimens treated with the experimental paste revealed greater tubular occlusion, with intra tubular deposits and increased mineral content. Specimens treated with n-HAp alone had higher microhardness values and inhibitory effect on the cariogenic bacteria. CONCLUSION: Non-Collagenous Protein analogs incorporated in n-HAp could remineralize the demineralised dentin and had antibacterial efficacy against S mutans.

Discrimination of simple objects decoded from the output of retinal ganglion cells upon sinusoidal electrical stimulation.

Objective. Most neuroprosthetic implants employ pulsatile square-wave electrical stimuli, which are significantly different from physiological inter-neuronal communication. In case of retinal neuroprosthetics, which use a certain type of pulsatile stimuli, reliable object and contrast discrimination by implanted blind patients remained challenging. Here we investigated to what extent simple objects can be discriminated from the output of retinal ganglion cells (RGCs) upon sinusoidal stimulation.Approach. Spatially confined objects were formed by different combinations of 1024 stimulating microelectrodes. The RGC activity in theex vivoretina of photoreceptor-degenerated mouse, of healthy mouse or of primate was recorded simultaneously using an interleaved recording microelectrode array implemented in a CMOS-based chip.Main results. We report that application of sinusoidal electrical stimuli (40 Hz) in epiretinal configuration instantaneously and reliably modulates the RGC activity in spatially confined areas at low stimulation threshold charge densities (40 nC mm-2). Classification of overlapping but spatially displaced objects (1° separation) was achieved by distinct spiking activity of selected RGCs. A classifier (regularized logistic regression) discriminated spatially displaced objects (size: 5.5° or 3.5°) with high accuracy (90% or 62%). Stimulation with low artificial contrast (10%) encoded by different stimulus amplitudes generated RGC activity, which was classified with an accuracy of 80% for large objects (5.5°).Significance. We conclude that time-continuous smooth-wave stimulation provides robust, localized neuronal activation in photoreceptor-degenerated retina, which may enable future artificial vision at high temporal, spatial and contrast resolution.

Evaluation of vascular endothelial growth factor - A release from platelet-rich fibrin, platelet-rich fibrin matrix, and dental pulp at different time intervals.

BACKGROUND: Lack of collateral blood supply and the low compliance environment of pulp makes its healing, a challenge. Vascular endothelial growth factor (VEGF) is a primary angiogenic growth factor. Knowledge of dose and time-dependent expression of VEGF from platelet concentrates, namely platelet-rich fibrin (PRF) and PRF matrix (PRFM), along with vital pulp can aid in developing strategies to improve the outcome of vital pulp therapy and regenerative procedures. Hence, the aim of this study was to compare VEGF kinetics of PRF, PRFM, and dental pulp. MATERIALS AND METHODS: The PRF, PRFM, and vital dental pulp were placed in culture media for a week; the supernatant was collected from these samples at days 1, 4, and 7. VEGF-A expression was evaluated using ELISA and compared with the weight of the sample so as to quantify the release of VEGF-A per milligram of sample. RESULTS: PRF exhibited maximum VEGF-A release on day 4 and was sustained till day 7. In contrast, PRFM and dental pulp showed no significant release of VEGF-A till day 7. However, on day 7, there was a rapid increase in VEGF-A expression from dental pulp that was comparable to PRF. On comparing the release of VEGF-A per milligram of tissue, pulp exhibited the maximum values. CONCLUSION: Among the platelet concentrates, differential expression of VEGF-A was superior in PRF. The use of PRF in partial pulpitis should be explored in order to restore pulp vascularity and hasten pulpal healing.

The efficacy of transdermal and oral diclofenac for post-endodontic pain control: A randomised controlled trial.

OBJECTIVE: The aim of the present study was to compare the effect of transdermal diclofenac patch against oral diclofenac for post-endodontic pain control. MATERIALS AND METHODS: Thirty-two patients with symptomatic irreversible pulpitis in single-rooted premolar teeth of either arch were treated endodontically in a single visit by a single endodontist. Oral diclofenac (50 mg twice daily) for group I and transdermal diclofenac patch (100 mg once daily) for group II were administered as post-endodontic analgesics for two days. Visual analogue scale (VAS) chart was used to record pain intensity scores preoperatively and at intervals of 4, 8, 12 and 24 h postoperatively for 2 days. Paracetamol 650 mg tablets were provided as rescue medication. RESULTS: There was a significant decrease in the postoperative pain intensity scores for both groups. The postoperative scores gradually decreased from day 1 to day 2 in both groups. Twelve out of sixteen patients who had received diclofenac tablets complained of gastric discomfort. CONCLUSION: Transdermal diclofenac patch was as effective as an oral diclofenac tablet and can be used as an alternative and effective analgesic for post-endodontic pain management, especially in patients with gastric discomfort.

Characterizing Retinal Ganglion Cell Responses to Electrical Stimulation Using Generalized Linear Models.

The ability to preferentially stimulate different retinal pathways is an important area of research for improving visual prosthetics. Recent work has shown that different classes of retinal ganglion cells (RGCs) have distinct linear electrical input filters for low-amplitude white noise stimulation. The aim of this study is to provide a statistical framework for characterizing how RGCs respond to white-noise electrical stimulation. We used a nested family of Generalized Linear Models (GLMs) to partition neural responses into different components-progressively adding covariates to the GLM which captured non-stationarity in neural activity, a linear dependence on the stimulus, and any remaining non-linear interactions. We found that each of these components resulted in increased model performance, but that even the non-linear model left a substantial fraction of neural variability unexplained. The broad goal of this paper is to provide a much-needed theoretical framework to objectively quantify stimulus paradigms in terms of the types of neural responses that they elicit (linear vs. non-linear vs. stimulus-independent variability). In turn, this aids the prosthetic community in the search for optimal stimulus parameters that avoid indiscriminate retinal activation and adaptation caused by excessively large stimulus pulses, and avoid low fidelity responses (low signal-to-noise ratio) caused by excessively weak stimulus pulses.

Effect of Staining and Bleaching on Color stability and Surface Roughness of Three Resin Composites: An in vitro study.

AIM: This study evaluated the effect of staining and subsequent bleaching on the color stability and surface roughness of three resin composites. MATERIALS AND METHODS: One hundred and eight customized plastic disks from a plastic mold with an outer diameter of 10 mm and thickness of 1.02 mm were fabricated. Samples were divided into three groups of 36 specimens each - Group I (Estelite® α - Supranano), Group II (Filtek™ Z250 XT - Nanohybrid), and Group III (Filtek™ P90-Silorane). Subsequently, baseline surface color and roughness values were tabulated using spectrophotometer and profilometer, respectively. The specimens were then subjected to staining with coffee and turmeric for a period of 3 h/day for 40 days and following this, bleaching of the samples was done using a bleaching agent carbamide peroxide gel 15% for 8 h/day for 14 consecutive days. RESULTS: Estelite® α performed better by maintaining color stability with minimal roughness compared to Filtek™ P90 and Filtek™Z250 XT. Turmeric had a greater potential to stain composites compared to coffee in all the groups.